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Bibliography on: Metagenomics

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ESP: PubMed Auto Bibliography 08 Aug 2022 at 01:30 Created: 

Metagenomics

While genomics is the study of DNA extracted from individuals — individual cells, tissues, or organisms — metagenomics is a more recent refinement that analyzes samples of pooled DNA taken from the environment, not from an individual. Like genomics, metagenomic methods have great potential in many areas of biology, but none so much as in providing access to the hitherto invisible world of unculturable microbes, often estimated to comprise 90% or more of bacterial species and, in some ecosystems, the bulk of the biomass. A recent describes how this new science of metagenomics is beginning to reveal the secrets of our microbial world: The opportunity that stands before microbiologists today is akin to a reinvention of the microscope in the expanse of research questions it opens to investigation. Metagenomics provides a new way of examining the microbial world that not only will transform modern microbiology but has the potential to revolutionize understanding of the entire living world. In metagenomics, the power of genomic analysis is applied to entire communities of microbes, bypassing the need to isolate and culture individual bacterial community members.

Created with PubMed® Query: metagenomic OR metagenomics OR metagenome NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2022-08-06

Ray AE, Zaugg J, Benaud N, et al (2022)

Atmospheric chemosynthesis is phylogenetically and geographically widespread and contributes significantly to carbon fixation throughout cold deserts.

The ISME journal [Epub ahead of print].

Cold desert soil microbiomes thrive despite severe moisture and nutrient limitations. In Eastern Antarctic soils, bacterial primary production is supported by trace gas oxidation and the light-independent RuBisCO form IE. This study aims to determine if atmospheric chemosynthesis is widespread within Antarctic, Arctic and Tibetan cold deserts, to identify the breadth of trace gas chemosynthetic taxa and to further characterize the genetic determinants of this process. H2 oxidation was ubiquitous, far exceeding rates reported to fulfill the maintenance needs of similarly structured edaphic microbiomes. Atmospheric chemosynthesis occurred globally, contributing significantly (p < 0.05) to carbon fixation in Antarctica and the high Arctic. Taxonomic and functional analyses were performed upon 18 cold desert metagenomes, 230 dereplicated medium-to-high-quality derived metagenome-assembled genomes (MAGs) and an additional 24,080 publicly available genomes. Hydrogenotrophic and carboxydotrophic growth markers were widespread. RuBisCO IE was discovered to co-occur alongside trace gas oxidation enzymes in representative Chloroflexota, Firmicutes, Deinococcota and Verrucomicrobiota genomes. We identify a novel group of high-affinity [NiFe]-hydrogenases, group 1m, through phylogenetics, gene structure analysis and homology modeling, and reveal substantial genetic diversity within RuBisCO form IE (rbcL1E), and high-affinity 1h and 1l [NiFe]-hydrogenase groups. We conclude that atmospheric chemosynthesis is a globally-distributed phenomenon, extending throughout cold deserts, with significant implications for the global carbon cycle and bacterial survival within environmental reservoirs.

RevDate: 2022-08-06

Zhang H, Wang M, Wang H, et al (2022)

Metagenome sequencing and 768 microbial genomes from cold seep in South China Sea.

Scientific data, 9(1):480.

Cold seep microbial communities are fascinating ecosystems on Earth which provide unique models for understanding the living strategies in deep-sea distinct environments. In this study, 23 metagenomes were generated from samples collected in the Site-F cold seep field in South China Sea, including the sea water closely above the invertebrate communities, the cold seep fluids, the fluids under the invertebrate communities and the sediment column around the seep vent. By binning tools, we retrieved a total of 768 metagenome assembled genome (MAGs) that were estimated to be >60% complete. Of the MAGs, 61 were estimated to be >90% complete, while an additional 105 were >80% complete. Phylogenomic analysis revealed 597 bacterial and 171 archaeal MAGs, of which nearly all were distantly related to known cultivated isolates. In the 768 MAGs, the abundant Bacteria in phylum level included Proteobacteria, Desulfobacterota, Bacteroidota, Patescibacteria and Chloroflexota, while the abundant Archaea included Asgardarchaeota, Thermoplasmatota, and Thermoproteota. These results provide a dataset available for further interrogation of deep-sea microbial ecology.

RevDate: 2022-08-06

Ao Y, Xu J, Z Duan (2022)

A novel cardiovirus species identified in feces of wild Himalayan marmots.

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases pii:S1567-1348(22)00144-7 [Epub ahead of print].

Recently a growing number of novel cardioviruses have been frequently discovered, which boosts interest in the search for the genetic diversity of cardioviruses. However, wild-marmot cardioviruses have been rarely reported. Here, a novel cardiovirus (tentatively named HHMCDV) was identified in fecal samples from wild Himalayan marmots in Qinghai Tibetan Plateau, China, by viral metagenomics analysis. 3 out of 99 fecal samples from Himalayan marmots were positive for HHMCDV, with the viral loads ranging from 2.7 × 105 to 1.3 × 107 gene copies/g. The complete genomic sequence of HHMCDV was 8108 nucleotides in length, with the typical cardiovirus genome organization and motifs. Coincidentally, while the data was analyzing, one marmot cardiovirus HT7 partial sequence was available in the Genbank, showing 95.1%, 95.6% and 96.0% amino acid (aa) identity in P1, P2 and P3, respectively. However, sequence analysis revealed that HHMCDV and HT7 are more closely related to species Cardiovirus F strain with 65.7%, 61.9-65.6%, 58.9-59.7%, 71.1-71.7%, 69.1-69.4% and 71.4-72.2% aa identity in polyprotein, P1, P2, P3, 2C and 3CD proteins, respectively. Phylogenetic analysis of P1, P2, P3 and 3CD aa sequences indicated that HHMCDV and HT7 clustered tightly and formed a distinct cluster in the Cardiovirus genus. Based on these data, we propose that HHMCDV and HT7 should be two different members of a potential novel species within the genus Cardiovirus. Further studies are needed to investigate the epidemiology and potential pathogenicity of the virus in Himalayan marmots.

RevDate: 2022-08-06

Liu Y, Luo G, Hao Ngo H, et al (2022)

New approach of bioprocessing towards lignin biodegradation.

Bioresource technology pii:S0960-8524(22)01059-8 [Epub ahead of print].

Bio-utilization of lignocellulosic biomass is of huge significance as it can directly replace petroleum resources by producing liquid fuels and organic chemical products in a more sustainable way. However, studies on developing lignin-degrading microbial resources are still very few, which affects on establishing a consolidated bioprocessing of lignocellulosic resource. The main aim of this work is to discover thermostable laccases for lignin thermo-biodegradation by metagenome-mining and biochemical characterization. Results indicate that 124 putative thermostable laccase genes were identified from generated metagenomes. Significantly, 3 rationally selected proteins showed actual activity and structural stability at temperatures up to 60°C and pH values as low as 4.87. These active recombinant enzymes verify a practical advance in the functional prediction of target proteins, and simultaneous sequence-to-function relationships in this metagenome. In short, the identified thermostable laccase genes in this work could expand range of lignin biocatalysts and contribute to build an efficient lignin biorefinery.

RevDate: 2022-08-05

Hong D, Wang P, Zhang J, et al (2022)

Plasma metagenomic next-generation sequencing of microbial cell-free DNA detects pathogens in patients with suspected infected pancreatic necrosis.

BMC infectious diseases, 22(1):675.

BACKGROUND: Infected pancreatic necrosis (IPN) is a life-threatening complication of acute pancreatitis (AP). Timely diagnosis of IPN could facilitate appropriate treatment, but there is a lack of reliable non-invasive screening tests. In this study, we aimed to evaluate the diagnostic value of plasma metagenomic next-generation sequencing (mNGS) based on circulating microbial cell-free DNA in patients with suspected IPN.

METHODS: From October 2020 to October 2021, 44 suspected IPN patients who underwent plasma mNGS were reviewed. Confirmatory diagnosis of IPN within two weeks after the index blood sampling was considered the reference standard. The confirmation of IPN relied on the microbiological results of drains obtained from the necrotic collections. The distribution of the pathogens identified by plasma mNGS was analyzed. Positive percent agreement (PPA) and negative percent agreement (NPA) were evaluated based on the conformity between the overall mNGS results and culture results of IPN drains. In addition, the clinical outcomes were compared between mNGS positive and negative patients.

RESULTS: Across all the study samples, thirteen species of bacteria and five species of fungi were detected by mNGS. The positivity rate of plasma mNGS was 54.55% (24/44). Of the 24 mNGS positive cases, twenty (83.33%, 95% CI, 68.42-98.24%) were consistent with the culture results of IPN drains. The PPA and NPA of plasma mNGS for IPN were 80.0% (20/25; 95% CI, 64.32-95.68%) and 89.47% (17/19; 95% CI, 75.67-100%), respectively. Compared with the mNGS negative group, patients in the positive group had more new-onset septic shock [12 (50.0%) vs. 4 (20.0%), p = 0.039].

CONCLUSION: IPN relevant pathogens can be identified by plasma mNGS, potentially facilitating appropriate treatment. The clinical application of mNGS in this cohort appears feasible.

RevDate: 2022-08-05

Kim K, Lee S, Park SC, et al (2022)

Role of an unclassified Lachnospiraceae in the pathogenesis of type 2 diabetes: a longitudinal study of the urine microbiome and metabolites.

Experimental & molecular medicine [Epub ahead of print].

Recent investigations have revealed that the human microbiome plays an essential role in the occurrence of type 2 diabetes (T2D). However, despite the importance of understanding the involvement of the microbiota throughout the body in T2D, most studies have focused specifically on the intestinal microbiota. Extracellular vesicles (EVs) have been recently found to provide important evidence regarding the mechanisms of T2D pathogenesis, as they act as key messengers between intestinal microorganisms and the host. Herein, we explored microorganisms potentially associated with T2D by tracking changes in microbiota-derived EVs from patient urine samples collected three times over four years. Mendelian randomization analysis was conducted to evaluate the causal relationships among microbial organisms, metabolites, and clinical measurements to provide a comprehensive view of how microbiota can influence T2D. We also analyzed EV-derived metagenomic (N = 393), clinical (N = 5032), genomic (N = 8842), and metabolite (N = 574) data from a prospective longitudinal Korean community-based cohort. Our data revealed that GU174097_g, an unclassified Lachnospiraceae, was associated with T2D (β = -189.13; p = 0.00006), and it was associated with the ketone bodies acetoacetate and 3-hydroxybutyrate (r = -0.0938 and -0.0829, respectively; p = 0.0022 and 0.0069, respectively). Furthermore, a causal relationship was identified between acetoacetate and HbA1c levels (β = 0.0002; p = 0.0154). GU174097_g reduced ketone body levels, thus decreasing HbA1c levels and the risk of T2D. Taken together, our findings indicate that GU174097_g may lower the risk of T2D by reducing ketone body levels.

RevDate: 2022-08-05

Zhou X, Bi X, Yang T, et al (2022)

Metagenomic insights into microbial nitrogen metabolism in two-stage anoxic/oxic-moving bed biofilm reactor system with multiple chambers for municipal wastewater treatment.

Bioresource technology pii:S0960-8524(22)01058-6 [Epub ahead of print].

To explore the microbial nitrogen metabolism of a two-stage anoxic/oxic (A/O)-moving bed biofilm reactor (MBBR), biofilms of the system's chambers were analyzed using metagenomic sequencing. Significant differences in microbial populations were found among the pre-anoxic, oxic and post-anoxic MBBRs (P < 0.01). Nitrospira and Nitrosomonas had positive correlations with ammonia nitrogen (NH4+-N) removal, and were also predominant in oxic MBBRs. These organisms were the hosts of functional genes for nitrification. The denitrifying genera were predominant in anoxic MBBRs, including Thiobacillus and Sulfurisoma in pre-anoxic MBBRs and Dechloromonas and Thauera in post-anoxic MBBRs. The four genera had positive correlations with total nitrate and nitrite nitrogen (NOX--N) removal and were the hosts of functional genes for denitrification. Specific functional biofilms with different microbial nitrogen metabolisms were formed in each chamber of this system. This work provides a microbial theoretical support for the two-stage A/O-MBBR system.

RevDate: 2022-08-05

Podlesny D, Durdevic M, Paramsothy S, et al (2022)

Identification of clinical and ecological determinants of strain engraftment after fecal microbiota transplantation using metagenomics.

Cell reports. Medicine pii:S2666-3791(22)00254-3 [Epub ahead of print].

Fecal microbiota transplantation (FMT) is a promising therapeutic approach for microbiota-associated pathologies, but our understanding of the post-FMT microbiome assembly process and its ecological and clinical determinants is incomplete. Here we perform a comprehensive fecal metagenome analysis of 14 FMT trials, involving five pathologies and >250 individuals, and determine the origins of strains in patients after FMT. Independently of the underlying clinical condition, conspecific coexistence of donor and recipient strains after FMT is uncommon and donor strain engraftment is strongly positively correlated with pre-FMT recipient microbiota dysbiosis. Donor strain engraftment was enhanced through antibiotic pretreatment and bowel lavage and dependent on donor and recipient ɑ-diversity; strains from relatively abundant species were more likely and from predicted oral, oxygen-tolerant, and gram-positive species less likely to engraft. We introduce a general mechanistic framework for post-FMT microbiome assembly in alignment with ecological theory, which can guide development of optimized, more targeted, and personalized FMT therapies.

RevDate: 2022-08-05

Roslund MI, Parajuli A, Hui N, et al (2022)

A Placebo-controlled double-blinded test of the biodiversity hypothesis of immune-mediated diseases: Environmental microbial diversity elicits changes in cytokines and increase in T regulatory cells in young children.

Ecotoxicology and environmental safety, 242:113900 pii:S0147-6513(22)00740-0 [Epub ahead of print].

BACKGROUND: According to the biodiversity hypothesis of immune-mediated diseases, lack of microbiological diversity in the everyday living environment is a core reason for dysregulation of immune tolerance and - eventually - the epidemic of immune-mediated diseases in western urban populations. Despite years of intense research, the hypothesis was never tested in a double-blinded and placebo-controlled intervention trial.

OBJECTIVE: We aimed to perform the first placebo-controlled double-blinded test that investigates the effect of biodiversity on immune tolerance.

METHODS: In the intervention group, children aged 3-5 years were exposed to playground sand enriched with microbially diverse soil, or in the placebo group, visually similar, but microbially poor sand colored with peat (13 participants per treatment group). Children played twice a day for 20 min in the sandbox for 14 days. Sand, skin and gut bacterial, and blood samples were taken at baseline and after 14 days. Bacterial changes were followed for 28 days. Sand, skin and gut metagenome was determined by high throughput sequencing of bacterial 16 S rRNA gene. Cytokines were measured from plasma and the frequency of blood regulatory T cells was defined as a percentage of total CD3 +CD4 + T cells.

RESULTS: Bacterial richness (P < 0.001) and diversity (P < 0.05) were higher in the intervention than placebo sand. Skin bacterial community, including Gammaproteobacteria, shifted only in the intervention treatment to resemble the bacterial community in the enriched sand (P < 0.01). Mean change in plasma interleukin-10 (IL-10) concentration and IL-10 to IL-17A ratio supported immunoregulation in the intervention treatment compared to the placebo treatment (P = 0.02). IL-10 levels (P = 0.001) and IL-10 to IL-17A ratio (P = 0.02) were associated with Gammaproteobacterial community on the skin. The change in Treg frequencies was associated with the relative abundance of skin Thermoactinomycetaceae 1 (P = 0.002) and unclassified Alphaproteobacteria (P < 0.001). After 28 days, skin bacterial community still differed in the intervention treatment compared to baseline (P < 0.02).

CONCLUSIONS: This is the first double-blinded placebo-controlled study to show that daily exposure to microbial biodiversity is associated with immune modulation in humans. The findings support the biodiversity hypothesis of immune-mediated diseases. We conclude that environmental microbiota may contribute to child health, and that adding microbiological diversity to everyday living environment may support immunoregulation.

RevDate: 2022-08-05

Zhang Z, Zhang G, F Ju (2022)

Using Culture-Enriched Phenotypic Metagenomics for Targeted High-Throughput Monitoring of the Clinically Important Fraction of the β-Lactam Resistome.

Environmental science & technology [Epub ahead of print].

High bacterial community diversity and complexity greatly challenge the cost-efficient monitoring of clinically prevalent antibiotic-resistant bacteria, which are usually present as rare and important populations involved in the environmental dissemination of clinical resistance. Here, we introduce culture-enriched phenotypic metagenomics that integrates culture enrichment, phenotypic screening, and metagenomic analyses as an emerging standardized methodology for targeted resistome monitoring and apply it to decipher the extended-spectrum β-lactam resistome in a municipal wastewater treatment plant (WWTP) and its receiving river. The results showed that clinically prevalent carbapenemase genes (e.g., the NDM and KPC families) and extended-spectrum β-lactamase genes (e.g., the CTX-M, TEM, and OXA families) were prevalent in the WWTP and showed prominent potential in horizontal dissemination. Strikingly, carbapenem and polymyxin resistance genes co-occurred in the highly virulent nosocomial pathogens Enterobacter kobei and Citrobacter freundii. Overall, this study exemplifies phenotypic metagenomics for high-throughput surveillance of a targeted clinically important fraction of antibiotic resistomes and substantially expands current knowledge on extended-spectrum β-lactam resistance in WWTPs.

RevDate: 2022-08-05

Ceylani T, HT Teker (2022)

The effect of young blood plasma administration on gut microbiota in middle-aged rats.

Archives of microbiology, 204(9):541.

Numerous in-depth studies continue to reveal the many benefits of gut microbiota and young blood plasma administration. Dysbiosis, which occurs in the intestinal microbiota, especially in the aging process, is associated with many metabolic and cognitive disorders. Therefore, many studies aim to reverse the dysbiosis that occurs. There are also studies showing that young blood plasma application reverses the effects of aging at the level of many tissues and organs. Today, while research continues to reveal all the benefits of young blood plasma application in terms of health, blood plasma centers are also being established. In this study, we aimed to reveal the impact of young blood plasma, administered for 1 month, on the intestinal microbiota of middle-aged rats. After detailed metagenome analysis, alpha diversity indices demonstrated greater bacterial richness in the microbiota of plasma-administered rats compared with control rats. In addition, the Firmicutes/Bacteroidetes ratio was significantly diminished in plasma group microbiota, confirming possible rejuvenation properties of young plasma. Furthermore, increased counts of Bifidobacterium longum, Coprococcus catus, and Romboutsia ilealis species were measured in plasma-administered rats. The study revealed many fluctuations in different bacterial taxonomic units of the microbiota that could be valuable in future research on blood-based anti-aging treatments.

RevDate: 2022-08-05

Zhang X, Ren H, Zhao C, et al (2022)

Metagenomic analysis reveals crosstalk between gut microbiota and glucose-lowering drugs targeting the gastrointestinal tract in Chinese patients with type 2 diabetes: a 6 month, two-arm randomised trial.

Diabetologia [Epub ahead of print].

AIMS/HYPOTHESIS: The use of oral glucose-lowering drugs, particularly those designed to target the gut ecosystem, is often observed in association with altered gut microbial composition or functional capacity in individuals with type 2 diabetes. The gut microbiota, in turn, plays crucial roles in the modulation of drug efficacy. We aimed to assess the impacts of acarbose and vildagliptin on human gut microbiota and the relationships between pre-treatment gut microbiota and therapeutic responses.

METHODS: This was a randomised, open-labelled, two-arm trial in treatment-naive type 2 diabetes patients conducted in Beijing between December 2016 and December 2017. One hundred participants with overweight/obesity and newly diagnosed type 2 diabetes were recruited from the Pinggu Hospital and randomly assigned to the acarbose (n=50) or vildagliptin (n=50) group using sealed envelopes. The treatment period was 6 months. Blood, faecal samples and visceral fat data from computed tomography images were collected before and after treatments to measure therapeutic outcomes and gut microbiota. Metagenomic datasets from a previous type 2 diabetes cohort receiving acarbose or glipizide for 3 months were downloaded and processed. Statistical analyses were applied to identify the treatment-related changes in clinical variables, gut microbiota and associations.

RESULTS: Ninety-two participants were analysed. After 6 months of acarbose (n=44) or vildagliptin (n=48) monotherapy, both groups achieved significant reductions in HbA1c (from 60 to 46 mmol/mol [from 7.65% to 6.40%] in the acarbose group and from 59 to 44 mmol/mol [from 7.55% to 6.20%] in the vildagliptin group) and visceral fat areas (all adjusted p values for pre-post comparisons <0.05). Both arms showed drug-specific and shared changes in relative abundances of multiple gut microbial species and pathways, especially the common reductions in Bacteroidetes species. Three months and 6 months of acarbose-induced changes in microbial composition were highly similar in type 2 diabetes patients from the two independent studies. Vildagliptin treatment significantly enhanced fasting active glucagon-like peptide-1 (GLP-1) levels. Baseline gut microbiota, rather than baseline GLP-1 levels, were strongly associated with GLP-1 response to vildagliptin, and to a lesser extent with GLP-1 response to acarbose.

CONCLUSIONS/INTERPRETATION: This study reveals common microbial responses in type 2 diabetes patients treated with two glucose-lowering drugs targeting the gut differently and acceptable performance of baseline gut microbiota in classifying individuals with different GLP-1 responses to vildagliptin. Our findings highlight bidirectional interactions between gut microbiota and glucose-lowering drugs.

TRIAL REGISTRATION: ClinicalTrials.gov NCT02999841 FUNDING: National Key Research and Development Project: 2016YFC1304901.

RevDate: 2022-08-05

Sampara P, Luo Y, Lin X, et al (2022)

Integrating Genome-Resolved Metagenomics with Trait-Based Process Modeling to Determine Biokinetics of Distinct Nitrifying Communities within Activated Sludge.

Environmental science & technology [Epub ahead of print].

Conventional bioprocess models for wastewater treatment are based on aggregated bulk biomass concentrations and do not incorporate microbial physiological diversity. Such a broad aggregation of microbial functional groups can fail to predict ecosystem dynamics when high levels of physiological diversity exist within trophic guilds. For instance, functional diversity among nitrite-oxidizing bacteria (NOB) can obfuscate engineering strategies for their out-selection in activated sludge (AS), which is desirable to promote energy-efficient nitrogen removal. Here, we hypothesized that different NOB populations within AS can have different physiological traits that drive process performance, which we tested by estimating biokinetic growth parameters using a combination of highly replicated respirometry, genome-resolved metagenomics, and process modeling. A lab-scale AS reactor subjected to a selective pressure for over 90 days experienced resilience of NOB activity. We recovered three coexisting Nitrospira population genomes belonging to two sublineages, which exhibited distinct growth strategies and underwent a compositional shift following the selective pressure. A trait-based process model calibrated at the NOB genus level better predicted nitrite accumulation than a conventional process model calibrated at the NOB guild level. This work demonstrates that trait-based modeling can be leveraged to improve our prediction, control, and design of functionally diverse microbiomes driving key environmental biotechnologies.

RevDate: 2022-08-05

Hakimjavadi H, George SH, Taub M, et al (2022)

The vaginal microbiome is associated with endometrial cancer grade and histology.

Cancer research communications, 2(6):447-455.

The human microbiome has been strongly correlated with disease pathology and outcomes, yet remains relatively underexplored in patients with malignant endometrial disease. In this study, vaginal microbiome samples were prospectively collected at the time of hysterectomy from 61 racially and ethnically diverse patients from three disease conditions: 1) benign gynecologic disease (controls, n=11), 2) low-grade endometrial carcinoma (n=30), and 3) high-grade endometrial carcinoma (n=20). Extracted DNA underwent shotgun metagenomics sequencing, and microbial α and β diversities were calculated. Hierarchical clustering was used to describe community state types (CST), which were then compared by microbial diversity and grade. Differential abundance was calculated, and machine learning utilized to assess the predictive value of bacterial abundance to distinguish grade and histology. Both α- and β-diversity were associated with patient tumor grade. Four vaginal CST were identified that associated with grade of disease. Different histologies also demonstrated variation in CST within tumor grades. Using supervised clustering algorithms, critical microbiome markers at the species level were used to build models that predicted benign vs carcinoma, high-grade carcinoma versus benign, and high-grade versus low-grade carcinoma with high accuracy. These results confirm that the vaginal microbiome segregates not just benign disease from endometrial cancer, but is predictive of histology and grade. Further characterization of these findings in large, prospective studies is needed to elucidate their potential clinical applications.

RevDate: 2022-08-05

Al Bataineh MT, Künstner A, Dash NR, et al (2022)

Altered Composition of the Oral Microbiota in Depression Among Cigarette Smokers: A Pilot Study.

Frontiers in psychiatry, 13:902433.

Alterations in the oral microbiota composition may influence mental health. However, linkages between compositional changes in the oral microbiota and their role in mental health among cigarette smokers remain largely unknown. In this study, we used shotgun metagenomics data for the oral microbiome of 105 participants. The data showed Bacteroidota, Fusobacteriota, Firmicutes, Proteobacteria, and Actinobacteria to be the most abundant phyla; Streptococcus, Haemophilus D, and Veillonella are the most abundant genera. Then, we clustered our subjects into avoidance and activation groups based on the behavioral activation for depression scale (BADS). Interestingly, the avoidance group exhibited a higher oral microbiome richness and diversity (alpha diversity). Differential abundance testing between BADS avoidance and activation groups showed the phyla Bacteroidota (effect size 0.5047, q = 0.0037), Campylobacterota (effect size 0.4012, q = 0.0276), Firmicutes A (effect size 0.3646, q = 0.0128), Firmicutes I (effect size 0.3581, q = 0.0268), and Fusobacteriota (effect size 0.6055, q = 0.0018) to be significantly increased in the avoidance group, but Verrucomicrobiota (effect size-0.6544, q = 0.0401), was found to be significantly decreased in the avoidance risk group. Network analysis of the 50 genera displaying the highest variation between both groups identified Campylobacter B, Centipeda, and Veillonella as hub nodes in the avoidance group. In contrast, Haemophilus and Streptococcus were identified as hub nodes in the activation group. Next, we investigated functional profiles of the oral microbiota based on BADS avoidance and activation groups and found Lysine degradations pathway was significantly enriched between both groups (ANCOM-BC, q = 0.0692). Altogether, we provide evidence for the presence of depression-related changes in the oral microbiota of smokers and possible functional contribution. The identified differences provide new information to enrich our understanding of oral microbiota-brain axis interplay and their potential impact on mental health.

RevDate: 2022-08-05

Xue Y, Zheng M, Wu S, et al (2022)

Changes in the Species and Functional Composition of Activated Sludge Communities Revealed Mechanisms of Partial Nitrification Established by Ultrasonication.

Frontiers in microbiology, 13:960608.

To achieve energy-efficient shortcut nitrogen removal of wastewater in the future, selective elimination of nitrite-oxidizing bacteria (NOB) while enriching ammonia-oxidizing microorganisms is a crucial step. However, the underlying mechanisms of partial nitrification are still not well understood, especially the newly discovered ultrasound-based partial nitrification. To elucidate this issue, in this study two bioreactors were set up, with one established partial nitrification by ultrasonication while the other didn't. During the operation of both reactors, the taxonomic and functional composition of the microbial community were investigated through metagenomics analysis. The result showed that during ultrasonic partial nitrification, ammonia-oxidizing archaea (AOA), Nitrososphaerales, was enriched more than ammonia-oxidizing bacteria (AOB), Nitrosomonas. The enrichment of microorganisms in the community increased the abundance of genes involved in microbial energy generation from lipid and carbohydrates. On the other hand, the abundance of NOB, Nitrospira and Nitrolancea, and Comammox Nitrospira decreased. Selective inhibition of NOB was highly correlated with genes involved in signal transduction enzymes, such as encoding histidine kinase and serine/threonine kinase. These findings provided deep insight into partial nitrification and contributed to the development of shortcut nitrification in wastewater treatment plants.

RevDate: 2022-08-05

Cuetero-Martínez Y, Cobos-Vasconcelos DL, Aguirre-Garrido JF, et al (2022)

Next-generation sequencing for surveillance of antimicrobial resistance and pathogenicity in municipal wastewater treatment plants.

Current medicinal chemistry pii:CMC-EPUB-125266 [Epub ahead of print].

The World Health Organization (WHO) ranks antimicrobial resistance (AMR) and various pathogens among the top 10 health threats. It is estimated that by 2050, the number of human deaths due to AMR will reach 10 million annually. On the other hand, several infectious outbreaks such as SARS, H1N1 influenza, Ebola, Zika fever, and COVID-19 have severely affected human populations worldwide in the last 20 years. These recent global diseases have generated the need to monitor outbreaks of pathogens and AMR to establish effective public health strategies. This review presents AMR and pathogenicity associated with wastewater treatment plants (WWTP), focusing on Next Generation Sequencing (NGS) monitoring as a complementary system to clinical surveillance. In this regard, WWTP may be monitored at three main points. First, at the inlet (raw wastewater or influent) to identify a broad spectrum of AMR and pathogens contained in the excretions of residents served by sewer networks, with a specific spatio-temporal location. Second, at the effluent, to ensure the elimination of AMR and pathogens in the treated water, considering the rising demand for safe wastewater reuse. Third, in sewage sludge or biosolids, since their beneficial use or final disposal can represent a significant risk to public health. This review is divided into two sections to address the importance and implications of AMR and pathogen surveillance in wastewater and WWTP, based on NGS. The first section presents the fundamentals of surveillance techniques applied in WWTP (metataxonomics, metagenomics, functional metagenomics, metaviromics, and metatranscriptomics). Their scope and limitations are analyzed to show how microbiological and qPCR techniques complement NGS surveillance, overcoming its limitations. The second section discusses the contribution of 36 NGS research papers on WWTP surveillance, highlighting the current situation and perspectives. In both sections, research challenges and opportunities are presented.

RevDate: 2022-08-04

Singh AK, Kumari M, Sharma N, et al (2022)

Metagenomic views on taxonomic and functional profiles of the Himalayan Tsomgo cold lake and unveiling its deterzome potential.

Current genetics [Epub ahead of print].

Cold habitat is considered a potential source for detergent industry enzymes. This study aims at the metagenomic investigation of Tsomgo lake for taxonomic and functional annotation, unveiling the deterzome potential of the residing microbiota at this site. The present investigation revealed molecular profiling of microbial community structure and functional potential of the high-altitude Tsomgo lake samples of two different temperatures, harvested during March and August. Bacteria were found to be the most dominant phyla, with traces of genomic pieces of evidence belonging to archaea, viruses, and eukaryotes. Proteobacteria and Actinobacteria were noted to be the most abundant bacterial phyla in the cold lake. In-depth metagenomic investigation of the cold aquatic habitat revealed novel genes encoding detergent enzymes, amylase, protease, and lipase. Further, metagenome-assembled genomes (MAGs) belonging to the psychrophilic bacterium, Arthrobacter alpinus, were constructed from the metagenomic data. The annotation depicted the presence of detergent enzymes and genes for low-temperature adaptation in Arthrobacter alpinus. Psychrophilic microbial isolates were screened for lipase, protease, and amylase activities to further strengthen the metagenomic findings. A novel strain of Acinetobacter sp. was identified with the dual enzymatic activity of protease and amylase. The bacterial isolates exhibited hydrolyzing activity at low temperatures. This metagenomic study divulged novel genomic resources for detergent industry enzymes, and the bacterial isolates secreting cold-active amylase, lipase, and protease enzymes. The findings manifest that Tsomgo lake is a potential bioresource of cold-active enzymes, vital for various industrial applications.

RevDate: 2022-08-04

Kim N, Gim JA, Lee BJ, et al (2022)

Crosstalk between mucosal microbiota, host gene expression, and sociomedical factors in the progression of colorectal cancer.

Scientific reports, 12(1):13447.

Various omics-based biomarkers related to the occurrence, progression, and prognosis of colorectal cancer (CRC) have been identified. In this study, we attempted to identify gut microbiome-based biomarkers and detect their association with host gene expression in the initiation and progression of CRC by integrating analysis of the gut mucosal metagenome, RNA sequencing, and sociomedical factors. We performed metagenome and RNA sequencing on colonic mucosa samples from 13 patients with advanced CRC (ACRC), 10 patients with high-risk adenoma (HRA), and 7 normal control (NC) individuals. All participants completed a questionnaire on sociomedical factors. The interaction and correlation between changes in the microbiome and gene expression were assessed using bioinformatic analysis. When comparing HRA and NC samples, which can be considered to represent the process of tumor initiation, 28 genes and five microbiome species were analyzed with correlation plots. When comparing ACRC and HRA samples, which can be considered to represent the progression of CRC, seven bacterial species and 21 genes were analyzed. When comparing ACRC and NC samples, 16 genes and five bacterial species were analyzed, and four correlation plots were generated. A network visualizing the relationship between bacterial and host gene expression in the initiation and progression of CRC indicated that Clostridium spiroforme and Tyzzerella nexilis were hub bacteria in the development and progression of CRC. Our study revealed the interactions of and correlation between the colonic mucosal microbiome and host gene expression to identify potential roles of the microbiome in the initiation and progression of CRC. Our results provide gut microbiome-based biomarkers that may be potential diagnostic markers and therapeutic targets in patients with CRC.

RevDate: 2022-08-04

Wu L, Zhang SL, Huang HW, et al (2022)

[Diagnostic efficacy of metagenomic next-generation sequencing for intracranial bacterial infection pathogens after neurosurgery].

Zhonghua yi xue za zhi, 102(29):2272-2277.

Objective: To explore the diagnostic efficacy of metagenomicnext-generation sequencing (mNGS) technique for pathogen diagnosis of intracranial infection after neurosurgery. Methods: Patients with suspected intracranial infection after neurosurgery who were treated in Beijing Tiantan Hospital of Capital Medical University from May 2017 to October 2018 were selected. Cerebrospinal fluid samples were collected for mNGS detection and bacterial culture. The sensitivity, specificity, positive predictive value and negative predictive value of these two methods were calculated, and their differences were compared. Results: A total of 80 cerebrospinal fluid samples from patient with suspected intracranial infection after neurosurgery were included, including 53 males and 27 females, with a mean age of (41±19) years old(age range: 2-80 years).After clinical review, a clinical diagnosis was made by two neurosurgery specialists through comprehensively interpretation of the patient's clinical data, laboratory tests and imaging examinations. Finally, 42 cases of intracranial infection and 38 cases of non-infection were clinically diagnosed. The sensitivity and specificity of mNGS detection were 83.33%(35/42) and 76.32%(29/38), and the positive predictive value and negative predictive value were 79.55%(35/44) and 80.56%(29/36). Meanwhile, the sensitivity and specificity of bacterial culture were 59.52%(28/42) and 68.42%(26/38), the positive predictive value and negative predictive value were 68.00% (28/40) and 60.47%(26/40). The sensitivity of mNGS detection washigher than that of bacterial culture, and the difference was statistically significant(χ2=5.83, P=0.015).Compared with bacterial culture, there was no statistically significant difference in the specificity of mNGS detection(χ2=0.59, P=0.441). Conclusion: mNGS detection technique can improve the detection rate of intracranial infection pathogens after neurosurgery, and may become a promising auxiliary diagnostic tool for pathogen detection.

RevDate: 2022-08-05
CmpDate: 2022-08-05

Marx V (2022)

Why the ocean virome matters.

Nature methods, 19(8):924-927.

RevDate: 2022-08-04

Jiang B, Zeng Q, Li J, et al (2022)

Performance enhancement, membrane fouling mitigation and eco-friendly strategy by electric field coupled membrane bioreactor for treating mariculture wastewater.

Bioresource technology pii:S0960-8524(22)01054-9 [Epub ahead of print].

An eco-friendly strategy for mariculture wastewater treatment using an electric field attached membrane bioreactor (E-MBR) was evaluated and compared with a conventional membrane bioreactor (C-MBR). The removal efficiencies of total nitrogen (TN) and chemical oxygen demand (COD) increased significantly and the membrane fouling rate reduced by 44.8% in the E-MBR. The underlying mechanisms included the enriched nitrifiers and denitrifiers, the enhanced salinity-resistance, the increased activities and upregulated genes of key enzymes involved in nitrification and denitrification for improving the performance of mariculture wastewater treatment, and the enriched extracellular polymeric substance (EPS)-degrading genera, the downregulated EPS biosynthesis genes, the repressed biofilm-forming bacteria, the enhanced zeta potential absolute value and the generated H2O2 for membrane fouling mitigation by electrical stimulation. Compared with the C-MBR, the energy consumption, carbon emissions, and nitrogen footprint were reduced. These findings provide novel insights into mariculture wastewater treatment using an applied electric field.

RevDate: 2022-08-04

Liu L, Liu H, Zhang W, et al (2022)

Microbial diversity and adaptive strategies in the Mars-like Qaidam Basin, North Tibetan Plateau, China.

Environmental microbiology reports [Epub ahead of print].

The Qaidam Basin on the northern Tibetan Plateau, China, is one of the driest deserts at high elevations, and it has been considered a representative Mars analogue site. Despite recent advances in the diversity of microbial communities in the Qaidam Basin, our understanding of their genomic information, functional potential and adaptive strategies remains very limited. Here, we conducted a combination of physicochemical and metagenomic analyses to investigate the taxonomic composition and adaptive strategies of microbial life in the regolith across the Qaidam Basin. 16S ribosomal RNA (rRNA) gene-based and metagenomic analyses both reveal that microbial communities in the Qaidam Basin are dominated by the bacterial phylum Actinobacteria. The low levels of moisture and organic carbon contents appear to have essential constraints on microbial biomass and diversity. A total of 50 high-quality metagenome-assembled genomes were reconstructed and analysed. Our results reveal the potential of microorganisms to use ambient trace gases to meet energy and carbon needs in this nutrient-limited desert. Furthermore, we find that DNA repair mechanisms and protein protection are likely essential for microbial life in response to stressors of hyperaridity, intense ultraviolet radiation and tremendous temperature fluctuations in this Mars analogue. These findings shed light on the diversity and survival strategies of microbial life inhabiting Mar-like environments, which provide implications for potential life on early Mars.

RevDate: 2022-08-04

Mancabelli L, Ciociola T, Lugli GA, et al (2022)

Guideline for the analysis of the microbial communities of the human upper airways.

Journal of oral microbiology, 14(1):2103282 pii:2103282.

The recent COVID-19 pandemic prompted a rapid-growing interest in the investigation of the human microbiota of the upper airways. In fact, the resident microbial community of this body district may have an influence on the onset of SARS-CoV-2 infection and its clinical course in terms of presence, symptom severity, and outcomes. However, several microbiological methodologies are available to study the human microbiota, reflecting the extensive fragmentation of methodological approaches. We investigate the impact of two critical steps that can induce biases in the downstream analyses, i.e. sampling method and microbial DNA extraction kit employed. We observed major discrepancies regarding the total amount of prokaryotic DNA that could be retrieved from a biological sample and the proportion between bacterial DNA and human host DNA. Moreover, shotgun DNA sequencing and taxonomic profile reconstruction also revealed correlations between sampling methods and the procedures applied for microbial DNA extraction. Based on all the data collected in this study, we formulate indications regarding the most efficient and reliable methodological procedures for the metagenomic analyses of the upper airways' microbiota to maximize accuracy and reproducibility.

RevDate: 2022-08-04

Wen K, Liu L, Zhao M, et al (2022)

The Changes in Microbiotic Composition of Different Intestinal Tracts and the Effects of Supplemented Lactobacillus During the Formation of Goose Fatty Liver.

Frontiers in microbiology, 13:906895.

Intestinal bacteria play an important role in the formation of fatty liver in animals by participating in the digestion and degradation of nutrients, producing various metabolites, and altering the barrier effect of the intestine. However, changes in the gut microbiota during the formation of goose fatty liver are unclear. In this study, 80 healthy Landes geese with similar body weights at 70 days of age were randomly divided into two groups: the control group (n = 48; fed ad libitum) and the overfeeding group (n = 32; overfed). The intestinal contents were collected at 0, 12, and 24 days of overfeeding. The 16S rRNA and metagenomic sequencing analyses showed that the dominant phyla were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. At the genus level, Phyllobacterium, Bacteroides, Helicobacter, Lactobacillus, Enterococcus, and Romboutsia were the dominant genera in the goose intestine, and most of them were probiotics. In the control group, the relative abundance of Firmicutes in the jejunum and ileum gradually decreased with time, while that of Proteobacteria increased, whereas in the overfeeding group, the relative abundance of Firmicutes in the jejunum and ileum decreased and then increased with time, while that of Proteobacteria showed an opposite trend. In addition, supplementing Lactobacillus to the diet reduced body weight and fatty liver weight in overfed geese, but increased the weight of abdominal fat, suggesting that Lactobacillus supplementation might affect the transport of nascent fat from the liver to abdominal fat. In conclusion, the species of intestinal-dominant bacteria in the geese are relatively stable, but their relative abundance and function are affected by a number of factors. Overfeeding promotes the metabolism of nutrients in the jejunum and ileum and increases bacterial adaptability to environmental changes by enhancing their ability to process environmental and genetic information more efficiently. These findings suggest that the effect of overfeeding on the composition of intestinal microbiota may indirectly influence the formation of goose fatty liver through the gut/liver axis.

RevDate: 2022-08-04

Liu H, Han X, Zhao N, et al (2022)

The Gut Microbiota Determines the High-Altitude Adaptability of Tibetan Wild Asses (Equus kiang) in Qinghai-Tibet Plateau.

Frontiers in microbiology, 13:949002.

It was acknowledged long ago that microorganisms have played critical roles in animal evolution. Tibetan wild asses (TWA, Equus kiang) are the only wild perissodactyls on the Qinghai-Tibet Plateau (QTP) and the first national protected animals; however, knowledge about the relationships between their gut microbiota and the host's adaptability remains poorly understood. Herein, 16S rRNA and meta-genomic sequencing approaches were employed to investigate the gut microbiota-host associations in TWA and were compared against those of the co-resident livestock of yak (Bos grunnies) and Tibetan sheep (Ovis aries). Results revealed that the gut microbiota of yak and Tibetan sheep underwent convergent evolution. By contrast, the intestinal microflora of TWA diverged in a direction enabling the host to subsist on sparse and low-quality forage. Meanwhile, high microbial diversity (Shannon and Chao1 indices), cellulolytic activity, and abundant indicator species such as Spirochaetes, Bacteroidetes, Prevotella_1, and Treponema_2 supported forage digestion and short-chain fatty acid production in the gut of TWA. Meanwhile, the enterotype identification analysis showed that TWA shifted their enterotype in response to low-quality forage for a better utilization of forage nitrogen and short-chain fatty acid production. Metagenomic analysis revealed that plant biomass degrading microbial consortia, genes, and enzymes like the cellulolytic strains (Prevotella ruminicola, Ruminococcus flavefaciens, Ruminococcus albus, Butyrivibrio fibrisolvens, and Ruminobacter amylophilus), as well as carbohydrate metabolism genes (GH43, GH3, GH31, GH5, and GH10) and enzymes (β-glucosidase, xylanase, and β-xylosidase, etc.) had a significantly higher enrichment in TWA. Our results indicate that gut microbiota can improve the adaptability of TWA through plant biomass degradation and energy maintenance by the functions of gut microbiota in the face of nutritional deficiencies and also provide a strong rationale for understanding the roles of gut microbiota in the adaptation of QTP wildlife when facing harsh feeding environments.

RevDate: 2022-08-04

De D, Nayak T, Chowdhury S, et al (2022)

Insights of Host Physiological Parameters and Gut Microbiome of Indian Type 2 Diabetic Patients Visualized via Metagenomics and Machine Learning Approaches.

Frontiers in microbiology, 13:914124.

Type 2 diabetes (T2D) is a serious public health issue and may also contribute to modification in the structure of the intestinal microbiota, implying a link between T2D and microbial inhabitants in the digestive tract. This work aimed to develop efficient models for identifying essential physiological markers for improved T2D classification using machine learning algorithms. Using amplicon metagenomic approaches, an effort has also been made to understand the alterations in core gut microbial members in Indian T2D patients with respect to their control normal glucose tolerance (NGT). Our data indicate the level of fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) were the most useful physiological indicators while random forest and support vector machine with RBF Kernel were effective predictions models for identifications of T2D. The dominating gut microbial members Allopreotella, Rikenellaceae RC9 gut group, Haemophilus, Ruminococcus torques group, etc. in Indian T2D patients showed a strong association with both FBG and HbA1c. These members have been reported to have a crucial role in gut barrier breakdown, blood glucose, and lipopolysaccharide level escalation, or as biomarkers. While the dominant NGT microbiota (Akkermansia, Ligilactobacillus, Enterobacter, etc.) in the colon has been shown to influence inflammatory immune responses by acting as an anti-inflammatory agent and maintaining the gut barrier. The topology study of co-occurrence network analysis indicates that changes in network complexity in T2D lead to variations in the different gut microbial members compared to NGT. These studies provide a better understanding of the gut microbial diversity in Indian T2D patients and show the way for the development of valuable diagnostics strategies to improve the prediction and modulation of the T2D along with already established methods.

RevDate: 2022-08-03

Gaire TN, Odland C, Zhang B, et al (2022)

The impacts of viral infection and subsequent antimicrobials on the microbiome-resistome of growing pigs.

Microbiome, 10(1):118.

BACKGROUND: Antimicrobials are used in food-producing animals for purposes of preventing, controlling, and/or treating infections. In swine, a major driver of antimicrobial use is porcine reproductive and respiratory syndrome (PRRS), which is caused by a virus that predisposes infected animals to secondary bacterial infections. Numerous antimicrobial protocols are used to treat PRRS, but we have little insight into how these treatment schemes impact antimicrobial resistance (AMR) dynamics within the fecal microbiome of commercial swine. The aim of this study was to determine whether different PRRS-relevant antimicrobial treatment protocols were associated with differences in the fecal microbiome and resistome of growing pigs. To accomplish this, we used a metagenomics approach to characterize and compare the longitudinal wean-to-market resistome and microbiome of pigs challenged with PRRS virus and then exposed to different antimicrobial treatments, and a group of control pigs not challenged with PRRS virus and having minimal antimicrobial exposure. Genomic DNA was extracted from pen-level composite fecal samples from each treatment group and subjected to metagenomic sequencing and microbiome-resistome bioinformatic and statistical analysis. Microbiome-resistome profiles were compared over time and between treatment groups.

RESULTS: Fecal microbiome and resistome compositions both changed significantly over time, with a dramatic and stereotypic shift between weaning and 9 days post-weaning (dpw). Antimicrobial resistance gene (ARG) richness and diversity were significantly higher at earlier time points, while microbiome richness and diversity were significantly lower. The post-weaning shift was characterized by transition from a Bacteroides-dominated enterotype to Lactobacillus- and Streptococcus-dominated enterotypes. Both the microbiome and resistome stabilized by 44 dpw, at which point the trajectory of microbiome-resistome maturation began to diverge slightly between the treatment groups, potentially due to physical clustering of the pigs. Challenge with PRRS virus seemed to correspond to the re-appearance of many very rare and low-abundance ARGs within the feces of challenged pigs. Despite very different antimicrobial exposures after challenge with PRRS virus, resistome composition remained largely similar between the treatment groups. Differences in ARG abundance between the groups were mostly driven by temporal changes in abundance that occurred prior to antimicrobial exposures, with the exception of ermG, which increased in the feces of treated pigs, and was significantly more abundant in the feces of these pigs compared to the pigs that did not receive post-PRRS antimicrobials.

CONCLUSIONS: The fecal microbiome-resistome of growing pigs exhibited a stereotypic trajectory driven largely by weaning and physiologic aging of the pigs. Events such as viral illness, antimicrobial exposures, and physical grouping of the pigs exerted significant yet relatively minor influence over this trajectory. Therefore, the AMR profile of market-age pigs is the culmination of the life history of the individual pigs and the populations to which they belong. Disease status alone may be a significant driver of AMR in market-age pigs, and understanding the interaction between disease processes and antimicrobial exposures on the swine microbiome-resistome is crucial to developing effective, robust, and reproducible interventions to control AMR. Video Abstract.

RevDate: 2022-08-03

Wang Y, Xu J, Chen H, et al (2022)

A balanced gut microbiota is essential to maintain health in captive sika deer.

Applied microbiology and biotechnology [Epub ahead of print].

Certain animals harbor a high proportion of pathogens, particular the zoonotic pathogens, in their gut microbiome but are usually asymptomic; however, their carried pathogens may seriously threaten the public health. By understanding how the microbiome overcomes the negative effects of pathogens to maintain host health, we can develop novel solutions to control animal-mediated pathogen transmission including identification and application of beneficial microbes. Here, we analyzed the gut microbiota of 10 asymptomic captive sika deer individuals by full-length 16S rDNA sequencing. Twenty-nine known pathogens capable of infecting humans were identified, and the accumulated proportions of the identified pathogens were highly variable among individuals (2.33 to 39.94%). The relative abundances of several beneficial bacteria, including Lactobacillus and Bifidobacterium, were found to be positively correlated with the relative abundances of accumulated pathogens. Whole-genome metagenomic analysis revealed that the beneficial- and pathogenic-associated functions, such as genes involved in the synthesis of short chain fatty acids and virulence factors, were also positively correlated in the microbiome, indicating that the beneficial and pathogenic functions were maintained at a relatively balanced ratio. Furthermore, the bacteriophages that target the identified pathogens were found to be positively correlated with the pathogenic content in the microbiome. Several high-quality genomes of beneficial bacteria affiliated with Lactobacillus and Bifidobacterium and bacteriophages were recovered from the metagenomic data. Overall, this study provides novel insights into the interplay between beneficial and pathogenic content to ensure maintenance of a healthy gut microbiome, and also contributes to discovery of novel beneficial microbes and functions that control pathogens. KEY POINTS: • Certain asymptomic captive sika deer individuals harbor relatively high amounts of zoonotic pathogens. • The beneficial microbes and the beneficial functions are balanced with the pathogenic contents in the gut microbiome. • Several high-quality genomes of beneficial bacteria and bacteriophages are recovered by metagenomics.

RevDate: 2022-08-03

Sun JH, Zhang XH, Mo XD, et al (2022)

[Application value of metagenomic next-generation sequencing for infectious pathogens in patients receiving allogeneic hematopoietic stem cell transplantation].

Zhonghua nei ke za zhi, 61(8):928-932.

Objective: To investigate the application value of Metagenomic Next-Generation sequencing (mNGS) in infectious patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Methods: Patients suspected with local or systemic infections were retrospectively included after allo-HSCT in our department from April 2019 to November 2020. Pathogenic microorganisms were tested by mNGS in samples from peripheral blood, cerebrospinal fluid, alveolar lavage Liquid, abscess, etc. Other diagnostic methods such as bacterial/fungal culture, viral PCR detection were simultaneously explored comparing with mNGS results. Results: A total of 112 samples in 83 patients were detected by mNGS, and 34 pathogenic microorganisms were determined. Among these positive samples, 11 strains of bacteria (17 times) with the most common Escherichia coli (4/17) were reported. There were 7 strains of fungi (10 times) detected with primary Candida albicans (7/29). Although arvovirus 30.2% (39/129) were predominantly detected, its diagnostic relevance with infections was not definite. Other pathogenic viruses including cytomegalovirus (CMV) 25.6% (33/129) and Epstein Barr virus (EBV) 14.0% (18/129)were of significance. Comparing with golden diagnostic criteria, the sensitivity of mNGS was 86.5%, and specificity was 45.0%. Regarding single pathogen infection, the consistency of mNGS and conventional methods was 82.9% (29/35), while it was 16/17 in combination infections. Conclusion: mNGS could be a potential method to determine pathogens in patients suspected with infections after allo-HSCT.

RevDate: 2022-08-03

Wang ZX, Wu X, Xu J, et al (2022)

[Value of metagenomic next-generation sequencing in the etiology diagnosis of bacterial meningitis in children].

Zhonghua er ke za zhi = Chinese journal of pediatrics, 60(8):769-773.

Objective: To explore the value of metagenomic next-generation sequencing (mNGS) in the etiology diagnosis of bacterial meningitis in children. Methods: The etiological results of 189 children diagnosed with "bacterial meningitis" or "purulent meningitis" or "central nervous system infection" in the Children's Hospital of Fudan University from 1st January 2019 to 31st December 2020 were analyzed retrospectively. The cerebrospinal fluid (CFS) of the children with bacterial meningitis was detected by culture and mNGS respectively, and the difference of pathogen detection rate between the 2 methods was analyzed. According to the age at the time of visit, the children were divided into neonatal group (≤28 days of age) and non-neonatal group (>28 days of age), and χ2 test was used to compare the positive rate between the 2 groups. Taking CFS culture as the gold standard, the sensitivity and specificity of mNGS in the diagnosing of bacterial meningitis in children were analyzed. Results: Among these 189 children with bacterial meningitis, 116 were males and 73 were females. A total of 76 strains of pathogens were detected in blood and (or) CSF cultures, of which 50 strains (65.8%) were Gram-positive bacteria; among those, 18 strains (23.7%) of Streptococcus agalactiae, 17 strains (19.7%) of Escherichia coli and 15 strains (19.7%) of Streptococcus pneumoniae were detected with higher detection rate. The infection rate of Gram-positive bacteria in the non-neonatal group was higher than that in the neonatal group (76.0% (38/50) vs. 50.0% (13/26), χ2=5.24, P=0.020).The same CSF samples of 48 cases were tested by mNGS and culture at the same time, and the detection rate of mNGS was higher than that of CSF culture (20 cases (41.7%) vs. 12 cases (25.0%), χ2=16.45, P<0.001). The consistency of mNGS and culture results was 79.2% (38/48), and the same pathogen was detected in 11 children with both positive mNGS and CSF culture. Taking the results of CSF culture as the gold standard, the sensitivity of mNGS in the diagnosing of bacterial meningitis was 91.7%, and the specificity was 75.0%. Conclusions: The mNGS technology can improve the pathogen detection rate of bacterial meningitis in children, and has a high consistency with CSF culture. In suspected cases where the pathogen cannot be identified by traditional methods, CSF mNGS should be considered timely.

RevDate: 2022-08-03

Dehority W, Spence D, DL Dinwiddie (2020)

Severe Acute Respiratory Syndrome Coronavirus 2: Genomic Observations and Emerging Therapies.

Pediatric allergy, immunology, and pulmonology, 33(2):49-52.

Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of the disease COVID-19, first emerged in late December 2019 in China, and has subsequently become a pandemic with unprecedented clinical impact. The virus appears to more severely affect older individuals and those with co-morbid medical conditions, specifically those with chronic lung disease, obesity, heart failure and diabetes. Fortunately, children appear to be less severely affected, though mortality and severe disease have been reported. In addition, children's role in spreading the disease (potentially through asymptomatic shedding of the virus) remains an important area requiring further investigation. The emergence of SARS-CoV-2 has highlighted the importance of metagenomic next generation sequencing as a tool for pandemic investigation. Though no proven therapeutic options currently exist, ongoing genomic and clinical trial data may help inform the identification and development of both repurposed and novel therapeutic agents for use in this disease.

RevDate: 2022-08-03

PLOS ONE Editors (2022)

Retraction: Enumeration of citrus endophytic bacterial communities based on illumine metagenomics technique.

PloS one, 17(8):e0272191 pii:PONE-D-22-20018.

RevDate: 2022-08-03

Aishwarya S, K Gunasekaran (2022)

Meta-analysis of the microbial biomarkers in the gut - lung crosstalk in COVID-19, community acquired pneumonia and Clostridium difficile infections.

Letters in applied microbiology [Epub ahead of print].

Respiratory infections are the leading causes of mortality and the current pandemic COVID-19 is one such trauma that imposed catastrophic devastation to the health and economy of the world. Unraveling the correlations and interplay of the human microbiota in the gut- lung axis would offer incredible solutions to the underlying mystery of the disease progression. The study compared the microbiota profiles of six samples namely healthy gut, healthy lung, COVID-19 infected gut, COVID-19 infected lungs, Clostridium difficile infected gut and community acquired pneumonia infected lungs. The metagenome datasets were processed, normalized, classified and the rarefaction curves were plotted. The microbial biomarkers for COVID-19 infections were identified as the abundance of Candida and Escherichia in lungs with Ruminococcus in the gut. Candida and Staphylococcus could play a vital role as putative prognostic biomarkers of community acquired pneumonia whereas abundance of Faecalibacterium and Clostridium are associated with the Clostridium difficile infections in gut. A machine learning random forest classifier applied to the datasets efficiently classified the biomarkers. The study offers an extensive and incredible understanding of the existence of gut lung axis during dysbiosis of two anatomically different organs.

RevDate: 2022-08-03

Richter DJ, Watteaux R, Vannier T, et al (2022)

Genomic evidence for global ocean plankton biogeography shaped by large-scale current systems.

eLife, 11: pii:78129.

Biogeographical studies have traditionally focused on readily visible organisms, but recent technological advances are enabling analyses of the large-scale distribution of microscopic organisms, whose biogeographical patterns have long been debated. Here we assessed the global structure of plankton geography and its relation to the biological, chemical, and physical context of the ocean (the 'seascape') by analyzing metagenomes of plankton communities sampled across oceans during the Tara Oceans expedition, in light of environmental data and ocean current transport. Using a consistent approach across organismal sizes that provides unprecedented resolution to measure changes in genomic composition between communities, we report a pan-ocean, size-dependent plankton biogeography overlying regional heterogeneity. We found robust evidence for a basin-scale impact of transport by ocean currents on plankton biogeography, and on a characteristic timescale of community dynamics going beyond simple seasonality or life history transitions of plankton.

RevDate: 2022-08-03

Bai Z, Zhang YZ, Miyano S, et al (2022)

Identification of bacteriophage genome sequences with representation learning.

Bioinformatics (Oxford, England) pii:6654586 [Epub ahead of print].

MOTIVATION: Bacteriophages/Phages are the viruses that infect and replicate within bacteria and archaea. Phages are used to therapeutically provide another potential solution for solving antibiotic resistance, which is one of the threats to global health. To develop phage therapies, the identification of phages from metagenome sequences is the first step. Currently, there are two main methods for identifying phages: database-based (alignment-based) methods and alignment-free methods. Database-based methods typically use a large number of sequences as references; alignment-free methods usually learn the features of the sequences with machine learning and deep learning models.

RESULTS: We propose INHERIT which use a deep representation learning model to integrate both database-based and alignment-free methods, combining the strengths of both. Pre-training is used as an alternative way of acquiring knowledge representations from existing databases, while the BERT-style deep learning framework retains the advantage of alignment-free methods. We compare INHERIT with four existing methods on a third-party benchmark dataset. Our experiments show that INHERIT achieves a better performance with the F1-score of 0.9932. In addition, we find that pre-training two species separately helps the non-alignment deep learning model make more accurate predictions.

AVAILABILITY: The codes of INHERIT are now available in: https://github.com/Celestial-Bai/INHERIT.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RevDate: 2022-08-03

Zulk JJ, Clark JR, Ottinger S, et al (2022)

Phage Resistance Accompanies Reduced Fitness of Uropathogenic Escherichia coli in the Urinary Environment.

mSphere [Epub ahead of print].

Urinary tract infection (UTI) is among the most common infections treated worldwide each year and is caused primarily by uropathogenic Escherichia coli (UPEC). Rising rates of antibiotic resistance among uropathogens have spurred a consideration of alternative treatment strategies, such as bacteriophage (phage) therapy; however, phage-bacterial interactions within the urinary environment are poorly defined. Here, we assess the activity of two phages, namely, HP3 and ES17, against clinical UPEC isolates using in vitro and in vivo models of UTI. In both bacteriologic medium and pooled human urine, we identified phage resistance arising within the first 6 to 8 h of coincubation. Whole-genome sequencing revealed that UPEC strains resistant to HP3 and ES17 harbored mutations in genes involved in lipopolysaccharide (LPS) biosynthesis. Phage-resistant strains displayed several in vitro phenotypes, including alterations to adherence to and invasion of human bladder epithelial HTB-9 cells and increased biofilm formation in some isolates. Interestingly, these phage-resistant UPEC isolates demonstrated reduced growth in pooled human urine, which could be partially rescued by nutrient supplementation and were more sensitive to several outer membrane-targeting antibiotics than parental strains. Additionally, phage-resistant UPEC isolates were attenuated in bladder colonization in a murine UTI model. In total, our findings suggest that while resistance to phages, such as HP3 and ES17, may arise readily in the urinary environment, phage resistance is accompanied by fitness costs which may render UPEC more susceptible to host immunity or antibiotics. IMPORTANCE UTI is one of the most common causes of outpatient antibiotic use, and rising antibiotic resistance threatens the ability to control UTI unless alternative treatments are developed. Bacteriophage (phage) therapy is gaining renewed interest; however, much like with antibiotics, bacteria can readily become resistant to phages. For successful UTI treatment, we must predict how bacteria will evade killing by phage and identify the downstream consequences of phage resistance during bacterial infection. In our current study, we found that while phage-resistant bacteria quickly emerged in vitro, these bacteria were less capable of growing in human urine and colonizing the murine bladder. These results suggest that phage therapy poses a viable UTI treatment if phage resistance confers fitness costs for the uropathogen. These results have implications for developing cocktails of phage with multiple different bacterial targets, of which each is evaded only at the cost of bacterial fitness.

RevDate: 2022-08-03

Shi LD, Zhou YJ, Tang XJ, et al (2022)

Coupled Aerobic Methane Oxidation and Arsenate Reduction Contributes to Soil-Arsenic Mobilization in Agricultural Fields.

Environmental science & technology [Epub ahead of print].

Microbial oxidation of organic compounds can promote arsenic release by reducing soil-associated arsenate to the more mobile form arsenite. While anaerobic oxidation of methane has been demonstrated to reduce arsenate, it remains elusive whether and to what extent aerobic methane oxidation (aeMO) can contribute to reductive arsenic mobilization. To fill this knowledge gap, we performed incubations of both microbial laboratory cultures and soil samples from arsenic-contaminated agricultural fields in China. Incubations with laboratory cultures showed that aeMO could couple to arsenate reduction, wherein the former bioprocess was carried out by aerobic methanotrophs and the latter by a non-methanotrophic bacterium belonging to a novel and uncultivated representative of Burkholderiaceae. Metagenomic analyses combined with metabolite measurements suggested that formate served as the interspecies electron carrier linking aeMO to arsenate reduction. Such coupled bioprocesses also take place in the real world, supported by a similar stoichiometry and gene activity in the incubations with natural paddy soils, and contribute up to 76.2% of soil-arsenic mobilization into pore waters in the top layer of the soils where oxygen was present. Overall, this study reveals a previously overlooked yet significant contribution of aeMO to reductive arsenic mobilization.

RevDate: 2022-08-02

De Bernardini N, Basile A, Zampieri G, et al (2022)

Integrating metagenomic binning with flux balance analysis to unravel syntrophies in anaerobic CO2 methanation.

Microbiome, 10(1):117.

BACKGROUND: Carbon fixation through biological methanation has emerged as a promising technology to produce renewable energy in the context of the circular economy. The anaerobic digestion microbiome is the fundamental biological system operating biogas upgrading and is paramount in power-to-gas conversion. Carbon dioxide (CO2) methanation is frequently performed by microbiota attached to solid supports generating biofilms. Despite the apparent simplicity of the microbial community involved in biogas upgrading, the dynamics behind most of the interspecies interaction remain obscure. To understand the role of the microbial species in CO2 fixation, the biofilm generated during the biogas upgrading process has been selected as a case study. The present work investigates via genome-centric metagenomics, based on a hybrid Nanopore-Illumina approach the biofilm developed on the diffusion devices of four ex situ biogas upgrading reactors. Moreover, genome-guided metabolic reconstruction and flux balance analysis were used to propose a biological role for the dominant microbes.

RESULTS: The combined microbiome was composed of 59 species, with five being dominant (> 70% of total abundance); the metagenome-assembled genomes representing these species were refined to reach a high level of completeness. Genome-guided metabolic analysis appointed Firmicutes sp. GSMM966 as the main responsible for biofilm formation. Additionally, species interactions were investigated considering their co-occurrence in 134 samples, and in terms of metabolic exchanges through flux balance simulation in a simplified medium. Some of the most abundant species (e.g., Limnochordia sp. GSMM975) were widespread (~ 67% of tested experiments), while others (e.g., Methanothermobacter wolfeii GSMM957) had a scattered distribution. Genome-scale metabolic models of the microbial community were built with boundary conditions taken from the biochemical data and showed the presence of a flexible interaction network mainly based on hydrogen and carbon dioxide uptake and formate exchange.

CONCLUSIONS: Our work investigated the interplay between five dominant species within the biofilm and showed their importance in a large spectrum of anaerobic biogas reactor samples. Flux balance analysis provided a deeper insight into the potential syntrophic interaction between species, especially Limnochordia sp. GSMM975 and Methanothermobacter wolfeii GSMM957. Finally, it suggested species interactions to be based on formate and amino acids exchanges. Video Abstract.

RevDate: 2022-08-02

Shkoporov AN, Stockdale SR, Lavelle A, et al (2022)

Viral biogeography of the mammalian gut and parenchymal organs.

Nature microbiology [Epub ahead of print].

The mammalian virome has been linked to health and disease but our understanding of how it is structured along the longitudinal axis of the mammalian gastrointestinal tract (GIT) and other organs is limited. Here, we report a metagenomic analysis of the prokaryotic and eukaryotic virome occupying luminal and mucosa-associated habitats along the GIT, as well as parenchymal organs (liver, lung and spleen), in two representative mammalian species, the domestic pig and rhesus macaque (six animals per species). Luminal samples from the large intestine of both mammals harboured the highest loads and diversity of bacteriophages (class Caudoviricetes, family Microviridae and others). Mucosal samples contained much lower viral loads but a higher proportion of eukaryotic viruses (families Astroviridae, Caliciviridae, Parvoviridae). Parenchymal organs contained bacteriophages of gut origin, in addition to some eukaryotic viruses. Overall, GIT virome composition was specific to anatomical region and host species. Upper GIT and mucosa-specific viruses were greatly under-represented in distal colon samples (a proxy for faeces). Nonetheless, certain viral and phage species were ubiquitous in all samples from the oral cavity to the distal colon. The dataset and its accompanying methodology may provide an important resource for future work investigating the biogeography of the mammalian gut virome.

RevDate: 2022-08-02

Kim H, Jeon S, Kim J, et al (2022)

Investigation of memory-enhancing effects of Streptococcus thermophilus EG007 in mice and elucidating molecular and metagenomic characteristics using nanopore sequencing.

Scientific reports, 12(1):13274.

Over the past decades, accumulating evidences have highlighted the gut microbiota as a key player in the brain functioning via microbiota-gut-brain axis, and accordingly, the beneficial role of several probiotic strains in cognitive ability also have been actively investigated. However, the majority of the research have demonstrated the effects against age-related cognitive decline or neurological disease. To this end, we aimed to investigate lactic acid bacteria strains having beneficial effects on the cognitive function of healthy young mice and elucidate underlying characteristics by carrying out nanopore sequencing-based genomics and metagenomics analysis. 8-week consumption of Streptococcus thermophilus EG007 demonstrated marked enhancements in behavior tests assessing short-term spatial and non-spatial learning and memory. It was revealed that EG007 possessed genes encoding various metabolites beneficial for a health condition in many aspects, including gamma-aminobutyric acid producing system, a neurotransmitter associated with mood and stress response. Also, by utilizing 16S-23S rRNA operon as a taxonomic marker, we identified more accurate species-level compositional changes in gut microbiota, which was increase of certain species, previously reported to have associations with mental health or down-regulation of inflammation or infection-related species. Moreover, correlation analysis revealed that the EG007-mediated altered microbiota had a significant correlation with the memory traits.

RevDate: 2022-08-02

Brusilovsky M, Rochman M, Shoda T, et al (2022)

Vitamin D receptor and STAT6 interactome governs oesophageal epithelial barrier responses to IL-13 signalling.

Gut pii:gutjnl-2022-327276 [Epub ahead of print].

OBJECTIVE: The contribution of vitamin D (VD) deficiency to the pathogenesis of allergic diseases remains elusive. We aimed to define the impact of VD on oesophageal allergic inflammation.

DESIGN: We assessed the genomic distribution and function of VD receptor (VDR) and STAT6 using histology, molecular imaging, motif discovery and metagenomic analysis. We examined the role of VD supplementation in oesophageal epithelial cells, in a preclinical model of IL-13-induced oesophageal allergic inflammation and in human subjects with eosinophilic oesophagitis (EoE).

RESULTS: VDR response elements were enriched in oesophageal epithelium, suggesting enhanced VDR binding to functional gene enhancer and promoter regions. Metagenomic analysis showed that VD supplementation reversed dysregulation of up to 70% of the transcriptome and epigenetic modifications (H3K27Ac) induced by IL-13 in VD-deficient cells, including genes encoding the transcription factors HIF1A and SMAD3, endopeptidases (SERPINB3) and epithelial-mesenchymal transition mediators (TGFBR1, TIAM1, SRC, ROBO1, CDH1). Molecular imaging and chromatin immunoprecipitation showed VDR and STAT6 colocalisation within the regulatory regions of the affected genes, suggesting that VDR and STAT6 interactome governs epithelial tissue responses to IL-13 signalling. Indeed, VD supplementation reversed IL-13-induced epithelial hyperproliferation, reduced dilated intercellular spaces and barrier permeability, and improved differentiation marker expression (filaggrin, involucrin). In a preclinical model of IL-13-mediated oesophageal allergic inflammation and in human EoE, VD levels inversely associated with severity of oesophageal eosinophilia and epithelial histopathology.

CONCLUSIONS: Collectively, these findings identify VD as a natural IL-13 antagonist with capacity to regulate the oesophageal epithelial barrier functions, providing a novel therapeutic entry point for type 2 immunity-related diseases.

RevDate: 2022-08-02

Wang C, Mantilla-Calderon D, Xiong Y, et al (2022)

Investigation of Antibiotic Resistome in Hospital Wastewater during the COVID-19 Pandemic: Is the Initial Phase of the Pandemic Contributing to Antimicrobial Resistance?.

Environmental science & technology [Epub ahead of print].

Since the COVID-19 pandemic started, there has been much speculation about how COVID-19 and antimicrobial resistance may be interconnected. In this study, untreated wastewater was sampled from Hospital A designated to treat COVID-19 patients during the first wave of the COVID-19 pandemic alongside Hospital B that did not receive any COVID-19 patients. Metagenomics was used to determine the relative abundance and mobile potential of antibiotic resistant genes (ARGs), prior to determining the correlation of ARGs with time/incidence of COVID-19. Our findings showed that ARGs resistant to macrolides, sulfonamides, and tetracyclines were positively correlated with time in Hospital A but not in Hospital B. Likewise, minor extended spectrum beta-lactamases (ESBLs) and carbapenemases of classes B and D were positively correlated with time, suggesting the selection of rare and/or carbapenem-resistant genes in Hospital A. Non-carbapenemase blaVEB also positively correlated with both time and intI1 and was copresent with other ARGs including carbapenem-resistant genes in 6 metagenome-assembled genomes (MAGs). This study highlighted concerns related to the dissemination of antimicrobial resistance (AMR) during the COVID-19 pandemic that may arise from antibiotic use and untreated hospital wastewater.

RevDate: 2022-08-02

Wegener G, Laso-Pérez R, Orphan VJ, et al (2022)

Anaerobic Degradation of Alkanes by Marine Archaea.

Annual review of microbiology [Epub ahead of print].

Alkanes are saturated apolar hydrocarbons that range from its simplest form, methane, to high-molecular-weight compounds. Although alkanes were once considered biologically recalcitrant under anaerobic conditions, microbiological investigations have now identified several microbial taxa that can anaerobically degrade alkanes. Here we review recent discoveries in the anaerobic oxidation of alkanes with a specific focus on archaea that use specific methyl coenzyme M reductases to activate their substrates. Our understanding of the diversity of uncultured alkane-oxidizing archaea has expanded through the use of environmental metagenomics and enrichment cultures of syntrophic methane-, ethane-, propane-, and butane-oxidizing marine archaea with sulfate-reducing bacteria. A recently cultured group of archaea directly couples long-chain alkane degradation with methane formation, expanding the range of substrates used for methanogenesis. This article summarizes the rapidly growing knowledge of the diversity, physiology, and habitat distribution of alkane-degrading archaea. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

RevDate: 2022-08-02

Tchitchek N, Nguekap Tchoumba O, Pires G, et al (2022)

Low-dose interleukin-2 shapes a tolerogenic gut microbiota that improves autoimmunity and gut inflammation.

JCI insight pii:159406 [Epub ahead of print].

Gut microbiota (GM) dysbiosis is associated with inflammatory bowel diseases and also with cardiometabolic, neurologic, and autoimmune diseases. GM composition has a direct effect on the immune system, and vice versa, and particularly on regulatory T cell (Treg) homeostasis. Low-dose interleukin-2 (IL-2LD) stimulates Tregs and is a promising treatment for autoimmune and inflammatory diseases. We aimed to evaluate the impacts of IL-2LD on GM, and correlatively on the immune system. We used 16S ribosomal RNA profiling and metagenomics to characterize GM of mice and humans treated or not with IL-2LD. We performed faecal microbiota transplantation (FMT) from IL-2LD-treated to naïve recipient mice and evaluated its effects in models of gut inflammation and diabetes. IL-2LD markedly affects GM composition in mice and humans. Transfer of an IL-2-tuned microbiota by FMT protected C57BL/6J mice from dextran sulphate sodium-induced colitis and prevented diabetes in NOD mice. Metagenomic analyses highlighted a role for several species impacted by IL-2LD and for microbial pathways involved in the biosynthesis of amino acids, short-chain fatty acids, and L-arginine. Our results demonstrate that IL-2LD induces changes in GM that are involved in the immunoregulatory effects of IL-2LD and suggest a cross-talk between Tregs and GM. These results provide novel insights for understanding the mode of action of Treg-directed therapies.

RevDate: 2022-08-02

Pellegrinetti TA, Cotta SR, Sarmento H, et al (2022)

Bacterial Communities Along Environmental Gradients in Tropical Soda Lakes.

Microbial ecology [Epub ahead of print].

Soda lake environments are known to be variable and can have distinct differences according to geographical location. In this study, we investigated the effects of different environmental conditions of six adjacent soda lakes in the Pantanal biome (Mato Grosso do Sul state, Brazil) on bacterial communities and their functioning using a metagenomic approach combined with flow cytometry and chemical analyses. Ordination analysis using flow cytometry and water chemistry data from two sampling periods (wet and dry) clustered soda lakes into three different profiles: eutrophic turbid (ET), oligotrophic turbid (OT), and clear vegetated oligotrophic (CVO). Analysis of bacterial community composition and functioning corroborated this ordination; the exception was one ET lake, which was similar to one OT lake during the wet season, indicating drastic shifts between seasons. Microbial abundance and diversity increased during the dry period, along with a considerable number of limnological variables, all indicative of a strong effect of the precipitation-evaporation balance in these systems. Cyanobacteria were associated with high electric conductivity, pH, and nutrient availability, whereas Actinobacteria, Alphaproteobacteria, and Betaproteobacteria were correlated with landscape morphology variability (surface water, surface perimeter, and lake volume) and with lower salinity and pH levels. Stress response metabolism was enhanced in OT and ET lakes and underrepresented in CVO lakes. The microbiome dataset of this study can serve as a baseline for restoring impacted soda lakes. Altogether, the results of this study demonstrate the sensitivity of tropical soda lakes to climate change, as slight changes in hydrological regimes might produce drastic shifts in community diversity.

RevDate: 2022-08-02

FitzGerald J, Patel S, Eckenberger J, et al (2022)

Improved gut microbiome recovery following drug therapy is linked to abundance and replication of probiotic strains.

Gut microbes, 14(1):2094664.

Probiotics have been used for decades to alleviate the negative side-effects of oral antibiotics, but our mechanistic understanding on how they work is so far incomplete. Here, we performed a metagenomic analysis of the fecal microbiota in participants who underwent a 14-d Helicobacter pylori eradication therapy with or without consumption of a multi-strain probiotic intervention (L. paracasei CNCM I-1518, L. paracasei CNCM I-3689, L. rhamnosus CNCM I-3690, and four yogurt strains) in a randomized, double-blinded, controlled clinical trial. Using a strain-level analysis for detection and metagenomic determination of replication rate, ingested strains were detected and replicated transiently in fecal samples and in the gut during and following antibiotic administration. Consumption of the fermented milk product led to a significant, although modest, improvement in the recovery of microbiota composition. Stratification of participants into two groups based on the degree to which their microbiome recovered showed i) a higher fecal abundance of the probiotic L. paracasei and L. rhamnosus strains and ii) an elevated replication rate of one strain (L. paracasei CNCMI-1518) in the recovery group. Collectively, our findings show a small but measurable benefit of a fermented milk product on microbiome recovery after antibiotics, which was linked to the detection and replication of specific probiotic strains. Such functional insight can form the basis for the development of probiotic-based intervention aimed to protect gut microbiome from drug treatments.

RevDate: 2022-08-02

Sakamoto N, Akeda Y, Sugawara Y, et al (2022)

Role of Chromosome- and/or Plasmid-Located blaNDM on the Carbapenem Resistance and the Gene Stability in Escherichia coli.

Microbiology spectrum [Epub ahead of print].

The spread of New Delhi metallo-β-lactamase (NDM)-producing Enterobacterales represents a public health risk. The horizontal transfer of plasmids encoding the NDM gene, blaNDM, usually mediates its spread to other bacteria within the family. In contrast, Enterobacterales with a chromosome-located blaNDM is rarely reported. The phenotypic differences between chromosome- and plasmid-located carbapenemase genes are poorly understood. To determine the significance in terms of the location of drug resistance genes, we examined carbapenemase activity and stability of chromosome- and plasmid-located blaNDM. Escherichia coli M719 possessing both chromosomes- and plasmid-located blaNDM genes was used as a wild-type strain (WT) for the construction of mutants, ΔpblaNDM and ΔcblaNDM, wherein chromosome- or plasmid-located blaNDM, was knocked out, respectively. The mutant ΔpblaNDM showed lower hydrolyzing activity against imipenem and gene expression than the WT or ΔcblaNDM mutant. The MICs of both mutant strains were still above the breakpoint of imipenem and meropenem. Moreover, the chromosome-located blaNDM gene was stable for at least 30 days in the absence of antimicrobial pressure, whereas the ΔcblaNDM mutant lost blaNDM to 87% at 30 days compared to that of the initial inoculum. Organisms harboring the plasmid-located carbapenemase genes were found to provide a higher level of carbapenem resistance than those with chromosome-located genes. However, the latter organisms with chromosomal carbapenemase genes exhibited more stable carbapenem resistance than did the former ones. In summary, chromosomally located carbapenemase genes require further monitoring and more attention should be paid to them. IMPORTANCE Carbapenem-resistant Enterobacterales (CRE) carrying blaNDM have spread worldwide since they were first reported in 2009. Many studies using whole-genome sequencing have identified the genetic structures, plasmid scaffolds of blaNDM, and mechanisms of spread via horizontal transfer. Chromosome-located blaNDM and integration mechanisms from plasmids have rarely been reported, and their significance is not fully understood. Here, we showed that the chromosome-located blaNDM was associated with lower levels of carbapenem resistance and carbapenemase activity than the plasmid-located blaNDM. However, it conferred carbapenem resistance above the breakpoints and the loss of chromosome-located blaNDM was not observed in the absence of antibiotic pressure. This study suggests that CRE strains carrying chromosome-located blaNDM may persist in clinical and environmental settings for a long period even without antibiotic pressure and need to be monitored along with plasmid-located blaNDM.

RevDate: 2022-08-02

Ma R, Zhao M, Wang H, et al (2022)

Virome of Giant Panda-Infesting Ticks Reveals Novel Bunyaviruses and Other Viruses That Are Genetically Close to Those from Giant Pandas.

Microbiology spectrum [Epub ahead of print].

Tick infestations have been reported as one of the factors threatening the health of giant pandas, but studies of viral pathogens carried by ticks feeding on the blood of giant pandas are limited. To assess whether blood-sucking ticks of giant pandas can carry viral pathogens and if so, whether the viruses in ticks are associated with those previously detected in giant panda hosts, we determined the viromes of ticks detached from giant pandas in a field stocking area in Sichuan Province, southwest China. Using viral metagenomics we identified 32 viral species in ticks, half of which (including anellovirus [n = 9], circovirus [n = 3], and gemycircularvirus [n = 4]) showed homology to viruses carried by giant pandas and their associated host species (such as red pandas and mosquitoes) in the same living domain. Remarkably, several viruses in this study phylogenetically assigned as bunyavirus, hepe-like virus, and circovirus were detected with relatively high abundance, but whether these newly identified tick-associated viruses can replicate in ticks and then transmit to host animals during a blood meal will require further investigation. These findings further expand our understanding of the role of giant panda-infesting ticks in the local ecosystem, especially related to viral acquisition and transmission, and lay a foundation to assess the risk for giant panda exposure to tick-borne viruses. IMPORTANCE Ticks rank only second to mosquitoes as blood-feeding arthropods, capable of spreading pathogens (including viruses, bacteria, and parasites) to hosts during a blood meal. To better understand the relationship between viruses carried by ticks and viruses that have been reported in giant pandas, it is necessary to analyze the viromes of giant panda-parasitic blood-sucking ticks. This study collected 421 ticks on the body surface of giant pandas in Sichuan Province, China. We characterized the extensive genetic diversity of viruses harbored by these ticks and reported frequent communication of viruses between giant pandas and their ticks. While most of the virome discovered here are nonpathogenic viruses from giant pandas and potentially tick-specific viruses, we revealed some possible tick-borne viruses, represented by novel bunyaviruses. This research contributes to the literature because currently there are few studies on the virome of giant panda-infesting ticks.

RevDate: 2022-08-01

Lin CY, Jha AR, Oba PM, et al (2022)

Longitudinal fecal microbiome and metabolite data demonstrate rapid shifts and subsequent stabilization after an abrupt dietary change in healthy adult dogs.

Animal microbiome, 4(1):46.

BACKGROUND: Diet has a large influence on gut microbiota diversity and function. Although previous studies have investigated the effect of dietary interventions on the gut microbiome, longitudinal changes in the gut microbiome, microbial functions, and metabolite profiles post dietary interventions have been underexplored. How long these outcomes require to reach a steady-state, how they relate to one another, and their impact on host physiological changes are largely unknown. To address these unknowns, we collected longitudinal fecal samples following an abrupt dietary change in healthy adult beagles (n = 12, age: 5.16 ± 0.87 year, BW: 13.37 ± 0.68 kg) using a crossover design. All dogs were fed a kibble diet (control) from d1-14, and then fed that same diet supplemented with fiber (HFD) or a protein-rich canned diet (CD) from d15-27. Fresh fecal samples were collected on d13, 16, 20, 24, and 27 for metabolite and microbiome assessment. Fecal microbial diversity and composition, metabolite profiles, and microbial functions dramatically diverged and stabilized within a few days (2 d for metabolites; 6 d for microbiota) after dietary interventions. Fecal acetate, propionate, and total short-chain fatty acids increased after change to HFD, while fecal isobutyrate, isovalerate, total branched-chain fatty acids, phenol, and indole increased after dogs consumed CD. Relative abundance of ~ 100 bacterial species mainly belonging to the Firmicutes, Proteobacteria, and Actinobacteria phyla increased in HFD. These shifts in gut microbiome diversity and composition were accompanied by functional changes. Transition to HFD led to increases in the relative abundance of KEGG orthology (KO) terms related to starch and sucrose metabolism, fatty acid biosynthesis, and amino sugar and nucleotide sugar metabolism, while transition to CD resulted in increased relative abundance of KO terms pertaining to inositol phosphate metabolism and sulfur metabolism. Significant associations among fecal microbial taxa, KO terms, and metabolites were observed, allowing for high-accuracy prediction of diet group by random forest analysis.

CONCLUSIONS: Longitudinal sampling and a multi-modal approach to characterizing the gastrointestinal environment allowed us to demonstrate how drastically and quickly dietary changes impact the fecal microbiome and metabolite profiles of dogs following an abrupt dietary change and identify key microbe-metabolite relationships that allowed for treatment prediction.

RevDate: 2022-08-01

Limberg J, Egan CE, Mora HA, et al (2022)

Metagenomic Sequencing of the Gallbladder Microbiome: Bacterial Diversity Does Not Vary by Surgical Pathology.

Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract [Epub ahead of print].

INTRODUCTION: Alterations in the microbiome contribute to the pathogenesis of many gastrointestinal diseases. However, the composition of the microbiome in gallbladder disease is not well described.

METHODS: We aimed to characterize the biliary microbiome in cholecystectomy patients. Bile and biliary stones were collected at cholecystectomy for a variety of surgical indications between 2017 and 2019. DNA was extracted and metagenomic sequencing was performed with subsequent taxonomic classification using Kraken2. The fraction of bacterial to total DNA reads, relative abundance of bacterial species, and overall species diversity were compared between pathologies and demographics.

RESULTS: A total of 74 samples were obtained from 49 patients: 46 bile and 28 stones, with matched pairs from 25 patients. The mean age was 48 years, 76% were female, 29% were Hispanic, and 29% of patients had acute cholecystitis. The most abundant species were Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pasteurianus. The bacterial fraction in bile and stone samples was higher in acute cholecystitis compared to other non-infectious pathologies (p < 0.05). Neither the diversity nor differential prevalence of specific bacterial species varied significantly between infectious and other non-infectious gallbladder pathologies. Multivariate analysis of the non-infectious group revealed that patients over 40 years of age had increased bacterial fractions (p < 0.05).

CONCLUSIONS: Metagenomic sequencing permits characterization of the gallbladder microbiome in cholecystectomy patients. Although a higher prevalence of bacteria was seen in acute cholecystitis, species and diversity were similar regardless of surgical indication. Additional study is required to determine how the microbiome can contribute to the development of symptomatic gallbladder disease.

RevDate: 2022-08-01

Hallstrøm S, Raina JB, Ostrowski M, et al (2022)

Chemotaxis may assist marine heterotrophic bacterial diazotrophs to find microzones suitable for N2 fixation in the pelagic ocean.

The ISME journal [Epub ahead of print].

Heterotrophic bacterial diazotrophs (HBDs) are ubiquitous in the pelagic ocean, where they have been predicted to carry out the anaerobic process of nitrogen fixation within low-oxygen microenvironments associated with marine pelagic particles. However, the mechanisms enabling particle colonization by HBDs are unknown. We hypothesized that HBDs use chemotaxis to locate and colonize suitable microenvironments, and showed that a cultivated marine HBD is chemotactic toward amino acids and phytoplankton-derived DOM. Using an in situ chemotaxis assay, we also discovered that diverse HBDs at a coastal site are motile and chemotactic toward DOM from various phytoplankton taxa and, indeed, that the proportion of diazotrophs was up to seven times higher among the motile fraction of the bacterial community compared to the bulk seawater community. Finally, three of four HBD isolates and 16 of 17 HBD metagenome assembled genomes, recovered from major ocean basins and locations along the Australian coast, each encoded >85% of proteins affiliated with the bacterial chemotaxis pathway. These results document the widespread capacity for chemotaxis in diverse and globally relevant marine HBDs. We suggest that HBDs could use chemotaxis to seek out and colonize low-oxygen microenvironments suitable for nitrogen fixation, such as those formed on marine particles. Chemotaxis in HBDs could therefore affect marine nitrogen and carbon biogeochemistry by facilitating nitrogen fixation within otherwise oxic waters, while also altering particle degradation and the efficiency of the biological pump.

RevDate: 2022-08-01

Liu Y, Cheuk-Hay Lau H, Cheng WY, et al (2022)

Gut microbiome in colorectal cancer: Clinical diagnosis and treatment.

Genomics, proteomics & bioinformatics pii:S1672-0229(22)00086-9 [Epub ahead of print].

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers and the leading cause of cancer-associated deaths. Epidemiological studies have shown that both genetic and environmental risk factors contribute to the development of CRC. Several metagenomic studies of CRC have identified gut dysbiosis as a fundamental risk factor in the evolution of colorectal malignancy. Although enormous efforts and substantial progresses have been made in understanding the relationship between the human gut microbiome and CRC, the precise mechanisms involved remain elusive. Recent data have shown a direct causative role of the gut microbiome in DNA damage, inflammation, and drug resistance in CRC, suggesting that modulation of the gut microbiome can act as a powerful tool in CRC prevention and therapy. Here, we provide an overview of the relationship between the gut microbiome and CRC, and explore relevant mechanisms of colorectal tumorigenesis. We next highlight the potential of bacterial species as clinical biomarkers, as well as their roles in therapeutic response. Factors limiting the clinical translation of the gut microbiome and strategies for resolving the current challenges are further discussed.

RevDate: 2022-08-01

Wei W, Cao J, Wu XC, et al (2022)

Diagnostic performance of metagenomic next-generation sequencing in non-tuberculous mycobacterial pulmonary disease when applied to clinical practice.

Infection [Epub ahead of print].

OBJECTIVE: To compare non-tuberculous mycobacterial pulmonary disease (NTMPD) diagnosis by metagenomic next-generation sequencing (mNGS) with Bactec mycobacterial growth indicator tube (MGIT) 960.

METHODS: A total of 422 patients with suspected NTMPD in Shanghai Pulmonary Hospital between January 2020 and May 2021 were retrospectively analyzed; 194 were diagnosed with NTMPD. The diagnostic performance of mNGS and MGIT 960 for NTMPD was assessed. Receiver operating characteristic (ROC) curves and areas under curve (AUCs) were compared.

RESULTS: The sensitivity of mNGS in NTMPD diagnosis was 81.4% and higher than that of MGIT 960 (53.6%). The specificity of mNGS in NTMPD diagnosis was 97.8%, similar to that of MGIT 960 (100%). The sensitivity of combined mNGS and MGIT 960 in NTMPD diagnosis was 91.8%. The sensitivity of mNGS for bronchoalveolar lavage fluid (BALF), pulmonary puncture tissue fluid, and sputum was 84.8%, 80.6%, and 77.5%, respectively; all were higher than that of MGIT 960 (P < 0.05). The AUC of mNGS and MGIT 960 was 0.897 and 0.768, respectively. The AUC of mNGS were BALF (0.916), pulmonary puncture tissue fluid (0.903), and sputum (0.870).

CONCLUSION: The sensitivity of mNGS was superior to that of Bactec MGIT 960; the specificity in NTMPD diagnosis was similar. mNGS shows effective performance in NTMPD diagnosis.

RevDate: 2022-08-01

Naufal M, Wu JH, YH Shao (2022)

Glutamate Enhances Osmoadaptation of Anammox Bacteria under High Salinity: Genomic Analysis and Experimental Evidence.

Environmental science & technology [Epub ahead of print].

An osmoprotectant that alleviates the bacterial osmotic stress can improve the bioreactor treatment of saline wastewater. However, proposed candidates are expensive, and osmoprotectants of anammox bacteria and their ecophysiological roles are not fully understood. In this study, a comparative analysis of 34 high-quality public metagenome-assembled genomes from anammox bacteria revealed two distinct groups of osmoadaptation. Candidatus Scalindua and Kuenenia share a close phylogenomic relation and osmoadaptation gene profile and have pathways for glutamate transport and metabolisms for enhanced osmoadaptation. The batch assay results demonstrated that the reduced Ca. Kuenenia activity in saline conditions was substantially alleviated with the addition and subsequent synergistic effects of potassium and glutamate. The operational test of two reactors demonstrated that the reduced anammox performance under brine conditions rapidly recovered by 35.7-43.1% as a result of glutamate treatment. The Ca. Kuenenia 16S rRNA and hydrazine gene expressions were upregulated significantly (p < 0.05), and the abundance increased by approximately 19.9%, with a decrease in dominant heterotrophs. These data demonstrated the effectiveness of glutamate in alleviating the osmotic stress of Ca. Kuenenia. This study provides genomic insight into group-specific osmoadaptation of anammox bacteria and can facilitate the precision management of anammox reactors under high salinity.

RevDate: 2022-08-01

Zheng X, Dai X, Zhu Y, et al (2022)

(Meta)Genomic Analysis Reveals Diverse Energy Conservation Strategies Employed by Globally Distributed Gemmatimonadota.

mSystems [Epub ahead of print].

Gemmatimonadota is a phylum-level lineage distributed widely but rarely reported. Only six representatives of Gemmatimonadota have so far been isolated and cultured in laboratory. The physiology, ecology, and evolutionary history of this phylum remain unknown. The 16S rRNA gene survey of our salt lake and deep-sea sediments, and Earth Microbiome Project (EMP) samples, reveals that Gemmatimonadota exist in diverse environments globally. In this study, we retrieved 17 metagenome-assembled genomes (MAGs) from salt lake sediments (12 MAGs) and deep-sea sediments (5 MAGs). Analysis of these MAGs and the nonredundant MAGs or genomes from public databases reveals Gemmatimonadota can degrade various complex organic substrates, and mainly employ heterotrophic pathways (e.g., glycolysis and tricarboxylic acid [TCA] cycle) for growth via aerobic respiration. And the processes of sufficient energy being stored in glucose through gluconeogenesis, followed by the synthesis of more complex compounds, are prevalent in Gemmatimonadota. A highly expandable pangenome for Gemmatimonadota has been observed, which presumably results from their adaptation to thriving in diverse environments. The enrichment of the Na+/H+ antiporter in the SG8-23 order represents their adaptation to salty habitats. Notably, we identified a novel lineage of the SG8-23 order, which is potentially anoxygenic phototrophic. This lineage is not closely related to the phototrophs in the order of Gemmatimonadales. The two orders differ distinctly in the gene organization and phylogenetic relationship of their photosynthesis gene clusters, indicating photosystems in Gemmatimonadota have evolved in two independent routes. IMPORTANCE The phylum Gemmatimonadota is widely distributed in various environments. However, their physiology, ecology and evolutionary history remain unknown, primary due to the limited cultured isolates and available genomes. We were intrigued to find out how widespread this phylum is, and how it can thrive under diverse conditions. Our results here expand the knowledge of the genetic and metabolic diversity of Gemmatimonadota, and shed light on the diverse energy conservation strategies (i.e., oxidative phosphorylation, substrate phosphorylation, and photosynthetic phosphorylation) responsible for their global distribution. Moreover, gene organization and phylogenetic analysis of photosynthesis gene clusters in Gemmatimonadota provide a valuable insight into the evolutionary history of photosynthesis.

RevDate: 2022-08-01

Frouin E, Lecoeuvre A, Armougom F, et al (2022)

Comparative Metagenomics Highlight a Widespread Pathway Involved in Catabolism of Phosphonates in Marine and Terrestrial Serpentinizing Ecosystems.

mSystems [Epub ahead of print].

Serpentinizing hydrothermal systems result from water circulating into the subsurface and interacting with mantle-derived rocks notably near mid-ocean ridges or continental ophiolites. Serpentinization and associated reactions produce alkaline fluids enriched in molecular hydrogen, methane, and small organic molecules that are assumed to feed microbial inhabitants. In this study, we explored the relationships linking serpentinization to associated microbial communities by comparative metagenomics of serpentinite-hosted systems, basalt-hosted vents, and hot springs. The shallow Prony bay hydrothermal field (PBHF) microbiome appeared to be more related to those of ophiolitic sites than to the Lost City hydrothermal field (LCHF) microbiome, probably because of the meteoric origin of its fluid, like terrestrial alkaline springs. This study emphasized the ubiquitous importance of a set of genes involved in the catabolism of phosphonates and highly enriched in all serpentinizing sites compared to other ecosystems. Because most of the serpentinizing systems are depleted in inorganic phosphate, the abundance of genes involved in the carbon-phosphorus lyase pathway suggests that the phosphonates constitute a source of phosphorus in these ecosystems. Additionally, hydrocarbons such as methane, released upon phosphonate catabolism, may contribute to the overall budget of organic molecules in serpentinizing systems. IMPORTANCE This first comparative metagenomic study of serpentinite-hosted environments provides an objective framework to understand the functioning of these peculiar ecosystems. We showed a taxonomic similarity between the PBHF and other terrestrial serpentinite-hosted ecosystems. At the same time, the LCHF microbial community was closer to deep basalt-hosted hydrothermal fields than continental ophiolites, despite the influence of serpentinization. This study revealed shared functional capabilities among serpentinite-hosted ecosystems in response to environmental stress, the metabolism of abundant dihydrogen, and the metabolism of phosphorus. Our results are consistent with the generalized view of serpentinite environments but provide deeper insight into the array of factors that may control microbial activities in these ecosystems. Moreover, we show that metabolism of phosphonate is widespread among alkaline serpentinizing systems and could play a crucial role in phosphorus and methane biogeochemical cycles. This study opens a new line of investigation of the metabolism of reduced phosphorus compounds in serpentinizing environments.

RevDate: 2022-08-01

Tao S, Zou H, Li J, et al (2022)

Landscapes of Enteric Virome Signatures in Early-Weaned Piglets.

Microbiology spectrum [Epub ahead of print].

Diarrhea caused by early-weaning-induced stress can increase mortality rates and reduce growth performance of piglets, seriously harming the livestock industry. To date, studies on the gut microbiome of early-weaned piglets have focused almost exclusively on bacteria, while studies on their gut virome are extremely lacking. Here, we used metagenomic and metatranscriptomic sequencing combined with bioinformatic analysis techniques to preliminarily characterize the intestinal virome of early-weaned piglets at different biological classification levels. The alpha diversity of enteroviruses was generally elevated in early-weaned piglets with diarrhea, compared to healthy piglets, whereas the two groups of piglets showed no significant difference in beta diversity. In addition, the species compositions of the gut virome were similar between healthy piglets and piglets with diarrhea, while their respective dominant species were somewhat different. We also identified 58 differential DNA viruses and 16 differential RNA viruses between the two groups of piglets at all biological taxonomic levels. Of these, 1 (family Dhakavirus) and 6 (phylum Artverviricota, class Revtraviricetes, order Ortervirales, family Retroviridae, genus Gammaretrovirus, and species Kirsten murine sarcoma virus) specific viruses disappeared from the intestines of healthy piglets and piglets with diarrhea, respectively. Moreover, we found that some DNA and RNA viruses formed strong correlations among themselves or between them. IMPORTANCE This study systematically reveals the biological diversity, structure, and composition of intestinal DNA and RNA virus profiles in early-weaned piglets. Furthermore, characteristics of differences in gut viromes between early-weaned healthy piglets and piglets with diarrhea were also elucidated. Importantly, some potential biomarkers for early-weaned piglets with diarrhea were identified. These findings fill a gap for the early-weaned piglet gut virome and lay the foundation for the development of strategies to target enteroviruses for the prevention and treatment of early-weaning-induced piglet diarrhea.

RevDate: 2022-08-01

Call TB, Davis EK, Bean JD, et al (2022)

Bacterial Metabolism and Transport Genes Are Associated with the Preference of Drosophila melanogaster for Dietary Yeast.

Applied and environmental microbiology [Epub ahead of print].

Many animal traits are influenced by their associated microorganisms ("microbiota"). To expand our understanding of the relationship between microbial genotype and host phenotype, we report an analysis of the influence of the microbiota on the dietary preference of the fruit fly Drosophila melanogaster. First, we confirmed through experiments on flies reared bacteria-free ("axenic") or in monoassociation with two different strains of bacteria that the microbiota significantly influences fruit fly dietary preference across a range of ratios of dietary yeast:dietary glucose. Then, focusing on microbiota-dependent changes in fly dietary preference for yeast (DPY), we performed a metagenome-wide association (MGWA) study to define microbial species specificity for this trait and to predict bacterial genes that influence it. In a subsequent mutant analysis, we confirmed that disrupting a subset of the MGWA-predicted genes influences fly DPY, including for genes involved in thiamine biosynthesis and glucose transport. Follow-up tests revealed that the bacterial influence on fly DPY did not depend on bacterial modification of the glucose or protein content of the fly diet, suggesting that the bacteria mediate their effects independent of the fly diet or through more specific dietary changes than broad ratios of protein and glucose. Together, these findings provide additional insight into bacterial determinants of host nutrition and behavior by revealing specific genetic disruptions that influence D. melanogaster DPY. IMPORTANCE Associated microorganisms ("microbiota") impact the physiology and behavior of their hosts, and defining the mechanisms underlying these interactions is a major gap in the field of host-microbe interactions. This study expands our understanding of how the microbiota can influence dietary preference for yeast (DPY) of a model host, Drosophila melanogaster. First, we show that fly preferences for a range of different dietary yeast:dietary glucose ratios vary significantly with the identity of the microbes that colonize the fruit flies. We then performed a metagenome-wide association study to identify candidate bacterial genes that contributed to some of these bacterial influences. We confirmed that disrupting some of the predicted genes, including genes involved in glucose transport and thiamine biosynthesis, resulted in changes to fly DPY and show that the influence of two of these genes is not through changes in dietary ratios of protein to glucose. Together, these efforts expand our understanding of the bacterial genetic influences on a feeding behavior of a model animal host.

RevDate: 2022-08-01

Goetting-Minesky MP, Godovikova V, Zheng W, et al (2022)

Characterization of Treponema denticola Major Surface Protein (Msp) by Deletion Analysis and Advanced Molecular Modeling.

Journal of bacteriology [Epub ahead of print].

Treponema denticola, a keystone pathogen in periodontitis, is a model organism for studying Treponema physiology and host-microbe interactions. Its major surface protein Msp forms an oligomeric outer membrane complex that binds fibronectin, has cytotoxic pore-forming activity, and disrupts several intracellular processes in host cells. T. denticola msp is an ortholog of the Treponema pallidum tprA to -K gene family that includes tprK, whose remarkable in vivo hypervariability is proposed to contribute to T. pallidum immune evasion. We recently identified the primary Msp surface-exposed epitope and proposed a model of the Msp protein as a β-barrel protein similar to Gram-negative bacterial porins. Here, we report fine-scale Msp mutagenesis demonstrating that both the N and C termini as well as the centrally located Msp surface epitope are required for native Msp oligomer expression. Removal of as few as three C-terminal amino acids abrogated Msp detection on the T. denticola cell surface, and deletion of four residues resulted in complete loss of detectable Msp. Substitution of a FLAG tag for either residues 6 to 13 of mature Msp or an 8-residue portion of the central Msp surface epitope resulted in expression of full-length Msp but absence of the oligomer, suggesting roles for both domains in oligomer formation. Consistent with previously reported Msp N-glycosylation, proteinase K treatment of intact cells released a 25 kDa polypeptide containing the Msp surface epitope into culture supernatants. Molecular modeling of Msp using novel metagenome-derived multiple sequence alignment (MSA) algorithms supports the hypothesis that Msp is a large-diameter, trimeric outer membrane porin-like protein whose potential transport substrate remains to be identified. IMPORTANCE The Treponema denticola gene encoding its major surface protein (Msp) is an ortholog of the T. pallidum tprA to -K gene family that includes tprK, whose remarkable in vivo hypervariability is proposed to contribute to T. pallidum immune evasion. Using a combined strategy of fine-scale mutagenesis and advanced predictive molecular modeling, we characterized the Msp protein and present a high-confidence model of its structure as an oligomer embedded in the outer membrane. This work adds to knowledge of Msp-like proteins in oral treponemes and may contribute to understanding the evolutionary and potential functional relationships between T. denticola Msp and the orthologous T. pallidum Tpr proteins.

RevDate: 2022-08-01

Huang J, Zheng X, Kang W, et al (2022)

Metagenomic and metabolomic analyses reveal synergistic effects of fecal microbiota transplantation and anti-PD-1 therapy on treating colorectal cancer.

Frontiers in immunology, 13:874922.

Anti-PD-1 immunotherapy has saved numerous lives of cancer patients; however, it only exerts efficacy in 10-15% of patients with colorectal cancer. Fecal microbiota transplantation (FMT) is a potential approach to improving the efficacy of anti-PD-1 therapy, whereas the detailed mechanisms and the applicability of this combination therapy remain unclear. In this study, we evaluated the synergistic effect of FMT with anti-PD-1 in curing colorectal tumor-bearing mice using a multi-omics approach. Mice treated with the combination therapy showed superior survival rate and tumor control, compared to the mice received anti-PD-1 therapy or FMT alone. Metagenomic analysis showed that composition of gut microbiota in tumor-bearing mice treated with anti-PD-1 therapy was remarkably altered through receiving FMT. Particularly, Bacteroides genus, including FMT-increased B. thetaiotaomicron, B. fragilis, and FMT-decreased B. ovatus might contribute to the enhanced efficacy of anti-PD-1 therapy. Furthermore, metabolomic analysis upon mouse plasma revealed several potential metabolites that upregulated after FMT, including punicic acid and aspirin, might promote the response to anti-PD-1 therapy via their immunomodulatory functions. This work broadens our understanding of the mechanism by which FMT improves the efficacy of anti-PD-1 therapy, which may contribute to the development of novel microbiota-based anti-cancer therapies.

RevDate: 2022-08-01

Guo W, Cui X, Wang Q, et al (2022)

Clinical evaluation of metagenomic next-generation sequencing for detecting pathogens in bronchoalveolar lavage fluid collected from children with community-acquired pneumonia.

Frontiers in medicine, 9:952636.

This study is to evaluate the usefulness of pathogen detection using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) specimens from children with community-acquired pneumonia (CAP). We retrospectively collected BALF specimens from 121 children with CAP at Tianjin Children's Hospital from February 2021 to December 2021. The diagnostic performances of mNGS and conventional tests (CT) (culture and targeted polymerase chain reaction tests) were compared, using composite diagnosis as the reference standard. The results of mNGS and CT were compared based on pathogenic and non-pathogenic organisms. Pathogen profiles and co-infections between the mild CAP and severe CAP groups were also analyzed. The overall positive coincidence rate was 86.78% (105/121) for mNGS and 66.94% (81/121) for CT. The proportion of patients diagnosed using mNGS plus CT increased to 99.18%. Among the patients, 17.36% were confirmed only by mNGS; Streptococcus pneumoniae accounted for 52.38% and 23.8% of the patients were co-infected. Moreover, Bordetella pertussis and Human bocavirus (HBoV) were detected only using mNGS. Mycoplasma pneumoniae, which was identified in 89 (73.55%) of 121 children with CAP, was the most frequent pathogen detected using mNGS. The infection rate of M. pneumoniae in the severe CAP group was significantly higher than that in the mild CAP group (P = 0.007). The symptoms of single bacterial infections (except for mycoplasma) were milder than those of mycoplasma infections. mNGS identified more bacterial infections when compared to the CT methods and was able to identify co-infections which were initially missed on CT. Additionally, it was able to identify pathogens that were beyond the scope of the CT methods. The mNGS method is a powerful supplement to clinical diagnostic tools in respiratory infections, as it can increase the precision of diagnosis and guide the use of antibiotics.

RevDate: 2022-08-01

Shahab M, N Shahab (2022)

Coevolution of the Human Host and Gut Microbiome: Metagenomics of Microbiota.

Cureus, 14(6):e26310.

It is estimated that humans have trillions of microbial cells living in their gut as part of their microbiota. Each human being has an entirely unique microbiome and human gut microbiota composition has been shown to alter with age due to several factors including physical stress, diet, use of antibiotics, prolonged treatments, chronic disease processes, physiological changes, and geographical location. The gut microbiome contributes to overall well-being in a multitude of ways, including digestion, metabolism, immunity, and the creation of vital compounds that the body cannot synthesize on its own. Disequilibrium in the microbiota has been correlated to obesity, heart disease, irritable bowel disease, and certain cancers. The evolution of the human host allowed for the diversity of the microbial community present in the gut. Although previous studies portray the correlation between diet and disequilibrium in host microbiota, the evolutionary dynamics of bacterial commensal flora and the extent to which it is beneficial are still unclear and need additional investigation.

RevDate: 2022-08-01

Bouchiat C, Ginevra C, Benito Y, et al (2022)

Improving the Diagnosis of Bacterial Infections: Evaluation of 16S rRNA Nanopore Metagenomics in Culture-Negative Samples.

Frontiers in microbiology, 13:943441.

While 16S rRNA PCR-Sanger sequencing has paved the way for the diagnosis of culture-negative bacterial infections, it does not provide the composition of polymicrobial infections. We aimed to evaluate the performance of the Nanopore-based 16S rRNA metagenomic approach, using both partial and full-length amplification of the gene, and to explore its feasibility and suitability as a routine diagnostic tool for bacterial infections in a clinical laboratory. Thirty-one culture-negative clinical samples from mono- and polymicrobial infections based on Sanger-sequencing results were sequenced on MinION using both the in-house partial amplification and the Nanopore dedicated kit for the full-length amplification of the 16S rRNA gene. Contamination, background noise definition, bacterial identification, and time-effectiveness issues were addressed. Cost optimization was also investigated with the miniaturized version of the flow cell (Flongle). The partial 16S approach had a greater sensitivity compared to the full-length kit that detected bacterial DNA in only 24/31 (77.4%) samples. Setting a threshold of 1% of total reads overcame the background noise issue and eased the interpretation of clinical samples. Results were obtained within 1 day, discriminated polymicrobial samples, and gave accurate bacterial identifications compared to Sanger-based results. We also found that multiplexing and using Flongle flow cells was a cost-effective option. The results confirm that Nanopore technology is user-friendly as well as cost- and time-effective. They also indicate that 16S rRNA targeted metagenomics is a suitable approach to be implemented for the routine diagnosis of culture-negative samples in clinical laboratories.

RevDate: 2022-08-01

Du D, Jiang W, Feng L, et al (2022)

Effect of Saccharomyces cerevisiae culture mitigates heat stress-related dame in dairy cows by multi-omics.

Frontiers in microbiology, 13:935004.

The effect of heat stress on ruminants is an important issue. In recent years, the growth of the Chinese dairy industry has rapidly increased, generating RMB 468,738 million revenue in 2021. A decreased milk yield is the most recognized impact of heat stress on dairy cows and results in significant economic loss to dairy producers. Heat stress also lowers immunity and antioxidant capacity and changes the bacterial composition and metabolites of the rumen. The purpose of this study was to investigate the effect of addition Saccharomyces cerevisiae culture on heat-stressed cows. The impact of S. cerevisiae culture on microbiota composition, functional profiles, and metabolomics was assessed in heat-stressed cows. A total of 45 Holstein cows in mid-lactation were selected and randomly divided into three groups (15 cows per group). Groups D-C, D-A, and D-B were fed with the basal diet, the basal diet + first S. cerevisiae culture 100 g/day, and the basal diet + second S. cerevisiae culture 30 g/day, respectively. The trial lasted 60 days. There was an increased abundance of the Phylum Firmicutes in the rumen of heat-stressed dairy cows fed with S. cerevisiae, of which four genera had significantly higher abundance, Ruminococcus_gauvreauii_group, Butyrivibrio_2, Moryella, and Ruminiclostridium_6. At the functional level, ten pathways differed significantly between the three groups (P < 0.05), with an increase in fatty acid biosynthesis, fatty acid metabolism, PPAR signaling pathway, ferroptosis, and biotin metabolism in the treatment groups. More differential metabolites were found in the D-C and D-A groups than in the D-C and D-B groups. These results indicate that S. cerevisiae cultures can influence the health status of heat-stressed cows by modulating rumen microbial composition, function, and metabolites, thereby improving rumen cellulolytic capacity. This study can provide or offer suggestions or recommendations for the development and utilization of feed additives.

RevDate: 2022-08-01

Ayala-Muñoz D, Burgos WD, Sánchez-España J, et al (2022)

Novel Microorganisms Contribute to Biosulfidogenesis in the Deep Layer of an Acidic Pit Lake.

Frontiers in bioengineering and biotechnology, 10:867321 pii:867321.

Cueva de la Mora is a permanently stratified acidic pit lake with extremely high concentrations of heavy metals at depth. In order to evaluate the potential for in situ sulfide production, we characterized the microbial community in the deep layer using metagenomics and metatranscriptomics. We retrieved 18 high quality metagenome-assembled genomes (MAGs) representing the most abundant populations. None of the MAGs were closely related to either cultured or non-cultured organisms from the Genome Taxonomy or NCBI databases (none with average nucleotide identity >95%). Despite oxygen concentrations that are consistently below detection in the deep layer, some archaeal and bacterial MAGs mapped transcripts of genes for sulfide oxidation coupled with oxygen reduction. Among these microaerophilic sulfide oxidizers, mixotrophic Thermoplasmatales archaea were the most numerous and represented 24% of the total community. Populations associated with the highest predicted in situ activity for sulfate reduction were affiliated with Actinobacteria, Chloroflexi, and Nitrospirae phyla, and together represented about 9% of the total community. These MAGs, in addition to a less abundant Proteobacteria MAG in the genus Desulfomonile, contained transcripts of genes in the Wood-Ljungdahl pathway. All MAGs had significant genetic potential for organic carbon oxidation. Our results indicate that novel acidophiles are contributing to biosulfidogenesis in the deep layer of Cueva de la Mora, and that in situ sulfide production is limited by organic carbon availability and sulfur oxidation.

RevDate: 2022-08-01

Zhang Z, Wang H, Guo Y, et al (2022)

Metagenome Analysis of the Bacterial Characteristics in Invasive Klebsiella Pneumoniae Liver Abscesses.

Frontiers in cellular and infection microbiology, 12:812542.

Background: Klebsiella pneumoniae liver abscess (KPLA) combined with extrahepatic migratory infection (EMI) is defined as invasive KPLA (IKPLA) and is associated with a poor prognosis. The mechanism of IKPLA formation is yet to be elucidated. In this study, metagenomic sequencing was used to compare the bacterial characteristics between IKPLA and KPLA to explore the underlying mechanism of invasiveness.

Methods: Clinical details, imaging, and microbial features were retrospectively evaluated by medical record review. Metagenomic sequencing was performed on the pus samples of liver abscesses whose culture results were indicative of monomicrobial Klebsiella pneumoniae (K. pneumoniae). Bacterial diversity and composition in IKPLA and KPLA were comparatively analyzed, and the key pathways and genes that may affect invasiveness were further explored.

Results: Sixteen patients were included in this study. Five patients with EMI were included in the IKPLA group, and the other eleven patients without EMI were assigned to the KPLA group. There was no statistical difference in the hypermucoviscous phenotype and serotype of K. pneumoniae between the two groups. The bacterial diversity of IKPLA was lower than that of KPLA. The abundant taxa in the IKPLA group were primarily species of unclassified Enterobacteriaceae and K. pneumoniae. The KPLA group had a high abundance of the genera Tetrasphaera and Leuconostoc. Metabolic pathway genes represented most of the enriched genes in IKPLA. Fourteen pathogenic genes with significant differences in abundance were identified between the two groups, including ybtS, fepC, phoQ, acrB, fimK, magA, entC, arnT, iucA, fepG, oqxB, entA, tonB, and entF (p < 0.001).

Conclusion: The diversity and bacterial composition of IKPLA were significantly different from those of KPLA. Microbiological changes in the abscess, activation of the related metabolic pathways, and the pathogenic gene expression may constitute a novel mechanism that regulates the invasiveness of KPLA.

RevDate: 2022-08-01

Sun L, Zhang S, Yang Z, et al (2022)

Clinical Application and Influencing Factor Analysis of Metagenomic Next-Generation Sequencing (mNGS) in ICU Patients With Sepsis.

Frontiers in cellular and infection microbiology, 12:905132.

Objective: To analyze the clinical application and related influencing factors of metagenomic next-generation sequencing (mNGS) in patients with sepsis in intensive care unit (ICU).

Methods: The study included 124 patients with severe sepsis admitted to the ICU in the First Affiliated Hospital of Zhengzhou University from June 2020 to September 2021. Two experienced clinicians took blood mNGS and routine blood cultures of patients meeting the sepsis diagnostic criteria within 24 hours after sepsis was considered, and collection the general clinical data.

Results: mNGS positive rate was higher than traditional blood culture (67.74% vs. 19.35%). APACHE II score [odds ratio (OR)=1.096], immune-related diseases (OR=6.544), and hypertension (OR=2.819) were considered as positive independent factors for mNGS or culture-positive. The sequence number of microorganisms and pathogen detection (mNGS) type had no effect on prognosis. Age (OR=1.016), female (OR=5.963), myoglobin (OR=1.005), and positive virus result (OR=8.531) were independent risk factors of sepsis mortality. Adjusting antibiotics according to mNGS results, there was no statistical difference in the prognosis of patients with sepsis.

Conclusion: mNGS has the advantages of rapid and high positive rate in the detection of pathogens in patients with severe sepsis. Patients with high APACHE II score, immune-related diseases, and hypertension are more likely to obtain positive mNGS results. The effect of adjusting antibiotics according to mNGS results on the prognosis of sepsis needs to be further evaluated.

RevDate: 2022-08-01

Li B, Wang Y, Hu T, et al (2022)

Root-Associated Microbiota Response to Ecological Factors: Role of Soil Acidity in Enhancing Citrus Tolerance to Huanglongbing.

Frontiers in plant science, 13:937414.

The citrus orchards in southern China are widely threatened by low soil pH and Huanglongbing (HLB) prevalence. Notably, the lime application has been used to optimize soil pH, which is propitious to maintain root health and enhance HLB tolerance of citrus; however, little is known about the interactive effects of soil acidity on the soil properties and root-associated (rhizoplane and endosphere) microbial community of HLB-infected citrus orchard. In this study, the differences in microbial community structures and functions between the acidified and amended soils in the Gannan citrus orchard were investigated, which may represent the response of the host-associated microbiome in diseased roots and rhizoplane to dynamic soil acidity. Our findings demonstrated that the severity of soil acidification and aluminum toxicity was mitigated after soil improvement, accompanied by the increase in root activity and the decrease of HLB pathogen concentration in citrus roots. Additionally, the Illumina sequencing-based community analysis showed that the application of soil amendment enriched functional categories involved in host-microbe interactions and nitrogen and sulfur metabolisms in the HLB-infected citrus rhizoplane; and it also strongly altered root endophytic microbial community diversity and structure, which represented by the enrichment of beneficial microorganisms in diseased roots. These changes in rhizoplane-enriched functional properties and microbial composition may subsequently benefit the plant's health and tolerance to HLB disease. Overall, this study advances our understanding of the important role of root-associated microbiota changes and ecological factors, such as soil acidity, in delaying and alleviating HLB disease.

RevDate: 2022-08-01

Patidar P, T Prakash (2022)

Decoding the roles of extremophilic microbes in the anaerobic environments: Past, Present, and Future.

Current research in microbial sciences, 3:100146 pii:S2666-5174(22)00043-8.

The genome of an organism is directly or indirectly correlated with its environment. Consequently, different microbes have evolved to survive and sustain themselves in a variety of environments, including unusual anaerobic environments. It is believed that their genetic material could have played an important role in the early evolution of their existence in the past. Presently, out of the uncountable number of microbes found in different ecosystems we have been able to discover only one percent of the total communities. A large majority of the microbial populations exists in the most unusual and extreme environments. For instance, many anaerobic bacteria are found in the gastrointestinal tract of humans, soil, and hydrothermal vents. The recent advancements in Metagenomics and Next Generation Sequencing technologies have improved the understanding of their roles in these environments. Presently, anaerobic bacteria are used in various industries associated with biofuels, fermentation, production of enzymes, vaccines, vitamins, and dairy products. This broad applicability brings focus to the significant contribution of their genomes in these functions. Although the anaerobic microbes have become an irreplaceable component of our lives, a major and important section of such anaerobic microbes still remain unexplored. Therefore, it can be said that unlocking the role of the microbial genomes of the anaerobes can be a noteworthy discovery not just for mankind but for the entire biosystem as well.

RevDate: 2022-08-01

Najar IN, Sharma P, Das S, et al (2022)

Bacterial diversity, physicochemical and geothermometry of South Asian hot springs.

Current research in microbial sciences, 3:100125 pii:S2666-5174(22)00022-0.

Extreme ecosystems with enormous arrays of physicochemical or biological physiognomies serve as an important indicator of various processes occurred and/or occurring in and on the Earth. Among extreme habitats, hot springs represent geothermal features which are complex systems with a well-defined plumbing system. Besides geological tectonic based hypsography and orology annotations, the hot springs have served as hot spots for ages where there is an amalgamation of nature, religion, faith, health, and science. Thus, there remains an escalating scope to study these hot springs all over the world. The Himalayan Geothermal Belt (HGB) banquets three densely demographic countries i.e. Pakistan, India and China, that hosts numerous hot springs. Studies on the hot springs distributed over these countries reveal Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria as the predominant bacterial phyla. The bacterial diversity shows a significant positive correlation with physicochemical parameters like temperature, pH, Na+, HCO3 -, etc. Physicochemical analyses of these hot springs indicate the water mainly as Na-Cl, Na-HCO3, SO4-Cl, and mixed type, with temperature ranging approximately between 100-250°C as predicted by various geothermometers. Numerous studies although done, not much of a comprehensive database of the analysis are provided on the hot springs harboured by the HGB. This review aims to give a cumulative illustration on comparative facets of various characteristic features of hot springs distributed over the HGB. These are found to be of great importance with respect to the exploitation of geothermal energy and microflora in various sectors of industries and biotechnology. They are also important sources in terms of socio-economic perspective, and routes to eco-medical tourism.

RevDate: 2022-07-31

Xi Y, Zhou J, Lin Z, et al (2022)

Patients with infectious diseases undergoing mechanical ventilation in the intensive care unit have better prognosis after receiving metagenomic next-generation sequencing assay.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(22)00457-X [Epub ahead of print].

OBJECTIVES: To evaluate the relation between mNGS and the prognosis of patients with infectious diseases undergoing mechanical ventilation in the intensive care unit (ICU).

DESIGN: This is a single-center observational study, comparing non-randomly assigned diagnostic approaches. We analyzed the medical records of 228 patients with suspected infectious diseases undergoing mechanical ventilation in the ICU from March 2018 to May 2020. The concordance of pathogen results was also assessed for the results of mNGS, culture and PCR assays.

RESULTS: The 28-day mortality of the patients in the mNGS group was lower after the baseline difference correction (19.23% (20/104) vs. 29.03% (36/124) , p=0.039). Subgroup analysis showed that mNGS assay associates with improved 28-day mortality of non-immunosuppressive patients (14.06% vs. 29.82%, p=0.018) . Not performing mNGS assay, higher APACHE II score and hypertension are independent risk factors for 28-day mortality. The mNGS assay presented advantage in pathogen positivity (69.8% double positive and 25.0% mNGS positive only), and the concordance between thest two assays were 79.0%.

CONCLUSIONS: mNGS survey may be associated with a better prognosis as the reduction of 28-day mortality of patients with infectious diseases on mechanical ventilation in ICU. This technique presented advantage in pathogen positivity than traditional methods.

RevDate: 2022-07-31

Liang M, Fan Y, Zhang D, et al (2022)

Metagenomic next-generation sequencing for accurate diagnosis and management of lower respiratory tract infections.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(22)00456-8 [Epub ahead of print].

OBJECTIVES: This study aimed to evaluate the clinical value of metagenomic next-generation sequencing (mNGS) in patients with suspected lower respiratory tract infections (LRTIs).

METHODS: This retrospective study reviewed patients with suspected LRTIs in Wuhan Union Hospital. Data including demographic, laboratory, and radiological profiles; treatment; and outcomes were recorded and analyzed.

RESULTS: mNGS identified pathogenic microbes in 100/140 (71.4%) patients, although 135 (96.4%) had received empiric antibiotic treatment before the mNGS tests. Single bacterial infection (35/100, 35%) was the most common type of infection in patients with positive mNGS results, followed by single fungal infection (14/100, 14%), bacterial-viral co-infection (14/100, 14%), single viral infection (12/100, 12%), bacterial-fungal co-infection (9/100, 9%), fungal-viral co-infection (9/100, 9%), and bacterial-fungal-viral co-infection (7/100, 7%). Moreover, compared with culture test, mNGS showed higher sensitivity (63/85, 74.1% vs. 22/85, 25.9% P=0.001) and lower processing time (24 h vs 48 h). Antibiotic treatment was adjusted or confirmed based on the mNGS results in 123 (87.9%) patients, including 5 (3.6%), 33 (23.6%) and 85 (60.7%) patients in whom treatment was downgraded, upgraded and unchanged, respectively, and almost all patients, regardless of escalation, de-escalation, or no change in treatment, showed significant improvement in clinical symptoms and inflammatory indicators. Additionally, 17 (12.1%) patients were referred to Wuhan Pulmonary Hospital for further treatment because of confirmed or suspected tuberculosis.

CONCLUSIONS: mNGS could be a promising technique for microbiological diagnosis and antibiotic management, potentially improving outcomes of patients.

RevDate: 2022-07-31

Fang X, Cai Y, Chen X, et al (2022)

The role of metagenomic next-generation sequencing in the pathogen detection of invasive osteoarticular infection.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(22)00455-6 [Epub ahead of print].

OBJECTIVE: This study aimed to analyzed the pathogenic bacteria spectrum in invasive and primary osteoarticular infection (IOI and POI), and compared the pathogen detection rate of metagenomic next-generation sequencing (mNGS) and microbial culture in IOI and POI.

METHODS: The suspected POI and IOI cases from 2008 to 2021 were included. The diagnosis of POI or IOI were made by at least two orthopaedic surgeons, two infectious diseases specialist and one senior microbiologist. Demographic characteristics, microbial culture results and so on were recorded. The pathogenic bacteria spectrum in IOI and POI were analyzed and the ability of mNGS and microbial culture in pathogen detection in IOI and POI were compared.

RESULTS: There were 63 POI cases and 92 cases, the common pathogen in POI and IOI were both Staphylococcus aureus. There are more cases with negative microbial culture results and multiple infections in IOI, and many cases were caused by rare and fastidious bacteria. The introduction of the mNGS could significantly increase the pathogen detection rate to 92.39% in IOI, which was 8.69% higher than that of microbial culture (P=0.007), while the improvement in POI was limited to about 2%.

CONCLUSIONS: mNGS was an ideal tool for IOI pathogen detection.

RevDate: 2022-07-31

Zhao F, Wang C, Song S, et al (2022)

Casein and red meat proteins differentially affect the composition of the gut microbiota in weaning rats.

Food chemistry, 397:133769 pii:S0308-8146(22)01731-9 [Epub ahead of print].

Casein and meat are food sources providing high-quality animal proteins for human consumption. However, little is known concerning potentially different effects of these animal protein sources during early stages of life. In the present study, casein and red meat proteins (beef and pork) were fed to young postweaning rats for 14 days based on the AIN-93G diet formula. Casein and red meat protein-based diets did not differentially affect the overall growth performance. However, they discriminately modulated the abundances of different potentially beneficial bacteria belonging to genus Lactobacillus. Intake of the casein-based diet increased the intestinal abundance of Lactococcus lactis with a pronounced potential for galactose utilization via the Tag6P pathway, and it also resulted in lower amounts of toxic ammonia in the rat cecum compared to red meat protein-based diets. We observed no adverse effects on colonic tissue in response to any of the protein-based diets based on histological observations.

RevDate: 2022-07-31

Mapelli F, Vergani L, Terzaghi E, et al (2022)

Pollution and edaphic factors shape bacterial community structure and functionality in historically contaminated soils.

Microbiological research, 263:127144 pii:S0944-5013(22)00184-7 [Epub ahead of print].

Studies about biodegradation potential in soils often refer to artificially contaminated and simplified systems, overlooking the complexity associated with contaminated sites in a real context. This work aims to provide a holistic view on microbiome assembly and functional diversity in the model site SIN Brescia-Caffaro (Italy), characterized by historical and uneven contamination by organic and inorganic compounds. Here, physical and chemical analyses and microbiota characterization were applied on one-hundred-twenty-seven soil samples to unravel the environmental factors driving bacterial community assembly and biodegradation potential in three former agricultural fields. Chemical analyses showed a patchy distribution of metals, metalloids and polychlorinated biphenyls (PCB) and allowed soil categorization according to depth and area of collections. Likewise, the bacterial community structure, described by molecular fingerprinting and 16S rRNA gene analyses, was significantly different according to collection site and depth. Pollutant concentrations (i.e., hexachloro-biphenyls, arsenic and mercury), nitrogen content and parameters related to soil texture were identified as main drivers of microbiota assembly, being significantly correlated to bacterial community composition. Moreover, bacteria putatively involved in the aerobic degradation of PCBs were enriched over the total bacterial community in topsoils, where the highest activity was recorded using fluorescein hydrolysis as proxy. Metataxonomic analyses revealed the presence of bacteria having metabolic pathways related to PCB degradation and tolerance to heavy metals and metalloids in the topsoil samples collected in all areas. Overall, the provided dissection of soil microbiota structure and its degradation potential in the SIN Brescia-Caffaro can contribute to target specific areas for rhizoremediation implementation. Metagenomics studies could be implemented in the future to understand if specific degradative pathways are present in historically polluted sites characterized by the co-occurrence of multiple classes of contaminants.

RevDate: 2022-07-19

Mackelprang R, Vaishampayan P, K Fisher (2022)

Adaptation to Environmental Extremes Structures Functional Traits in Biological Soil Crust and Hypolithic Microbial Communities.

mSystems [Epub ahead of print].

Biological soil crusts (biocrusts) are widespread in drylands and deserts. At the microhabitat scale, they also host hypolithic communities that live under semitranslucent stones. Both environmental niches experience exposure to extreme conditions such as high UV radiation, desiccation, temperature fluctuations, and resource limitation. However, hypolithic communities are somewhat protected from extremes relative to biocrust communities. Conditions are otherwise similar, so comparing them can answer outstanding questions regarding adaptations to environmental extremes. Using metagenomic sequencing, we assessed the functional potential of dryland soil communities and identified the functional underpinnings of ecological niche differentiation in biocrusts versus hypoliths. We also determined the effect of the anchoring photoautotroph (moss or cyanobacteria). Genes and pathways differing in abundance between biocrusts and hypoliths indicate that biocrust communities adapt to the higher levels of UV radiation, desiccation, and temperature extremes through an increased ability to repair damaged DNA, sense and respond to environmental stimuli, and interact with other community members and the environment. Intracellular competition appears to be crucial to both communities, with biocrust communities using the Type VI Secretion System (T6SS) and hypoliths favoring a diversity of antibiotics. The dominant primary producer had a reduced effect on community functional potential compared with niche, but an abundance of genes related to monosaccharide, amino acid, and osmoprotectant uptake in moss-dominated communities indicates reliance on resources provided to heterotrophs by mosses. Our findings indicate that functional traits in dryland communities are driven by adaptations to extremes and we identify strategies that likely enable survival in dryland ecosystems. IMPORTANCE Biocrusts serve as a keystone element of desert and dryland ecosystems, stabilizing soils, retaining moisture, and serving as a carbon and nitrogen source in oligotrophic environments. Biocrusts cover approximately 12% of the Earth's terrestrial surface but are threatened by climate change and anthropogenic disturbance. Given their keystone role in ecosystem functioning, loss will have wide-spread consequences. Biocrust microbial constituents must withstand polyextreme environmental conditions including high UV exposure, desiccation, oligotrophic conditions, and temperature fluctuations over short time scales. By comparing biocrust communities with co-occurring hypolithic communities (which inhabit the ventral sides of semitranslucent stones and are buffered from environmental extremes), we identified traits that are likely key adaptations to extreme conditions. These include DNA damage repair, environmental sensing and response, and intracellular competition. Comparison of the two niches, which differ primarily in exposure levels to extreme conditions, makes this system ideal for understanding how functional traits are structured by the environment.

RevDate: 2022-07-19

Bolliri C, Fontana A, Cereda E, et al (2022)

Gut microbiota in monozygotic twins discordant for Parkinson's disease.

Annals of neurology [Epub ahead of print].

Differences in gut microbiota between Parkinson's disease (PD) patients and controls seem to depend on multiple - frequently unmeasured - confounders. Monozygotic twins offer a unique model for controlling several factors responsible for interpersonal variation in gut microbiota. Fecal samples from 20 monozygotic twin pairs (N=40) discordant for PD were studied (metagenomic shotgun analysis). Paired-data analysis detected minimal differences in bacterial taxa abundance at species level (Bacteroides pectinophilus [P=0.037], Bifidobacterium pseudocatenulatum [P=0.050] and Bifidobacterium catenulatum [P=0.025]) and in predicted metabolic pathways (primary bile acid biosynthesis [P=0.037]). Additional studies are warranted to understand the role of gut microbiota in the pathogenesis of PD. This article is protected by copyright. All rights reserved.

RevDate: 2022-07-19

Wang Y, Zhang Y, Lane NE, et al (2022)

Population-based metagenomics analysis reveals altered gut microbiome in sarcopenia: data from the Xiangya Sarcopenia Study.

Journal of cachexia, sarcopenia and muscle [Epub ahead of print].

BACKGROUND: Several studies have examined gut microbiota and sarcopenia using 16S ribosomal RNA amplicon sequencing; however, this technique may not be able to identify altered specific species and functional capacities of the microbes. We performed shotgun metagenomic sequencing to compare the gut microbiome composition and function between individuals with and without sarcopenia.

METHODS: Participants were from a community-based observational study conducted among the residents of rural areas in China. Appendicular skeletal muscle mass was assessed using direct segmental multi-frequency bioelectrical impedance and grip strength using a Jamar Hydraulic Hand dynamometer. Physical performance was evaluated using the Short Physical Performance Battery, 5-time chair stand test and gait speed with the 6 m walk test. Sarcopenia and its severity were diagnosed according to the Asian Working Group for Sarcopenia 2019 algorithm. The gut microbiome was profiled by shotgun metagenomic sequencing to determine the microbial composition and function. A gut microbiota-based model for classification of sarcopenia was constructed using the random forest model, and its performance was assessed using the area under receiver-operating characteristic curve (AUC).

RESULTS: The study sample included 1417 participants (women: 58.9%; mean age: 63.3 years; sarcopenia prevalence: 10.0%). β-diversity indicated by Bray-Curtis distance (genetic level: P = 0.004; taxonomic level of species: P = 0.020), but not α-diversity indicated by Shannon index (genetic level: P = 0.962; taxonomic level of species: P = 0.922), was significantly associated with prevalent sarcopenia. After adjusting for potential confounders, participants with sarcopenia had higher relative abundance of Desulfovibrio piger (P = 0.003, Q = 0.090), Clostridium symbiosum (P < 0.001, Q = 0.035), Hungatella effluvii (P = 0.003, Q = 0.090), Bacteroides fluxus (P = 0.002, Q = 0.089), Absiella innocuum (P = 0.002, Q = 0.072), Coprobacter secundus (P = 0.002, Q = 0.085) and Clostridium citroniae (P = 0.001, Q = 0.060) than those without sarcopenia. The relative abundance of six species (Desulfovibrio piger, Clostridium symbiosum, Hungatella effluvii, Bacteroides fluxus, Absiella innocuum, and Clostridium citroniae) was also positively associated with sarcopenia severity. A differential species-based model was constructed to separate participants with sarcopenia from controls. The value of the AUC was 0.852, suggesting that model has a decent discriminative performance. Desulfovibrio piger ranked the highest in this model. Functional annotation analysis revealed that the phenylalanine, tyrosine, and tryptophan biosynthesis were depleted (P = 0.006, Q = 0.071), while alpha-Linolenic acid metabolism (P = 0.008, Q = 0.094), furfural degradation (P = 0.001, Q = 0.029) and staurosporine biosynthesis (P = 0.006, Q = 0.072) were enriched in participants with sarcopenia. Desulfovibrio piger was significantly associated with staurosporine biosynthesis (P < 0.001).

CONCLUSIONS: This large population-based observational study provided empirical evidence that alterations in the gut microbiome composition and function were observed among individuals with sarcopenia.

RevDate: 2022-07-19

Chen M, Conroy JL, Geyman EC, et al (2022)

Stable carbon isotope values of syndepositional carbonate spherules and micrite record spatial and temporal changes in photosynthesis intensity.

Geobiology [Epub ahead of print].

Marine and lacustrine carbonate minerals preserve carbon cycle information, and their stable carbon isotope values (δ13 C) are frequently used to infer and reconstruct paleoenvironmental changes. However, multiple processes can influence the δ13 C values of bulk carbonates, confounding the interpretation of these values in terms of conditions at the time of mineral precipitation. Co-existing carbonate forms may represent different environmental conditions, yet few studies have analyzed δ13 C values of syndepositional carbonate grains of varying morphologies to investigate their origins. Here, we combine stable isotope analyses, metagenomics, and geochemical modeling to interpret δ13 C values of syndepositional carbonate spherules (>500 μm) and fine-grained micrite (<63 μm) from a ~1600-year-long sediment record of a hypersaline lake located on the coral atoll of Kiritimati, Republic of Kiribati (1.9°N, 157.4°W). Petrographic, mineralogic, and stable isotope results suggest that both carbonate fractions precipitate in situ with minor diagenetic alterations. The δ13 C values of spherules are high compared to the syndepositional micrite and cannot be explained by mineral differences or external perturbations, suggesting a role for local biological processes. We use geochemical modeling to test the hypothesis that the spherules form in the surface microbial mat during peak diurnal photosynthesis when the δ13 C value of dissolved inorganic carbon is elevated. In contrast, we hypothesize that the micrite may precipitate more continuously in the water as well as in sub-surface, heterotrophic layers of the microbial mat. Both metagenome and geochemical model results support a critical role for photosynthesis in influencing carbonate δ13 C values. The down-core spherule-micrite offset in δ13 C values also aligns with total organic carbon values, suggesting that the difference in the δ13 C values of spherules and micrite may be a more robust, inorganic indicator of variability in productivity and local biological processes through time than the δ13 C values of individual carbonate forms.

RevDate: 2022-07-30

Yang G, Xu C, Varjani S, et al (2022)

Metagenomic insights into improving mechanisms of Fe0 nanoparticles on volatile fatty acids production from potato peel waste anaerobic fermentation.

Bioresource technology pii:S0960-8524(22)01032-X [Epub ahead of print].

The management of potato peel waste (PPW) has been a challenge faced by the potato industry. This investigation assessed the feasibility of PPW for volatile fatty acids (VFAs) production via anaerobic fermentation, and investigated the impact of Fe0 nanoparticles (Fe0 NPs) supplementation on the VFAs production. It is found that PPW is a potential feedstock for producing VFAs, achieving a yield of 480.4 mg COD/g-VS. Meanwhile, the supplementation of Fe0 NPs significantly promoted the VFAs productivity and quality. The higher enrichment of VFAs-producing bacteria, including Clostridium, Proteiniphilum, Fonticella and Pygmaiobacter, contributed to the promotion of the VFAs yield. Furthermore, metagenomic analysis revealed that the encoding genes responsible for carbohydrate metabolism (especially starch), membrane transport, glycolysis and the formation of acetic and butyric acids were remarkably up-regulated,which could be the essential reason for the enhanced metabolic activity and VFAs productivity. This work provides a promising strategy for recycling PPW.

RevDate: 2022-07-30

Stevenson SJR, Lee KC, Handley KM, et al (2022)

Substrate degradation pathways, conserved functions and community composition of the hindgut microbiota in the herbivorous marine fish Kyphosus sydneyanus.

Comparative biochemistry and physiology. Part A, Molecular & integrative physiology pii:S1095-6433(22)00141-6 [Epub ahead of print].

Symbiotic gut microbiota in the herbivorous marine fish Kyphosus sydneyanus play an important role in digestion by converting refractory algal carbohydrate into short-chain fatty acids. Here we characterised community composition using both 16S rRNA gene amplicon sequencing and shotgun-metagenome sequencing. Sequencing was carried out on lumen and mucosa samples (radial sections) from three axial sections taken from the hindgut of wild-caught fish. Both lumen and mucosa communities displayed distinct distributions along the hindgut, likely an effect of the differing selection pressures within these hindgut locations, as well as considerable variation among individual fish. In contrast, metagenomic sequences displayed a high level of functional similarity between individual fish and gut sections in the relative abundance of genes (based on sequencing depth) that encoded enzymes involved in algal-derived substrate degradation. These results suggest that the host gut environment selects for functional capacity in symbionts rather than taxonomic identity. Functional annotation of the enzymes encoded by the gut microbiota was carried out to infer the metabolic pathways used by the gut microbiota for the degradation of important dietary substrates: mannitol, alginate, laminarin, fucoidan and galactan (e.g. agar and carrageenan). This work provides the first evidence of the genomic potential of K. sydneyanus hindgut microbiota to convert highly refractory algal carbohydrates into metabolically useful short-chain fatty acids.

RevDate: 2022-07-30

Li Y, Li GY, Feng YW, et al (2022)

Study on the clinical indications for plasma as an alternative to the bronchoalveolar lavage fluid metagenomic next-generation sequencing test to detect consistent pathogens for septic patients in intensive care units.

RevDate: 2022-07-30

Chen S, Kang Y, Li D, et al (2022)

Diagnostic performance of metagenomic next-generation sequencing for the detection of pathogens in bronchoalveolar lavage fluid in patients with pulmonary infections: Systematic review and meta-analysis.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(22)00450-7 [Epub ahead of print].

BACKGROUND: The identification of pathogens in patients with pulmonary infection has always been a major challenge in medicine. Compared with sputum and throat swabs, bronchoalveolar lavage fluid (BALF) can better reflect the actual state in the lungs. However, there has not been a meta-analysis of the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) in detecting pathogens in BALF from patients with pulmonary infections.

METHODS: Data sources were PubMed, Web of Science, Embase, and the China National Knowledge Infrastructure. The pooled sensitivity and specificity were estimated by using random-effects or fixed-effect models. Subgroup analysis was performed to reveal the effect of potential explanatory factors on the diagnostic performance measures.

RESULTS: The pooled sensitivity was 78% (95% confidence interval: 67-87%; I2 = 92%) and the pooled specificity was 77% (95% confidence interval: 64-94%; I2 = 74%) for mNGS. Subgroup analyses for the sensitivity of mNGS revealed that patients with pulmonary infections who were severely ill or immunocompromised significantly affected heterogeneity (P < 0.001). The positive detection rate of mNGS for pathogens in BALF of severely or immunocompromised pulmonary-infected patients was 92% (95% confidence interval: 78-100%).

CONCLUSION: mNGS has high diagnostic performance for BALF pathogens in patients with pulmonary infections, especially in critically ill or immunocompromised patients.

RevDate: 2022-07-30

Divers TJ, Tomlinson JE, BC Tennant (2022)

The history of Theiler's disease and the search for its aetiology.

Veterinary journal (London, England : 1997) pii:S1090-0233(22)00093-4 [Epub ahead of print].

Theiler's disease (serum hepatitis) may occur in outbreaks or as single cases of acute hepatitis and is often associated with prior administration of equine-origin biologics approximately 4-10 weeks before the onset of clinical signs. Cases have also been described without any prior administration of blood products. The clinical disease has a low morbidity but high mortality and only adult horses are affected. The course of the disease is short, with horses either dying or completely recovering in a few days. Pathology in affected horses is predominantly centrilobular hepatocyte necrosis with mononuclear cell infiltration of the lesser affected periportal regions of the liver. Subclinical cases of the disease also occur. Based on the epidemiology and pathology of the disease, a viral cause, similar to hepatitis B in humans, has long been suspected. This paper reviews both historical and recent findings on Theiler's disease. Reported epidemics of Theiler's disease in the early 1900s are reviewed, along with their similarities to outbreaks of serum hepatitis in humans following yellow fever virus vaccinations in the 1930s and 1940s. Recent metagenomics-based studies to determine the aetiology of Theiler's disease are discussed, along with both clinical and experimental findings supporting equine parvovirus-hepatitis (EqPV-H) as the likely cause of this 100-year-old disease.

RevDate: 2022-07-29

Min J, Kim P, Yun S, et al (2022)

Zoo animal manure as an overlooked reservoir of antibiotic resistance genes and multidrug-resistant bacteria.

Environmental science and pollution research international [Epub ahead of print].

Animal fecal samples collected in the summer and winter from 11 herbivorous animals, including sable antelope (SA), long-tailed goral (LTG), and common eland (CE), at a public zoo were examined for the presence of antibiotic resistance genes (ARGs). Seven antibiotics, including meropenem and azithromycin, were used to isolate culturable multidrug-resistant (MDR) strains. The manures from three animals (SA, LTG, and CE) contained 104-fold higher culturable MDR bacteria, including Chryseobacterium, Sphingobacterium, and Stenotrophomonas species, while fewer MDR bacteria were isolated from manure from water buffalo, rhinoceros, and elephant against all tested antibiotics. Three MDR bacteria-rich samples along with composite samples were further analyzed using nanopore-based technology. ARGs including lnu(C), tet(Q), and mef(A) were common and often associated with transposons in all tested samples, suggesting that transposons carrying ARGs may play an important role for the dissemination of ARGs in our tested animals. Although several copies of ARGs such as aph(3')-IIc, blaL1, blaIND-3, and tet(42) were found in the sequenced genomes of the nine MDR bacteria, the numbers and types of ARGs appeared to be less than expected in zoo animal manure, suggesting that MDR bacteria in the gut of the tested animals had intrinsic resistant phenotypes in the absence of ARGs.

RevDate: 2022-07-29

Sugden S, Holert J, Cardenas E, et al (2022)

Microbiome of the freshwater sponge Ephydatia muelleri shares compositional and functional similarities with those of marine sponges.

The ISME journal [Epub ahead of print].

Sponges are known for hosting diverse communities of microbial symbionts, but despite persistent interest in the sponge microbiome, most research has targeted marine sponges; freshwater sponges have been the focus of less than a dozen studies. Here, we used 16 S rRNA gene amplicon sequencing and shotgun metagenomics to characterize the microbiome of the freshwater sponge Ephydatia muelleri and identify potential indicators of sponge-microbe mutualism. Using samples collected from the Sooke, Nanaimo, and Cowichan Rivers on Vancouver Island, British Columbia, we show that the E. muelleri microbiome is distinct from the ambient water and adjacent biofilms and is dominated by Sediminibacterium, Comamonas, and unclassified Rhodospirillales. We also observed phylotype-level differences in sponge microbiome taxonomic composition among different rivers. These differences were not reflected in the ambient water, suggesting that other environmental or host-specific factors may drive the observed geographic variation. Shotgun metagenomes and metagenome-assembled genomes further revealed that freshwater sponge-associated bacteria share many genomic similarities with marine sponge microbiota, including an abundance of defense-related proteins (CRISPR, restriction-modification systems, and transposases) and genes for vitamin B12 production. Overall, our results provide foundational information on the composition and function of freshwater sponge-associated microbes, which represent an important yet underappreciated component of the global sponge microbiome.

RevDate: 2022-07-29

Bay V, Gür S, O Bayraktar (2022)

Plant-derived tormentic acid alters the gut microbiota of the silkworm (Bombyx mori).

Scientific reports, 12(1):13005.

In recent years, phytochemicals have started to attract more attention due to their contribution to health and bioactivity. Microorganisms in the intestines of organisms contribute to the processing, function, and biotransformation of these substances. The silkworm (Bombyx mori) is one of the organisms used for the biotransformation of phytochemicals due to its controlled reproduction and liability to microbial manipulation. In this study, a bioactive compound, tormentic acid (TA), extracted from Sarcopoterium spinosum was used in the silkworm diet, and the alterations of intestinal microbiota of the silkworm were assessed. To do this, silkworms were fed on a diet with various tormentic acid content, and 16S metagenomic analysis was performed to determine the alterations in the gut microbiota profile of these organisms. Diet with different TA content did not cause a change in the bacterial diversity of the samples. A more detailed comparison between different feeding groups indicated increased abundance of bacteria associated with health, i.e., Intestinibacter spp., Flavonifractor spp., Senegalimassilia spp., through the utilization of bioactive substances such as flavonoids. In conclusion, it might be said that using TA as a supplementary product might help ameliorate the infected gut, promote the healthy gut, and relieve the undesirable effects of medicines on the gastrointestinal system.

RevDate: 2022-07-29

Coker MO, Lebeaux RM, Hoen AG, et al (2022)

Metagenomic analysis reveals associations between salivary microbiota and body composition in early childhood.

Scientific reports, 12(1):13075.

Several studies have shown that body mass index is strongly associated with differences in gut microbiota, but the relationship between body weight and oral microbiota is less clear especially in young children. We aimed to evaluate if there is an association between child growth and the saliva microbiome. We hypothesized that associations between growth and the saliva microbiome would be moderate, similarly to the association between growth and the gut microbiome. For 236 toddlers participating in the New Hampshire Birth Cohort Study, we characterized the association between multiple longitudinal anthropometric measures of body height, body weight and body mass. Body Mass Index (BMI) z-scores were calculated, and dual-energy x-ray absorptiometry (DXA) was used to estimate body composition. Shotgun metagenomic sequencing of saliva samples was performed to taxonomically and functionally profile the oral microbiome. We found that within-sample diversity was inversely related to body mass measurements while community composition was not associated. Although the magnitude of associations were small, some taxa were consistently associated with growth and modified by sex. Certain taxa were associated with decreased weight or growth (including Actinomyces odontolyticus and Prevotella melaninogenica) or increased growth (such as Streptococcus mitis and Corynebacterium matruchotii) across anthropometric measures. Further exploration of the functional significance of this relationship will enhance our understanding of the intersection between weight gain, microbiota, and energy metabolism and the potential role of these relationships on the onset of obesity-associated diseases in later life.

RevDate: 2022-07-29

Jantharadej K, Kongprajug A, Mhuantong W, et al (2022)

Comparative genomic analyses of pathogenic bacteria and viruses and antimicrobial resistance genes in an urban transportation canal.

The Science of the total environment pii:S0048-9697(22)04750-7 [Epub ahead of print].

Water commuting is a major urban transportation method in Thailand. However, urban boat commuters risk exposure to microbially contaminated bioaerosols or splash. We aimed to investigate the microbial community structures, identify bacterial and viral pathogens, and assess the abundance of antimicrobial resistance genes (ARGs) using next-generation sequencing (NGS) at 10 sampling sites along an 18 km transportation boat route in the Saen Saep Canal, which traverses cultural, commercial, and suburban land-based zones. The shotgun metagenomic (Illumina HiSeq) and 16 s rRNA gene amplicon (V4 region) (Illumina MiSeq) sequencing platforms revealed diverse microbial clusters aligned with the zones, with explicit segregation between the cultural and suburban sites. The shotgun metagenomic sequencing further identified bacterial and viral pathogens, and ARGs. The predominant bacterial pathogens (>0.5 % relative abundance) were the Burkholderia cepacia complex, Arcobacter butzleri, Burkholderia vietnamiensis, Klebsiella pneumoniae, and the Enterobacter cloacae complex. The viruses (0.28 %-0.67 % abundance in all microbial sequences) comprised mainly vertebrate viruses and bacteriophages, with encephalomyocarditis virus (33.3 %-58.2 % abundance in viral sequences), hepatitis C virus genotype 1, human alphaherpesvirus 1, and human betaherpesvirus 6A among the human viral pathogens. The 15 ARG types contained 611 ARG subtypes, including those resistant to beta-lactam, which was the most diverse and abundant group (206 subtypes; 17.0 %-27.5 %), aminoglycoside (94 subtypes; 9.6 %-15.3 %), tetracycline (80 subtypes; 15.6 %-20.2 %), and macrolide (79 subtypes; 14.5 %-32.1 %). Interestingly, the abundance of ARGs associated with resistance to beta-lactam, trimethoprim, and sulphonamide, as well as A. butzleri and crAssphage, at the cultural sites was significantly different from the other sites (p < 0.05). We demonstrated the benefits of using NGS to deliver insights into microbial communities, and antimicrobial resistance, both of which pose a risk to human health. Using NGSmay facilitate microbial risk mitigation and management for urban water commuters and proximal residents.

RevDate: 2022-07-29

Ebrahimian F, De Bernardini N, Tsapekos P, et al (2022)

Effect of pressure on biomethanation process and spatial stratification of microbial communities in trickle bed reactors under decreasing gas retention time.

Bioresource technology pii:S0960-8524(22)01030-6 [Epub ahead of print].

The current study investigated the effect of elevating gas pressure on biomethanation in trickle-bed reactors (TBRs). The increased pressure led to successful biomethanation (CH4 > 90%) at a gas retention time (GRT) of 21 min, due to the improved transfer rates of H2 and CO2. On the contrary, the non-pressurized TBR performance was reduced at GRTs shorter than 40 min. Metagenomic analysis revealed that the microbial populations collected from the lower and middle parts of the reactor under the same GRT were more homogeneous compared with those developed in the upper layer. Comparison with previous experiments suggest that microbial stratification is mainly driven by the nutrient provision strategy. Methanobacterium species was the most dominant methanogen and it was mainly associated with the bottom and middle parts of TBRs. Overall, the increased pressure did not affect markedly the microbial composition, while the GRT was the most important parameter shaping the microbiomes.

RevDate: 2022-07-29

Qiu B, Xi Y, Liu F, et al (2022)

Gut microbiome is associated with the response to Chemoradiotherapy in Patients with Non-small cell lung Cancer.

International journal of radiation oncology, biology, physics pii:S0360-3016(22)00749-0 [Epub ahead of print].

PURPOSE: To explore the dynamic change of gut microbiota and its predictive role on progression-free survival (PFS) in non-small cell lung cancer (NSCLC) after concurrent chemoradiotherapy (CCRT).

METHODS AND MATERIALS: 41 NSCLC patients in two phase II trials (xxxx) had been analyzed. A total of 102 fecal samples had been collected at 3 time points (T0, before CCRT; T1, 2 weeks after the initiation of CCRT; T2, the end of CCRT). Gut microbiota composition and functionality were analyzed by 16S rRNA gene sequencing and shotgun metagenomics, respectively. Alpha diversity, taxonomic composition and KEGG functional pathways were compared between patients in long-PFS group (PFS≥11.0 months) and short-PFS group (PFS<11.0 months). A random forest classifier was constructed to identify microbial signature related with PFS. Clinical and microbial factors potentially predictive of PFS were assessed in the univariate and multivariate Cox regression analysis.

RESULTS: The abundance of Bacteroidota and Proteobacteria increased, while the abundance of Firmicutes decreased after CCRT. Shannon index (p=0.006) and PD index (p=0.022) were significantly higher in long-PFS group than those in short-PFS group at T1. The PFS-prediction microbial signature at T1 included unclassified members of the Lanchospiraceae spp., such as NK4A136 and UCG-003 groups, Dorea sp., various strains from within the Eubacterium hallii and E. siraeum groups, and an unclassified member of the Muribaculaceae, which yielded an area under the ROC curve of 0.87. These discriminatory genera mostly belong to phylum Firmicutes/family Clostridia. Multivariate analysis indicated PD index (HR=8.036, P=0.016) and the abundance of Dorea sp. at T1 (HR=4.186, P=0.043) were independent predictors of PFS. The KEGG pathways at T1 overrepresented in long-PFS group included fatty acid metabolism, fatty acid biosynthesis and arginine biosynthesis; and those overrepresented in short-PFS group included lipopolysaccharide biosynthesis, ascorbate and aldarate metabolism and biosynthesis of vancomycin group antibiotics.

CONCLUSIONS: Gut microbiota composition and functionality at 2 weeks after the initiation of CCRT were associated with PFS in NSCLC. Further research is needed to confirm these results.

RevDate: 2022-07-29

Moshiri N (2020)

TreeSwift: A massively scalable Python tree package.

SoftwareX, 11:.

Phylogenetic trees are essential to evolutionary biology, and numerous methods exist that attempt to extract phylogenetic information applicable to a wide range of disciplines, such as epidemiology and metagenomics. Currently, the three main Python packages for trees are Bio.Phylo, DendroPy, and the ETE Toolkit, but as dataset sizes grow, parsing and manipulating ultra-large trees becomes impractical for these tools. To address this issue, we present TreeSwift, a user-friendly and massively scalable Python package for traversing and manipulating trees that is ideal for algorithms performed on ultra-large trees.

RevDate: 2022-07-29

Liu D, Zhang Y, Wu L, et al (2022)

Effects of Exercise Intervention on Type 2 Diabetes Patients With Abdominal Obesity and Low Thigh Circumference (EXTEND): Study Protocol for a Randomized Controlled Trial.

Frontiers in endocrinology, 13:937264.

Introduction: Type 2 diabetes patients have abdominal obesity and low thigh circumference. Previous studies have mainly focused on the role of exercise in reducing body weight and fat mass, improving glucose and lipid metabolism, with a lack of evaluation on the loss of muscle mass, diabetes complications, energy metabolism, and brain health. Moreover, whether the potential physiological benefit of exercise for diabetes mellitus is related to the modulation of the microbiota-gut-brain axis remains unclear. Multi-omics approaches and multidimensional evaluations may help systematically and comprehensively correlate physical exercise and the metabolic benefits.

Methods and Analysis: This study is a randomized controlled clinical trial. A total of 100 sedentary patients with type 2 diabetes will be allocated to either an exercise or a control group in a 1:1 ratio. Participants in the exercise group will receive a 16-week combined aerobic and resistance exercise training, while those in the control group will maintain their sedentary lifestyle unchanged. Additionally, all participants will receive a diet administration to control the confounding effects of diet. The primary outcome will be the change in body fat mass measured using bioelectrical impedance analysis. The secondary outcomes will include body fat mass change rate (%), and changes in anthropometric indicators (body weight, waist, hip, and thigh circumference), clinical biochemical indicators (glycated hemoglobin, blood glucose, insulin sensitivity, blood lipid, liver enzyme, and renal function), brain health (appetite, mood, and cognitive function), immunologic function, metagenomics, metabolomics, energy expenditure, cardiopulmonary fitness, exercise-related indicators, fatty liver, cytokines (fibroblast growth factor 21, fibroblast growth factor 19, adiponectin, fatty acid-binding protein 4, and lipocalin 2), vascular endothelial function, autonomic nervous function, and glucose fluctuation.

Discussion: This study will evaluate the effect of a 16-week combined aerobic and resistance exercise regimen on patients with diabetes. The results will provide a comprehensive evaluation of the physiological effects of exercise, and reveal the role of the microbiota-gut-brain axis in exercise-induced metabolic benefits to diabetes.

Clinical Trial Registration: http://www.chictr.org.cn/searchproj.aspx, identifier ChiCTR2100046148.

RevDate: 2022-07-28

Fu M, Cao LJ, Xia HL, et al (2022)

The performance of detecting Mycobacterium tuberculosis complex in lung biopsy tissue by metagenomic next-generation sequencing.

BMC pulmonary medicine, 22(1):288.

BACKGROUND: Tuberculosis (TB) is a chronic infectious disease caused by the Mycobacterium tuberculosis complex (MTBC), which is the leading cause of death from infectious diseases. The rapid and accurate microbiological detection of the MTBC is crucial for the diagnosis and treatment of TB. Metagenomic next-generation sequencing (mNGS) has been shown to be a promising and satisfying application of detection in infectious diseases. However, relevant research about the difference in MTBC detection by mNGS between bronchoalveolar lavage fluid (BALF) and lung biopsy tissue specimens remains scarce.

METHODS: We used mNGS to detect pathogens in BALF and lung biopsy tissue obtained by CT-guide percutaneous lung puncture (CPLP) or radial endobronchial ultrasound transbronchial lung biopsy (R-EBUS-TBLB) from 443 hospitalized patients in mainland China suspected of pulmonary infections between May 1, 2019 and October 31, 2021. Aim to evaluate the diagnostic performance of mNGS for detecting MTBC and explore differences in the microbial composition in the 2 specimen types.

RESULTS: Among the 443 patients, 46 patients finally were diagnosed with TB, of which 36 patients were detected as MTBC positive by mNGS (8.93%). Striking differences were noticed in the higher detection efficiency of lung biopsy tissue compared with BALF (P = 0.004). There were no significant differences between the 2 specimen types in the relative abundance among the 27 pathogens detected by mNGS from the 36 patients.

CONCLUSIONS: This study demonstrates that mNGS could offer an effective detection method of MTBC in BALF or lung tissue biopsy samples in patients suspected of TB infections. When it comes to the situations that BALF samples have limited value to catch pathogens for special lesion sites or the patients have contraindications to bronchoalveolar lavage (BAL) procedures, lung biopsy tissue is an optional specimen for MTBC detection by mNGS. However, whether lung tissue-mNGS is superior to BALF-mNGS in patients with MTBC infection requires further prospective multicenter randomized controlled studies with more cases.

RevDate: 2022-07-28

Schulz F, Abergel C, T Woyke (2022)

Giant virus biology and diversity in the era of genome-resolved metagenomics.

Nature reviews. Microbiology [Epub ahead of print].

The discovery of giant viruses, with capsids as large as some bacteria, megabase-range genomes and a variety of traits typically found only in cellular organisms, was one of the most remarkable breakthroughs in biology. Until recently, most of our knowledge of giant viruses came from ~100 species-level isolates for which genome sequences were available. However, these isolates were primarily derived from laboratory-based co-cultivation with few cultured protists and algae and, thus, did not reflect the true diversity of giant viruses. Although virus co-cultures enabled valuable insights into giant virus biology, many questions regarding their origin, evolution and ecological importance remain unanswered. With advances in sequencing technologies and bioinformatics, our understanding of giant viruses has drastically expanded. In this Review, we summarize our understanding of giant virus diversity and biology based on viral isolates as laboratory cultivation has enabled extensive insights into viral morphology and infection strategies. We then explore how cultivation-independent approaches have heightened our understanding of the coding potential and diversity of the Nucleocytoviricota. We discuss how metagenomics has revolutionized our perspective of giant viruses by revealing their distribution across our planet's biomes, where they impact the biology and ecology of a wide range of eukaryotic hosts and ultimately affect global nutrient cycles.

RevDate: 2022-07-28

Li G, Jiang Y, Li Q, et al (2022)

Comparative and functional analyses of fecal microbiome in Asian elephants.

Antonie van Leeuwenhoek [Epub ahead of print].

Asian elephant is large herbivorous animal with elongated hindgut. To explore fecal microbial community composition with various ages, sex and diets, and their role in plant biomass degrading and nutrition conversation. We generated 119 Gb by metagenome sequencing from 10 different individual feces and identified 5.3 million non-redundant genes. The comprehensive analysis established that the Bacteroidetes, Firmicutes and Proteobacteria constituted the most dominant phyla in overall fecal samples. In different individuals, the alpha diversity of the fecal microbiota in female was lower than male, and the alpha diversity of the fecal microbiota in older was higher than younger, and the fecal microbial diversity was the most complex in wild elephant. But the predominant population compositions were similar to each other. Moreover, the newborn infant elephant feces assembled and maintained a diverse but host-specific fecal microbial population. The discovery speculated that Asian elephant maybe have start to building microbial populations before birth. Meanwhile, these results illustrated that host phylogeny, diets, ages and sex are significant factors for fecal microbial community composition. Therefore, we put forward the process of Asian elephant fecal microbial community composition that the dominant populations were built first under the guidance of phylogeny, and then shaped gradually a unique and flexible gut microbial community structure under the influences of diet, age and sex. This study found also that the Bacteroidetes were presumably the main drivers of plant fiber-degradation. A large of secondary metabolite biosynthetic gene clusters, and genes related to enediyne biosynthesis were found and showed that the Asian elephant fecal microbiome harbored a diverse and abundant genetic resource. A picture of antibiotic resistance genes (ARGs) reservoirs of fecal microbiota in Asian elephants was provided. Surprisingly, there was such wide range of ARGs in newborn infant elephant. Further strengthening our speculation that the fetus of Asian elephant has colonized prototypical fecal microbiota before birth. However, it is necessary to point out that the data give a first inside into the gut microbiota of Asian elephants but too few individuals were studied to draw general conclusions for differences among wild and captured elephants, female and male or different ages. Further studies are required. Additionally, the cultured actinomycetes from Asian elephant feces also were investigated, which the feces of Asian elephants could be an important source of actinomycetes.

RevDate: 2022-07-28

Yang CX, He ZW, Liu WZ, et al (2022)

Chronic effects of benzalkonium chlorides on short chain fatty acids and methane production in semi-continuous anaerobic digestion of waste activated sludge.

The Science of the total environment pii:S0048-9697(22)04717-9 [Epub ahead of print].

As an emerging pollutant, benzalkonium chlorides (BACs) potentially enriched in waste activated sludge (WAS). However, the microbial response mechanism under chronic effects of BACs on acidogenesis and methanogenesis in anaerobic digestion (AD) has not been clearly disclosed. This study investigated the AD (by-)products and microbial evolution under low to high BACs concentrations from bioreactor startup to steady running. It was found that BACs can lead to an increase of WAS hydrolysis and fermentation, but a disturbance to acidogenic bacteria also occurred at low BACs concentration. A noticeable inhibition to methanogenesis occurred when BAC concentration was up to 15 mg/g TSS. Metagenomic analysis revealed the key genes involved in acetic acid (HAc) biosynthesis (i.e. phosphate acetyltransferase, PTA), β-oxidation pathway (acetyl-CoA C-acetyltransferase) and propionic acid (HPr) conversion was slightly promoted compared with control. Furthermore, BACs inhibited the acetotrophic methanogenesis (i.e. acetyl-CoA synthetase), especially BAC concentration was up to 15 mg/g TSS, thereby enhanced short chain fatty acids (SCFAs) accumulation. Overall, chronic stimulation of functional microorganisms with increasing concentrations of BACs impact WAS fermentation.

RevDate: 2022-07-28

Frankot MA, O'Hearn CM, Blancke AM, et al (2022)

Acute gut microbiome changes after traumatic brain injury are associated with chronic deficits in decision-making and impulsivity in male rats.

Behavioral neuroscience pii:2022-85473-001 [Epub ahead of print].

The mechanisms underlying chronic psychiatric-like impairments after traumatic brain injury (TBI) are currently unknown. The goal of the present study was to assess the role of diet and the gut microbiome in psychiatric symptoms after TBI. Rats were randomly assigned to receive a high-fat diet (HFD) or calorie-matched low-fat diet (LFD). After 2 weeks of free access, rats began training on the rodent gambling task (RGT), a measure of risky decision-making and motor impulsivity. After training, rats received a bilateral frontal TBI or a sham procedure and continued postinjury testing for 10 weeks. Fecal samples were collected before injury and 3-, 30-, and 60 days postinjury to evaluate the gut microbiome. HFD altered the microbiome, but ultimately had low-magnitude effects on behavior and did not modify functional outcomes after TBI. Injury-induced functional deficits were far more robust; TBI substantially decreased optimal choice and increased suboptimal choice and motor impulsivity on the RGT. TBI also affected the microbiome, and a model comparison approach revealed that bacterial diversity measured 3 days postinjury was predictive of chronic psychiatric-like deficits on the RGT. A functional metagenomic analysis identified changes to dopamine and serotonin synthesis pathways as a potential candidate mechanism. Thus, the gut may be a potential acute treatment target for psychiatric symptoms after TBI, as well as a biomarker for injury and deficit severity. However, further research will be needed to confirm and extend these findings. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

RevDate: 2022-07-28

Hansen AK, Sanchez AN, Y Kwak (2022)

Divergent Host-Microbe Interaction and Pathogenesis Proteins Detected in Recently Identified Liberibacter Species.

Microbiology spectrum [Epub ahead of print].

Candidatus (Ca.) Liberibacter taxa are economically important bacterial plant pathogens that are not culturable; however, genome-enabled insights can help us develop a deeper understanding of their host-microbe interactions and evolution. The draft genome of a recently identified Liberibacter taxa, Ca. Liberibacter capsica, was curated and annotated here with a total draft genome size of 1.1 MB with 1,036 proteins, which is comparable to other Liberibacter species with complete genomes. A total of 459 orthologous clusters were identified among Ca. L. capsica, Ca. L. asiaticus, Ca. L. psyllaurous, Ca. L. americanus, Ca. L. africanus, and L. crescens, and these genes within these clusters consisted of housekeeping and environmental response functions. We estimated the rates of molecular evolution for each of the 443 one-to-one ortholog clusters and found that all Ca. L. capsica orthologous pairs were under purifying selection when the synonymous substitutions per synonymous site (dS) were not saturated. These results suggest that these genes are largely maintaining their conserved functions. We also identified the most divergent single-copy orthologous proteins in Ca. L. capsica by analyzing the ortholog pairs that represented the highest nonsynonymous substitutions per nonsynonymous site (dN) values for each pairwise comparison. From these analyses, we found that 21 proteins which are known to be involved in pathogenesis and host-microbe interactions, including the Tad pilus complex, were consistently divergent between Ca. L. capsica and the majority of other Liberibacter species. These results further our understanding of the evolutionary genetics of Ca. L. capsica and, more broadly, the evolution of Liberibacter. IMPORTANCE "Candidatus" (Ca.) Liberibacter taxa are economically important plant pathogens vectored by insects; however, these host-dependent bacterial taxa are extremely difficult to study because they are unculturable. Recently, we identified a new Ca. Liberibacter lineage (Ca. Liberibacter capsica) from a rare insect metagenomic sample. In this current study, we report that the draft genome of Ca. Liberibacter capsica is similar in genome size and protein content compared to the other Ca. Liberibacter taxa. We provide evidence that many of their shared genes, which encode housekeeping and environmental response functions, are evolving under purifying selection, suggesting that these genes are maintaining similar functions. Our study also identifies 21 proteins that are rapidly evolving amino acid changes in Ca. Liberibacter capsica compared to the majority of other Liberibacter taxa. Many of these proteins represent key genes involved in Liberibacter-host interactions and pathogenesis and are valuable candidate genes for future studies.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).

Timelines

ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.

Biographies

Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )