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Bibliography on: Endosymbiosis

The Electronic Scholarly Publishing Project: Providing world-wide, free access to classic scientific papers and other scholarly materials, since 1993.


ESP: PubMed Auto Bibliography 25 Sep 2022 at 02:07 Created: 


A symbiotic relationship in which one of the partners lives within the other, especially if it lives within the cells of the other, is known as endosymbiosis. Mitochondria, chloroplasts, and perhaps other cellular organelles are believed to have originated from a form of endosymbiosis. The endosymbiotic origin of eukaryotes seems to have been a biological singularity — that is, it happened once, and only once, in the history of life on Earth.

Created with PubMed® Query: endosymbiont NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2022-09-24

Niu R, Zhu X, Wang L, et al (2022)

Evaluation of Hamiltonella on Aphis gossypii fitness based on life table parameters and RNA sequencing.

Pest management science [Epub ahead of print].

BACKGROUND: Insect endosymbionts are widespread in nature and known to play key roles in regulating host biology. As a secondary endosymbiont, bacteria in the genus Hamiltonella help cotton aphids (Aphis gossypii) defend against parasitism by parasitoid wasps, however, the potential negative impacts of these bacteria on cotton aphid biology remain largely unclear.

RESULTS: This study aims to evaluate the potential impacts of Hamiltonella on the growth and development of cotton aphids based on life table parameters and RNA sequencing. The results showed that infection with Hamiltonella resulted in smaller body type and lower body weight in aphids. Compared to the control group, there were significant differences in the finite and intrinsic rates of increase and mean generation time. Furthermore, the RNA sequencing data revealed that the genes related to energy synthesis and nutrient metabolism pathways were significantly downregulated and genes related to molting and nervous system pathways were significantly upregulated in the Hamiltonella population.

CONCLUSION: Our results confirm that Hamiltonella retarded the growth and development of cotton aphids accompanied by the downregulation of genes related to energy synthesis and nutrient metabolism, which provides new insights into aphid-symbiont interactions and may support the development of improved aphid management strategies.

RevDate: 2022-09-24

Bing XL, Xia CB, Ye QT, et al (2022)

Wolbachia manipulates reproduction of spider mites by influencing herbivore salivary proteins.

Pest management science [Epub ahead of print].

BACKGROUND: The endosymbiont Wolbachia is known for manipulating host reproduction. Wolbachia can also affect host fitness by mediating interactions between plant and herbivores. However, it remains unclear whether saliva proteins are involved in this process.

RESULTS: We found that Wolbachia infection decreased the number of deposited eggs but increased the egg hatching rate in the spider mite Tetranychus urticae Koch (Acari: Tetranychidae), a cosmopolitan pest that infects more than 1000 species of plants. Transcriptomic and proteomic analyses revealed that Wolbachia-infected mites upregulated the gene expression levels of many T. urticae salivary proteins including a cluster of Tetranychidae-specific, functionally uncharacterized SHOT1s (secreted host-responsive proteins of Tetranychidae). The SHOT1 genes were expressed more in the feeding stages (nymphs and adults) of miters than in eggs and highly enriched in the proterosomas. RNA interference experiments showed knockdown of SHOT1s significantly decreased Wolbachia density, increased the number of deposited eggs and decreased the egg hatching rate.

CONCLUSION: Together, these results indicate that SHOT1s are positively correlated with Wolbachia density and account for Wolbachia-mediated phenotypes. Our results provide new evidence that herbivore salivary proteins are related to Wolbachia-mediated manipulations of host performance on plants. This article is protected by copyright. All rights reserved.

RevDate: 2022-09-23

Warecki B, Titen SWA, Alam MS, et al (2022)

Wolbachia action in the sperm produces developmentally deferred chromosome segregation defects during the Drosophila mid-blastula transition.

eLife, 11: pii:81292.

Wolbachia, a vertically transmitted endosymbiont infecting many insects, spreads rapidly through uninfected populations by a mechanism known as cytoplasmic incompatibility (CI). In CI, a paternally delivered modification of the sperm leads to chromatin defects and lethality during and after the first mitosis of embryonic development in multiple species. However, whether CI-induced defects in later stage embryos are a consequence of the first division errors or caused by independent defects remains unresolved. To address this question, we focused on ~1/3 of embryos from CI crosses in Drosophila simulans that develop apparently normally through the first and subsequent pre-blastoderm divisions before exhibiting mitotic errors during the mid-blastula transition and gastrulation. We performed single embryo PCR and whole genome sequencing to find a large percentage of these developed CI-derived embryos bypass the first division defect. Using fluorescence in situ hybridization, we find increased chromosome segregation errors in gastrulating CI-derived embryos that had avoided the first division defect. Thus, Wolbachia action in the sperm induces developmentally deferred defects that are not a consequence of the first division errors. Like the immediate defect, the delayed defect is rescued through crosses to infected females. These studies inform current models on the molecular and cellular basis of CI.

RevDate: 2022-09-23

Johnson KP (2022)

Genomic Approaches to Uncovering the Coevolutionary History of Parasitic Lice.

Life (Basel, Switzerland), 12(9): pii:life12091442.

Next-generation sequencing technologies are revolutionizing the fields of genomics, phylogenetics, and population genetics. These new genomic approaches have been extensively applied to a major group of parasites, the lice (Insecta: Phthiraptera) of birds and mammals. Two louse genomes have been assembled and annotated to date, and these have opened up new resources for the study of louse biology. Whole genome sequencing has been used to assemble large phylogenomic datasets for lice, incorporating sequences of thousands of genes. These datasets have provided highly supported trees at all taxonomic levels, ranging from relationships among the major groups of lice to those among closely related species. Such approaches have also been applied at the population scale in lice, revealing patterns of population subdivision and inbreeding. Finally, whole genome sequence datasets can also be used for additional study beyond that of the louse nuclear genome, such as in the study of mitochondrial genome fragmentation or endosymbiont function.

RevDate: 2022-09-21

Weiss BL, Rio RVM, S Aksoy (2022)

Microbe Profile: Wigglesworthia glossinidia: the tsetse fly's significant other.

Microbiology (Reading, England), 168(9):.

Wigglesworthia glossinidia is an obligate, maternally transmitted endosymbiont of tsetse flies. The ancient association between these two organisms accounts for many of their unique physiological adaptations. Similar to other obligate mutualists, Wigglesworthia's genome is dramatically reduced in size, yet it has retained the capacity to produce many B-vitamins that are found at inadequate quantities in the fly's vertebrate blood-specific diet. These Wigglesworthia-derived B-vitamins play essential nutritional roles to maintain tsetse's physiological homeostasis as well as that of other members of the fly's microbiota. In addition to its nutritional role, Wigglesworthia contributes towards the development of tsetse's immune system during the larval period. Tsetse produce amidases that degrade symbiotic peptidoglycans and prevent activation of antimicrobial responses that can damage Wigglesworthia. These amidases in turn exhibit antiparasitic activity and decrease tsetse's ability to be colonized with parasitic trypanosomes, which reduce host fitness. Thus, the Wigglesworthia symbiosis represents a fine-tuned association in which both partners actively contribute towards achieving optimal fitness outcomes.

RevDate: 2022-09-21

Brinker P, Chen F, Chehida YB, et al (2022)

Microbiome composition is shaped by geography and population structure in the parasitic wasp Asobara japonica, but not in the presence of the endosymbiont Wolbachia.

Molecular ecology [Epub ahead of print].

The microbial community composition is crucial for diverse life-history traits in many organisms. However, we still lack a sufficient understanding of how the host microbiome is acquired and maintained, a pressing issue in times of global environmental change. Here we investigated to what extent host genotype, environmental conditions, and the endosymbiont Wolbachia influence the bacterial communities in the parasitic wasp Asobara japonica. We sampled multiple wasp populations across ten locations in their natural distribution range in Japan and sequenced the host genome (whole genome sequencing) and microbiome (16S rRNA gene). We compared the host population structure and bacterial community composition of wasps that reproduce sexually and are uninfected with Wolbachia with wasps that reproduce asexually and carry Wolbachia. The bacterial communities in asexual wasps were highly similar due to a strong effect of Wolbachia rather than host genomic structure. In contrast, in sexual wasps, bacterial communities appear primarily shaped by a combination of population structure and environmental conditions. Our research highlights that multiple factors shape the bacterial communities of an organism and that the presence of a single endosymbiont can strongly alter their compositions. This information is crucial to understanding how organisms and their associated microbiome will react in the face of environmental change.

RevDate: 2022-09-20

Brophy M, Walker KR, Adamson JE, et al (2022)

Tropical and Temperate Lineages of Rhipicephalus sanguineus s.l. Ticks (Acari: Ixodidae) Host Different Strains of Coxiella-like Endosymbionts.

Journal of medical entomology pii:6702472 [Epub ahead of print].

Nonpathogenic bacteria likely play important roles in the biology and vector competence of ticks and other arthropods. Coxiella, a gram-negative gammaproteobacterium, is one of the most commonly reported maternally inherited endosymbionts in ticks and has been associated with over 40 tick species. Species-specific Coxiella-like endosymbionts (CLEs) have been reported in the brown dog tick, Rhipicephalus sanguineus sensu lato (Acari: Ixodidae), throughout the world, while recent research suggests low Coxiella diversity among tick species. We investigated CLE diversity among R. sanguineus s.l. ticks across Arizona. We detected 37 recurrent sequence variants (SVs) of the symbiont, indicating greater diversity in these symbiotic bacteria than previously reported. However, two SVs accounted for the vast majority of 16S rRNA amplicon reads. These two dominant CLEs were both closely related to Candidatus C. mudrowiae, an identified symbiont of Rhipicephalus turanicus ticks. One strain strongly associated with the tropical lineage of R. sanguineus s.l. while the other was found almost exclusively in the temperate lineage, supporting the conclusion that CLEs are primarily vertically transmitted. However, occasional mismatches between tick lineage and symbiont SV indicate that horizontal symbiont transfer may occur, perhaps via cofeeding of ticks from different lineages on the same dog. This study advances our understanding of CLE diversity in Rh. sanguineus s.l.

RevDate: 2022-09-17
CmpDate: 2022-09-15

Brown KT, Mello-Athayde MA, Sampayo EM, et al (2022)

Environmental memory gained from exposure to extreme pCO2 variability promotes coral cellular acid-base homeostasis.

Proceedings. Biological sciences, 289(1982):20220941.

Ocean acidification is a growing threat to coral growth and the accretion of coral reef ecosystems. Corals inhabiting environments that already endure extreme diel pCO2 fluctuations, however, may represent acidification-resilient populations capable of persisting on future reefs. Here, we examined the impact of pCO2 variability on the reef-building coral Pocillopora damicornis originating from reefs with contrasting environmental histories (variable reef flat versus stable reef slope) following reciprocal exposure to stable (218 ± 9) or variable (911 ± 31) diel pCO2 amplitude (μtam) in aquaria over eight weeks. Endosymbiont density, photosynthesis and net calcification rates differed between origins but not treatment, whereas primary calcification (extension) was affected by both origin and acclimatization to novel pCO2 conditions. At the cellular level, corals from the variable reef flat exhibited less intracellular pH (pHi) acidosis and faster pHi recovery rates in response to experimental acidification stress (pH 7.40) than corals originating from the stable reef slope, suggesting environmental memory gained from lifelong exposure to pCO2 variability led to an improved ability to regulate acid-base homeostasis. These results highlight the role of cellular processes in maintaining acidification resilience and suggest that prior exposure to pCO2 variability may promote more acidification-resilient coral populations in a changing climate.

RevDate: 2022-09-14

Kinjo Y, Bourguignon T, Hongoh Y, et al (2022)

Coevolution of Metabolic Pathways in Blattodea and Their Blattabacterium Endosymbionts, and Comparisons with Other Insect-Bacteria Symbioses.

Microbiology spectrum [Epub ahead of print].

Many insects harbor bacterial endosymbionts that supply essential nutrients and enable their hosts to thrive on a nutritionally unbalanced diet. Comparisons of the genomes of endosymbionts and their insect hosts have revealed multiple cases of mutually-dependent metabolic pathways that require enzymes encoded in 2 genomes. Complementation of metabolic reactions at the pathway level has been described for hosts feeding on unbalanced diets, such as plant sap. However, the level of collaboration between symbionts and hosts that feed on more variable diets is largely unknown. In this study, we investigated amino acid and vitamin/cofactor biosynthetic pathways in Blattodea, which comprises cockroaches and termites, and their obligate endosymbiont Blattabacterium cuenoti (hereafter Blattabacterium). In contrast to other obligate symbiotic systems, we found no clear evidence of "collaborative pathways" for amino acid biosynthesis in the genomes of these taxa, with the exception of collaborative arginine biosynthesis in 2 taxa, Cryptocercus punctulatus and Mastotermes darwiniensis. Nevertheless, we found that several gaps specific to Blattabacterium in the folate biosynthetic pathway are likely to be complemented by their host. Comparisons with other insects revealed that, with the exception of the arginine biosynthetic pathway, collaborative pathways for essential amino acids are only observed in phloem-sap feeders. These results suggest that the host diet is an important driving factor of metabolic pathway evolution in obligate symbiotic systems. IMPORTANCE The long-term coevolution between insects and their obligate endosymbionts is accompanied by increasing levels of genome integration, sometimes to the point that metabolic pathways require enzymes encoded in two genomes, which we refer to as "collaborative pathways". To date, collaborative pathways have only been reported from sap-feeding insects. Here, we examined metabolic interactions between cockroaches, a group of detritivorous insects, and their obligate endosymbiont, Blattabacterium, and only found evidence of collaborative pathways for arginine biosynthesis. The rarity of collaborative pathways in cockroaches and Blattabacterium contrasts with their prevalence in insect hosts feeding on phloem-sap. Our results suggest that host diet is a factor affecting metabolic integration in obligate symbiotic systems.

RevDate: 2022-09-13

Gabr A, Stephens TG, D Bhattacharya (2022)

Loss of key endosymbiont genes may facilitate early host control of the chromatophore in Paulinella.

iScience, 25(9):104974.

The primary plastid endosymbiosis (∼124 Mya) that occurred in the heterotrophic amoeba lineage, Paulinella, is at an earlier stage of evolution than in Archaeplastida, and provides an excellent model for studying organelle integration. Using genomic data from photosynthetic Paulinella, we identified a plausible mechanism for the evolution of host control of endosymbiont (termed the chromatophore) biosynthetic pathways and functions. Specifically, random gene loss from the chromatophore and compensation by nuclear-encoded gene copies enables host control of key pathways through a minimal number of evolutionary innovations. These gene losses impact critical enzymatic steps in nucleotide biosynthesis and the more peripheral components of multi-protein DNA replication complexes. Gene retention in the chromatophore likely reflects the need to maintain a specific stoichiometric balance of the encoded products (e.g., involved in DNA replication) rather than redox state, as in the highly reduced plastid genomes of algae and plants.

RevDate: 2022-09-13
CmpDate: 2022-09-13

Medina GA, Flores-Martin SN, Pereira WA, et al (2022)

Long-term survive of Aliarcobacter butzleri in two models symbiotic interaction with Acanthamoeba castellanii.

Archives of microbiology, 204(10):610.

Aliarcobacter butzleri (formerly known as Arcobacter butzleri) is an emerging food-borne zoonotic pathogen that establishes in vitro endosymbiotic relationships with Acanthamoeba castellanii, a free-living amoeba. Previously, we described that this bacterium acts as an endocytobiont of A. castellanii, surviving for at least 10 days in absence of bacterial replication. Thus, the aim of this study was to evaluate the ability of A. butzleri to survive as a long-term endosymbiont of A. castellanii for 30 days in two models of symbiotic interaction with A. castellanii: (i) endosymbiotic culture followed by gentamicin protection assay and (ii) transwell co-culture assay. The results allow us to conclude that A. butzleri is capable of surviving as an endosymbiont of A. castellanii for at least 30 days, without multiplying, under controlled laboratory conditions. In addition, in the absence of nutrients and as both microorganisms remain in the same culture, separated by semi-permeable membranes, A. castellanii does not promote the survival of A. butzleri, nor does it multiply. Our findings suggest that the greater survival capacity of A. butzleri is associated with their endosymbiont status inside A. castellanii, pointing out the complexity of this type of symbiotic relationship.

RevDate: 2022-09-09

Štarhová Serbina L, Gajski D, Pafčo B, et al (2022)

Microbiome of pear psyllids: A tale about closely related species sharing their endosymbionts.

Environmental microbiology [Epub ahead of print].

Psyllids are phloem-feeding insects that can transmit plant pathogens such as phytoplasmas, intracellular bacteria causing numerous plant diseases worldwide. Their microbiomes are essential for insect physiology and may also influence the capacity of vectors to transmit pathogens. Using 16S rRNA gene metabarcoding, we compared the microbiomes of three sympatric psyllid species associated with pear trees in Central Europe. All three species are able to transmit 'Candidatus Phytoplasma pyri', albeit with different efficiencies. Our results revealed potential relationships between insect biology and microbiome composition that varied during psyllid ontogeny and between generations in Cacopsylla pyri and C. pyricola, as well as between localities in C. pyri. In contrast, no variations related to psyllid life cycle and geography were detected in C. pyrisuga. In addition to the primary endosymbiont Carsonella ruddii, we detected another highly abundant endosymbiont (unclassified Enterobacteriaceae). C. pyri and C. pyricola shared the same taxon of Enterobacteriaceae which is related to endosymbionts harboured by other psyllid species from various families. In contrast, C. pyrisuga carried a different Enterobacteriaceae taxon related to the genus Sodalis. Our study provides new insights into host-symbiont interactions in psyllids and highlights the importance of host biology and geography in shaping microbiome structure.

RevDate: 2022-09-06
CmpDate: 2022-09-02

Twort VG, Blande D, A Duplouy (2022)

One's trash is someone else's treasure: sequence read archives from Lepidoptera genomes provide material for genome reconstruction of their endosymbionts.

BMC microbiology, 22(1):209.

BACKGROUND: Maternally inherited bacterial symbionts are extremely widespread in insects. They owe their success to their ability to promote their own transmission through various manipulations of their hosts' life-histories. Many symbionts however very often go undetected. Consequently, we have only a restricted idea of the true symbiont diversity in insects, which may hinder our understanding of even bigger questions in the field such as the evolution or establishment of symbiosis.

RESULTS: In this study, we screened publicly available Lepidoptera genomic material for two of the most common insect endosymbionts, namely Wolbachia and Spiroplasma, in 1904 entries, encompassing 106 distinct species. We compared the performance of two screening software, Kraken2 and MetaPhlAn2, to identify the bacterial infections and using a baiting approach we reconstruct endosymbiont genome assemblies. Of the 106 species screened, 20 (19%) and nine (8.5%) were found to be infected with either Wolbachia or Spiroplasma, respectively. Construction of partial symbiotic genomes and phylogenetic analyses suggested the Wolbachia strains from the supergroup B were the most prevalent type of symbionts, while Spiroplasma infections were scarce in the Lepidoptera species screened here.

CONCLUSIONS: Our results indicate that many of the host-symbiont associations remain largely unexplored, with the majority of associations we identify never being recorded before. This highlights the usefulness of public databases to explore the hidden diversity of symbiotic entities, allowing the development of hypotheses regarding host-symbiont associations. The ever-expanding genomic databases provide a diverse databank from which one can characterize and explore the true diversity of symbiotic entities.

RevDate: 2022-09-11

Wang R, Sun R, Zhang Z, et al (2022)

"Candidatus Euplotechlamydia quinta," a novel chlamydia-like bacterium hosted by the ciliate Euplotes octocarinatus (Ciliophora, Spirotrichea).

The Journal of eukaryotic microbiology [Epub ahead of print].

Our knowledge of ciliate endosymbiont diversity greatly expanded over the past decades due to the development of characterization methods for uncultivable bacteria. Chlamydia-like bacteria have been described as symbionts of free-living amoebae and other phylogenetically diverse eukaryotic hosts. In the present work, a systematic survey of the bacterial diversity associated with the ciliate Euplotes octocarinatus strain Zam5b-1 was performed, using metagenomic screening as well as classical full-cycle rRNA approach, and a novel chlamydial symbiont was characterized. The metagenomic screening revealed 16S rRNA gene sequences from Polynucleobacter necessarius, three previously reported accessory symbionts, and a novel chlamydia-like bacterium. Following the full-cycle rRNA approach, we obtained the full-length 16S rRNA gene sequence of this chlamydia-like bacterium and developed probes for diagnostic fluorescence in situ hybridizations. The phylogenetic analysis of the 16S rRNA gene sequences unambiguously places the new bacterium in the family Rhabdochlamydiaceae. This is the first report of chlamydia-like bacterium being found in Euplotes. Based on the obtained data, the bacterium is proposed as a new candidate genus and species: "Candidatus Euplotechlamydia quinta."

RevDate: 2022-09-20
CmpDate: 2022-08-30

Jha B, Reverte M, Ronet C, et al (2022)

In and out: Leishmania metastasis by hijacking lymphatic system and migrating immune cells.

Frontiers in cellular and infection microbiology, 12:941860.

The lymphatic system plays a crucial role in mounting immune response against intracellular pathogens, and recent studies have documented its role in facilitating tumor dissemination linked largely with cancer cells. However, in mucocutaneous leishmaniasis (MCL) caused by Leishmania Viannia subgenus showing infectious metastasis and resulting in severe distant secondary lesions, the route of escape of these parasites to secondary sites has not yet been investigated in detail. Our results demonstrated that when infection was associated with inflammation and additionally exacerbated by the presence of dsRNA viral endosymbiont (LRV1), lymphatic vessels could serve as efficient routes for infected cells to egress from the primary site and colonize distant organs. We challenged this hypothesis by using the intracellular Leishmania protozoan parasites Leishmania guyanensis (Lgy) associated with or without a dsRNA viral endosymbiont, exacerbating the infection and responsible for a strong inflammatory response, and favoring metastasis of the infection. We analyzed possible cargo cells and the routes of dissemination through flow cytometry, histological analysis, and in vivo imaging in our metastatic model to show that parasites disseminated not only intracellularly but also as free extracellular parasites using migrating immune cells, lymph nodes (LNs), and lymph vessels, and followed intricate connections of draining and non-draining lymph node to finally end up in the blood and in distant skin, causing new lesions.

RevDate: 2022-09-21
CmpDate: 2022-08-30

Kopelyanskiy D, Desponds C, Prevel F, et al (2022)

Leishmania guyanensis suppressed inducible nitric oxide synthase provoked by its viral endosymbiont.

Frontiers in cellular and infection microbiology, 12:944819.

Inducible nitric oxide synthase (iNOS) is essential to the production of nitric oxide (NO), an efficient effector molecule against intracellular human pathogens such as Leishmania protozoan parasites. Some strains of Leishmania are known to bear a viral endosymbiont termed Leishmania RNA virus 1 (LRV1). Recognition of LRV1 by the innate immune sensor Toll-like receptor-3 (TLR3) leads to conditions worsening the disease severity in mice. This process is governed by type I interferon (type I IFNs) arising downstream of TLR3 stimulation and favoring the formation of secondary metastatic lesions. The formation of these lesions is mediated by the inflammatory cytokine IL-17A and occurs in the absence, or low level of, protective cytokine IFN-γ. Here, we described that the presence of LRV1 led to the initial expression of iNOS and low production of NO that failed to control infection. We subsequently showed that LRV1-triggered type I IFN was essential but insufficient to induce robust iNOS induction, which requires strong activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Leishmania guyanensis carrying LRV1 (LgyLRV1+) parasites mitigated strong iNOS production by limiting NF-kB activation via the induction of tumor necrosis factor-alpha-induced protein 3 (TNFAIP3), also known as A20. Moreover, our data suggested that production of LRV1-induced iNOS could be correlated with parasite dissemination and metastasis via elevated secretion of IL-17A in the draining lymph nodes. Our findings support an additional strategy by which LRV1-bearing Leishmania guyanensis evaded killing by nitric oxide and suggest that low levels of LRV1-induced NO might contribute to parasite metastasis.

RevDate: 2022-08-30

Špitalská E, Minichová L, Hamšíková Z, et al (2022)

Bartonella, Rickettsia, Babesia, and Hepatozoon Species in Fleas (Siphonaptera) Infesting Small Mammals of Slovakia (Central Europe).

Pathogens (Basel, Switzerland), 11(8):.

Fleas (Siphonaptera) as obligate, blood-feeding ectoparasites are, together with ticks, hosted by small mammals and can transmit causative agents of serious infections. This study aimed to determine and characterize the presence and genetic diversity of Bartonella, Rickettsia, and apicomplexan parasites (Babesia, Hepatozoon) in fleas feeding on small mammals from three different habitat types (suburban, natural, and rural) in Slovakia. The most common pathogen in the examined fleas was Bartonella spp. (33.98%; 95% CI: 30.38-37.58), followed by Rickettsia spp. (19.1%; 95% CI: 16.25-22.24) and apicomplexan parasites (4.36%; 95% CI: 2.81-5.91). Bartonella strains belonging to B. taylorii, B. grahamii, B. elizabethae, Bartonella sp. wbs11, and B. rochalimae clades were identified in Ctenophthalmus agyrtes, C. congener, C. assimilis, C. sciurorum, C. solutus, C. bisoctodentatus, Palaeopsylla similis, Megabothris turbidus, and Nosopsyllus fasciatus within all habitats. The presence of Rickettsia helvetica, R. monacensis, and rickettsiae, belonging to the R. akari and R. felis clusters, and endosymbionts with a 96-100% identity with the Rickettsia endosymbiont of Nosopsyllus laeviceps laeviceps were also revealed in C. agyrtes, C. solutus, C. assimilis, C. congener, M. turbidus, and N. fasciatus. Babesia and Hepatozoon DNA was detected in the fleas from all habitat types. Hepatozoon sp. was detected in C. agyrtes, C. assimilis, and M. turbidus, while Babesia microti was identified from C. agyrtes, C. congener, and P. similis. The present study demonstrated the presence of zoonotic pathogens in fleas, parasitizing the wild-living small mammals of southwestern and central Slovakia and widens our knowledge of the ecology and genomic diversity of Bartonella, Rickettsia, Babesia, and Hepatozoon.

RevDate: 2022-08-30
CmpDate: 2022-08-29

Zong Q, Mao B, Zhang HB, et al (2022)

Comparative Ubiquitome Analysis Reveals Deubiquitinating Effects Induced by Wolbachia Infection in Drosophila melanogaster.

International journal of molecular sciences, 23(16):.

The endosymbiotic Wolbachia bacteria frequently cause cytoplasmic incompatibility (CI) in their insect hosts, where Wolbachia-infected males cross with uninfected females, leading to no or fewer progenies, indicating a paternal modification by Wolbachia. Recent studies have identified a Wolbachia protein, CidB, containing a DUB (deubiquitylating enzyme) domain, which can be loaded into host sperm nuclei and involved in CI, though the DUB activity is not necessary for CI in Drosophila melanogaster. To investigate whether and how Wolbachia affect protein ubiquitination in testes of male hosts and are thus involved in male fertility, we compared the protein and ubiquitinated protein expressions in D. melanogaster testes with and without Wolbachia. A total of 643 differentially expressed proteins (DEPs) and 309 differentially expressed ubiquitinated proteins (DEUPs) were identified to have at least a 1.5-fold change with a p-value of <0.05. Many DEPs were enriched in metabolic pathway, ribosome, RNA transport, and post-translational protein modification pathways. Many DEUPs were involved in metabolism, ribosome, and proteasome pathways. Notably, 98.1% DEUPs were downregulated in the presence of Wolbachia. Four genes coding for DEUPs in ubiquitin proteasome pathways were knocked down, respectively, in Wolbachia-free fly testes. Among them, Rpn6 and Rpn7 knockdown caused male sterility, with no mature sperm in seminal vesicles. These results reveal deubiquitylating effects induced by Wolbachia infection, suggesting that Wolbachia can widely deubiquitinate proteins that have crucial functions in male fertility of their hosts, but are not involved in CI. Our data provide new insights into the regulatory mechanisms of endosymbiont/host interactions and male fertility.

RevDate: 2022-08-25

Richter I, Radosa S, Cseresnyés Z, et al (2022)

Toxin-Producing Endosymbionts Shield Pathogenic Fungus against Micropredators.

mBio [Epub ahead of print].

The fungus Rhizopus microsporus harbors a bacterial endosymbiont (Mycetohabitans rhizoxinica) for the production of the antimitotic toxin rhizoxin. Although rhizoxin is the causative agent of rice seedling blight, the toxinogenic bacterial-fungal alliance is, not restricted to the plant disease. It has been detected in numerous environmental isolates from geographically distinct sites covering all five continents, thus raising questions regarding the ecological role of rhizoxin beyond rice seedling blight. Here, we show that rhizoxin serves the fungal host in fending off protozoan and metazoan predators. Fluorescence microscopy and coculture experiments with the fungivorous amoeba Protostelium aurantium revealed that ingestion of R. microsporus spores is toxic to P. aurantium. This amoebicidal effect is caused by the dominant bacterial rhizoxin congener rhizoxin S2, which is also lethal toward the model nematode Caenorhabditis elegans. By combining stereomicroscopy, automated image analysis, and quantification of nematode movement, we show that the fungivorous nematode Aphelenchus avenae actively feeds on R. microsporus that is lacking endosymbionts, whereas worms coincubated with symbiotic R. microsporus are significantly less lively. This study uncovers an unexpected ecological role of rhizoxin as shield against micropredators. This finding suggests that predators may function as an evolutionary driving force to maintain toxin-producing endosymbionts in nonpathogenic fungi. IMPORTANCE The soil community is a complex system characterized by predator-prey interactions. Fungi have developed effective strategies to defend themselves against predators. Understanding these strategies is of critical importance for ecology, medicine, and biotechnology. In this study, we shed light on the defense mechanisms of the phytopathogenic Rhizopus-Mycetohabitans symbiosis that has spread worldwide. We report an unexpected role of rhizoxin, a secondary metabolite produced by the bacterium M. rhizoxinica residing within the hyphae of R. microsporus. We show that this bacterial secondary metabolite is utilized by the fungal host to successfully fend off fungivorous protozoan and metazoan predators and thus identified a fundamentally new function of this infamous cytotoxic compound. This endosymbiont-dependent predator defense illustrates an unusual strategy employed by fungi that has broader implications, since it may serve as a model for understanding how animal predation acts as an evolutionary driving force to maintain endosymbionts in nonpathogenic fungi.

RevDate: 2022-08-26

Nishide Y, Oguchi K, Murakami M, et al (2022)

Endosymbiotic bacteria of the boar louse Haematopinus apri (Insecta: Phthiraptera: Anoplura).

Frontiers in microbiology, 13:962252.

Insects exclusively feeding on vertebrate blood are usually dependent on symbiotic bacteria for provisioning of B vitamins. Among them, sucking lice are prominent in that their symbiotic bacteria as well as their symbiotic organs exhibit striking diversity. Here we investigated the bacterial diversity associated with the boar louse Haematopinus apri in comparison with the hog louse Haematopinus suis. Amplicon sequencing analysis identified the primary endosymbiont predominantly detected from all populations of H. apri with some minor secondary bacterial associates. Sequencing and phylogenetic analysis of bacterial 16S rRNA gene confirmed that the endosymbionts of the boar louse H. apri, the hog louse H. suis and the cattle louse Haematopinus eurysternus form a distinct clade in the Gammaproteobacteria. The endosymbiont clade of Haematopinus spp. was phylogenetically distinct from the primary endosymbionts of other louse lineages. Fluorescence in situ hybridization visualized the endosymbiont localization within midgut epithelium, ovarial ampulla and posterior oocyte of H. apri, which were substantially the same as the endosymbiont localization previously described in H. suis and H. eurysternus. Mitochondrial haplotype analysis revealed that, although the domestic pig was derived from the wild boar over the past 8,000 years of human history, the populations of H. apri constituted a distinct sister clade to the populations of H. suis. Based on these results, we discussed possible evolutionary trajectories of the boar louse, the hog louse and their endosymbionts in the context of swine domestication. We proposed 'Candidatus Haematopinicola symbiotica' for the distinct clade of the endosymbionts of Haematopinus spp.

RevDate: 2022-08-26

Davies OK, Dorey JB, Stevens MI, et al (2022)

Unparalleled mitochondrial heteroplasmy and Wolbachia co-infection in the non-model bee, Amphylaeus morosus.

Current research in insect science, 2:100036.

Mitochondrial heteroplasmy is the occurrence of more than one type of mitochondrial DNA within a single individual. Although generally reported to occur in a small subset of individuals within a species, there are some instances of widespread heteroplasmy across entire populations. Amphylaeus morosus is an Australian native bee species in the diverse and cosmopolitan bee family Colletidae. This species has an extensive geographical range along the eastern Australian coast, from southern Queensland to western Victoria, covering approximately 2,000 km. Seventy individuals were collected from five localities across this geographical range and sequenced using Sanger sequencing for the mitochondrial cytochrome c oxidase subunit I (COI) gene. These data indicate that every individual had the same consistent heteroplasmic sites but no other nucleotide variation, suggesting two conserved and widespread heteroplasmic mitogenomes. Ion Torrent shotgun sequencing revealed that heteroplasmy occurred across multiple mitochondrial protein-coding genes and is unlikely explained by transposition of mitochondrial genes into the nuclear genome (NUMTs). DNA sequence data also demonstrated a consistent co-infection of Wolbachia across the A. morosus distribution with every individual infected with both bacterial strains. Our data are consistent with the presence of two mitogenomes within all individuals examined in this species and suggest a major divergence from standard patterns of mitochondrial inheritance. Because the host's mitogenome and the Wolbachia genome are genetically linked through maternal inheritance, we propose three possible hypotheses that could explain maintenance of the widespread and conserved co-occurring bacterial and mitochondrial genomes in this species.

RevDate: 2022-08-24

Qi Y, Ai L, Zhu C, et al (2022)

Wild Hedgehogs and Their Parasitic Ticks Coinfected with Multiple Tick-Borne Pathogens in Jiangsu Province, Eastern China.

Microbiology spectrum [Epub ahead of print].

The increasing awareness of emerging tickborne pathogens (TBPs) has inspired much research. In the present study, the coinfections of TBPs both in ticks and their wild hedgehog hosts in Jiangsu province, Eastern China were determined by metagenome next-generation sequencing and nested PCR. As a result, Rickettsia japonica (81.1%), novel Rickettsia sp. SFGR-1 (5.1%), Anaplasma bovis (12%), A. platys (6.3%), novel Ehrlichia spp. Ehr-1 (16%) and Ehr-2 (0.6%), E. ewingii-like strain (0.6%), Coxiella burnetii (10.9%), and a novel Coxiella-like endosymbiont (CLE) strain (61.1%) were detected in Haemaphysalis flava ticks. A. bovis (43.8%), Ehrlichia sp. Ehr-1 (83.3%), and C. burnetii (80%) were detected in Erinaceus amurensis hedgehogs. Coinfection rates with various TBPs were 71.5% and 83.3% in ticks and hedgehogs, respectively, both with double-pathogen/endosymbiont coinfection rates over 50%. We found the following. (i) Er. amurensis hedgehogs seem to contribute to the natural cycles of R. japonica, A. bovis, Ehrlichia sp., and C. burnetii and may be reservoirs of them except for R. japonica, and A. bovis is proved to infect hedgehogs for the first time. (ii) H. flava is proved to harbor various TBPs as a reservoir host, including CLE identified for the first time, which could inhibit coinfection of C. burnetii while promoting that of Rickettsia spp. in H. flava. (iii) Four novel TBP species were identified. This study provides useful epidemiological information crucial for assessing the potential infection risks to humans, thus benefiting the development of strategies to prevent and control tick-borne diseases. IMPORTANCE In the present study, we found the following. (i) Er. amurensis hedgehogs seem to contribute to the natural cycles of R. japonica, A. bovis, Ehrlichia sp., and C. burnetii and may be reservoirs of them except for R. japonica, and A. bovis is proved to infect hedgehogs for the first time. (ii) H. flava is proved to harbor various tickborne pathogens (TBPs) as a reservoir host, including Coxiella-like endosymbiont (CLE) identified for the first time, which could inhibit coinfection of C. burnetii while promoting that of Rickettsia spp. in H. flava. (iii) Four novel TBP species were identified. This study provides useful epidemiological information on TBPs harbored and transmitted by ticks and their hosts, for assessing the potential infection risks to humans, thus benefiting the developing strategies for tick-borne diseases prevention and control.

RevDate: 2022-08-23

Breusing C, Klobusnik NH, Hauer MA, et al (2022)

Genome assembly of the chemosynthetic endosymbiont of the hydrothermal vent snail Alviniconcha adamantis from the Mariana Arc.

G3 (Bethesda, Md.) pii:6673915 [Epub ahead of print].

Chemosynthetic animal-microbe symbioses sustain hydrothermal vent communities in the global deep sea. In the Indo-Pacific Ocean, hydrothermal ecosystems are often dominated by gastropod species of the genus Alviniconcha, which live in association with chemosynthetic Gammaproteobacteria or Campylobacteria. While the symbiont genomes of most extant Alviniconcha species have been sequenced, no genome information is currently available for the gammaproteobacterial endosymbiont of A. adamantis - a comparatively shallow living species that is thought to be the ancestor to all other present Alviniconcha lineages. Here, we report the first genome sequence for the symbiont of A. adamantis from the Chamorro Seamount at the Mariana Arc. Our phylogenomic analyses show that the A. adamantis symbiont is most closely related to Chromatiaceae endosymbionts of the hydrothermal vent snails A. strummeri and Chrysomallon squamiferum, but represents a distinct bacterial species or possibly genus. Overall, functional capacity of the A. adamantis symbiont appeared to be similar to other chemosynthetic Gammaproteobacteria, though several flagella and chemotaxis genes were detected, which are absent in other gammaproteobacterial Alviniconcha symbionts. These differences might suggest potential contrasts in symbiont transmission dynamics, host recognition or nutrient transfer. Furthermore, an abundance of genes for ammonia transport and urea usage could indicate adaptations to the oligotrophic waters of the Mariana region, possibly via recycling of host- and environment-derived nitrogenous waste products. This genome assembly adds to the growing genomic resources for chemosynthetic bacteria from hydrothermal vents and will be valuable for future comparative genomic analyses assessing gene content evolution in relation to environment and symbiotic lifestyle.

RevDate: 2022-09-07
CmpDate: 2022-08-24

Sgroi G, Iatta R, Lovreglio P, et al (2022)

Detection of Endosymbiont Candidatus Midichloria mitochondrii and Tickborne Pathogens in Humans Exposed to Tick Bites, Italy.

Emerging infectious diseases, 28(9):1824-1832.

During 2021, we collected blood and serum samples from 135 persons exposed to tick bites in southern Italy. We serologically and molecularly screened for zoonotic tickborne pathogens and only molecularly screened for Candidatus Midichloria mitochondrii. Overall, 62 (45.9%) persons tested positive for tickborne pathogens. Coxiella burnetii was detected most frequently (27.4%), along with Rickettsia spp. (21.5%) and Borrelia spp. (10.4%). We detected Candidatus M. mitochondrii DNA in 46 (34.1%) participants who had statistically significant associations to tickborne pathogens (p<0.0001). Phylogenetic analysis of Candidatus M. mitochondrii sequences revealed 5 clades and 8 human sequence types that correlated with vertebrates, Ixodes spp. ticks, and countries in Europe. These data demonstrated a high circulation of tickborne pathogens and Candidatus M. mitochondrii DNA in persons participating in outdoor activities in southern Italy. Our study shows how coordinated surveillance among patients, clinicians, and veterinarians could inform a One Health approach for monitoring and controlling the circulation of tickborne pathogens.

RevDate: 2022-08-23

Hirunkanokpun S, Ahantarig A, Baimai V, et al (2022)

Correction to: Spotted fever group Rickettsia, Anaplasma and Coxiella‑like endosymbiont in Haemaphysalis ticks from mammals in Thailand.

RevDate: 2022-08-23

Sadanandane C, Gunasekaran K, Panneer D, et al (2022)

Studies on the fitness characteristics of wMel- and wAlbB-introgressed Aedes aegypti (Pud) lines in comparison with wMel- and wAlbB-transinfected Aedes aegypti (Aus) and wild-type Aedes aegypti (Pud) lines.

Frontiers in microbiology, 13:947857.

Wolbachia, an intracellular maternally transmitted endosymbiont, has been shown to interfere with the replication of dengue virus in Aedes aegypti mosquitoes. The Wolbachia-transinfected Ae. aegypti has been currently released in many countries to test its effectiveness in preventing the transmission of dengue virus. ICMR-Vector Control Research Centre in collaboration with World Mosquito Program Monash University, Australia, has generated two new Wolbachia-introgressed Ae. aegypti Puducherry (Pud) lines via backcrossing Ae. aegypti females of Australian (Aus) strains, infected with wMel and wAlbB Wolbachia with wild-type Ae. aegypti Puducherry (Pud) males. Wolbachia infections are known to induce a fitness cost and confer benefit on the host mosquito populations that will influence spread of the Wolbachia into native wild mosquito populations during the field release. Hence, the induced fitness cost or benefit/advantage in the two newly generated Ae. aegypti (Pud) lines was assessed in the laboratory in comparison with the wild-type Ae. aegypti (Pud) strain. In addition, maternal transmission (MT) efficiency, induced cytoplasmic incompatibility (CI), and insecticide resistance status of the two (Pud) lines were determined to assess the likely frequency of wMel and wAlbB infections in the native wild population after field invasion. The study shows that wMel and wAlbB infections did not induce any fitness cost on the two newly generated (Pud) lines. Rather, in terms of wing length, fecundity, egg hatch rate, and adult survival, the Wolbachia introgression conferred fitness benefits on the (Pud) lines compared to uninfected Wolbachia free wild Ae. aegypti population. wMel and wAlbB exhibited a high maternal transmission (99-100%) and induced nearly complete (98-100%) cytoplasmic incompatibility. Both the (Pud) lines were resistant to deltamethrin, malathion, DDT, and temephos, and the level of resistance was almost the same between the two lines as in the wild type. Overall, the stable association of wMel and wAlbB established with Ae. aegypti and the reproductive advantages of the (Pud) lines encourage a pilot release in the field for population replacement potential.

RevDate: 2022-09-20
CmpDate: 2022-08-23

Bekkar A, Isorce N, Snäkä T, et al (2022)

Dissection of the macrophage response towards infection by the Leishmania-viral endosymbiont duo and dynamics of the type I interferon response.

Frontiers in cellular and infection microbiology, 12:941888.

Leishmania RNA virus 1 (LRV1) is a double-stranded RNA virus found in some strains of the human protozoan parasite Leishmania, the causative agent of leishmaniasis, a neglected tropical disease. Interestingly, the presence of LRV1 inside Leishmania constitutes an important virulence factor that worsens the leishmaniasis outcome in a type I interferon (IFN)-dependent manner and contributes to treatment failure. Understanding how macrophages respond toward Leishmania alone or in combination with LRV1 as well as the role that type I IFNs may play during infection is fundamental to oversee new therapeutic strategies. To dissect the macrophage response toward infection, RNA sequencing was performed on murine wild-type and Ifnar-deficient bone marrow-derived macrophages infected with Leishmania guyanensis (Lgy) devoid or not of LRV1. Additionally, macrophages were treated with poly I:C (mimetic virus) or with type I IFNs. By implementing a weighted gene correlation network analysis, the groups of genes (modules) with similar expression patterns, for example, functionally related, coregulated, or the members of the same functional pathway, were identified. These modules followed patterns dependent on Leishmania, LRV1, or Leishmania exacerbated by the presence of LRV1. Not only the visualization of how individual genes were embedded to form modules but also how different modules were related to each other were observed. Thus, in the context of the observed hyperinflammatory phenotype associated to the presence of LRV1, it was noted that the biomarkers tumor-necrosis factor α (TNF-α) and the interleukin 6 (IL-6) belonged to different modules and that their regulating specific Src-family kinases were segregated oppositely. In addition, this network approach revealed the strong and sustained effect of LRV1 on the macrophage response and genes that had an early, late, or sustained impact during infection, uncovering the dynamics of the IFN response. Overall, this study contributed to shed light and dissect the intricate macrophage response toward infection by the Leishmania-LRV1 duo and revealed the crosstalk between modules made of coregulated genes and provided a new resource that can be further explored to study the impact of Leishmania on the macrophage response.

RevDate: 2022-09-17

Fujii S, Somei K, Asaeda Y, et al (2022)

Heterologous expression and biochemical comparison of two homologous SoxX proteins of endosymbiotic Candidatus Vesicomyosocius okutanii and free-living Hydrogenovibrio crunogenus from deep-sea environments.

Protein expression and purification, 200:106157 pii:S1046-5928(22)00114-0 [Epub ahead of print].

Candidatus Vesicomyosocius okutanii is a currently uncultured endosymbiotic bacterium of Phreagena okutanii, a clam that inhabits deep-sea vent environments. The genome of Ca. V. okutanii encodes a sulfur-oxidizing (Sox) enzyme complex, presumably generating biological energy for the host from inorganic sulfur compounds. Here, Ca. V. okutanii SoxX (VoSoxX), a mono-heme cytochrome c component of the Sox complex, was shown to be phylogenetically related to its homologous counterpart (HcSoxX) from a free-living deep-sea bacterium, Hydrogenovibrio crunogenus. Both proteins were heterologously expressed in Escherichia coli co-expressing cytochrome c maturation genes for comparative biochemical analysis. The VoSoxX recombinant had significantly lower thermal stability than HcSoxX, reflecting the difference in growth conditions of the source bacteria. The endosymbiont inhabits a mild intracellular environment, whereas the free-living bacterium dwells in a harsh environment. This study represents the first successful case of heterologous expression of genes from Ca. V. okutanii, allowing further biochemical studies of the molecular mechanism of sulfur oxidation in deep-sea environments.

RevDate: 2022-08-25

Qi S, Al Naggar Y, Li J, et al (2022)

Acaricide flumethrin-induced sublethal risks in honeybees are associated with gut symbiotic bacterium Gilliamella apicola through microbe-host metabolic interactions.

Chemosphere, 307(Pt 3):136030 pii:S0045-6535(22)02523-1 [Epub ahead of print].

Flumethrin is one of the few acaricides that permit the control of Varroa disease or varroosis in bee colonies. However, flumethrin accumulates in hive products. We previously discovered that sublethal doses of flumethrin induce significant physiological stress in honeybees (Apis mellifera L.), however its potential impacts on the honeybee gut microenvironment remains unknown. To fill this gap, honeybees were exposed to a field-relevant concentration of flumethrin (10 μg/L) for 14 d and its potential impacts on gut system were evaluated. The results indicated that flumethrin triggered immune responses in the gut but had limited effects on survival and gut microbial composition. However, survival stress drastically increased in bees exposed to antibiotics, suggesting that the gut microbiota is closely related to flumethrin-induced dysbiosis in the bee gut. Based on a non-targeted metabolomics approach, flumethrin at 10 μg/L considerably altered the composition of intestinal metabolites, and we discovered that this metabolic stress was closely linked with a reduction of gut core bacterial endosymbiont Gilliamella spp. through a combination of microbiological and metabolomics investigations. Finally, an in vitro study showed that while flumethrin does not directly inhibit the growth of Gilliamella apicola isolates, it does have a significant impact on the glycerophospholipid metabolism in bacteria cells, which was also observed in host bees. These findings indicated that even though flumethrin administered at environmental relevant concentrations does not significantly induce death in honeybees, it still alters the metabolism balance between honeybees and the gut symbiotic bacterium, G. apicola. The considerable negative impact of flumethrin on the honeybee gut microenvironment emphasizes the importance of properly monitoring acaricide to avoid potential environmental concerns, and further studies are needed to illustrate the mode of action of bee health-gut microbiota-exogenous pesticides.

RevDate: 2022-09-14
CmpDate: 2022-09-14

Oliveira CYB, Abreu JL, Santos EP, et al (2022)

Light induces peridinin and docosahexaenoic acid accumulation in the dinoflagellate Durusdinium glynnii.

Applied microbiology and biotechnology, 106(18):6263-6276.

Peridinin is a light-harvesting carotenoid present in phototrophic dinoflagellates and has great potential for new drug applications and cosmetics development. Herein, the effects of irradiance mediated by light-emitting diodes on growth performance, carotenoid and fatty acid profiles, and antioxidant activity of the endosymbiotic dinoflagellate Durusdinium glynnii were investigated. The results demonstrate that D. glynnii is particularly well adapted to low-light conditions; however, it can be high-light-tolerant. In contrast to other light-harvesting carotenoids, the peridinin accumulation in D. glynnii occurred during high-light exposure. The peridinin to chlorophyll-a ratio varied as a function of irradiance, while the peridinin to total carotenoids ratio remained stable. Under optimal irradiance for growth, there was a peak in docosahexaenoic acid (DHA) bioaccumulation. This study contributes to the understanding of the photoprotective role of peridinin in endosymbiont dinoflagellates and highlights the antioxidant activity of peridinin-rich extracts. KEY POINTS: • Peridinin has a protective role against chlorophyll photo-oxidation • High light conditions induce cellular peridinin accumulation • D. glynnii accumulates high amounts of DHA under optimal light supply.

RevDate: 2022-09-02
CmpDate: 2022-09-02

Aquino MF, A Simoes-Barbosa (2022)

A Microbial Piñata: Bacterial Endosymbionts of Trichomonas vaginalis Come in Different Flavors.

mBio, 13(4):e0132322.

The protozoan parasite Trichomonas vaginalis causes trichomoniasis, a prevalent human urogenital infection with significant morbidity that is commonly associated with vaginal dysbiosis. Exacerbation of T. vaginalis pathogenicity has been related to endosymbionts, including mycoplasma, and thought for a while to be solely attributable to Mycoplasma hominis. In a recent publication, Margarita and colleagues ( showed that endosymbiosis extends to a second species of mycoplasma known as "Candidatus Mycoplasma girerdii." Those authors confirmed the strong association of T. vaginalis with both species of mycoplasma by reassessing clinical samples. Additionally, they showed that in vitro symbiosis of protozoa and bacteria resulted in the modulation of gene expression of T. vaginalis and enhancement of parasite cytoadhesion and hemolytic activity in culture assays. In this commentary, we portray T. vaginalis as a synergistically interacting multimicrobe organism-a "microbial piñata"-whose endosymbionts contribute significantly to the pathophysiology of this medically important protozoan parasite.

RevDate: 2022-08-15
CmpDate: 2022-08-15

Zuber L, Domínguez-Santos R, García-Ferris C, et al (2022)

Identification of the Gene Repertoire of the IMD Pathway and Expression of Antimicrobial Peptide Genes in Several Tissues and Hemolymph of the Cockroach Blattella germanica.

International journal of molecular sciences, 23(15):.

Antimicrobial peptide (AMP) genes, triggered by Toll and IMD pathways, are essential components of the innate immune system in the German cockroach Blattella germanica. Besides their role in killing pathogenic bacteria, AMPs could be involved in controlling its symbiotic systems (endosymbiont and microbiota). We found that the IMD pathway was active in the adult female transcriptomes of six tissues (salivary glands, foregut, midgut, hindgut, Malpighian tubules and fat body) and hemolymph. Total expression of AMP genes was high in hemolymph and salivary glands and much lower in the other sample types. The expression of specific AMP genes was very heterogeneous among sample types. Two genes, defensin_g10 and drosomycin_g5, displayed relevant expression in the seven sample types, although higher in hemolymph. Other genes only displayed high expression in one tissue. Almost no expression of attacin-like and blattellicin genes was observed in any sample type, although some of them were among the genes with the highest expression in adult female whole bodies. The expression of AMP genes in salivary glands could help control pathogens ingested with food and even determine gut microbiota composition. The low expression levels in midgut and hindgut are probably related to the presence of beneficial microbiota. Furthermore, a reduction in the expression of AMP genes in fat body could be the way to prevent damage to the population of the endosymbiont Blattabacterium cuenoti within bacteriocytes.

RevDate: 2022-08-23

Hirunkanokpun S, Ahantarig A, Baimai V, et al (2022)

Spotted fever group Rickettsia, Anaplasma and Coxiella-like endosymbiont in Haemaphysalis ticks from mammals in Thailand.

Veterinary research communications [Epub ahead of print].

Ticks are ectoparasites of vertebrates and vectors of various pathogenic microorganisms. In this study, the presence of bacteria and protozoa was evaluated by PCR and DNA sequencing in 233 mammal ticks collected from 8 provinces in Thailand. Sequence and phylogenetic analyses of partial rickettsial ompA, ompB, sca4 and partial Coxiella 16S rRNA, GroEL, rpoB genes clearly revealed, for the first time, a co-infection of SFG Rickettsia belonging to R. massiliae subgroup and Coxiella-like endosymbiont (CLE), Cox-hein, in a male of Haemaphysalis heinrichi tick infesting Burmese ferret-badger in Loei province. Moreover, a male of H. hystricis tick infesting the same host was infected with another CLE, Cox-hys. Based on the 16S rRNA gene sequence, Anaplasma sp., closely related to Anaplasma bovis was also detected in a male of H. heinrichi infesting the same Burmese ferret-badger. In addition, the third CLE, Cox-asia, found in H. asiatica collected from Asian palm civet in Chiang Rai province, was different from both Cox-hein and Cox-hys. This study provided important data and broadened our knowledge on tick-borne pathogens and endosymbionts in Thailand and Southeast Asia.

RevDate: 2022-08-30
CmpDate: 2022-08-09

Gao RF, Wang Y, Wang Y, et al (2022)

Genome insights from the identification of a novel Pandoraea sputorum isolate and its characteristics.

PloS one, 17(8):e0272435.

In this study, we sequenced a bacteria isolate Pandoraea sp. 892iso isolated from a Phytophthora rubi strain which is an important plant pathogenic oomycete, identified through genome and combined the data with existing genomic data from other 28 the genus of Pandoraea species. Next, we conducted a comparative genomic analysis of the genome structure, evolutionary relationships, and pathogenic characteristics of Pandoraea species. Our results identified Pandoraea sp. 892iso as Pandoraea sputorum at both the genome and gene levels. At the genome level, we carried out phylogenetic analysis of single-copy, gene co-linearity, ANI (average nucleotide identity) and AAI (average amino acid identity) indices, rpoB similarity, MLSA phylogenetic analysis, and genome-to-genome distance calculator calculations to identify the relationship between Pandoraea sp. 892iso and P. sputorum. At the gene level, the quorum sensing genes ppnI and ppnR and the OXA-159 gene were assessed. It is speculated that Pandoraea sp. 892iso is the endosymbiont of the Oomycetes strain of Phytophthora rubi.

RevDate: 2022-08-17

Kwak Y, Argandona JA, Degnan PH, et al (2022)

Chromosomal-level assembly of Bactericera cockerelli reveals rampant gene family expansions impacting genome structure, function and insect-microbe-plant-interactions.

Molecular ecology resources [Epub ahead of print].

Lineage specific expansions and gene duplications are some of the most important sources of evolutionary novelty in eukaryotes. Although not as prevalent in eukaryotes compared to bacteria, horizontal gene transfer events can also result in key adaptations for insects, especially for those involved in insect-microbe interactions. In this study we assemble the first chromosomal assembly of the psyllid Bactericera cockerelli and reveal that the B. cockerelli genome has experienced significantly more gene expansion events compared to other Hemipteran representatives with fully sequenced genomes. We also reveal that B. cockerelli's genome is the largest psyllid genome (567 Mb) sequenced to date and is ~15% larger than the other two psyllid species genomes sequenced (Pachypsylla venusta and Diaphorina citri). Structurally, B. cockerelli appears to have an additional chromosome compared to the distantly related psyllid species P. venusta due to a previous chromosomal fission or fusion event. The increase in genome size and dynamic nature of the B. cockerelli genome may largely be contributed to the widespread expansion of type I and II repeat elements that are rampant across all of B. cockerelli's. chromosomes. These repeat elements are distributed near equally in both euchromatic and heterochromatic regions. Furthermore, significant gene family expansions and gene duplications were uncovered for genes that are expected to be important in its adaptation to insect-plant and microbe interactions, which include transcription factors, proteases, odorant receptors, and horizontally transferred genes that are involved in the nutritional symbioses with their long-term nutritional endosymbiont Carsonella.

RevDate: 2022-08-05

Tibbs-Cortes LE, Tibbs-Cortes BW, S Schmitz-Esser (2022)

Tardigrade Community Microbiomes in North American Orchards Include Putative Endosymbionts and Plant Pathogens.

Frontiers in microbiology, 13:866930.

The microbiome of tardigrades, a phylum of microscopic animals best known for their ability to survive extreme conditions, is poorly studied worldwide and completely unknown in North America. An improved understanding of tardigrade-associated bacteria is particularly important because tardigrades have been shown to act as vectors of the plant pathogen Xanthomonas campestris in the laboratory. However, the potential role of tardigrades as reservoirs and vectors of phytopathogens has not been investigated further. This study analyzed the microbiota of tardigrades from six apple orchards in central Iowa, United States, and is the first analysis of the microbiota of North American tardigrades. It is also the first ever study of the tardigrade microbiome in an agricultural setting. We utilized 16S rRNA gene amplicon sequencing to characterize the tardigrade community microbiome across four contrasts: location, substrate type (moss or lichen), collection year, and tardigrades vs. their substrate. Alpha diversity of the tardigrade community microbiome differed significantly by location and year of collection but not by substrate type. Our work also corroborated earlier findings, demonstrating that tardigrades harbor a distinct microbiota from their environment. We also identified tardigrade-associated taxa that belong to genera known to contain phytopathogens (Pseudomonas, Ralstonia, and the Pantoea/Erwinia complex). Finally, we observed members of the genera Rickettsia and Wolbachia in the tardigrade microbiome; because these are obligate intracellular genera, we consider these taxa to be putative endosymbionts of tardigrades. These results suggest the presence of putative endosymbionts and phytopathogens in the microbiota of wild tardigrades in North America.

RevDate: 2022-09-08
CmpDate: 2022-09-08

Jin C, Mo Y, Zhao L, et al (2022)

Host-Endosymbiont Relationship Impacts the Retention of Bacteria-Containing Amoeba Spores in Porous Media.

Environmental science & technology, 56(17):12347-12357.

Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, Dictyostelium discoideum, and a representative bacterium, Burkholderia agricolaris B1qs70, were used to prepare amoeba spores that carried bacteria. After interacting with B. agricolaris, the retention of D. discoideum spores was enhanced compared to noninfected spores. Diverse proteins, especially proteins contributing to the looser exosporium structure and cell adhesion functionality, are secreted in higher quantities on the exosporium surface of infected spores compared to that of noninfected ones. Comprehensive examinations using a quartz crystal microbalance with dissipation (QCM-D), a parallel plate chamber, and a single-cell force microscope present coherent evidence that changes in the exosporium of D. discoideum spores due to infection by B. agricolaris enhance the connections between spores in the suspension and the spores that were previously deposited on the collector surface, thus resulting in more retention compared to the uninfected ones in porous media. This work provides novel insight into the retention of amoeba spores after bacterial infection in porous media and suggests that the host-endosymbiont relationship regulates the fate of biocolloids in drinking water systems, groundwater, and other porous environments.

RevDate: 2022-09-10
CmpDate: 2022-09-08

Wang J, Gou QY, Luo GY, et al (2022)

Total RNA sequencing of Phlebotomus chinensis sandflies in China revealed viral, bacterial, and eukaryotic microbes potentially pathogenic to humans.

Emerging microbes & infections, 11(1):2080-2092.

Phlebotomus chinensis sandfly is a neglected insect vector in China that is well-known for carrying Leishmania. Recent studies have expanded its pathogen repertoire with two novel arthropod-borne phleboviruses capable of infecting humans and animals. Despite these discoveries, our knowledge of the general pathogen diversity and overall microbiome composition of this vector species is still very limited. Here we carried out a meta-transcriptomics analysis that revealed the actively replicating/transcribing RNA viruses, DNA viruses, bacteria, and eukaryotic microbes, namely, the "total microbiome", of several sandfly populations in China. Strikingly, "microbiome" made up 1.8% of total non-ribosomal RNA and comprised more than 87 species, among which 70 were novel, including divergent members of the genera Flavivirus and of the family Trypanosomatidae. Importantly, among these microbes we were able to reveal four distinguished types of human and/or mammalian pathogens, including two phleboviruses (hedi and wuxiang viruses), one novel Spotted fever group rickettsia, as well as a member of Leishmania donovani complex, among which hedi virus and Leishmania each had > 50% pool prevalence rate and relatively high abundance levels. Our study also showed the ubiquitous presence of an endosymbiont, namely Wolbachia, although no anti-viral or anti-pathogen effects were detected based on our data. In summary, our results uncovered the much un-explored diversity of microbes harboured by sandflies in China and demonstrated that high pathogen diversity and abundance are currently present in multiple populations, implying disease potential for exposed local human population or domestic animals.

RevDate: 2022-09-13
CmpDate: 2022-09-13

Rosário AAD, Dias-Lima AG, Lambert SM, et al (2022)

Identification and molecular characterization of Wolbachia strains and natural infection for Leishmania sp. in neotropical Phlebotominae (Diptera: Psychodidae) species, leishmaniasis vectors.

Acta tropica, 235:106624.

Recently, Wolbachia infection has been described in leishmaniasis vector sandflies. This endosymbiont bacterium is present in 60% of insects, and has been suggested as a mechanism of biological control of vector insects, because it causes a series of changes in the invertebrate host. In addition, recent studies have shown that this bacterium can prevent the development of parasites in vector insects. In this context, the present study aims to molecularly characterize the circulating strain of this bacterium in sandflies in the State of Bahia, Brazil, as well as the natural infection rate of Leishmania sp., and to evaluate the coinfection between Wolbachia and Leishmania. Seven hundred and forty-five (745) specimens of sandflies were collected in nine municipalities of Bahia, belonging to two species, Lutzomyia longipalpis (Lutz and Neiva, 1912) and Nyssomyia whitmani (Antunes and Coutinho, 1939). The results confirm infection by the protozoan Leishmania infantum and Wolbachia in both species collected. The identified strain of Wolbachia in sandflies was wStv MI, known to lead to a phenotype of cytoplasmic incompatibility in vector insects.

RevDate: 2022-08-26
CmpDate: 2022-08-26

Patra AK, Kwon YM, Y Yang (2022)

Complete gammaproteobacterial endosymbiont genome assembly from a seep tubeworm Lamellibrachia satsuma.

Journal of microbiology (Seoul, Korea), 60(9):916-927.

Siboglinid tubeworms thrive in hydrothermal vent and seep habitats via a symbiotic relationship with chemosynthetic bacteria. Difficulties in culturing tubeworms and their symbionts in a laboratory setting have hindered the study of host-microbe interactions. Therefore, released symbiont genomes are fragmented, thereby limiting the data available on the genome that affect subsequent analyses. Here, we present a complete genome of gammaproteobacterial endosymbiont from the tubeworm Lamellibrachia satsuma collected from a seep in Kagoshima Bay, assembled using a hybrid approach that combines sequences generated from the Illumina and Oxford Nano-pore platforms. The genome consists of a single circular chromosome with an assembly size of 4,323,754 bp and a GC content of 53.9% with 3,624 protein-coding genes. The genome is of high quality and contains no assembly gaps, while the completeness and contamination are 99.33% and 2.73%, respectively. Comparative genome analysis revealed a total of 1,724 gene clusters shared in the vent and seep tubeworm symbionts, while 294 genes were found exclusively in L. satsuma symbionts such as transposons, genes for defense mechanisms, and inorganic ion transportations. The addition of this complete endosymbiont genome assembly would be valuable for comparative studies particularly with tubeworm symbiont genomes as well as with other chemosynthetic microbial communities.

RevDate: 2022-07-29

Gabriel E, Krauß N, T Lamparter (2022)

Evidence for evolutionary relationship between archaeplastidal and cyanobacterial phytochromes based on their chromophore pockets.

Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology [Epub ahead of print].

Phytochromes are photoreceptor proteins with a bilin chromophore that undergo photoconversion between two spectrally different forms, Pr and Pfr. In plants, phytochromes play a central role in growth and differentiation during the entire life cycle. Phytochromes of plants and other groups of archaeplastida have a common evolutionary origin in prokaryotes, but the exact prokaryotic origin is as yet uncertain. Two possibilities are presently discussed: either, archaeplastidal phytochromes arose from the last eukaryotic common ancestor (LECA) or they arose from the cyanobacterial endosymbiont that gave rise to plastids. We first constructed standard phylogenetic trees based on N-terminal protein sequences of the chromophore module. As usual, variation of algorithms and parameters led to different trees. A relationship between cyanobacteria and archaeplastida was observed in 7 out of 36 trees. The lack of consistency between results obtained from variation of parameters of tree constructions reflects the uncertainty of archaeplastidal origin. To gain more information about a possible cyanobacterial and archaeplastidal relationship, we performed phylogenetic studies based on the amino acids that line the chromophore pockets. These amino acids are highly conserved and could provide more accurate information about long evolutionary time scales, but the reduction of traits could also lead to insignificant results. From 30 selected chromophore-binding amino acids, 6 were invariant. The subsequent studies were thus based on the information dependent on 24 or fewer amino acid positions. Again, multiple trees were constructed to get information about the robustness of relationships. The very low number of information-containing traits resulted in low bootstrap values and many indistinguishable leaves. However, the major groups fungi, bacteria, cyanobacteria, and plants remained united. Without exception, cyanobacteria and archaeplastida were always closely linked. In this respect, the results were more robust than those of the classic approach, based on long contiguous sequences. We therefore consider cyanobacteria as the most likely origin of archaeplastidal phytochromes.

RevDate: 2022-07-29

Matsuo E, Morita K, Nakayama T, et al (2022)

Comparative Plastid Genomics of Green-Colored Dinoflagellates Unveils Parallel Genome Compaction and RNA Editing.

Frontiers in plant science, 13:918543.

Dinoflagellates possess plastids that are diverse in both pigmentation and evolutionary background. One of the plastid types found in dinoflagellates is pigmented with chlorophylls a and b (Chl a + b) and originated from the endosymbionts belonging to a small group of green algae, Pedinophyceae. The Chl a + b-containing plastids have been found in three distantly related dinoflagellates Lepidodinium spp., strain MGD, and strain TGD, and were proposed to be derived from separate partnerships between a dinoflagellate (host) and a pedinophycean green alga (endosymbiont). Prior to this study, a plastid genome sequence was only available for L. chlorophorum, which was reported to bear the features that were not found in that of the pedinophycean green alga Pedinomonas minor, a putative close relative of the endosymbiont that gave rise to the current Chl a + b-containing plastid. In this study, we sequenced the plastid genomes of strains MGD and TGD to compare with those of L. chlorophorum as well as pedinophycean green algae. The mapping of the RNA-seq reads on the corresponding plastid genome identified RNA editing on plastid gene transcripts in the three dinoflagellates. Further, the comparative plastid genomics revealed that the plastid genomes of the three dinoflagellates achieved several features, which are not found in or much less obvious than the pedinophycean plastid genomes determined to date, in parallel.

RevDate: 2022-08-03
CmpDate: 2022-07-29

Calle-Tobón A, Pérez-Pérez J, Forero-Pineda N, et al (2022)

Local-scale virome depiction in Medellín, Colombia, supports significant differences between Aedes aegypti and Aedes albopictus.

PloS one, 17(7):e0263143.

Aedes spp. comprise the primary group of mosquitoes that transmit arboviruses such as dengue, Zika, and chikungunya viruses to humans, and thus these insects pose a significant burden on public health worldwide. Advancements in next-generation sequencing and metagenomics have expanded our knowledge on the richness of RNA viruses harbored by arthropods such as Ae. aegypti and Ae. albopictus. Increasing evidence suggests that vector competence can be modified by the microbiome (comprising both bacteriome and virome) of mosquitoes present in endemic zones. Using an RNA-seq-based metataxonomic approach, this study determined the virome structure, Wolbachia presence and mitochondrial diversity of field-caught Ae. aegypti and Ae. albopictus mosquitoes in Medellín, Colombia, a municipality with a high incidence of mosquito-transmitted arboviruses. The two species are sympatric, but their core viromes differed considerably in richness, diversity, and abundance; although the community of viral species identified was large and complex, the viromes were dominated by few virus species. BLAST searches of assembled contigs suggested that at least 17 virus species (16 of which are insect-specific viruses [ISVs]) infect the Ae. aegypti population. Dengue virus 3 was detected in one sample and it was the only pathogenic virus detected. In Ae. albopictus, up to 11 ISVs and one plant virus were detected. Therefore, the virome composition appears to be species-specific. The bacterial endosymbiont Wolbachia was identified in all Ae. albopictus samples and in some Ae. aegypti samples collected after 2017. The presence of Wolbachia sp. in Ae. aegypti was not related to significant changes in the richness, diversity, or abundance of this mosquito's virome, although it was related to an increase in the abundance of Aedes aegypti To virus 2 (Metaviridae). The mitochondrial diversity of these mosquitoes suggested that the Ae. aegypti population underwent a change that started in the second half of 2017, which coincides with the release of Wolbachia-infected mosquitoes in Medellín, indicating that the population of wMel-infected mosquitoes released has introduced new alleles into the wild Ae. aegypti population of Medellín. However, additional studies are required on the dispersal speed and intergenerational stability of wMel in Medellín and nearby areas as well as on the introgression of genetic variants in the native mosquito population.

RevDate: 2022-07-31

Hoffman T, Sjödin A, Öhrman C, et al (2022)

Co-Occurrence of Francisella, Spotted Fever Group Rickettsia, and Midichloria in Avian-Associated Hyalomma rufipes.

Microorganisms, 10(7):.

The migratory behavior of wild birds contributes to the geographical spread of ticks and their microorganisms. In this study, we aimed to investigate the dispersal and co-occurrence of Francisella and spotted fever group Rickettsia (SFGR) in ticks infesting birds migrating northward in the African-Western Palaearctic region (AWPR). Birds were trapped with mist nests across the Mediterranean basin during the 2014 and 2015 spring migration. In total, 575 ticks were collected from 244 birds. We screened the ticks for the species Francisella tularensis, the genus Francisella, and SFGR by microfluidic real-time PCR. Confirmatory analyses and metagenomic sequencing were performed on tick samples that putatively tested positive for F. tularensis during initial screenings. Hyalomma rufipes was the most common tick species and had a high prevalence of Francisella, including co-occurrence of Francisella and SFGR. Metagenomic analysis of total DNA extracted from two H. rufipes confirmed the presence of Francisella, Rickettsia, and Midichloria. Average nucleotide identity and phylogenetic inference indicated the highest identity of the metagenome-assembled genomes to a Francisella-like endosymbiont (FLE), Rickettsia aeschlimannii, and Midichloria mitochondrii. The results of this study suggest that (i) FLE- and SFGR-containing ticks are dispersed by northbound migratory birds in the AWPR, (ii) H. rufipes likely is not involved in transmission of F. tularensis in the AWPR, and (iii) a dual endosymbiosis of FLEs and Midichloria may support some of the nutritional requirements of H. rufipes.

RevDate: 2022-07-31

Mendoza-Hoffmann F, Zarco-Zavala M, Ortega R, et al (2022)

Evolution of the Inhibitory and Non-Inhibitory ε, ζ, and IF1 Subunits of the F1FO-ATPase as Related to the Endosymbiotic Origin of Mitochondria.

Microorganisms, 10(7):.

The F1FO-ATP synthase nanomotor synthesizes >90% of the cellular ATP of almost all living beings by rotating in the "forward" direction, but it can also consume the same ATP pools by rotating in "reverse." To prevent futile F1FO-ATPase activity, several different inhibitory proteins or domains in bacteria (ε and ζ subunits), mitochondria (IF1), and chloroplasts (ε and γ disulfide) emerged to block the F1FO-ATPase activity selectively. In this study, we analyze how these F1FO-ATPase inhibitory proteins have evolved. The phylogeny of the α-proteobacterial ε showed that it diverged in its C-terminal side, thus losing both the inhibitory function and the ATP-binding/sensor motif that controls this inhibition. The losses of inhibitory function and the ATP-binding site correlate with an evolutionary divergence of non-inhibitory α-proteobacterial ε and mitochondrial δ subunits from inhibitory bacterial and chloroplastidic ε subunits. Here, we confirm the lack of inhibitory function of wild-type and C-terminal truncated ε subunits of P. denitrificans. Taken together, the data show that ζ evolved to replace ε as the primary inhibitor of the F1FO-ATPase of free-living α-proteobacteria. However, the ζ inhibitory function was also partially lost in some symbiotic α-proteobacteria and totally lost in some strictly parasitic α-proteobacteria such as the Rickettsiales order. Finally, we found that ζ and IF1 likely evolved independently via convergent evolution before and after the endosymbiotic origin mitochondria, respectively. This led us to propose the ε and ζ subunits as tracer genes of the pre-endosymbiont that evolved into the actual mitochondria.

RevDate: 2022-08-05

Schuler H, Dittmer J, Borruso L, et al (2022)

Investigating the microbial community of Cacopsylla spp. as potential factor in vector competence of phytoplasma.

Environmental microbiology [Epub ahead of print].

Phytoplasmas are obligatory intracellular bacteria that colonize the phloem of many plant species and cause hundreds of plant diseases worldwide. In nature, phytoplasmas are primarily transmitted by hemipteran vectors. While all phloem-feeding insects could in principle transmit phytoplasmas, only a limited number of species have been confirmed as vectors. Knowledge about factors that might determine the vector capacity is currently scarce. Here, we characterized the microbiomes of vector and non-vector species of apple proliferation (AP) phytoplasma 'Candidatus Phytoplasma mali' to investigate their potential role in the vector capacity of the host. We performed high-throughput 16S rRNA metabarcoding of the two principal AP-vectors Cacopsylla picta and Cacopsylla melanoneura and eight Cacopsylla species, which are not AP-vectors but co-occur in apple orchards. The microbiomes of all species are dominated by Carsonella, the primary endosymbiont of psyllids and a second uncharacterized Enterobacteriaceae endosymbiont. Each Cacopsylla species harboured a species-specific phylotype of both symbionts. Moreover, we investigated differences between the microbiomes of AP-vector versus non-vector species and identified the predominant endosymbionts but also Wolbachia and several minor taxa as potential indicator species. Our study highlights the importance of considering the microbiome in future investigations of potential factors influencing host vector competence. We investigated the potential role of symbiotic bacteria in the acquisition and transmission of phytoplasma. By comparing the two main psyillid vector species of Apple proliferation (AP) phytoplasma and eight co-occurring species, which are not able to vector AP-phytoplasma, we found differences in the microbial communities of AP-vector and non-vector species, which appear to be driven by the predominant symbionts in both vector species and Wolbachia and several minor taxa in the non-vector species. In contrast, infection with AP-phytoplasma did not affect microbiome composition in both vector species. Our study provides new insights into the endosymbiont diversity of Cacopsylla spp. and highlights the importance of considering the microbiome when investigating potential factors influencing host vector competence.

RevDate: 2022-08-22
CmpDate: 2022-08-16

Sawadogo SP, Kabore DA, Tibiri EB, et al (2022)

Lack of robust evidence for a Wolbachia infection in Anopheles gambiae from Burkina Faso.

Medical and veterinary entomology, 36(3):301-308.

The endosymbiont Wolbachia can have major effects on the reproductive fitness, and vectorial capacity of host insects and may provide new avenues to control mosquito-borne pathogens. Anopheles gambiae s.l is the major vector of malaria in Africa but the use of Wolbachia in this species has been limited by challenges in establishing stable transinfected lines and uncertainty around native infections. High frequencies of infection of Wolbachia have been previously reported in An. gambiae collected from the Valle du Kou region of Burkina Faso in 2011 and 2014. Here, we re-evaluated the occurrence of Wolbachia in natural samples, collected from Valle du Kou over a 12-year time span, and in addition, expanded sampling to other sites in Burkina Faso. Our results showed that, in contrast to earlier reports, Wolbachia is present at an extremely low prevalence in natural population of An. gambiae. From 5341 samples analysed, only 29 were positive for Wolbachia by nested PCR representing 0.54% of prevalence. No positive samples were found with regular PCR. Phylogenetic analysis of 16S rRNA gene amplicons clustered across supergroup B, with some having similarity to sequences previously found in Anopheles from Burkina Faso. However, we cannot discount the possibility that the amplicon positive samples we detected were due to environmental contamination or were false positives. Regardless, the lack of a prominent native infection in An. gambiae s.l. is encouraging for applications utilizing Wolbachia transinfected mosquitoes for malaria control.

RevDate: 2022-08-09
CmpDate: 2022-07-26

Ramos LFC, Martins M, Murillo JR, et al (2022)

Interspecies Isobaric Labeling-Based Quantitative Proteomics Reveals Protein Changes in the Ovary of Aedes aegypti Coinfected With ZIKV and Wolbachia.

Frontiers in cellular and infection microbiology, 12:900608.

Zika is a vector-borne disease caused by an arbovirus (ZIKV) and overwhelmingly transmitted by Ae. aegypti. This disease is linked to adverse fetal outcomes, mostly microcephaly in newborns, and other clinical aspects such as acute febrile illness and neurologic complications, for example, Guillain-Barré syndrome. One of the most promising strategies to mitigate arbovirus transmission involves releasing Ae. aegypti mosquitoes carrying the maternally inherited endosymbiont bacteria Wolbachia pipientis. The presence of Wolbachia is associated with a reduced susceptibility to arboviruses and a fitness cost in mosquito life-history traits such as fecundity and fertility. However, the mechanisms by which Wolbachia influences metabolic pathways leading to differences in egg production remains poorly known. To investigate the impact of coinfections on the reproductive tract of the mosquito, we applied an isobaric labeling-based quantitative proteomic strategy to investigate the influence of Wolbachia wMel and ZIKV infection in Ae. aegypti ovaries. To the best of our knowledge, this is the most complete proteome of Ae. aegypti ovaries reported so far, with a total of 3913 proteins identified, were also able to quantify 1044 Wolbachia proteins in complex sample tissue of Ae. aegypti ovary. Furthermore, from a total of 480 mosquito proteins modulated in our study, we discuss proteins and pathways altered in Ae. aegypti during ZIKV infections, Wolbachia infections, coinfection Wolbachia/ZIKV, and compared with no infection, focusing on immune and reproductive aspects of Ae. aegypti. The modified aspects mainly were related to the immune priming enhancement by Wolbachia presence and the modulation of the Juvenile Hormone pathway caused by both microorganism's infection.

RevDate: 2022-07-22

Mejia AJ, Jimenez L, Dutra HLC, et al (2022)

Attempts to use breeding approaches in Aedes aegypti to create lines with distinct and stable relative Wolbachia densities.

Heredity [Epub ahead of print].

Wolbachia is an insect endosymbiont being used for biological control in the mosquito Aedes aegypti because it causes cytoplasmic incompatibility (CI) and limits viral replication of dengue, chikungunya, and Zika viruses. While the genetic mechanism of pathogen blocking (PB) is not fully understood, the strength of both CI and PB are positively correlated with Wolbachia densities in the host. Wolbachia densities are determined by a combination of Wolbachia strain and insect genotype, as well as interactions with the environment. We employed both artificial selection and inbreeding with the goal of creating lines of Ae. aegypti with heritable and distinct Wolbachia densities so that we might better dissect the mechanism underlying PB. We were unable to shift the mean relative Wolbachia density in Ae. aegypti lines by either strategy, with relative densities instead tending to cycle over a narrow range. In lieu of this, we used Wolbachia densities in mosquito legs as predictors of relative densities in the remaining individual's carcass. Because we worked with outbred mosquitoes, our findings indicate either a lack of genetic variation in the mosquito for controlling relative density, natural selection against extreme densities, or a predominance of environmental factors affecting densities. Our study reveals that there are moderating forces acting on relative Wolbachia densities that may help to stabilize density phenotypes post field release. We also show a means to accurately bin vector carcasses into high and low categories for non-DNA omics-based studies of Wolbachia-mediated traits.

RevDate: 2022-09-08
CmpDate: 2022-08-09

Zhang XY, Li SS, Chen KL, et al (2022)

Growth dynamics and tissue localization of a Coxiella-like endosymbiont in the tick Haemaphysalis longicornis.

Ticks and tick-borne diseases, 13(5):102005.

A Coxiella-like endosymbiont (Coxiella-LE hereinafter) stably infects and influences Haemaphysalis longicornis development, indicating a mutualistic relationship of Coxiella-LE and ticks. To further elucidate the patterns of growth dynamics and tissue localization of Coxiella-LE in H. longicornis, 16S rRNA high-throughput sequencing, quantitative PCR (qPCR), and fluorescence in situ hybridization (FISH) were used in this study. The density of Coxiella-LE varied among different tick life stages, and fed female ticks had the highest density, followed by unfed female and unfed larval ticks. In the four organs that were dissected from fed female ticks, the ovary carried the highest density of Coxiella-LE, which was significantly different from salivary glands, midgut and Malpighian tubules. The high abundance of Coxiella-LE in fed female ticks and in the ovaries of fed female ticks in the bacterial microbiota analyses further confirmed that Coxiella-LE rapidly proliferates in the ovary after blood feeding. The ovaries continued to develop after engorgement and oviposition began on day 5, with a significant decrease in the density of Coxiella-LE in the ovaries occurring on day 7. FISH results indicated that Coxiella-LE is mainly colonized in the cytoplasm of the oocyte and proliferates with oogenesis. Coxiella-LE was expelled from the body with the mature oocyte, ensuring its vertical transmission. In the Malpighian tubules at different days after engorgement, the white flocculent materials were increasing, and the density of Coxiella-LE raised significantly on day 7. Unlike the localization pattern in the ovary, Coxiella-LE was initially distributed in a mass and continually increased during the development of Malpighian tubules until it filled the Malpighian tubules. These findings provide new insights on the growth dynamics and tissue localization of Coxiella-LE in ticks and are useful for further investigation on the interactions of symbiont and ticks .

RevDate: 2022-08-04

Chirgwin E, Yang Q, Umina PA, et al (2022)

Fungicides have transgenerational effects on Rhopalosiphum padi but not their endosymbionts.

Pest management science [Epub ahead of print].

BACKGROUND: While several agricultural fungicides are known to directly affect invertebrate pests, including aphids, the mechanisms involved are often unknown. One hypothesis is that fungicides with antibacterial activity suppress bacterial endosymbionts present in aphids which are important for aphid survival. Endosymbiont-related effects are expected to be transgenerational, given that these bacteria are maternally inherited. Here, we test for these associations using three fungicides (chlorothalonil, pyraclostrobin and trifloxystrobin) against the bird cherry-oat aphid, Rhopalosiphum padi, using a microinjected strain that carried both the primary endosymbiont Buchnera and the secondary endosymbiont Rickettsiella.

RESULTS: We show that the fungicide chlorothalonil did not cause an immediate effect on aphid survival, whereas both strobilurin fungicides (pyraclostrobin and trifloxystrobin) decreased survival after 48 h exposure. However, chlorothalonil substantially reduced the lifespan and fecundity of the F1 generation. Trifloxystrobin also reduced the lifespan and fecundity of F1 offspring, however, pyraclostrobin did not affect these traits. None of the fungicides consistently altered the density of Buchnera or Rickettsiella in whole aphids.

CONCLUSIONS: Our results suggest fungicides have sublethal impacts on R. padi that are not fully realized until the generation after exposure, and these sublethal impacts are not associated with the density of endosymbionts harbored by R. padi. However, we cannot rule out other effects of fungicides on endosymbionts that might influence fitness, like changes in their tissue distribution. We discuss these results within the context of fungicidal effects on aphid suppression across generations and point to potential field applications. © 2022 Society of Chemical Industry.

RevDate: 2022-09-20
CmpDate: 2022-07-22

Masson F, Rommelaere S, Schüpfer F, et al (2022)

Disproportionate investment in Spiralin B production limits in-host growth and favors the vertical transmission of Spiroplasma insect endosymbionts.

Proceedings of the National Academy of Sciences of the United States of America, 119(30):e2208461119.

Insects frequently harbor endosymbionts, which are bacteria housed within host tissues. These associations are stably maintained over evolutionary timescales through vertical transmission of endosymbionts from host mothers to their offspring. Some endosymbionts manipulate host reproduction to facilitate spread within natural populations. Consequently, such infections have major impacts on insect physiology and evolution. However, technical hurdles have limited our understanding of the molecular mechanisms underlying such insect-endosymbiont interactions. Here, we investigate the nutritional interactions between endosymbiotic partners using the tractable insect Drosophila melanogaster and its natural endosymbiont Spiroplasma poulsonii. Using a combination of functional assays, metabolomics, and proteomics, we show that the abundance and amino acid composition of a single Spiroplasma membrane lectin, Spiralin B (SpiB), dictates the amino acid requirements of the endosymbiont and determines its proliferation within host tissues. Ectopically increasing SpiB levels in host tissues disrupts localization of endosymbionts in the fly egg chambers and decreases vertical transmission. We find that SpiB is likely to be required by the endosymbiont to enter host oocytes, which may explain the massive investment of S. poulsonii in SpiB synthesis. SpiB both permits vertical transmission of the symbiont and limits its growth in nutrient-limiting conditions for the host; therefore, a single protein plays a pivotal role in ensuring durability of the interaction in a variable environment.

RevDate: 2022-07-21
CmpDate: 2022-07-21

Guo F, Castillo P, Li C, et al (2022)

Description of Rotylenchus zhongshanensis sp. nov. (Tylenchomorpha: Hoplolaimidae) and discovery of its endosymbiont Cardinium.

Journal of helminthology, 96:e48 pii:S0022149X22000384.

A new bisexual species of Rotylenchus is described and illustrated based on morphological, morphometric and molecular characterizations. Rotylenchus zhongshanensis sp. nov. is characterized by having a conoid lip region complying with the basic pattern for Hoplolaimidae, but with pharyngeal glands slightly overlapping intestine dorsally and cuticle thickened abnormally in female tail terminus. Females have robust stylet (30.1-33.8 μm). The pharyngeal gland has short dorsal (11.2-16.8 μm) overlap on the intestine. The vulva is located at 48.0-56.5% of body length, and phasmids are pore-like, 4-6 annuli posterior to the anus. For males, phasmids are pore-like, 11-17 annuli posterior to cloaca. The spicules are ventrally arcuate (21.0-28.5 μm) with gubernaculum in 5-8 μm length. The rRNA and mitochondrial COI genes were successfully sequenced from the assembled whole-genome sequences of the new species, and were used for reconstructing the phylogenetic relationships of the new species. A new strain of cyto-endosymbiont Cardinium was also discovered from the genome sequences of R. zhongshanensis sp. nov. The 16S rRNA phylogeny analyses revealed that this new bacterial strain is closed to that from cyst and root-lesion nematodes.

RevDate: 2022-09-16
CmpDate: 2022-09-16

Chaves EB, Nascimento-Pereira AC, Pinto JLM, et al (2022)

Detection of Wolbachia in Mosquitoes (Diptera: Culicidae) in the State of Maranhão, Brazil.

Journal of medical entomology, 59(5):1831-1836.

Recently, the endobacteria Wolbachia has emerged as a biological tool for the control of arboviruses. Thus, we investigated the rate of natural infection by Wolbachia in Culicidae species from Maranhão, Brazil. For this, we amplified the Wolbachia surface protein gene (wsp) from mosquitoes collected in six localities of Maranhão, and positive samples were subjected to new analysis using group-specific primers. In total, 448 specimens comprising 6 genera and 18 species of mosquitoes were analyzed. Wolbachia DNA was PCR-detected in 7 species, three of which are new records: Aedes scapularis (Rondani, 1848), Coquillettidia juxtamansonia (Chagas, 1907) and Cq. venezuelensis (Theobald, 1912), in addition to Ae. albopictus (Skuse, 1894) and Culex quinquefasciatus Say, 1823, which are commonly described as permissive to maintain this bacterium in natural environments, and two species of the subgenera Anopheles (Nyssorhynchus) Blanchard, 1902 and Culex (Melanoconion) Theobald, 1903 which could not be identified at species level. The infection rate of all species ranged from 0 to 80%, and the average value was 16.5%. This study increases the knowledge about the prevalence of Wolbachia in the culicid fauna and may help in selecting strains for biological control purposes.

RevDate: 2022-09-20

Gonçalves P, C Gonçalves (2022)

Horizontal gene transfer in yeasts.

Current opinion in genetics & development, 76:101950.

Horizontal gene transfer (HGT), defined as the exchange of genetic material other than from parent to progeny, is very common in bacteria and appears to constitute the most important mechanism contributing to enlarge a species gene pool. However, in eukaryotes, HGT is certainly much less common and some early insufficiently consubstantiated cases involving bacterial donors led some to consider that it was unlikely to occur in eukaryotes outside the host/endosymbiont relationship. More recently, plenty of reports of interdomain HGT have seen the light based on the strictest criteria, many concerning filamentous fungi and yeasts. Here, we attempt to summarize the most prominent instances of HGT reported in yeasts as well as what we have been able to learn so far concerning frequency and distribution, mechanisms, barriers, function of horizontally acquired genes, and the role of HGT in domestication.

RevDate: 2022-07-19
CmpDate: 2022-07-19

Mitra A, Acharya K, A Bhattacharya (2022)

Evolutionary analysis of globin domains from kinetoplastids.

Archives of microbiology, 204(8):493.

Globin (Gb) domains function in sensing gaseous ligands like oxygen and nitric oxide. In recent years, Gb domain containing heme binding adenylate cyclases (OsAC or GbAC) emerged as significant modulator of Leishmania response to hypoxia and oxidative stress. During progression of life cycle stages, kinetoplastids experience altered condition in insect vectors or other hosts. Moreover, marked diversity in life style has been accounted among kinetoplastids. Distribution and abundance of Gb-domains vary between different groups of kinetoplastids. While in bodonoids, Gbs are not combined with any other functional domains, in trypanosomatids it is either fused with adenylate cyclase (AC) or oxidoreductase (OxR) domains. In salivarian trypanosomatids and Leishmania (Viannia) subtypes, no gene product featuring Gbs can be identified. In this context, evolution of Gb-domains in kinetoplastids was explored. GbOxR derived Gbs clustered with bacterial flavohemoglobins (fHb) including one fHb from Advenella, an endosymbiont of monoxeneous trypanosomatids. Codon adaptation and other evolutionary analysis suggested that OsAC (LmjF.28.0090), the solitary Gb-domain featuring gene product in Leishmania, was acquired via possible horizontal gene transfer. Substantial functional divergence was estimated between orthologues of genes encoding GbAC or GbOxR; an observation also reflected in structural alignment and heme-binding residue predictions. Orthologue-paralogue and synteny analysis indicated genomic reduction in GbOxR and GbAC loci for dixeneous trypanosomatids.

RevDate: 2022-09-02
CmpDate: 2022-08-30

Carvajal-Agudelo JD, Ramírez-Chaves HE, Ossa-López PA, et al (2022)

Bacteria related to tick-borne pathogen assemblages in Ornithodoros cf. hasei (Acari: Argasidae) and blood of the wild mammal hosts in the Orinoquia region, Colombia.

Experimental & applied acarology, 87(2-3):253-271.

Interest in research on soft ticks has increased in recent decades, leading to valuable insight into their role as disease vectors. The use of metagenomics-based analyses have helped to elucidate ecological factors involved in pathogen, vector, and host dynamics. To understand the main bacterial assemblages present in Ornithodoros cf. hasei and its mammalian hosts, 84 ticks and 13 blood samples from bat hosts (Chiroptera) were selected, and the 16S rRNA gene V4 region was sequenced in five pools (each one related to each host-tick pairing). Bacterial taxonomic assignment analyses were performed by comparing operational taxonomic units (OTUs) shared between ticks and their host blood. This analysis showed the presence of Proteobacteria (38.8%), Enterobacteriaceae (25%), Firmicutes (12.3%), and Actinobacteria (10.9%) within blood samples, and Rickettsiaceae (39%), Firmicutes (25%), Actinobacteria (13.1%), and Proteobacteria (9%) within ticks. Species related to potentially pathogenic genera were detected in ticks, such as Borrelia sp., Bartonella tamiae, Ehrlichia sp. and Rickettsia-like endosymbiont, and the presence of these organisms was found in all analyzed bat species (Cynomops planirostris, Molossus pretiosus, Noctilio albiventris), and O. cf. hasei. About 41-48.6% of bacterial OTUs (genera and species) were shared between ticks and the blood of bat hosts. Targeted metagenomic screening techniques allowed the detection of tick-associated pathogens for O. cf. hasei and small mammals for the first time, enabling future research on many of these pathogens.

RevDate: 2022-07-16

Barman M, Samanta S, Upadhyaya G, et al (2022)

Unraveling the Basis of Neonicotinoid Resistance in Whitefly Species Complex: Role of Endosymbiotic Bacteria and Insecticide Resistance Genes.

Frontiers in microbiology, 13:901793.

Bemisia tabaci (whitefly) is one of the most detrimental agricultural insect pests and vectors of many plant viruses distributed worldwide. Knowledge of the distribution patterns and insecticide resistance of this cryptic species is crucial for its management. In this study, genetic variation of mitochondrial cytochrome oxidase subunit 1 (MtCoI) gene of B. tabaci was analyzed followed by a study of the infection profile of various endosymbionts in 26 whitefly populations collected from West Bengal, India. Phylogenetic analysis revealed Asia I as the major cryptic species (65.38%), followed by Asia II 5, China 3, and Asia II 7, which were diversified into 20 different haplotypes. In addition to the primary endosymbiont (C. poriera), each of the four whitefly species showed a variable population of three secondary endosymbionts, majorly Arsenophonus with the highest infection rate (73.07%), followed by Wolbachia and Rickettsia. Further phylogenetic analyses revealed the presence of two subgroups of Arsenophonus, viz., A1 and A2, and one each in Wolbachia (W1) and Rickettsia (R3). Resistance to thiamethoxam, imidacloprid, and acetamiprid insecticides was analyzed for a clear picture of pesticide resistance status. The highest susceptibility was noted toward thiamethoxam (LC50 = 5.36 mg/L), followed by imidacloprid and acetamiprid. The whitefly population from Purulia and Hooghly districts bearing Asia II 7 and Asia II 5 cryptic species, respectively, shows maximum resistance. The differences in mean relative titer of four symbiotic bacteria among field populations varied considerably; however, a significant positive linear correlation was observed between the resistance level and relative titer of Arsenophonus and Wolbachia in the case of imidacloprid and thiamethoxam, while only Wolbachia was found in case of acetamiprid. Expression analysis demonstrated differential upregulation of insecticide resistance genes with Purulia and Hooghly populations showing maximally upregulated P450 genes. Moreover, thiamethoxam and imidacloprid resistance ratio (RR) showed a significant correlation with CYP6CM1, CYP6DZ7, and CYP4C64 genes, while acetamiprid RR correlated with CYP6CX1, CYP6DW2, CYP6DZ7, and CYP4C64 genes. Taken together, these findings suggested that P450 mono-oxygenase and symbiotic bacteria together affected whitefly resistance to neonicotinoids. Hence, a symbiont-oriented management programme could be a better alternative to control or delay resistance development in whitefly and can be used for pesticide clean-up in an agricultural field.

RevDate: 2022-07-16

Manthey JD, Girón JC, JP Hruska (2022)

Impact of host demography and evolutionary history on endosymbiont molecular evolution: A test in carpenter ants (genus Camponotus) and their Blochmannia endosymbionts.

Ecology and evolution, 12(7):e9026.

Obligate endosymbioses are tight associations between symbionts and the hosts they live inside. Hosts and their associated obligate endosymbionts generally exhibit codiversification, which has been documented in taxonomically diverse insect lineages. Host demography (e.g., effective population sizes) may impact the demography of endosymbionts, which may lead to an association between host demography and the patterns and processes of endosymbiont molecular evolution. Here, we used whole-genome sequencing data for carpenter ants (Genus Camponotus; subgenera Camponotus and Tanaemyrmex) and their Blochmannia endosymbionts as our study system to address whether Camponotus demography shapes Blochmannia molecular evolution. Using whole-genome phylogenomics, we confirmed previous work identifying codiversification between carpenter ants and their Blochmannia endosymbionts. We found that Blochmannia genes have evolved at a pace ~30× faster than that of their hosts' molecular evolution and that these rates are positively associated with host rates of molecular evolution. Using multiple tests for selection in Blochmannia genes, we found signatures of positive selection and shifts in selection strength across the phylogeny. Host demography was associated with Blochmannia shifts toward increased selection strengths, but not associated with Blochmannia selection relaxation, positive selection, genetic drift rates, or genome size evolution. Mixed support for relationships between host effective population sizes and Blochmannia molecular evolution suggests weak or uncoupled relationships between host demography and Blochmannia population genomic processes. Finally, we found that Blochmannia genome size evolution was associated with genome-wide estimates of genetic drift and number of genes with relaxed selection pressures.

RevDate: 2022-07-18
CmpDate: 2022-06-30

Weiland SO, Detcharoen M, Schlick-Steiner BC, et al (2022)

Analyses of locomotion, wing morphology, and microbiome in Drosophila nigrosparsa after recovery from antibiotics.

MicrobiologyOpen, 11(3):e1291.

Antibiotics, such as tetracycline, have been frequently used to cure arthropods of Wolbachia endosymbionts. After the symbionts have been removed, the hosts must recover for some generations from the side effects of the antibiotics. However, most studies do not assess the direct and indirect longer-term effects of antibiotics used to remove Wolbachia, which may question the exact contribution of this endosymbiont to the effects observed. Here, we used the fly Drosophila nigrosparsa treated or not with tetracycline for three generations followed by two generations of recovery to investigate the effects of this antibiotic on the fly locomotion, wing morphology, and the gut microbiome. We found that antibiotic treatment did not affect fly locomotion two generations after being treated with the antibiotic. In addition, gut-microbiome restoration was tested as a more efficient solution to reduce the potential side effects of tetracycline on the microbiome. There was no significant difference in alpha diversity between gut restoration and other treatments, but the abundance of some bacterial taxa differed significantly between the gut-restoration treatment and the control. We conclude that in D. nigrosparsa the recovery period of two generations after being treated with the antibiotic is sufficient for locomotion, and suggest a general assessment of direct and indirect effects of antibiotics after a particular recovery time.

RevDate: 2022-07-16

Karsenti N, Purssell A, Lau R, et al (2022)

Surveillance of Amoebic Keratitis-Causing Acanthamoebae for Potential Bacterial Endosymbionts in Ontario, Canada.

Pathogens (Basel, Switzerland), 11(6):.

Acanthamoeba spp. are the causative pathogens of several infections, including amoebic keratitis (AK), a vision-threatening infection. Acanthamoebae from corneal specimens of patients with AK harbor bacterial endosymbionts, which may increase virulence. We sought to understand the spectrum of bacterial endosymbionts present in clinical isolates of Acanthamoeba spp. identified in our reference parasitology laboratory. Isolates of Acanthamoeba spp. obtained from our biobank of anonymized corneal scrapings were screened for potential endosymbionts by PCR using primer pairs detecting bacteria belonging to orders Chlamydiales, Rickettsiales, or Legionellales and pan16S primers. Three primer pairs specific to the 18s rRNA gene of Acanthamoeba spp. were used for the amplification of Acanthamoeba DNA used for sequencing. Sanger sequencing of all PCR products was performed, followed by BLAST analysis for species identification. We screened 26 clinical isolates of Acanthamoeba spp. for potential endosymbionts. Five isolates (19%) were found to contain bacterial DNA belonging to Legionellales. Three (11%) contained members of the Rickettsiales and Pseudomonas genticulata was detected in a Rickettsia-positive sample. One strain (4%) contained Neochlamydia hartmannellae, a member of the Chlamydiales order. Bacterial endosymbionts are prevalent in clinical strains of Acanthamoeba causing AK isolated from corneal scrapings. The demonstration of these organisms in clinical Acanthamoeba isolates supports a potential exploration of anti-endosymbiont therapeutics as an adjuvant therapy in the treatment of AK.

RevDate: 2022-07-16

Takahashi T (2022)

Method for Stress Assessment of Endosymbiotic Algae in Paramecium bursaria as a Model System for Endosymbiosis.

Microorganisms, 10(6):.

Endosymbiosis between heterotrophic host and microalga often breaks down because of environmental conditions, such as temperature change and exposure to toxic substances. By the time of the apparent breakdown of endosymbiosis, it is often too late for the endosymbiotic system to recover. In this study, I developed a technique for the stress assessment of endosymbiotic algae using Paramecium bursaria as an endosymbiosis model, after treatment with the herbicide paraquat, an endosymbiotic collapse inducer. Microcapillary flow cytometry was employed to evaluate a large number of cells in an approach that is more rapid than microscopy evaluation. In the assay, red fluorescence of the chlorophyll reflected the number of endosymbionts within the host cell, while yellow fluorescence fluctuated in response to the deteriorating viability of the endosymbiont under stress. Hence, the yellow/red fluorescence intensity ratio can be used as an algal stress index independent of the algal number. An optical evaluation revealed that the viability of the endosymbiotic algae within the host cell decreased after treatment with paraquat and that the remaining endosymbionts were exposed to high stress. The devised assay is a potential environmental monitoring method, applicable not only to P. bursaria but also to multicellular symbiotic units, such as corals.

RevDate: 2022-07-16
CmpDate: 2022-06-27

Hassan K, Chepkirui C, Llanos-López NA, et al (2022)

Meroterpenoids Possibly Produced by a Bacterial Endosymbiont of the Tropical Basidiomycete Echinochaete brachypora.

Biomolecules, 12(6):.

A mycelial culture of the African basidiomycete Echinochaete cf. brachypora was studied for biologically active secondary metabolites, and four compounds were isolated from its crude extract derived from shake flask fermentations, using preparative high-performance liquid chromatography (HPLC). The pure metabolites were identified using extensive nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Aside from the new metabolites 1-methoxyneomarinone (1) and (E)-3-methyl-5-(-12,13,14-trimethylcyclohex-10-en-6-yl)pent-2-enoic acid (4), the known metabolites neomarinone (2) and fumaquinone (4) were obtained. Such compounds had previously only been reported from Actinobacteria but were never isolated from the cultures of a fungus. This observation prompted us to evaluate whether the above metabolites may actually have been produced by an endosymbiontic bacterium that is associated with the basidiomycete. We have indeed been able to characterize bacterial 16S rDNA in the fungal mycelia, and the production of the metabolites stopped when the fungus was sub-cultured on a medium containing antibacterial antibiotics. Therefore, we have found strong evidence that compounds 1-4 are not of fungal origin. However, the endofungal bacterium was shown to belong to the genus Ralstonia, which has never been reported to produce similar metabolites to 1-4. Moreover, we failed to obtain the bacterial strain in pure culture to provide final proof for its identity. In any case, the current report is the first to document that polyporoid Basidiomycota are associated with endosymbionts and constitutes the first report on secondary metabolites from the genus Echinochaete.

RevDate: 2022-09-20
CmpDate: 2022-07-19

George EE, Tashyreva D, Kwong WK, et al (2022)

Gene Transfer Agents in Bacterial Endosymbionts of Microbial Eukaryotes.

Genome biology and evolution, 14(7):.

Gene transfer agents (GTAs) are virus-like structures that package and transfer prokaryotic DNA from donor to recipient prokaryotic cells. Here, we describe widespread GTA gene clusters in the highly reduced genomes of bacterial endosymbionts from microbial eukaryotes (protists). Homologs of the GTA capsid and portal complexes were initially found to be present in several highly reduced alphaproteobacterial endosymbionts of diplonemid protists (Rickettsiales and Rhodospirillales). Evidence of GTA expression was found in polyA-enriched metatranscriptomes of the diplonemid hosts and their endosymbionts, but due to biases in the polyA-enrichment methods, levels of GTA expression could not be determined. Examining the genomes of closely related bacteria revealed that the pattern of retained GTA head/capsid complexes with missing tail components was common across Rickettsiales and Holosporaceae (Rhodospirillales), all obligate symbionts with a wide variety of eukaryotic hosts. A dN/dS analysis of Rickettsiales and Holosporaceae symbionts revealed that purifying selection is likely the main driver of GTA evolution in symbionts, suggesting they remain functional, but the ecological function of GTAs in bacterial symbionts is unknown. In particular, it is unclear how increasing horizontal gene transfer in small, largely clonal endosymbiont populations can explain GTA retention, and, therefore, the structures may have been repurposed in endosymbionts for host interactions. Either way, their widespread retention and conservation in endosymbionts of diverse eukaryotes suggests an important role in symbiosis.

RevDate: 2022-07-16

Nian X, Tao X, Xiao Z, et al (2022)

Effects of Sublethal Concentrations of Tetracycline Hydrochloride on the Biological Characteristics and Wolbachia Titer in Parthenogenesis Trichogramma pretiosum.

Insects, 13(6):.

Trichogramma pretiosum Riley is an important natural enemy and biological control agent of lepidopteran pests. Wolbachia is an intracellular endosymbiont that induces parthenogenesis in the parasitoid T. pretiosum. In this paper, the sublethal effects of the antibiotic tetracycline hydrochloride on the development and reproduction of T. pretiosum were studied. Emerged females were fed with sublethal concentrations (LC5, LC15, and LC35) of tetracycline for ten generations. The biological parameters (longevity, parasitized eggs, and fecundity) of treated females significantly reduced compared with the control Moreover, the percentage of female offspring in the treatments significantly reduced, but the percentage of male offspring significantly increased. In addition, the Wolbachia titer sharply reduced after two generations of antibiotic treatments, but it could still be detected even after ten successive generations of antibiotic treatments, which indicated that Wolbachia was not completely removed by sublethal concentrations of tetracycline. The control lines with higher Wolbachia titers produced more female offspring than the tetracycline treatments with lower Wolbachia titers, indicating that the Wolbachia titer affected the sex determination of T. pretiosum. Our results show that sublethal concentrations of tetracycline had adverse effects on the development of T. pretiosum, and Wolbachia titers affected the sexual development of T. pretiosum eggs.

RevDate: 2022-09-08
CmpDate: 2022-09-08

Dzul-Rosado K, Maldonado-Borges JI, Puerto-Manzano FI, et al (2022)

First exploratory study of bacterial pathogens and endosymbionts in head lice from a Mayan community in southern Mexico.

Zoonoses and public health, 69(6):729-736.

Lice represent one of the most neglected group of vectors worldwide, particularly in Latin America. Records of bacterial agents related to head lice are non-existent in this region of the continent. Many of these communities often do not have adequate access to public services and/or health protection. The normalization of this condition prevents them from manifesting discomfort, such as bites and itching, which further aggravates the situation, as they can be vectors of important diseases. For this reason, the aim of this work was to identify the richness of bacterial pathogens (Acinetobacter, Bartonella, and Rickettsia) and endosymbionts (Wolbachia) in head lice of paediatric patients from the indigenous municipality of Hoctun, Yucatan, Mexico. DNA extraction was performed using the QIAamp DNA Mini Kit. For the detection of bacterial pathogens, fragments of the gltA, rpoB, and 16S rDNA genes were amplified. For the detection of Wolbachia, the wsp gene was amplified. Of the 28 lice analysed, the presence of two genera of bacterial pathogens was detected Acinetobacter (42.9% = 12/28) and Bartonella (7.14% = 2/28). We also detected the endosymbiont Wolbachia (71.42% = 20/28). Our results showed that DNA from three bacteria species (Acinetobacter baumannii, Bartonella quintana, and Wolbachia pipientis) was present with frequencies ranging from 3.57% to 71.42%. This work represents the first exploratory study of the diversity of agents associated with head lice (Pediculus humanus capitis) in Mexico and Latin America. Due to the findings generated in the present study, it is important to perform surveillance of head lice populations to identify the degree of spread of these pathogens and their impact on populations in the region.

RevDate: 2022-07-24
CmpDate: 2022-06-22

Chen L, Xiao Q, Shi M, et al (2022)

Detecting Wolbachia Strain wAlbB in Aedes albopictus Cell Lines.

Journal of visualized experiments : JoVE.

As a maternally harbored endosymbiont, Wolbachia infects large proportions of insect populations. Studies have recently reported the successful regulation of RNA virus transmission using Wolbachia-transfected mosquitoes. Key strategies to control viruses include the manipulation of host reproduction via cytoplasmic incompatibility and the inhibition of viral transcripts via immune priming and competition for host-derived resources. However, the underlying mechanisms of the responses of Wolbachia-transfected mosquitoes to viral infection are poorly understood. This paper presents a protocol for the in vitro identification of Wolbachia infection at the nucleic acid and protein levels in Aedes albopictus (Diptera: Culicidae) Aa23 cells to enhance the understanding of the interactions between Wolbachia and its insect vectors. Through the combined use of polymerase chain reaction (PCR), quantitative PCR, western blot, and immunological analytical methods, a standard morphologic protocol has been described for the detection of Wolbachia-infected cells that is more accurate than the use of a single method. This approach may also be applied to the detection of Wolbachia infection in other insect taxa.

RevDate: 2022-08-19
CmpDate: 2022-08-18

Lan Y, Sun J, Chen C, et al (2022)

Endosymbiont population genomics sheds light on transmission mode, partner specificity, and stability of the scaly-foot snail holobiont.

The ISME journal, 16(9):2132-2143.

The scaly-foot snail (Chrysomallon squamiferum) inhabiting deep-sea hydrothermal vents in the Indian Ocean relies on its sulphur-oxidising gammaproteobacterial endosymbionts for nutrition and energy. In this study, we investigate the specificity, transmission mode, and stability of multiple scaly-foot snail populations dwelling in five vent fields with considerably disparate geological, physical and chemical environmental conditions. Results of population genomics analyses reveal an incongruent phylogeny between the endosymbiont and mitochondrial genomes of the scaly-foot snails in the five vent fields sampled, indicating that the hosts obtain endosymbionts via horizontal transmission in each generation. However, the genetic homogeneity of many symbiont populations implies that vertical transmission cannot be ruled out either. Fluorescence in situ hybridisation of ovarian tissue yields symbiont signals around the oocytes, suggesting that vertical transmission co-occurs with horizontal transmission. Results of in situ environmental measurements and gene expression analyses from in situ fixed samples show that the snail host buffers the differences in environmental conditions to provide the endosymbionts with a stable intracellular micro-environment, where the symbionts serve key metabolic functions and benefit from the host's cushion. The mixed transmission mode, symbiont specificity at the species level, and stable intracellular environment provided by the host support the evolutionary, ecological, and physiological success of scaly-foot snail holobionts in different vents with unique environmental parameters.

RevDate: 2022-06-22

Colunga-Salas P, Sánchez-Montes S, Torres-Castro M, et al (2022)

Is vertical transmission the only pathway for Rickettsia felis?.

Transboundary and emerging diseases [Epub ahead of print].

The genus Rickettsia encompasses several species grouped into two main clusters, Typhus and the Transitional groups. The latter group contains Rickettsia felis, an endosymbiont of several arthropods with an uncertain human pathogenicity and whose most efficient transmission mechanism described thus far is transovarial. The aim of this study was to evaluate whether this pathway exists using phylogenetic analysis and partial sequences of the 17kDa and gltA genes and comparing them with host phylogeny using the cytb region. This is the first study that evaluates the vertical transmission of R. felis. In general, both phylogenies of R. felis showed no polytomies, as suspected if this pathway was the only pathway occurring. When phylogenies of the invertebrates and the gltA of R. felis were compared for strong coevolutionary insight, intricate relationships were observed, suggesting that other transmission pathways must occur, such as horizontal transmission. Further studies are needed to determine which other transmission routes occur in hematophagous arthropods.

RevDate: 2022-07-06

De Oliveira AL, Srivastava A, Espada-Hinojosa S, et al (2022)

The complete and closed genome of the facultative generalist Candidatus Endoriftia persephone from deep-sea hydrothermal vents.

Molecular ecology resources [Epub ahead of print].

The mutualistic interactions between Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone (short Endoriftia) have been extensively researched. However, the closed Endoriftia genome is still lacking. Here, by employing single-molecule real-time sequencing we present the closed chromosomal sequence of Endoriftia. In contrast to theoretical predictions of enlarged and mobile genetic element-rich genomes related to facultative endosymbionts, the closed Endoriftia genome is streamlined with fewer than expected coding sequence regions, insertion-, prophage-sequences and transposase-coding sequences. Automated and manually curated functional analyses indicated that Endoriftia is more versatile regarding sulphur metabolism than previously reported. We identified the presence of two identical rRNA operons and two long CRISPR regions in the closed genome. Additionally, pangenome analyses revealed the presence of three types of secretion systems (II, IV and VI) in the different Endoriftia populations indicating lineage-specific adaptations. The in depth mobilome characterization identified the presence of shared genomic islands in the different Endoriftia drafts and in the closed genome, suggesting that the acquisition of foreign DNA predates the geographical dispersal of the different endosymbiont populations. Finally, we found no evidence of epigenetic regulation in Endoriftia, as revealed by gene screenings and absence of methylated modified base motifs in the genome. As a matter of fact, the restriction-modification system seems to be dysfunctional in Endoriftia, pointing to a higher importance of molecular memory-based immunity against phages via spacer incorporation into CRISPR system. The Endoriftia genome is the first closed tubeworm endosymbiont to date and will be valuable for future gene oriented and evolutionary comparative studies.

RevDate: 2022-07-31

Lin GW, Chung CY, Cook CE, et al (2022)

Germline specification and axis determination in viviparous and oviparous pea aphids: conserved and divergent features.

Development genes and evolution, 232(2-4):51-65.

Aphids are hemimetabolous insects that undergo incomplete metamorphosis without pupation. The annual life cycle of most aphids includes both an asexual (viviparous) and a sexual (oviparous) phase. Sexual reproduction only occurs once per year and is followed by many generations of asexual reproduction, during which aphids propagate exponentially with telescopic development. Here, we discuss the potential links between viviparous embryogenesis and derived developmental features in the pea aphid Acyrthosiphon pisum, particularly focusing on germline specification and axis determination, both of which are key events of early development in insects. We also discuss potential evolutionary paths through which both viviparous and oviparous females might have come to utilize maternal germ plasm to drive germline specification. This developmental strategy, as defined by germline markers, has not been reported in other hemimetabolous insects. In viviparous females, furthermore, we discuss whether molecules that in other insects characterize germ plasm, like Vasa, also participate in posterior determination and how the anterior localization of the hunchback orthologue Ap-hb establishes the anterior-posterior axis. We propose that the linked chain of developing oocytes and embryos within each ovariole and the special morphology of early embryos might have driven the formation of evolutionary novelties in germline specification and axis determination in the viviparous aphids. Moreover, based upon the finding that the endosymbiont Buchnera aphidicola is closely associated with germ cells throughout embryogenesis, we propose presumptive roles for B. aphidicola in aphid development, discussing how it might regulate germline migration in both reproductive modes of pea aphids. In summary, we expect that this review will shed light on viviparous as well as oviparous development in aphids.

RevDate: 2022-06-09

Higgins SA, Mann M, M Heck (2022)

Strain tracking of 'Candidatus Liberibacter asiaticus', citrus greening disease pathogen, enabled by high-resolution microbiome analysis of the Asian citrus psyllid.

Phytopathology [Epub ahead of print].

The Asian citrus psyllid, Diaphorina citri, is an invasive insect and a vector of 'Candidatus Liberibacter asiaticus' (CLas), a bacterium whose growth in Citrus species results in huanglongbing (HLB), also known as citrus greening disease. Methods to enrich and sequence CLas from D. citri often rely on biased genome amplification and nevertheless contain significant quantities of host DNA. To overcome these hurdles, we developed a simple pre-treatment DNase and filtration (hereafter PDF) protocol to remove host DNA and directly sequence CLas and the complete, primarily uncultivable, microbiome from D. citri adults. The PDF protocol yielded CLas abundances upwards of 60% and facilitated direct measurement of CLas and endosymbiont replication rates in psyllids. The PDF protocol confirmed our strains derived from a progenitor Florida CLas strain and accumulated 156 genetic variants, underscoring the utility of this data for bacterial strain tracking. CLas genetic polymorphisms arising in lab-reared psyllid populations included prophage encoding regions with key functions in CLas pathogenesis, putative antibiotic resistance loci, and a single secreted effector. These variants suggest laboratory propagation of CLas may result in different phenotypic trajectories among laboratories, and may confound CLas physiology or therapeutic design and evaluation if these differences remain undocumented. Finally, we obtained genetic signatures affiliated with Citrus nuclear and organellar genomes, entomopathogenic fungal mitochondria, and commensal bacteria from laboratory-reared and field-collected D. citri adults. Hence, the PDF protocol can directly inform agricultural management strategies related to bacterial strain tracking, insect microbiome surveillance, and antibiotic resistance screening.

RevDate: 2022-08-18
CmpDate: 2022-06-23

Tvedte ES, Gasser M, Zhao X, et al (2022)

Accumulation of endosymbiont genomes in an insect autosome followed by endosymbiont replacement.

Current biology : CB, 32(12):2786-2795.e5.

Eukaryotic genomes can acquire bacterial DNA via lateral gene transfer (LGT).1 A prominent source of LGT is Wolbachia,2 a widespread endosymbiont of arthropods and nematodes that is transmitted maternally through female germline cells.3,4 The DNA transfer from the Wolbachia endosymbiont wAna to Drosophila ananassae is extensive5-7 and has been localized to chromosome 4, contributing to chromosome expansion in this lineage.6 As has happened frequently with claims of bacteria-to-eukaryote LGT, the contribution of wAna transfers to the expanded size of D. ananassae chromosome 4 has been specifically contested8 owing to an assembly where Wolbachia sequences were classified as contaminants and removed.9 Here, long-read sequencing with DNA from a Wolbachia-cured line enabled assembly of 4.9 Mbp of nuclear Wolbachia transfers (nuwts) in D. ananassae and a 24-kbp nuclear mitochondrial transfer. The nuwts are <8,000 years old in at least two locations in chromosome 4 with at least one whole-genome integration followed by rapid extensive duplication of most of the genome with regions that have up to 10 copies. The genes in nuwts are accumulating small indels and mobile element insertions. Among the highly duplicated genes are cifA and cifB, two genes associated with Wolbachia-mediated Drosophila cytoplasmic incompatibility. The wAna strain that was the source of nuwts was subsequently replaced by a different wAna endosymbiont. Direct RNA Nanopore sequencing of Wolbachia-cured lines identified nuwt transcripts, including spliced transcripts, but functionality, if any, remains elusive.

RevDate: 2022-07-16
CmpDate: 2022-06-20

Bordenstein SR, SR Bordenstein (2022)

Widespread phages of endosymbionts: Phage WO genomics and the proposed taxonomic classification of Symbioviridae.

PLoS genetics, 18(6):e1010227.

Wolbachia are the most common obligate, intracellular bacteria in animals. They exist worldwide in arthropod and nematode hosts in which they commonly act as reproductive parasites or mutualists, respectively. Bacteriophage WO, the largest of Wolbachia's mobile elements, includes reproductive parasitism genes, serves as a hotspot for genetic divergence and genomic rearrangement of the bacterial chromosome, and uniquely encodes a Eukaryotic Association Module with eukaryotic-like genes and an ensemble of putative host interaction genes. Despite WO's relevance to genome evolution, selfish genetics, and symbiotic applications, relatively little is known about its origin, host range, diversification, and taxonomic classification. Here we analyze the most comprehensive set of 150 Wolbachia and phage WO assemblies to provide a framework for discretely organizing and naming integrated phage WO genomes. We demonstrate that WO is principally in arthropod Wolbachia with relatives in diverse endosymbionts and metagenomes, organized into four variants related by gene synteny, often oriented opposite the putative origin of replication in the Wolbachia chromosome, and the large serine recombinase is an ideal typing tool to distinguish the four variants. We identify a novel, putative lytic cassette and WO's association with a conserved eleven gene island, termed Undecim Cluster, that is enriched with virulence-like genes. Finally, we evaluate WO-like Islands in the Wolbachia genome and discuss a new model in which Octomom, a notable WO-like Island, arose from a split with WO. Together, these findings establish the first comprehensive Linnaean taxonomic classification of endosymbiont phages, including non-Wolbachia phages from aquatic environments, that includes a new family and two new genera to capture the collective relatedness of these viruses.

RevDate: 2022-07-16

James EB, Pan X, Schwartz O, et al (2022)

SymbiQuant: A Machine Learning Object Detection Tool for Polyploid Independent Estimates of Endosymbiont Population Size.

Frontiers in microbiology, 13:816608.

Quantifying the size of endosymbiont populations is challenging because endosymbionts are typically difficult or impossible to culture and commonly polyploid. Current approaches to estimating endosymbiont population sizes include quantitative PCR (qPCR) targeting endosymbiont genomic DNA and flow-cytometry. While qPCR captures genome copy number data, it does not capture the number of bacterial cells in polyploid endosymbiont populations. In contrast, flow cytometry can capture accurate estimates of whole host-level endosymbiont population size, but it is not readily able to capture data at the level of endosymbiotic host cells. To complement these existing approaches for estimating endosymbiont population size, we designed and implemented an object detection/segmentation tool for counting the number of endosymbiont cells in micrographs of host tissues. The tool, called SymbiQuant, which makes use of recent advances in deep neural networks includes a graphic user interface that allows for human curation of tool output. We trained SymbiQuant for use in the model aphid/Buchnera endosymbiosis and studied Buchnera population dynamics and phenotype over aphid postembryonic development. We show that SymbiQuant returns accurate counts of endosymbionts, and readily captures Buchnera phenotype. By replacing our training data with data composed of annotated microscopy images from other models of endosymbiosis, SymbiQuant has the potential for broad application. Our tool, which is available on GitHub, adds to the repertoire of methods researchers can use to study endosymbiosis at the organismal, genome, and now endosymbiotic host tissue or cell levels.

RevDate: 2022-09-08
CmpDate: 2022-08-09

Lu M, Tang G, Ren Z, et al (2022)

Ehrlichia, Coxiella and Bartonella infections in rodents from Guizhou Province, Southwest China.

Ticks and tick-borne diseases, 13(5):101974.

Rodents are generally recognized to be the reservoir hosts of a great many zoonotic pathogens. In some areas of China, rodent-borne pathogens, as well as the role of rodents in the natural cycle of these pathogens, are still poorly investigated. To increase our knowledge on the distribution and epidemiology of rodent-borne bacterial pathogens, 81 rodent liver samples were collected in three locations of Guizhou province located in Southwest China, and screened for the presence of Ehrlichia, Coxiella, and Bartonella in them. A putative novel Ehrlichia species was identified in 5 Berylmys bowersi samples (100%, 5/5). Its 16S rRNA, gltA, and groEL genes have highest 99.84%, 89.11%, and 98.02% identities to those from known Ehrlichia species, and form distinct clades in the phylogenetic trees. Herein we name it "Candidatus Ehrlichia zunyiensis". Bartonella was tested positive in 8 A. agrarius (striped field mouse), 2 A. chevrieri (Chevrier's field mouse), 1 R. norvegicus (Norway rat), 1 N. confucianus, and 1 N. lotipes, with a total positive rate of 16.05% (13/81). Sequence analysis indicated high genetic diversity in these Bartonella strains. Unexpectedly, two Coxiella strains were identified from the rodents (1 Niviventer confucianus and 1 Mus pahari). Genetic and phylogenetic analysis indicated that both of them are closely related to the Coxiella endosymbiont of ticks. This result supported previous conjectures that vertebrate hosts such as rodents may play a role in the preservation and transmission of Coxiella endosymbiont of ticks.

RevDate: 2022-09-14
CmpDate: 2022-08-09

Kohga H, Mori T, Tanaka Y, et al (2022)

Crystal structure of the lipid flippase MurJ in a "squeezed" form distinct from its inward- and outward-facing forms.

Structure (London, England : 1993), 30(8):1088-1097.e3.

The bacterial peptidoglycan enclosing the cytoplasmic membrane is a fundamental cellular architecture. The integral membrane protein MurJ plays an essential role in flipping the cell wall building block Lipid II across the cytoplasmic membrane for peptidoglycan biosynthesis. Previously reported crystal structures of MurJ have elucidated its V-shaped inward- or outward-facing forms with an internal cavity for substrate binding. MurJ transports Lipid II using its cavity through conformational transitions between these two forms. Here, we report two crystal structures of inward-facing forms from Arsenophonus endosymbiont MurJ and an unprecedented crystal structure of Escherichia coli MurJ in a "squeezed" form, which lacks a cavity to accommodate the substrate, mainly because of the increased proximity of transmembrane helices 2 and 8. Subsequent molecular dynamics simulations supported the hypothesis that the squeezed form is an intermediate conformation. This study fills a gap in our understanding of the Lipid II flipping mechanism.

RevDate: 2022-07-16

Badrulisham AS, Abu Bakar MA, Md Zain BM, et al (2022)

Metabarcoding of Parasitic Wasp, Dolichogenidea metesae (Nixon) (Hymenoptera: Braconidae) That Parasitizing Bagworm, Metisa plana Walker (Lepidoptera: Psychidae).

Tropical life sciences research, 33(1):23-42.

Microbiome studies of the parasitoid wasp, Dolichogenidea metesae (Nixon) (Hymenoptera, Braconidae) are important because D. metesae has potential as a biological control agent to suppress the pest, Metisa plana Walker (Lepidoptera, Psychidae). Three field populations of parasitic wasps with different Integrated Pest Management (IPM) practices to control M. plana collected from Perak state (Tapah) and Johor state (Yong Peng and Batu Pahat districts) in Peninsular Malaysia were studied. Bacterial community composition and structure were analysed using α and β diversity metrics. Proteobacteria (83.31%) and Bacteroidetes (6.80%) were the most dominant phyla, whereas unknown family from order Rhizobiales was the most abundant family found in all populations followed by Pseudomonadaceae. Family Micrococcaceae was absent in Tapah. Rhizobiales gen. sp. and Pseudomonas sp. were abundant in all populations. Pearson's correlation analysis showed the strongest correlation between individuals of Batu Pahat and Yong Peng (r = 0.89827, p < 0.05), followed by Tapah and Yong Peng with r = 0.75358, p < 0.05 and Batu Pahat and Tapah (r = 0.69552, p < 0.05). We hypothesise that low diversity and richness in Tapah might be due to direct and indirect effect of insecticides application. This preliminary data was the first study to do inventory of the microbiomes in the gut of the D. metesae.

RevDate: 2022-08-19
CmpDate: 2022-07-14

Paight C, Hunter ES, CE Lane (2022)

Codependence of individuals in the Nephromyces species swarm requires heterospecific bacterial endosymbionts.

Current biology : CB, 32(13):2948-2955.e4.

Symbiosis is one of the most important evolutionary processes shaping the biodiversity on Earth. Symbiotic associations often bring together organisms from different domains of life, which can provide an unparalleled route to evolutionary innovation.1-4 The phylum Apicomplexa encompasses 6,000 ubiquitous animal parasites; however, species in the recently described apicomplexan family, Nephromycidae, are reportedly non-virulent.5,6 The members of the genus Nephromyces live within a specialized organ of tunicates, called the renal sac, in which they use concentrated uric acid as a primary nitrogen source.7,8 Here, we report genomic and transcriptomic data from the diverse genus Nephromyces, as well as the three bacterial symbionts that live within this species complex. We show that the diversity of Nephromyces is unexpectedly high within each renal sac, with as many as 20 different species inhabiting the renal sacs in wild populations. The many species of Nephromyces can host three different types of bacterial endosymbionts; however, FISH microscopy allowed us to demonstrate that each individual Nephromyces cell hosts only a single bacterial type. Through the reconstruction and analyses of the endosymbiont bacterial genomes, we infer that each bacterial type supplies its host with different metabolites. No individual species of Nephromyces, in combination with its endosymbiont, can produce a complete set of essential amino acids, and culture experiments demonstrate that individual Nephromyces species cannot form a viable infection. Therefore, we hypothesize that Nephromyces spp. depend on co-infection with congeners containing different bacterial symbionts in order to exchange metabolites to meet their needs.

RevDate: 2022-07-16
CmpDate: 2022-06-02

Liu W, Smith DAS, Raina G, et al (2022)

Global biogeography of warning coloration in the butterfly Danaus chrysippus.

Biology letters, 18(6):20210639.

Warning coloration provides a textbook example of natural selection, but the frequent observation of polymorphism in aposematic species presents an evolutionary puzzle. We investigated biogeography and polymorphism of warning patterns in the widespread butterfly Danaus chrysippus using records from citizen science (n = 5467), museums (n = 8864) and fieldwork (n = 2586). We find that polymorphism in three traits controlled by known mendelian loci is extensive. Broad allele frequency clines, hundreds of kilometres wide, suggest a balance between long-range dispersal and predation of unfamiliar morphs. Mismatched clines for the white hindwing and forewing tip in East Africa are consistent with a previous finding that the black wingtip allele has spread recently in the region through hitchhiking with a heritable endosymbiont. Light/dark background coloration shows more extensive polymorphism. The darker genotype is more common in cooler regions, possibly reflecting a trade-off between thermoregulation and predator warning. Overall, our findings show how studying local adaptation at the global scale provides a more complete picture of the evolutionary forces involved.

RevDate: 2022-07-19
CmpDate: 2022-06-02

Calatrava V, Stephens TG, Gabr A, et al (2022)

Retrotransposition facilitated the establishment of a primary plastid in the thecate amoeba Paulinella.

Proceedings of the National Academy of Sciences of the United States of America, 119(23):e2121241119.

The evolution of eukaryotic life was predicated on the development of organelles such as mitochondria and plastids. During this complex process of organellogenesis, the host cell and the engulfed prokaryote became genetically codependent, with the integration of genes from the endosymbiont into the host nuclear genome and subsequent gene loss from the endosymbiont. This process required that horizontally transferred genes become active and properly regulated despite inherent differences in genetic features between donor (endosymbiont) and recipient (host). Although this genetic reorganization is considered critical for early stages of organellogenesis, we have little knowledge about the mechanisms governing this process. The photosynthetic amoeba Paulinella micropora offers a unique opportunity to study early evolutionary events associated with organellogenesis and primary endosymbiosis. This amoeba harbors a “chromatophore,” a nascent photosynthetic organelle derived from a relatively recent cyanobacterial association (∼120 million years ago) that is independent of the evolution of primary plastids in plants (initiated ∼1.5 billion years ago). Analysis of the genome and transcriptome of Paulinella revealed that retrotransposition of endosymbiont-derived nuclear genes was critical for their domestication in the host. These retrocopied genes involved in photoprotection in cyanobacteria became expanded gene families and were “rewired,” acquiring light-responsive regulatory elements that function in the host. The establishment of host control of endosymbiont-derived genes likely enabled the cell to withstand photo-oxidative stress generated by oxygenic photosynthesis in the nascent organelle. These results provide insights into the genetic mechanisms and evolutionary pressures that facilitated the metabolic integration of the host–endosymbiont association and sustained the evolution of a photosynthetic organelle.

RevDate: 2022-07-16

Lu M, Tian J, Zhao H, et al (2022)

Molecular Survey of Vector-Borne Pathogens in Ticks, Sheep Keds, and Domestic Animals from Ngawa, Southwest China.

Pathogens (Basel, Switzerland), 11(5):.

Vector-borne pathogens are mainly transmitted by blood-feeding arthropods such as ticks, mosquitoes, fleas, lice, mites, etc. They pose a significant threat to animal and human health due to their worldwide distribution. Although much work has been performed on these pathogens, some neglected areas and undiscovered pathogens are still to be further researched. In this study, ticks (Haemaphysalis qinghaiensis), sheep keds (Melophagus ovinus), and blood samples from yaks and goats were collected in Ngawa Tibetan and Qiang Autonomous Prefecture located on the eastern edge of the Qinghai-Tibet Plateau, Southwest China. Several vector-borne bacterial pathogens were screened and studied. Anaplasma bovis strains representing novel genotypes were detected in ticks (8.83%, 37/419), yak blood samples (45.71%, 64/140), and goat blood samples (58.93%, 33/56). Two spotted fever group (SFG) Rickettsiae, Candidatus Rickettsia jingxinensis, and a novel Rickettsia species named Candidatus Rickettsia hongyuanensis were identified in ticks. Another Rickettsia species closely related to the Rickettsia endosymbiont of Polydesmus complanatus was also detected in ticks. Furthermore, a Coxiella species was detected in ticks (3.34%, 14/419), keds (1.89%, 2/106), and yak blood (0.71%, 1/140). Interestingly, another Coxiella species and a Coxiella-like bacterium were detected in a tick and a goat blood sample, respectively. These results indicate the remarkable diversity of vector-borne pathogens circulating in this area. Further investigations on their pathogenicity to humans and domestic animals are still needed.

RevDate: 2022-07-16

Csorba AB, Fora CG, Bálint J, et al (2022)

Endosymbiotic Bacterial Diversity of Corn Leaf Aphid, Rhopalosiphum maidis Fitch (Hemiptera: Aphididae) Associated with Maize Management Systems.

Microorganisms, 10(5):.

In this study, different maize fields cultivated under different management systems were sampled to test corn leaf aphid, Rhopalosiphum maidis, populations in terms of total and endosymbiotic bacterial diversity. Corn leaf aphid natural populations were collected from traditionally managed maize fields grown under high agricultural and natural landscape diversity as well as conventionally treated high-input agricultural fields grown in monoculture and with fertilizers use, hence with low natural landscape diversity. Total bacterial community assessment by DNA sequencing was performed using the Illumina MiSeq platform. In total, 365 bacterial genera were identified and 6 endosymbiont taxa. A high abundance of the primary endosymbiont Buchnera and secondary symbionts Serratia and Wolbachia were detected in all maize crops. Their frequency was found to be correlated with the maize management system used, probably with fertilizer input. Three other facultative endosymbionts ("Candidatus Hamiltonella", an uncultured Rickettsiales genus, and Spiroplasma) were also recorded at different frequencies under the two management regimes. Principal components analyses revealed that the relative contribution of the obligate and dominant symbiont Buchnera to the aphid endosymbiotic bacterial community was 72%, whereas for the managed system this was only 16.3%. When facultative symbionts alone were considered, the effect of management system revealed a DNA diversity of 23.3%.

RevDate: 2022-07-16
CmpDate: 2022-05-31

Salomon J, Fernandez Santos NA, Zecca IB, et al (2022)

Brown Dog Tick (Rhipicephalus sanguineus Sensu Lato) Infection with Endosymbiont and Human Pathogenic Rickettsia spp., in Northeastern México.

International journal of environmental research and public health, 19(10):.

Of the documented tick-borne diseases infecting humans in México, Rocky Mountain spotted fever (RMSF), caused by the Gram-negative bacterium Rickettsia rickettsii, is responsible for most fatalities. Given recent evidence of brown dog tick, Rhipicephalus sanguineus s.l., as an emerging vector of human RMSF, we aimed to evaluate dogs and their ticks for rickettsiae infections as an initial step in assessing the establishment of this pathosystem in a poorly studied region of northeastern México while evaluating the use of dogs as sentinels for transmission/human disease risk. We sampled owned dogs living in six disadvantaged neighborhoods of Reynosa, northeastern México to collect whole blood and ticks. Of 168 dogs assessed, tick infestation prevalence was 53%, composed of exclusively Rh. sanguineus s. l. (n = 2170 ticks). Using PCR and sequencing, we identified an overall rickettsiae infection prevalence of 4.1% (n = 12/292) in ticks, in which eight dogs harbored at least one infected tick. Rickettsiae infections included Rickettsia amblyommatis and Rickettsia parkeri, both of which are emerging human pathogens, as well as Candidatus Rickettsia andeanae. This is the first documentation of pathogenic Rickettsia species in Rh. sanguineus s.l. collected from dogs from northeastern México. Domestic dog infestation with Rickettsia-infected ticks indicates ongoing transmission; thus, humans are at risk for exposure, and this underscores the importance of public and veterinary health surveillance for these pathogens.

RevDate: 2022-07-16
CmpDate: 2022-06-30

Margarita V, Bailey NP, Rappelli P, et al (2022)

Two Different Species of Mycoplasma Endosymbionts Can Influence Trichomonas vaginalis Pathophysiology.

mBio, 13(3):e0091822.

Trichomonas vaginalis can host the endosymbiont Mycoplasma hominis, an opportunistic pathogenic bacterium capable of modulating T. vaginalis pathobiology. Recently, a new noncultivable mycoplasma, "Candidatus Mycoplasma girerdii," has been shown to be closely associated with women affected by trichomoniasis, suggesting a biological association. Although several features of "Ca. M. girerdii" have been investigated through genomic analysis, the nature of the potential T. vaginalis-"Ca. M. girerdii" consortium and its impact on the biology and pathogenesis of both microorganisms have not yet been explored. Here, we investigate the association between "Ca. M. girerdii" and T. vaginalis isolated from patients affected by trichomoniasis, demonstrating their intracellular localization. By using an in vitro model system based on single- and double-Mycoplasma infection of Mycoplasma-free isogenic T. vaginalis, we investigated the ability of the protist to establish a relationship with the bacteria and impact T. vaginalis growth. Our data indicate likely competition between M. hominis and "Ca. M. girerdii" while infecting trichomonad cells. Comparative dual-transcriptomics data showed major shifts in parasite gene expression in response to the presence of Mycoplasma, including genes associated with energy metabolism and pathogenesis. Consistent with the transcriptomics data, both parasite-mediated hemolysis and binding to host epithelial cells were significantly upregulated in the presence of either Mycoplasma species. Taken together, these results support a model in which this microbial association could modulate the virulence of T. vaginalis. IMPORTANCE T. vaginalis and M. hominis form a unique case of endosymbiosis that modulates the parasite's pathobiology. Recently, a new nonculturable mycoplasma species ("Candidatus Mycoplasma girerdii") has been described as closely associated with the protozoon. Here, we report the characterization of this endosymbiotic relationship. Clinical isolates of the parasite demonstrate that mycoplasmas are common among trichomoniasis patients. The relationships are studied by devising an in vitro system of single and/or double infections in isogenic protozoan recipients. Comparative growth experiments and transcriptomics data demonstrate that the composition of different microbial consortia influences the growth of the parasite and significantly modulates its transcriptomic profile, including metabolic enzymes and virulence genes such as adhesins and pore-forming proteins. The data on modulation from RNA sequencing (RNA-Seq) correlated closely with those of the cytopathic effect and adhesion to human target cells. We propose the hypothesis that the presence and the quantitative ratios of endosymbionts may contribute to modulating protozoan virulence. Our data highlight the importance of considering pathogenic entities as microbial ecosystems, reinforcing the importance of the development of integrated diagnostic and therapeutic strategies.

RevDate: 2022-08-05

Verhoeve VI, Fauntleroy TD, Risteen RG, et al (2022)

Cryptic Genes for Interbacterial Antagonism Distinguish Rickettsia Species Infecting Blacklegged Ticks From Other Rickettsia Pathogens.

Frontiers in cellular and infection microbiology, 12:880813.

Background: The genus Rickettsia (Alphaproteobacteria: Rickettsiales) encompasses numerous obligate intracellular species with predominantly ciliate and arthropod hosts. Notable species are pathogens transmitted to mammals by blood-feeding arthropods. Mammalian pathogenicity evolved from basal, non-pathogenic host-associations; however, some non-pathogens are closely related to pathogens. One such species, Rickettsia buchneri, is prevalent in the blacklegged tick, Ixodes scapularis. While I. scapularis transmits several pathogens to humans, it does not transmit Rickettsia pathogens. We hypothesize that R. buchneri established a mutualism with I. scapularis, blocking tick superinfection with Rickettsia pathogens.

Methods: To improve estimates for assessing R. buchneri infection frequency in blacklegged tick populations, we used comparative genomics to identify an R. buchneri gene (REIS_1424) not present in other Rickettsia species present throughout the I. scapularis geographic range. Bioinformatic and phylogenomics approaches were employed to propose a function for the hypothetical protein (263 aa) encoded by REIS_1424.

Results: REIS_1424 has few analogs in other Rickettsiales genomes and greatest similarity to non-Proteobacteria proteins. This cohort of proteins varies greatly in size and domain composition, possessing characteristics of Recombination hotspot (Rhs) and contact dependent growth inhibition (CDI) toxins, with similarity limited to proximal C-termini (~145 aa). This domain was named CDI-like/Rhs-like C-terminal toxin (CRCT). As such proteins are often found as toxin-antidote (TA) modules, we interrogated REIS_1423 (151 aa) as a putative antidote. Indeed, REIS_1423 is similar to proteins encoded upstream of CRCT domain-containing proteins. Accordingly, we named these proteins CDI-like/Rhs-like C-terminal toxin antidotes (CRCA). R. buchneri expressed both REIS_1423 and REIS_1424 in tick cell culture, and PCR assays showed specificity for R. buchneri over other rickettsiae and utility for positive detection in three tick populations. Finally, phylogenomics analyses uncovered divergent CRCT/CRCA modules in varying states of conservation; however, only R. buchneri and related Tamurae/Ixodes Group rickettsiae carry complete TA modules.

Conclusion: We hypothesize that Rickettsia CRCT/CRCA modules circulate in the Rickettsia mobile gene pool, arming rickettsiae for battle over arthropod colonization. While its functional significance remains to be tested, R. buchneri CRCT/CRCA serves as a marker to positively identify infection and begin deciphering the role this endosymbiont plays in the biology of the blacklegged tick.

RevDate: 2022-05-21

Guizzo MG, Tirloni L, Gonzalez SA, et al (2022)

Coxiella Endosymbiont of Rhipicephalus microplus Modulates Tick Physiology With a Major Impact in Blood Feeding Capacity.

Frontiers in microbiology, 13:868575.

In the past decade, metagenomics studies exploring tick microbiota have revealed widespread interactions between bacteria and arthropods, including symbiotic interactions. Functional studies showed that obligate endosymbionts contribute to tick biology, affecting reproductive fitness and molting. Understanding the molecular basis of the interaction between ticks and their mutualist endosymbionts may help to develop control methods based on microbiome manipulation. Previously, we showed that Rhipicephalus microplus larvae with reduced levels of Coxiella endosymbiont of R. microplus (CERM) were arrested at the metanymph life stage (partially engorged nymph) and did not molt into adults. In this study, we performed a transcriptomic differential analysis of the R. microplus metanymph in the presence and absence of its mutualist endosymbiont. The lack of CERM resulted in an altered expression profile of transcripts from several functional categories. Gene products such as DA-P36, protease inhibitors, metalloproteases, and evasins, which are involved in blood feeding capacity, were underexpressed in CERM-free metanymphs. Disregulation in genes related to extracellular matrix remodeling was also observed in the absence of the symbiont. Taken together, the observed alterations in gene expression may explain the blockage of development at the metanymph stage and reveal a novel physiological aspect of the symbiont-tick-vertebrate host interaction.

RevDate: 2022-08-24
CmpDate: 2022-08-11

Bashir F, Kovács S, Ábrahám Á, et al (2022)

Viable protoplast formation of the coral endosymbiont alga Symbiodinium spp. in a microfluidics platform.

Lab on a chip, 22(16):2986-2999.

Symbiodiniaceae is an important dinoflagellate family which lives in endosymbiosis with reef invertebrates, including coral polyps, making them central to the holobiont. With coral reefs currently under extreme threat from climate change, there is a pressing need to improve our understanding on the stress tolerance and stress avoidance mechanisms of Symbiodinium spp. Reactive oxygen species (ROS) such as singlet oxygen are central players in mediating various stress responses; however, the detection of ROS using specific dyes is still far from definitive in intact Symbiodinium cells due to the hindrance of uptake of certain fluorescent dyes because of the presence of the cell wall. Protoplast technology provides a promising platform for studying oxidative stress with the main advantage of removed cell wall, however the preparation of viable protoplasts remains a significant challenge. Previous studies have successfully applied cellulose-based protoplast preparation in Symbiodiniaceae; however, the protoplast formation and regeneration process was found to be suboptimal. Here, we present a microfluidics-based platform which allowed protoplast isolation from individually trapped Symbiodinium cells, by using a precisely adjusted flow of cell wall digestion enzymes (cellulase and macerozyme). Trapped single cells exhibited characteristic changes in their morphology, cessation of cell division and a slight decrease in photosynthetic activity during protoplast formation. Following digestion and transfer to regeneration medium, protoplasts remained photosynthetically active, regrew cell walls, regained motility, and entered exponential growth. Elevated flow rates in the microfluidic chambers resulted in somewhat faster protoplast formation; however, cell wall digestion at higher flow rates partially compromised photosynthetic activity. Physiologically competent protoplasts prepared from trapped cells in microfluidic chambers allowed for the first time the visualization of the intracellular localization of singlet oxygen (using Singlet Oxygen Sensor Green dye) in Symbiodiniaceae, potentially opening new avenues for studying oxidative stress.

RevDate: 2022-08-15
CmpDate: 2022-07-01

Chaput G, Ford J, DeDiego L, et al (2022)

Sodalis ligni Strain 159R Isolated from an Anaerobic Lignin-Degrading Consortium.

Microbiology spectrum, 10(3):e0234621.

Novel bacterial isolates with the capabilities of lignin depolymerization, catabolism, or both, could be pertinent to lignocellulosic biofuel applications. In this study, we aimed to identify anaerobic bacteria that could address the economic challenges faced with microbial-mediated biotechnologies, such as the need for aeration and mixing. Using a consortium seeded from temperate forest soil and enriched under anoxic conditions with organosolv lignin as the sole carbon source, we successfully isolated a novel bacterium, designated 159R. Based on the 16S rRNA gene, the isolate belongs to the genus Sodalis in the family Bruguierivoracaceae. Whole-genome sequencing revealed a genome size of 6.38 Mbp and a GC content of 55 mol%. To resolve the phylogenetic position of 159R, its phylogeny was reconstructed using (i) 16S rRNA genes of its closest relatives, (ii) multilocus sequence analysis (MLSA) of 100 genes, (iii) 49 clusters of orthologous groups (COG) domains, and (iv) 400 conserved proteins. Isolate 159R was closely related to the deadwood associated Sodalis guild rather than the tsetse fly and other insect endosymbiont guilds. Estimated genome-sequence-based digital DNA-DNA hybridization (dDDH), genome percentage of conserved proteins (POCP), and an alignment analysis between 159R and the Sodalis clade species further supported that isolate 159R was part of the Sodalis genus and a strain of Sodalis ligni. We proposed the name Sodalis ligni str. 159R (=DSM 110549 = ATCC TSD-177). IMPORTANCE Currently, in the paper industry, paper mill pulping relies on unsustainable and costly processes to remove lignin from lignocellulosic material. A greener approach is biopulping, which uses microbes and their enzymes to break down lignin. However, there are limitations to biopulping that prevent it from outcompeting other pulping processes, such as requiring constant aeration and mixing. Anaerobic bacteria are a promising alternative source for consolidated depolymerization of lignin and its conversion to valuable by-products. We presented Sodalis ligni str. 159R and its characteristics as another example of potential mechanisms that can be developed for lignocellulosic applications.

RevDate: 2022-07-23
CmpDate: 2022-05-17

Elaagip A, Absalon S, A Florentin (2022)

Apicoplast Dynamics During Plasmodium Cell Cycle.

Frontiers in cellular and infection microbiology, 12:864819.

The deadly malaria parasite, Plasmodium falciparum, contains a unique subcellular organelle termed the apicoplast, which is a clinically-proven antimalarial drug target. The apicoplast is a plastid with essential metabolic functions that evolved via secondary endosymbiosis. As an ancient endosymbiont, the apicoplast retained its own genome and it must be inherited by daughter cells during cell division. During the asexual replication of P. falciparum inside human red blood cells, both the parasite, and the apicoplast inside it, undergo massive morphological changes, including DNA replication and division. The apicoplast is an integral part of the cell and thus its development is tightly synchronized with the cell cycle. At the same time, certain aspects of its dynamics are independent of nuclear division, representing a degree of autonomy in organelle biogenesis. Here, we review the different aspects of organelle dynamics during P. falciparum intraerythrocytic replication, summarize our current understanding of these processes, and describe the many open questions in this area of parasite basic cell biology.

RevDate: 2022-07-16
CmpDate: 2022-05-17

Parejo S, Cabrera JJ, Jiménez-Leiva A, et al (2022)

Fine-Tuning Modulation of Oxidation-Mediated Posttranslational Control of Bradyrhizobium diazoefficiens FixK2 Transcription Factor.

International journal of molecular sciences, 23(9):.

FixK2 is a CRP/FNR-type transcription factor that plays a central role in a sophisticated regulatory network for the anoxic, microoxic and symbiotic lifestyles of the soybean endosymbiont Bradyrhizobium diazoefficiens. Aside from the balanced expression of the fixK2 gene under microoxic conditions (induced by the two-component regulatory system FixLJ and negatively auto-repressed), FixK2 activity is posttranslationally controlled by proteolysis, and by the oxidation of a singular cysteine residue (C183) near its DNA-binding domain. To simulate the permanent oxidation of FixK2, we replaced C183 for aspartic acid. Purified C183D FixK2 protein showed both low DNA binding and in vitro transcriptional activation from the promoter of the fixNOQP operon, required for respiration under symbiosis. However, in a B. diazoefficiens strain coding for C183D FixK2, expression of a fixNOQP'-'lacZ fusion was similar to that in the wild type, when both strains were grown microoxically. The C183D FixK2 encoding strain also showed a wild-type phenotype in symbiosis with soybeans, and increased fixK2 gene expression levels and FixK2 protein abundance in cells. These two latter observations, together with the global transcriptional profile of the microoxically cultured C183D FixK2 encoding strain, suggest the existence of a finely tuned regulatory strategy to counterbalance the oxidation-mediated inactivation of FixK2 in vivo.

RevDate: 2022-07-16
CmpDate: 2022-05-17

Buerger P, Vanstone RT, Maire J, et al (2022)

Long-Term Heat Selection of the Coral Endosymbiont Cladocopium C1acro (Symbiodiniaceae) Stabilizes Associated Bacterial Communities.

International journal of molecular sciences, 23(9):.

Heat-tolerant strains of the coral endosymbiont, Cladocopium C1acro (Symbiodiniaceae), have previously been developed via experimental evolution. Here, we examine physiological responses and bacterial community composition (using 16S rRNA gene metabarcoding) in cultures of 10 heat-evolved (SS) and 9 wild-type (WT) strains, which had been exposed for 6 years to 31 °C and 27 °C, respectively. We also examine whether the associated bacterial communities were affected by a three-week reciprocal transplantation to both temperatures. The SS strains had bacterial communities with lower diversities that showed more stability and lower variability when exposed to elevated temperatures compared with the WT strains. Amplicon sequence variants (ASVs) of the bacterial genera Labrenzia, Algiphilus, Hyphobacterium and Roseitalea were significantly more associated with the SS strains compared with the WT strains. WT strains showed higher abundance of ASVs assigned to the genera Fabibacter and Tropicimonas. We hypothesize that these compositional differences in associated bacterial communities between SS and WT strains also contribute to the thermal tolerance of the microalgae. Future research should explore functional potential between bacterial communities using metagenomics to unravel specific genomic adaptations.

RevDate: 2022-07-16
CmpDate: 2022-05-26

Zhou W, Zhang X, Wang A, et al (2022)

Widespread Sterol Methyltransferase Participates in the Biosynthesis of Both C4α- and C4β-Methyl Sterols.

Journal of the American Chemical Society, 144(20):9023-9032.

The 4-methyl steranes serve as molecular fossils and are used for studying both eukaryotic evolution and geological history. The occurrence of 4α-methyl steranes in sediments has long been considered evidence of products of partial demethylation mediated by sterol methyl oxidases (SMOs), while 4β-methyl steranes are attributed entirely to diagenetic generation from 4α-methyl steroids since possible biological sources of their precursor 4β-methyl sterols are unknown. Here, we report a previously unknown C4-methyl sterol biosynthetic pathway involving a sterol methyltransferase rather than the SMOs. We show that both C4α- and C4β-methyl sterols are end products of the sterol biosynthetic pathway in an endosymbiont of reef corals, Breviolum minutum, while this mechanism exists not only in dinoflagellates but also in eukaryotes from alveolates, haptophytes, and aschelminthes. Our discovery provides a previously untapped route for the generation of C4-methyl steranes and overturns the paradigm that all 4β-methyl steranes are diagenetically generated from the 4α isomers. This may facilitate the interpretation of molecular fossils and understanding of the evolution of eukaryotic life in general.

RevDate: 2022-07-16
CmpDate: 2022-05-27

Thayanukul P, Lertanantawong B, Sirawaraporn W, et al (2022)

Simple, sensitive, and cost-effective detection of wAlbB Wolbachia in Aedes mosquitoes, using loop mediated isothermal amplification combined with the electrochemical biosensing method.

PLoS neglected tropical diseases, 16(5):e0009600.

BACKGROUND: Wolbachia is an endosymbiont bacterium generally found in about 40% of insects, including mosquitoes, but it is absent in Aedes aegypti which is an important vector of several arboviral diseases. The evidence that Wolbachia trans-infected Ae. aegypti mosquitoes lost their vectorial competence and became less capable of transmitting arboviruses to human hosts highlights the potential of using Wolbachia-based approaches for prevention and control of arboviral diseases. Recently, release of Wolbachia trans-infected Ae. aegypti has been deployed widely in many countries for the control of mosquito-borne viral diseases. Field surveillance and monitoring of Wolbachia presence in released mosquitoes is important for the success of these control programs. So far, a number of studies have reported the development of loop mediated isothermal amplification (LAMP) assays to detect Wolbachia in mosquitoes, but the methods still have some specificity and cost issues.

We describe here the development of a LAMP assay combined with the DNA strand displacement-based electrochemical sensor (BIOSENSOR) method to detect wAlbB Wolbachia in trans-infected Ae. aegypti. Our developed LAMP primers used a low-cost dye detecting system and 4 oligo nucleotide primers which can reduce the cost of analysis while the specificity is comparable to the previous methods. The detection capacity of our LAMP technique was 1.4 nM and the detection limit reduced to 2.2 fM when combined with the BIOSENSOR. Our study demonstrates that a BIOSENSOR can also be applied as a stand-alone method for detecting Wolbachia; and it showed high sensitivity when used with the crude DNA extracts of macerated mosquito samples without DNA purification.

CONCLUSIONS/SIGNIFICANCE: Our results suggest that both LAMP and BIOSENSOR, either used in combination or stand-alone, are robust and sensitive. The methods have good potential for routine detection of Wolbachia in mosquitoes during field surveillance and monitoring of Wolbachia-based release programs, especially in countries with limited resources.

RevDate: 2022-07-16

Weyandt N, Aghdam SA, AMV Brown (2022)

Discovery of Early-Branching Wolbachia Reveals Functional Enrichment on Horizontally Transferred Genes.

Frontiers in microbiology, 13:867392.

Wolbachia is a widespread endosymbiont of insects and filarial nematodes that profoundly influences host biology. Wolbachia has also been reported in rhizosphere hosts, where its diversity and function remain poorly characterized. The discovery that plant-parasitic nematodes (PPNs) host Wolbachia strains with unknown roles is of interest evolutionarily, ecologically, and for agriculture as a potential target for developing new biological controls. The goal of this study was to screen communities for PPN endosymbionts and analyze genes and genomic patterns that might indicate their role. Genome assemblies revealed 1 out of 16 sampled sites had nematode communities hosting a Wolbachia strain, designated wTex, that has highly diverged as one of the early supergroup L strains. Genome features, gene repertoires, and absence of known genes for cytoplasmic incompatibility, riboflavin, biotin, and other biosynthetic functions placed wTex between mutualist C + D strains and reproductive parasite A + B strains. Functional terms enriched in group L included protoporphyrinogen IX, thiamine, lysine, fatty acid, and cellular amino acid biosynthesis, while dN/dS analysis suggested the strongest purifying selection on arginine and lysine metabolism, and vitamin B6, heme, and zinc ion binding, suggesting these as candidate roles in PPN Wolbachia. Higher dN/dS pathways between group L, wPni from aphids, wFol from springtails, and wCfeT from cat fleas suggested distinct functional changes characterizing these early Wolbachia host transitions. PPN Wolbachia had several putative horizontally transferred genes, including a lysine biosynthesis operon like that of the mitochondrial symbiont Midichloria, a spirochete-like thiamine synthesis operon shared only with wCfeT, an ATP/ADP carrier important in Rickettsia, and a eukaryote-like gene that may mediate plant systemic acquired resistance through the lysine-to-pipecolic acid system. The Discovery of group L-like variants from global rhizosphere databases suggests diverse PPN Wolbachia strains remain to be discovered. These findings support the hypothesis of plant-specialization as key to shaping early Wolbachia evolution and present new functional hypotheses, demonstrating promise for future genomics-based rhizosphere screens.

RevDate: 2022-07-16

Moustafa MAM, Mohamed WMA, Lau ACC, et al (2022)

Novel symbionts and potential human pathogens excavated from argasid tick microbiomes that are shaped by dual or single symbiosis.

Computational and structural biotechnology journal, 20:1979-1992.

Research on vector-associated microbiomes has been expanding due to increasing emergence of vector-borne pathogens and awareness of the importance of symbionts in the vector physiology. However, little is known about microbiomes of argasid (or soft-bodied) ticks due to limited access to specimens. We collected four argasid species (Argas japonicus, Carios vespertilionis, Ornithodoros capensis, and Ornithodoros sawaii) from the nests or burrows of their vertebrate hosts. One laboratory-reared argasid species (Ornithodoros moubata) was also included. Attempts were then made to isolate and characterize potential symbionts/pathogens using arthropod cell lines. Microbial community structure was distinct for each tick species. Coxiella was detected as the predominant symbiont in four tick species where dual symbiosis between Coxiella and Rickettsia or Coxiella and Francisella was observed in C. vespertilionis and O. moubata, respectively. Of note, A. japonicus lacked Coxiella and instead had Occidentia massiliensis and Thiotrichales as alternative symbionts. Our study found strong correlation between tick species and life stage. We successfully isolated Oc. massiliensis and characterized potential pathogens of genera Ehrlichia and Borrelia. The results suggest that there is no consistent trend of microbiomes in relation to tick life stage that fit all tick species and that the final interpretation should be related to the balance between environmental bacterial exposure and endosymbiont ecology. Nevertheless, our findings provide insights on the ecology of tick microbiomes and basis for future investigations on the capacity of argasid ticks to carry novel pathogens with public health importance.

RevDate: 2022-07-16

Kačar D, Schleissner C, Cañedo LM, et al (2022)

In vivo production of pederin by labrenzin pathway expansion.

Metabolic engineering communications, 14:e00198.

Pederin is a potent polyketide toxin that causes severe skin lesions in humans after contact with insects of genus Paederus. Due to its potent anticancer activities, pederin family compounds have raised the interest of pharmaceutical industry. Despite the extensive studies on the cluster of biosynthetic genes responsible for the production of pederin, it has not yet been possible to isolate and cultivate its bacterial endosymbiont producer. However, the marine bacterium Labrenzia sp. PHM005 was recently reported to produce labrenzin, the closest pederin analog. By cloning a synthetic pedO gene encoding one of the three O-methyltraferase of the pederin cluster into Labrenzia sp. PHM005 we have been able to produce pederin for the first time by fermentation in the new recombinant strain.

RevDate: 2022-07-16
CmpDate: 2022-05-03

Kumar D, Sharma SR, Adegoke A, et al (2022)

Recently Evolved Francisella-Like Endosymbiont Outcompetes an Ancient and Evolutionarily Associated Coxiella-Like Endosymbiont in the Lone Star Tick (Amblyomma americanum) Linked to the Alpha-Gal Syndrome.

Frontiers in cellular and infection microbiology, 12:787209.

Background: Ticks are hematophagous arthropods that transmit various bacterial, viral, and protozoan pathogens of public health significance. The lone star tick (Amblyomma americanum) is an aggressive human-biting tick that transmits bacterial and viral pathogens, and its bites are suspected of eliciting the alpha-gal syndrome, a newly emerged delayed hypersensitivity following consumption of red meat in the United States. While ongoing studies have attempted to investigate the contribution of different tick-inherent factors to the induction of alpha-gal syndrome, an otherwise understudied aspect is the contribution of the tick microbiome and specifically obligate endosymbionts to the establishment of the alpha-gal syndrome in humans.

Materials and Methods: Here we utilized a high-throughput metagenomic sequencing approach to cataloging the entire microbial communities residing within different developmental stages and tissues of unfed and blood-fed ticks from laboratory-maintained ticks and three new geographical locations in the United States. The Quantitative Insights Into Microbial Ecology (QIIME2) pipeline was used to perform data analysis and taxonomic classification. Moreover, using a SparCC (Sparse Correlations for Compositional data) network construction model, we investigated potential interactions between members of the microbial communities from laboratory-maintained and field-collected ticks.

Results: Overall, Francisellaceae was the most dominant bacteria identified in the microbiome of both laboratory-raised and field-collected Am. americanum across all tissues and developmental stages. Likewise, microbial diversity was seen to be significantly higher in field-collected ticks compared with laboratory-maintained ticks as seen with a higher number of both Operational Taxonomic Units and measures of species richness. Several potential positive and negative correlations were identified from our network analysis. We observed a strong positive correlation between Francisellaceae, Rickettsiaceae, and Midichloriaceae in both developmental stages and tissues from laboratory-maintained ticks, whereas ovarian tissues had a strong positive correlation of bacteria in the family Xanthobacteraceae and Rhizobiaceae. A negative interaction was observed between Coxiellaceae and Francisellaceae in Illinois, and all the bacteria detected from ticks from Delaware were negatively correlated.

Conclusion: This study is the first to catalog the microbiome of Am. americanum throughout its developmental stages and different tissue niches and report the potential replacement of Coxiellaceae by Francisellaceae across developmental stages and tissues tested except in ovarian tissues. These unique and significant findings advance our knowledge and open a new avenue of research to further understand the role of tick microbiome in tick-borne diseases and develop a holistic strategy to control alpha-gal syndrome.

RevDate: 2022-07-22
CmpDate: 2022-06-08

Noden BH, Henriquez BE, Roselli MA, et al (2022)

Use of an exclusion assay to detect novel rickettsiae in field collected Amblyomma americanum.

Ticks and tick-borne diseases, 13(4):101959.

In the south-central United States, several tick-borne diseases (TbDs) occur at or near their highest levels of incidence of anywhere in the U.S. The diversity of Rickettsia species found in Amblyomma americanum continues to be under-characterized in this region and throughout the U.S. and Canada where this tick species is expanding. One reason for this lack of knowledge about Rickettsia diversity is the high prevalence of the endosymbiont Rickettsia amblyommatis that obscures detection of other bacteria in this genus. Focusing on unknown rickettsial agents, we used a recently described R. amblyommatis exclusion assay to screen 1909 A. americanum collected in Oklahoma City, Oklahoma, which resulted in eight ticks that had unique rickettsial sequences. Through the process of characterizing primary and secondary rickettsiae, we identified ticks primarily infected with Rickettsia rhipicephali and a Rickettsia species (2019-CO-FNY) previously linked with a canine rickettsiosis case in Tulsa, Oklahoma. We also identified a Rickettsia agent that was 97% identical with an endosymbiont of Amblyomma tonelliae and which aligned with archaic rickettsial species. Through this study, we further demonstrate the usefulness of this exclusion assay for rapid screening in large cohort A. americanum studies to identify a small number of ticks that contain poorly described and previously undocumented rickettsiae.

RevDate: 2022-08-23
CmpDate: 2022-06-21

Kaur R, Singh S, N Joshi (2022)

Pervasive Endosymbiont Arsenophonus Plays a Key Role in the Transmission of Cotton Leaf Curl Virus Vectored by Asia II-1 Genetic Group of Bemisia tabaci.

Environmental entomology, 51(3):564-577.

Insects often coevolved with their mutualistic partners such as gut endosymbionts, which play a key in the physiology of host. Studies on such interactions between Bemisia tabaci and its primary and secondary endosymbionts have gained importance due to their indispensable roles in the biology of this insect. Present study reports the predominance of two secondary endosymbionts, Arsenophonus and Cardinium in the Asia II-1 genetic group of whitefly and elucidates their role in the transmission of its vectored Cotton leaf curl virus. Selective elimination of endosymbionts was optimized using serial concentration of ampicillin, chloramphenicol, kanamycin, tetracycline, and rifampicin administered to viruliferous whiteflies through sucrose diet. Primary endosymbiont, Portiera was unresponsive to all the antibiotics, however, rifampicin and tetracycline at 90 μg/ml selectively eliminated Arsenophonus from the whitefly. Elimination of Arsenophonus resulted in significant decrease in virus titer from viruliferous whitefly, further the CLCuV transmission efficiency of these whiteflies was significantly reduced compared to the control flies. Secondary endosymbiont, Cardinium could not be eliminated completely even with higher concentrations of antibiotics. Based on the findings, Arsenophonus plays a key role in the retention and transmission of CLCuV in the Asia II-1 genetic group of B. tabaci, while the role of Cardinium could not be established due to its unresponsiveness to antibiotics.


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.

Electronic Scholarly Publishing
961 Red Tail Lane
Bellingham, WA 98226

E-mail: RJR8222 @

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).


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


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 )