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Dagar J, Maurya S, Antil S, Abraham JS, Somasundaram S, Lal R, Makhija S, Toteja R. Symbionts of Ciliates and Ciliates as Symbionts. Indian J Microbiol 2024; 64:304-317. [PMID: 39010998 PMCID: PMC11246404 DOI: 10.1007/s12088-024-01203-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/06/2024] [Indexed: 07/17/2024] Open
Abstract
Endosymbiotic relationships between ciliates and others are critical for their ecological roles, physiological adaptations, and evolutionary implications. These can be obligate and facultative. Symbionts often provide essential nutrients, contribute to the ciliate's metabolism, aid in digestion, and offer protection against predators or environmental stressors. In turn, ciliates provide a protected environment and resources for their symbionts, facilitating their survival and proliferation. Ultrastructural and full-cycle rRNA approaches are utilized to identify these endosymbionts. Fluorescence in situ hybridization using "species- and group-specific probes" which are complementary to the genetic material (DNA or RNA) of a particular species or group of interest represent convenient tools for their detection directly in the environment. A systematic survey of these endosymbionts has been conducted using both traditional and metagenomic approaches. Ciliophora and other protists have a wide range of prokaryotic symbionts, which may contain potentially pathogenic bacteria. Ciliates can establish symbiotic relationships with a variety of hosts also, ranging from protists to metazoans. Understanding ciliate symbiosis can provide useful insights into the complex relationships that drive microbial communities and ecosystems in general.
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Affiliation(s)
- Jyoti Dagar
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
| | - Swati Maurya
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
| | - Sandeep Antil
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
| | | | | | - Rup Lal
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
| | - Seema Makhija
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
| | - Ravi Toteja
- Acharya Narendra Dev College, University of Delhi, New Delhi, India
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2
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Zhang B, Xiao L, Lyu L, Zhao F, Miao M. Exploring the landscape of symbiotic diversity and distribution in unicellular ciliated protists. MICROBIOME 2024; 12:96. [PMID: 38790063 PMCID: PMC11127453 DOI: 10.1186/s40168-024-01809-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 04/04/2024] [Indexed: 05/26/2024]
Abstract
BACKGROUND The eukaryotic-bacterial symbiotic system plays an important role in various physiological, developmental, and evolutionary processes. However, our current understanding is largely limited to multicellular eukaryotes without adequate consideration of diverse unicellular protists, including ciliates. RESULTS To investigate the bacterial profiles associated with unicellular organisms, we collected 246 ciliate samples spanning the entire Ciliophora phylum and conducted single-cell based metagenome sequencing. This effort has yielded the most extensive collection of bacteria linked to unicellular protists to date. From this dataset, we identified 883 bacterial species capable of cohabiting with ciliates, unveiling the genomes of 116 novel bacterial cohabitants along with 7 novel archaeal cohabitants. Highlighting the intimate relationship between ciliates and their cohabitants, our study unveiled that over 90% of ciliates coexist with bacteria, with individual hosts fostering symbiotic relationships with multiple bacteria concurrently, resulting in the observation of seven distinct symbiotic patterns among bacteria. Our exploration of symbiotic mechanisms revealed the impact of host digestion on the intracellular diversity of cohabitants. Additionally, we identified the presence of eukaryotic-like proteins in bacteria as a potential contributing factor to their resistance against host digestion, thereby expanding their potential host range. CONCLUSIONS As the first large-scale analysis of prokaryotic associations with ciliate protists, this study provides a valuable resource for future research on eukaryotic-bacterial symbioses. Video Abstract.
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Affiliation(s)
- Bing Zhang
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Liwen Xiao
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
| | - Liping Lyu
- Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education), and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Fangqing Zhao
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
| | - Miao Miao
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
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3
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Lehman SS, Verhoeve VI, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates the origins of pathogen effectors. mBio 2024; 15:e0075923. [PMID: 38564675 PMCID: PMC11077975 DOI: 10.1128/mbio.00759-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Recent metagenome-assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. The discovery of basal lineages (novel families Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles exposed an evolutionary timepoint for the transition to host dependency, which seemingly occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for later-evolving rickettsial pathogens. MAG analysis also substantially increased diversity for the genus Rickettsia and delineated a sister lineage (the novel genus Tisiphia) that stands to inform on the emergence of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages illuminates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, indicating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role in shaping the rvh effector landscape, as evinced by the discovery of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can yield insight into pathogen effector origins, particularly how effector architectures might become tailored to the discrete host cell functions of different eukaryotic hosts.IMPORTANCEWhile rickettsioses are deadly vector-borne human diseases, factors distinguishing Rickettsia pathogens from the innumerable bevy of environmental rickettsial endosymbionts remain lacking. Recent metagenome-assembled genome (MAG) studies revealed evolutionary timepoints for rickettsial transitions to host dependency. The rvh type IV secretion system was likely repurposed from congener killing in basal extracellular species to parasitizing host cells in later-evolving pathogens. Our analysis of MAG diversity for over two dozen rvh effectors unearthed their presence in some non-pathogens. However, most effectors were found in multiple divergent forms with variable architectures, indicating gene duplication and recombination-fashioned effector repertoires of Rickettsia pathogens. Lateral gene transfer substantially shaped pathogen effector arsenals, evinced by the discovery of effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchanges between Rickettsia and Legionella species. Our study exemplifies how MAGs yield insight into pathogen effector origins and evolutionary processes tailoring effectors to eukaryotic host cell biology.
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Affiliation(s)
- Stephanie S. Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Victoria I. Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Timothy P. Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F. Beckmann
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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4
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Castelli M, Nardi T, Gammuto L, Bellinzona G, Sabaneyeva E, Potekhin A, Serra V, Petroni G, Sassera D. Host association and intracellularity evolved multiple times independently in the Rickettsiales. Nat Commun 2024; 15:1093. [PMID: 38321113 PMCID: PMC10847448 DOI: 10.1038/s41467-024-45351-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/18/2024] [Indexed: 02/08/2024] Open
Abstract
The order Rickettsiales (Alphaproteobacteria) encompasses multiple diverse lineages of host-associated bacteria, including pathogens, reproductive manipulators, and mutualists. Here, in order to understand how intracellularity and host association originated in this order, and whether they are ancestral or convergently evolved characteristics, we built a large and phylogenetically-balanced dataset that includes de novo sequenced genomes and a selection of published genomic and metagenomic assemblies. We perform detailed functional reconstructions that clearly indicates "late" and parallel evolution of obligate host-association in different Rickettsiales lineages. According to the depicted scenario, multiple independent horizontal acquisitions of transporters led to the progressive loss of biosynthesis of nucleotides, amino acids and other metabolites, producing distinct conditions of host-dependence. Each clade experienced a different pattern of evolution of the ancestral arsenal of interaction apparatuses, including development of specialised effectors involved in the lineage-specific mechanisms of host cell adhesion and/or invasion.
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Affiliation(s)
- Michele Castelli
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Tiago Nardi
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | | | - Greta Bellinzona
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Elena Sabaneyeva
- Department of Cytology and Histology, Saint Petersburg State University, Petersburg, Russia
| | - Alexey Potekhin
- Department of Microbiology, Saint Petersburg State University, Petersburg, Russia
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | | | | | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy.
- IRCCS Policlinico San Matteo, Pavia, Italy.
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5
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Song Q, Zhao F, Hou L, Miao M. Cellular interactions and evolutionary origins of endosymbiotic relationships with ciliates. THE ISME JOURNAL 2024; 18:wrae117. [PMID: 38916437 PMCID: PMC11253213 DOI: 10.1093/ismejo/wrae117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/26/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
As unicellular predators, ciliates engage in close associations with diverse microbes, laying the foundation for the establishment of endosymbiosis. Originally heterotrophic, ciliates demonstrate the ability to acquire phototrophy by phagocytizing unicellular algae or by sequestering algal plastids. This adaptation enables them to gain photosynthate and develop resistance to unfavorable environmental conditions. The integration of acquired phototrophy with intrinsic phagotrophy results in a trophic mode known as mixotrophy. Additionally, ciliates can harbor thousands of bacteria in various intracellular regions, including the cytoplasm and nucleus, exhibiting species specificity. Under prolonged and specific selective pressure within hosts, bacterial endosymbionts evolve unique lifestyles and undergo particular reductions in metabolic activities. Investigating the research advancements in various endosymbiotic cases within ciliates will contribute to elucidate patterns in cellular interaction and unravel the evolutionary origins of complex traits.
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Affiliation(s)
- Qi Song
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
| | - Fangqing Zhao
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
- Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1 Xiangshan Road, Hangzhou 310024, China
| | - Lina Hou
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
| | - Miao Miao
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
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6
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Giovannini M, Petroni G, Castelli M. Novel evolutionary insights on the interactions of the Holosporales (Alphaproteobacteria) with eukaryotic hosts from comparative genomics. Environ Microbiol 2024; 26:e16562. [PMID: 38173299 DOI: 10.1111/1462-2920.16562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024]
Abstract
Holosporales are an alphaproteobacterial order engaging in obligate and complex associations with eukaryotes, in particular protists. The functional and evolutionary features of those interactions are still largely undisclosed. Here, we sequenced the genomes of two members of the species Bealeia paramacronuclearis (Holosporales, Holosporaceae) intracellularly associated with the ciliate protist Paramecium, which resulted in high correspondence. Consistent with the short-branched early-divergent phylogenetic position, Bealeia presents a larger functional repertoire than other Holosporaceae, comparable to those of other Holosporales families, particularly for energy metabolism and motility. Our analyses indicate that different Holosporales likely experienced at least partly autonomous genome reduction and adaptation to host interactions, for example regarding dependence on host biotin driven by multiple independent horizontal acquisitions of transporters. Among Alphaproteobacteria, this is reminiscent of the convergently evolved Rickettsiales, which however appear more diverse, possibly due to a probably more ancient origin. We identified in Bealeia and other Holosporales the plasmid-encoded putative genetic determinants of R-bodies, which may be involved in a killer trait towards symbiont-free hosts. While it is not clear whether these genes are ancestral or recently horizontally acquired, an intriguing and peculiar role of R-bodies is suggested in the evolution of the interactions of multiple Holosporales with their hosts.
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Affiliation(s)
| | | | - Michele Castelli
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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7
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: comprehensive analysis of the mobilome of a highly fragmented and repetitive genome reveals the capacity for ongoing lateral gene transfer in an obligate intracellular bacterium. mSphere 2023; 8:e0026823. [PMID: 37850800 PMCID: PMC10732058 DOI: 10.1128/msphere.00268-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/22/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Obligate intracellular bacteria, or those only capable of growth inside other living cells, have limited opportunities for horizontal gene transfer with other microbes due to their isolated replicative niche. The human pathogen Ot, an obligate intracellular bacterium causing scrub typhus, encodes an unusually high copy number of a ~40 gene mobile genetic element that typically facilitates genetic transfer across microbes. This proliferated element is heavily degraded in Ot and previously assumed to be inactive. Here, we conducted a detailed analysis of this element in eight Ot strains and discovered two strains with at least one intact copy. This implies that the element is still capable of moving across Ot populations and suggests that the genome of this bacterium may be even more dynamic than previously appreciated. Our work raises questions about intracellular microbial evolution and sounds an alarm for gene-based efforts focused on diagnosing and combatting scrub typhus.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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8
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Long H, Johri P, Gout JF, Ni J, Hao Y, Licknack T, Wang Y, Pan J, Jiménez-Marín B, Lynch M. Paramecium Genetics, Genomics, and Evolution. Annu Rev Genet 2023; 57:391-410. [PMID: 38012024 PMCID: PMC11334263 DOI: 10.1146/annurev-genet-071819-104035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The ciliate genus Paramecium served as one of the first model systems in microbial eukaryotic genetics, contributing much to the early understanding of phenomena as diverse as genome rearrangement, cryptic speciation, cytoplasmic inheritance, and endosymbiosis, as well as more recently to the evolution of mating types, introns, and roles of small RNAs in DNA processing. Substantial progress has recently been made in the area of comparative and population genomics. Paramecium species combine some of the lowest known mutation rates with some of the largest known effective populations, along with likely very high recombination rates, thereby harboring a population-genetic environment that promotes an exceptionally efficient capacity for selection. As a consequence, the genomes are extraordinarily streamlined, with very small intergenic regions combined with small numbers of tiny introns. The subject of the bulk of Paramecium research, the ancient Paramecium aurelia species complex, is descended from two whole-genome duplication events that retain high degrees of synteny, thereby providing an exceptional platform for studying the fates of duplicate genes. Despite having a common ancestor dating to several hundred million years ago, the known descendant species are morphologically indistinguishable, raising significant questions about the common view that gene duplications lead to the origins of evolutionary novelties.
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Affiliation(s)
- Hongan Long
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, Shandong Province, China;
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, Qingdao, Shandong Province, China
| | - Parul Johri
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jean-Francois Gout
- Department of Biological Sciences, Mississippi State University, Starkville, Mississippi, USA
| | - Jiahao Ni
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, Shandong Province, China;
| | - Yue Hao
- Cancer and Cell Biology Division, Translational Genomics Research Institute, Phoenix, Arizona, USA
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA;
| | - Timothy Licknack
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA;
| | - Yaohai Wang
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, Shandong Province, China;
| | - Jiao Pan
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, Shandong Province, China;
| | - Berenice Jiménez-Marín
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA;
| | - Michael Lynch
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA;
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9
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Floriano AM, Batisti Biffignandi G, Castelli M, Olivieri E, Clementi E, Comandatore F, Rinaldi L, Opara M, Plantard O, Palomar AM, Noël V, Vijay A, Lo N, Makepeace BL, Duron O, Jex A, Guy L, Sassera D. The evolution of intramitochondriality in Midichloria bacteria. Environ Microbiol 2023; 25:2102-2117. [PMID: 37305924 DOI: 10.1111/1462-2920.16446] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/31/2023] [Indexed: 06/13/2023]
Abstract
Midichloria spp. are intracellular bacterial symbionts of ticks. Representatives of this genus colonise mitochondria in the cells of their hosts. To shed light on this unique interaction we evaluated the presence of an intramitochondrial localization for three Midichloria in the respective tick host species and generated eight high-quality draft genomes and one closed genome, showing that this trait is non-monophyletic, either due to losses or multiple acquisitions. Comparative genomics supports the first hypothesis, as the genomes of non-mitochondrial symbionts are reduced subsets of those capable of colonising the organelles. We detect genomic signatures of mitochondrial tropism, including the differential presence of type IV secretion system and flagellum, which could allow the secretion of unique effectors and/or direct interaction with mitochondria. Other genes, including adhesion molecules, proteins involved in actin polymerisation, cell wall and outer membrane proteins, are only present in mitochondrial symbionts. The bacteria could use these to manipulate host structures, including mitochondrial membranes, to fuse with the organelles or manipulate the mitochondrial network.
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Affiliation(s)
- Anna Maria Floriano
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Université de Lyon, Université Lyon 1, CNRS, VetAgro Sup, Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France
| | - Gherard Batisti Biffignandi
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
| | - Michele Castelli
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
| | - Emanuela Olivieri
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Pavia Department, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, Pavia, Italy
| | - Emanuela Clementi
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
| | - Francesco Comandatore
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center 'Romeo ed Enrica Invernizzi', University of Milan, Milan, Italy
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR Regione Campania, Naples, Italy
| | - Maxwell Opara
- Zoonotic Parasites Research Group, Department of Parasitology and Entomology, Faculty of Veterinary Medicine, University of Abuja, Abuja, Nigeria
| | | | - Ana M Palomar
- Center of Rickettsiosis and Arthropod-Borne Diseases (CRETAV), San Pedro University Hospital, Center of Biomedical Research from La Rioja (CIBIR), Logroño, Spain
| | - Valérie Noël
- MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), University of Montpellier (UM), Montpellier, France
| | - Amrita Vijay
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Nathan Lo
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Olivier Duron
- MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), University of Montpellier (UM), Montpellier, France
| | - Aaron Jex
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lionel Guy
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Uppsala, Sweden
| | - Davide Sassera
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
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10
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Lu M, Ji Y, Zhao H, Wang W, Tian J, Duan C, Qin X, Guo Y, Chen G, Lei F, Meng C, Li K. Circulation of multiple Rickettsiales bacteria in ticks from Sichuan province, Southwest China. Microb Pathog 2023; 183:106313. [PMID: 37625661 DOI: 10.1016/j.micpath.2023.106313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/17/2023] [Accepted: 08/19/2023] [Indexed: 08/27/2023]
Abstract
During 2021, 403 ticks including Haemaphysalis qinghaiensis, Ixodes ovatus, Ixodes acutitarsus, and Rhipicephalus microplus were collected from three sites (590, 310, and 576 km away from each other) in Sichuan Province, China. A total of nine Rickettsiales species were identified in them, including three Rickettsia spp., five Anaplasma spp., and one Ehrlichia sp. Anaplasma ovis and a novel Rickettsia sp. named "Candidatus Rickettsia liangshanensis" were characterized in I. ovatus ticks from Liangshan, with positive rates of 11.11% and 45.56%, respectively. Anaplasma capra (13.33%) and Anaplasma bovis (15.33%) were detected in H. qinghaiensis ticks from Maerkang. Phylogenetic analysis based on 16S rRNA, gltA, and groEL gene sequences indicated that the A. bovis strains were divided into two groups. Additionally, a novel Ehrlichia species named "Candidatus Ehrlichia maerkangensis" was identified. It is closely related to "Candidatus Ehrlichia zunyiensis" which was previously reported in Berylmys bowersi rats from Zunyi City, Southwest China. In R. microplus from Mianyang, "Candidatus Rickettsia jingxinensis" was detected with a high prevalence (92.99%). Notably, a variant of R. raoultii was identified in I. acutitarsus (33.33%). This may be the first Rickettsiales bacterium reported in I. acutitarsus. Our results reveal the remarkable biodiversity of Rickettsiales in this area. Some of these bacteria are human pathogens, indicating the potential exposure risk to local people.
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Affiliation(s)
- Miao Lu
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping District, Beijing City, China
| | - Yuqi Ji
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China
| | - Hongqing Zhao
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping District, Beijing City, China
| | - Wen Wang
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping District, Beijing City, China
| | - Junhua Tian
- Wuhan Center for Disease Control and Prevention, 430024, Wuhan City, Hubei Province, China
| | - Chengyu Duan
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China
| | - Xincheng Qin
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping District, Beijing City, China
| | - Yawen Guo
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China
| | - Gaosong Chen
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China
| | - Fuyu Lei
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China
| | - Chao Meng
- College of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, 271016, Tai'an City, Shandong Province, China.
| | - Kun Li
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping District, Beijing City, China.
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11
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Uzum Z, Ershov D, Pavia MJ, Mallet A, Gorgette O, Plantard O, Sassera D, Stavru F. Three-dimensional images reveal the impact of the endosymbiont Midichloria mitochondrii on the host mitochondria. Nat Commun 2023; 14:4133. [PMID: 37438329 DOI: 10.1038/s41467-023-39758-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/28/2023] [Indexed: 07/14/2023] Open
Abstract
The hard tick, Ixodes ricinus, a main Lyme disease vector, harbors an intracellular bacterial endosymbiont. Midichloria mitochondrii is maternally inherited and resides in the mitochondria of I. ricinus oocytes, but the consequences of this endosymbiosis are not well understood. Here, we provide 3D images of wild-type and aposymbiotic I. ricinus oocytes generated with focused ion beam-scanning electron microscopy. Quantitative image analyses of endosymbionts and oocyte mitochondria at different maturation stages show that the populations of both mitochondrion-associated bacteria and bacterium-hosting mitochondria increase upon vitellogenisation, and that mitochondria can host multiple bacteria in later stages. Three-dimensional reconstructions show symbiosis-dependent morphologies of mitochondria and demonstrate complete M. mitochondrii inclusion inside a mitochondrion. Cytoplasmic endosymbiont located close to mitochondria are not oriented towards the mitochondria, suggesting that bacterial recolonization is unlikely. We further demonstrate individual globular-shaped mitochondria in the wild type oocytes, while aposymbiotic oocytes only contain a mitochondrial network. In summary, our study suggests that M. mitochondrii modulates mitochondrial fragmentation in oogenesis possibly affecting organelle function and ensuring its presence over generations.
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Affiliation(s)
- Zerrin Uzum
- Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur; CNRS UMR2001, Paris, France.
| | - Dmitry Ershov
- Image Analysis Hub, Cell Biology and Infection Department, Institut Pasteur, Paris, France
- Bioinformatics and Biostatistics HUB, Department of Computational Biology, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Michael J Pavia
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Adeline Mallet
- Ultrastructural BioImaging Core Facility, Institut Pasteur, Paris, France
| | - Olivier Gorgette
- Ultrastructural BioImaging Core Facility, Institut Pasteur, Paris, France
| | | | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Fabrizia Stavru
- Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur; CNRS UMR2001, Paris, France
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12
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: analysis of the mobilome of a highly fragmented and repetitive genome reveals ongoing lateral gene transfer in an obligate intracellular bacterium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.11.540415. [PMID: 37215039 PMCID: PMC10197636 DOI: 10.1101/2023.05.11.540415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The rickettsial human pathogen Orientia tsutsugamushi (Ot) is an obligate intracellular Gram-negative bacterium with one of the most highly fragmented and repetitive genomes of any organism. Around 50% of its ~2.3 Mb genome is comprised of repetitive DNA that is derived from the highly proliferated Rickettsiales amplified genetic element (RAGE). RAGE is an integrative and conjugative element (ICE) that is present in a single Ot genome in up to 92 copies, most of which are partially or heavily degraded. In this report, we analysed RAGEs in eight fully sequenced Ot genomes and manually curated and reannotated all RAGE-associated genes, including those encoding DNA mobilisation proteins, P-type (vir) and F-type (tra) type IV secretion system (T4SS) components, Ankyrin repeat- and tetratricopeptide repeat-containing effectors, and other piggybacking cargo. Originally, the heavily degraded Ot RAGEs led to speculation that they are remnants of historical ICEs that are no longer active. Our analysis, however, identified two Ot genomes harbouring one or more intact RAGEs with complete F-T4SS genes essential for mediating ICE DNA transfer. As similar ICEs have been identified in unrelated rickettsial species, we assert that RAGEs play an ongoing role in lateral gene transfer within the Rickettsiales. Remarkably, we also identified in several Ot genomes remnants of prophages with no similarity to other rickettsial prophages. Together these findings indicate that, despite their obligate intracellular lifestyle and host range restricted to mites, rodents and humans, Ot genomes are highly dynamic and shaped through ongoing invasions by mobile genetic elements and viruses.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, MD 21201
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, Department of Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, UK
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13
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Gillespie JJ, Salje J. Orientia and Rickettsia: different flowers from the same garden. Curr Opin Microbiol 2023; 74:102318. [PMID: 37080115 DOI: 10.1016/j.mib.2023.102318] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/22/2023]
Abstract
Recent discoveries of basal extracellular Rickettsiales have illuminated divergent evolutionary paths to host dependency in later-evolving lineages. Family Rickettsiaceae, primarily comprised of numerous protist- and invertebrate-associated species, also includes human pathogens from two genera, Orientia and Rickettsia. Once considered sister taxa, these bacteria form distinct lineages with newly appreciated lifestyles and morphological traits. Contrasting other rickettsial human pathogens in Family Anaplasmataceae, Orientia and Rickettsia species do not reside in host-derived vacuoles and lack glycolytic potential. With only a few described mechanisms, strategies for commandeering host glycolysis to support cytosolic growth remain to be discovered. While regulatory systems for this unique mode of intracellular parasitism are unclear, conjugative transposons unique to Orientia and Rickettsia species provide insights that are critical for determining how these obligate intracellular pathogens overtake eukaryotic cytosol.
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Affiliation(s)
- Joseph J Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, USA.
| | - Jeanne Salje
- Department of Biochemistry, Department of Pathology, and Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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14
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Dittmer J, Bredon M, Moumen B, Raimond M, Grève P, Bouchon D. The terrestrial isopod symbiont 'Candidatus Hepatincola porcellionum' is a potential nutrient scavenger related to Holosporales symbionts of protists. ISME COMMUNICATIONS 2023; 3:18. [PMID: 36882494 PMCID: PMC9992710 DOI: 10.1038/s43705-023-00224-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 02/09/2023] [Accepted: 02/23/2023] [Indexed: 03/09/2023]
Abstract
The order Holosporales (Alphaproteobacteria) encompasses obligate intracellular bacterial symbionts of diverse Eukaryotes. These bacteria have highly streamlined genomes and can have negative fitness effects on the host. Herein, we present a comparative analysis of the first genome sequences of 'Ca. Hepatincola porcellionum', a facultative symbiont occurring extracellularly in the midgut glands of terrestrial isopods. Using a combination of long-read and short-read sequencing, we obtained the complete circular genomes of two Hepatincola strains and an additional metagenome-assembled draft genome. Phylogenomic analysis validated its phylogenetic position as an early-branching family-level clade relative to all other established Holosporales families associated with protists. A 16S rRNA gene survey revealed that this new family encompasses diverse bacteria associated with both marine and terrestrial host species, which expands the host range of Holosporales bacteria from protists to several phyla of the Ecdysozoa (Arthropoda and Priapulida). Hepatincola has a highly streamlined genome with reduced metabolic and biosynthetic capacities as well as a large repertoire of transmembrane transporters. This suggests that this symbiont is rather a nutrient scavenger than a nutrient provider for the host, likely benefitting from a nutrient-rich environment to import all necessary metabolites and precursors. Hepatincola further possesses a different set of bacterial secretion systems compared to protist-associated Holosporales, suggesting different host-symbiont interactions depending on the host organism.
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Affiliation(s)
- Jessica Dittmer
- Dipartimento di Scienze Agrarie e Ambientali (DISAA), Università degli Studi di Milano, Via Celoria 2, 20133, Milano, Italy.
- UMR 1345, Université d'Angers, Institut Agro, INRAE, IRHS, SFR Quasav, 42 Rue Georges Morel, 49070, Beaucouzé, France.
| | - Marius Bredon
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, 3 Rue Jacques Fort, 86073, Poitiers, France
- Université Paris-Sorbonne, Centre de Recherche Saint-Antoine, Equipe Microbiote, Intestin et Inflammation, 27 Rue Chaligny, 75012, Paris, France
| | - Bouziane Moumen
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, 3 Rue Jacques Fort, 86073, Poitiers, France
| | - Maryline Raimond
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, 3 Rue Jacques Fort, 86073, Poitiers, France
| | - Pierre Grève
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, 3 Rue Jacques Fort, 86073, Poitiers, France
| | - Didier Bouchon
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, 3 Rue Jacques Fort, 86073, Poitiers, France.
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15
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Verhoeve VI, Lehman SS, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates origins of pathogen effectors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.26.530123. [PMID: 36909625 PMCID: PMC10002696 DOI: 10.1101/2023.02.26.530123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Recent metagenome assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. Discovery of basal lineages (Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles reveals an evolutionary timepoint for the transition to host dependency, which occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system (T4SS) and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for derived rickettsial pathogens. MAG analysis also substantially increased diversity for genus Rickettsia and delineated a basal lineage (Tisiphia) that stands to inform on the rise of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages indicates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, illuminating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role shaping the rvh effector landscape, as evinced by the discover of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can provide incredible insight on the origins of pathogen effectors and how their architectural modifications become tailored to eukaryotic host cell biology.
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Affiliation(s)
- Victoria I Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Stephanie S Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Timothy P Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F Beckmann
- Microbiology and Immunology, University of South Alabama, Mobile, AL, USA
| | - Joseph J Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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16
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Bruno A, Cafiso A, Sandionigi A, Galimberti A, Magnani D, Manfrin A, Petroni G, Casiraghi M, Bazzocchi C. Red mark syndrome: Is the aquaculture water microbiome a keystone for understanding the disease aetiology? Front Microbiol 2023; 14:1059127. [PMID: 36922974 PMCID: PMC10010170 DOI: 10.3389/fmicb.2023.1059127] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/01/2023] [Indexed: 03/02/2023] Open
Abstract
Aquaculture significantly contributes to the growing demand for food worldwide. However, diseases associated with intensive aquaculture conditions, especially the skin related syndromes, may have significant implications on fish health and industry. In farmed rainbow trout, red mark syndrome (RMS), which consists of multiple skin lesions, currently lacks recognized aetiological agents, and increased efforts are needed to elucidate the onset of these conditions. Most of the past studies were focused on analyzing skin lesions, but no study focused on water, a medium constantly interacting with fish. Indeed, water tanks are environmental niches colonized by microbial communities, which may be implicated in the onset of the disease. Here, we present the results of water and sediment microbiome analyses performed in an RMS-affected aquaculture facility, bringing new knowledge about the environmental microbiomes harbored under these conditions. On the whole, no significant differences in the bacterial community structure were reported in RMS-affected tanks compared to the RMS-free ones. However, we highlighted significant differences in microbiome composition when analyzing different samples source (i.e., water and sediments). Looking at the finer scale, we measured significant changes in the relative abundances of specific taxa in RMS-affected tanks, especially when analyzing water samples. Our results provide worthwhile insight into a mostly uncharacterized ecological scenario, aiding future studies on the aquaculture built environment for disease prevention and monitoring.
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Affiliation(s)
- Antonia Bruno
- ZooPlantLab, Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Alessandra Cafiso
- Department of Veterinary Medicine and Animal Science, University of Milan, Lodi, Italy
| | | | - Andrea Galimberti
- ZooPlantLab, Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Davide Magnani
- ZooPlantLab, Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Amedeo Manfrin
- Experimental Zooprophylactic Institute of the Venezie (IZSVe), Legnaro, Italy
| | | | - Maurizio Casiraghi
- ZooPlantLab, Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Chiara Bazzocchi
- Department of Veterinary Medicine and Animal Science, University of Milan, Lodi, Italy
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17
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Boscaro V, Manassero V, Keeling PJ, Vannini C. Single-cell Microbiomics Unveils Distribution and Patterns of Microbial Symbioses in the Natural Environment. MICROBIAL ECOLOGY 2023; 85:307-316. [PMID: 35048168 DOI: 10.1007/s00248-021-01938-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
Protist-bacteria associations are extremely common. Among them, those involving ciliates of the genus Euplotes are emerging as models for symbioses between prokaryotes and eukaryotes, and a great deal of information is available from cultured representatives of this system. Even so, as for most known microbial symbioses, data on natural populations is lacking, and their ecology remains largely unexplored; how well lab cultures represent actual diversity is untested. Here, we describe a survey on natural populations of Euplotes based on a single-cell microbiomic approach, focusing on taxa that include known endosymbionts of this ciliate. The results reveal an unexpected variability in symbiotic communities, with individual hosts of the same population harboring different sets of bacterial endosymbionts. Co-occurring Euplotes individuals of the same population can even have different essential symbionts, Polynucleobacter and "Candidatus Protistobacter," which might suggest that replacement events could be more frequent in nature than previously hypothesized. Accessory symbionts are even more variable: some showed a strong affinity for one host species, some for a sampling site, and two ("Candidatus Cyrtobacter" and "Candidatus Anadelfobacter") displayed an unusual pattern of competitive exclusion. These data represent the first insight into the prevalence and patterns of bacterial symbionts in natural populations of free-living protists.
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Affiliation(s)
- Vittorio Boscaro
- Department of Botany, University of British Columbia, Vancouver, Canada
| | | | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Claudia Vannini
- Department of Biology, University of Pisa, 56126, Pisa, Italy.
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18
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Characterization of a Pseudokeronopsis Strain (Ciliophora, Urostylida) and Its Bacterial Endosymbiont “Candidatus Trichorickettsia” (Alphaproteobacteria, Rickettsiales). DIVERSITY 2022. [DOI: 10.3390/d14121032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Symbiotic associations between bacteria and ciliate protists are rather common. In particular, several cases were reported involving bacteria of the alphaproteobacterial lineage Rickettsiales, but the diversity, features, and interactions in these associations are still poorly understood. In this work, we characterized a novel ciliate protist strain originating from Brazil and its associated Rickettsiales endosymbiont by means of live and ultrastructural observations, as well as molecular phylogeny. Though with few morphological peculiarities, the ciliate was found to be phylogenetically affiliated with Pseudokeronopsis erythrina, a euryhaline species, which is consistent with its origin from a lagoon with significant spatial and seasonal salinity variations. The bacterial symbiont was assigned to “Candidatus Trichorickettsia mobilis subsp. hyperinfectiva”, being the first documented case of a Rickettsiales associated with urostylid ciliates. It resided in the host cytoplasm and bore flagella, similarly to many, but not all, conspecifics in other host species. These findings highlight the ability of “Candidatus Trichorickettsia” to infect multiple distinct host species and underline the importance of further studies on this system, in particular on flagella and their regulation, from a functional and also an evolutionary perspective, considering the phylogenetic proximity with the well-studied and non-flagellated Rickettsia.
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19
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Origin of rickettsial host dependency unravelled. Nat Microbiol 2022; 7:1110-1111. [PMID: 35918417 DOI: 10.1038/s41564-022-01187-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Schön ME, Martijn J, Vosseberg J, Köstlbacher S, Ettema TJG. The evolutionary origin of host association in the Rickettsiales. Nat Microbiol 2022; 7:1189-1199. [PMID: 35798888 PMCID: PMC9352585 DOI: 10.1038/s41564-022-01169-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/30/2022] [Indexed: 12/14/2022]
Abstract
The evolution of obligate host-association of bacterial symbionts and pathogens remains poorly understood. The Rickettsiales are an alphaproteobacterial order of obligate endosymbionts and parasites that infect a wide variety of eukaryotic hosts, including humans, livestock, insects and protists. Induced by their host-associated lifestyle, Rickettsiales genomes have undergone reductive evolution, leading to small, AT-rich genomes with limited metabolic capacities. Here we uncover eleven deep-branching alphaproteobacterial metagenome assembled genomes from aquatic environments, including data from the Tara Oceans initiative and other publicly available datasets, distributed over three previously undescribed Rickettsiales-related clades. Phylogenomic analyses reveal that two of these clades, Mitibacteraceae and Athabascaceae, branch sister to all previously sampled Rickettsiales. The third clade, Gamibacteraceae, branch sister to the recently identified ectosymbiotic ‘Candidatus Deianiraea vastatrix’. Comparative analyses indicate that the gene complement of Mitibacteraceae and Athabascaceae is reminiscent of that of free-living and biofilm-associated bacteria. Ancestral genome content reconstruction across the Rickettsiales species tree further suggests that the evolution of host association in Rickettsiales was a gradual process that may have involved the repurposing of a type IV secretion system. Phylogenomic analyses reveal novel environmental clades of Rickettsiales providing insights into their evolution from free-living to host-associated lifestyle.
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Affiliation(s)
- Max E Schön
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Joran Martijn
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.,Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Julian Vosseberg
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Stephan Köstlbacher
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden. .,Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
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21
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George EE, Tashyreva D, Kwong WK, Okamoto N, Horák A, Husnik F, Lukeš J, Keeling PJ. Gene Transfer Agents in Bacterial Endosymbionts of Microbial Eukaryotes. Genome Biol Evol 2022; 14:6615375. [PMID: 35738252 PMCID: PMC9254644 DOI: 10.1093/gbe/evac099] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2022] [Indexed: 11/14/2022] Open
Abstract
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.
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Affiliation(s)
- Emma E George
- University of British Columbia, Department of Botany, Vancouver, V6T 1Z4, Canada
| | - Daria Tashyreva
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic
| | - Waldan K Kwong
- University of British Columbia, Department of Botany, Vancouver, V6T 1Z4, Canada.,Instituto Gulbenkian de Ciência, 6, 2780-156 Oeiras, Portugal
| | - Noriko Okamoto
- University of British Columbia, Department of Botany, Vancouver, V6T 1Z4, Canada.,Hakai Institute, Quadra Island, British Columbia, Canada
| | - Aleš Horák
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic.,University of South Bohemia, Faculty of Sciences, 370 05 České Budějovice (Budweis), Czech Republic
| | - Filip Husnik
- University of British Columbia, Department of Botany, Vancouver, V6T 1Z4, Canada.,Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Julius Lukeš
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic.,University of South Bohemia, Faculty of Sciences, 370 05 České Budějovice (Budweis), Czech Republic
| | - Patrick J Keeling
- University of British Columbia, Department of Botany, Vancouver, V6T 1Z4, Canada
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22
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Davison HR, Pilgrim J, Wybouw N, Parker J, Pirro S, Hunter-Barnett S, Campbell PM, Blow F, Darby AC, Hurst GDD, Siozios S. Genomic diversity across the Rickettsia and 'Candidatus Megaira' genera and proposal of genus status for the Torix group. Nat Commun 2022; 13:2630. [PMID: 35551207 PMCID: PMC9098888 DOI: 10.1038/s41467-022-30385-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 04/29/2022] [Indexed: 11/09/2022] Open
Abstract
Members of the bacterial genus Rickettsia were originally identified as causative agents of vector-borne diseases in mammals. However, many Rickettsia species are arthropod symbionts and close relatives of ‘Candidatus Megaira’, which are symbiotic associates of microeukaryotes. Here, we clarify the evolutionary relationships between these organisms by assembling 26 genomes of Rickettsia species from understudied groups, including the Torix group, and two genomes of ‘Ca. Megaira’ from various insects and microeukaryotes. Our analyses of the new genomes, in comparison with previously described ones, indicate that the accessory genome diversity and broad host range of Torix Rickettsia are comparable to those of all other Rickettsia combined. Therefore, the Torix clade may play unrecognized roles in invertebrate biology and physiology. We argue this clade should be given its own genus status, for which we propose the name ‘Candidatus Tisiphia’. The bacterial genus Rickettsia includes vector-borne pathogens and arthropod symbionts that are close relatives of symbionts of microeukaryotes classified under the genus ‘Candidatus Megaira’. Here, Davison et al. clarify the evolutionary relationships between these organisms by assembling 28 genomes of understudied species, and propose that a distinct clade known as Torix Rickettsia should be considered a separate genus.
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Affiliation(s)
- Helen R Davison
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Jack Pilgrim
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Nicky Wybouw
- Terrestrial Ecology Unit, Department of Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Joseph Parker
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91125, USA
| | | | - Simon Hunter-Barnett
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Paul M Campbell
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK.,School of Health and Life Sciences, Faculty of Biology Medicine and Health, the University of Manchester, Manchester, UK
| | - Frances Blow
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK.,Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, USA
| | - Alistair C Darby
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Gregory D D Hurst
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Stefanos Siozios
- Institute of Infection, Veterinary and Ecological sciences, University of Liverpool, Liverpool, L69 7ZB, UK.
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23
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Symbiont-Induced Phagosome Changes Rather than Extracellular Discrimination Contribute to the Formation of Social Amoeba Farming Symbiosis. Microbiol Spectr 2022; 10:e0172721. [PMID: 35442071 PMCID: PMC9241765 DOI: 10.1128/spectrum.01727-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Symbiont recognition is essential in many symbiotic relationships, especially for horizontally transferred symbionts. Therefore, how to find the right partner is a crucial challenge in these symbiotic relationships. Previous studies have demonstrated that both animals and plants have evolved various mechanisms to recognize their symbionts. However, studies about the mechanistic basis of establishing protist-bacterium symbioses are scarce. This study investigated this question using a social amoeba Dictyostelium discoideum and their Burkholderia symbionts. We found no evidence that D. discoideum hosts could distinguish different Burkholderia extracellularly in chemotaxis assays. Instead, symbiont-induced phagosome biogenesis contributed to the formation of social amoeba symbiosis, and D. discoideum hosts have a higher phagosome pH when carrying symbiotic Burkholderia than nonsymbiotic Burkholderia. In conclusion, the establishment of social amoeba symbiosis is not linked with extracellular discrimination but related to symbiont-induced phagosome biogenesis, which provides new insights into the mechanisms of endosymbiosis formation between protists and their symbionts. IMPORTANCE Protists are single-celled, extremely diverse eukaryotic microbes. Like animals and plants, they live with bacterial symbionts and have complex relationships. In protist-bacterium symbiosis, while some symbionts are strictly vertically transmitted, others need to reestablish and acquire symbionts from the environment frequently. However, the mechanistic basis of establishing protist-bacterium symbioses is mostly unclear. This study uses a novel amoeba-symbiont system to show that the establishment of this symbiosis is not linked with extracellular discrimination. Instead, symbiont-induced phagosome biogenesis contributes to the formation of social amoeba-bacterium symbiosis. This study increases our understanding of the mechanistic basis of establishing protist-bacterium symbioses.
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24
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Castelli M, Lanzoni O, Giovannini M, Lebedeva N, Gammuto L, Sassera D, Melekhin M, Potekhin A, Fokin S, Petroni G. 'Candidatus Gromoviella agglomerans', a novel intracellular Holosporaceae parasite of the ciliate Paramecium showing marked genome reduction. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:34-49. [PMID: 34766443 DOI: 10.1111/1758-2229.13021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Holosporales are an alphaproteobacterial lineage encompassing bacteria obligatorily associated with multiple diverse eukaryotes. For most representatives, little is known on the interactions with their hosts. In this study, we characterized a novel Holosporales symbiont of the ciliate Paramecium polycaryum. This bacterium inhabits the host cytoplasm, frequently forming quite large aggregates. Possibly due to such aggregates, host cells sometimes displayed lethal division defects. The symbiont was also able to experimentally stably infect another Paramecium polycaryum strain. The bacterium is phylogenetically related with symbionts of other ciliates and diplonemids, forming a putatively fast-evolving clade within the family Holosporaceae. Similarly to many close relatives, it presents a very small genome (<600 kbp), and, accordingly, a limited predicted metabolism, implying a heavy dependence on Paramecium, thanks also to some specialized membrane transporters. Characterized features, including the presence of specific secretion systems, are overall suggestive of a mild parasitic effect on the host. From an evolutionary perspective, a potential ancestral trend towards pronounced genome reduction and possibly linked to parasitism could be inferred, at least among fast-evolving Holosporaceae, with some lineage-specific traits. Interestingly, similar convergent features could be observed in other host-associated lineages, in particular Rickettsiales among Alphaproteobacteria.
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Affiliation(s)
- Michele Castelli
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Olivia Lanzoni
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
- Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
| | | | - Natalia Lebedeva
- Centre of Core Facilities "Culture Collections of Microorganisms", Saint Petersburg State University, Saint Petersburg, Russia
| | | | - Davide Sassera
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Maksim Melekhin
- Department of Microbiology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
- Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, Saint Petersburg, Russia
| | - Alexey Potekhin
- Department of Microbiology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
- Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, Saint Petersburg, Russia
| | - Sergei Fokin
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
- Department of Invertebrate Zoology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Giulio Petroni
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
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25
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Husnik F, Tashyreva D, Boscaro V, George EE, Lukeš J, Keeling PJ. Bacterial and archaeal symbioses with protists. Curr Biol 2021; 31:R862-R877. [PMID: 34256922 DOI: 10.1016/j.cub.2021.05.049] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Most of the genetic, cellular, and biochemical diversity of life rests within single-celled organisms - the prokaryotes (bacteria and archaea) and microbial eukaryotes (protists). Very close interactions, or symbioses, between protists and prokaryotes are ubiquitous, ecologically significant, and date back at least two billion years ago to the origin of mitochondria. However, most of our knowledge about the evolution and functions of eukaryotic symbioses comes from the study of animal hosts, which represent only a small subset of eukaryotic diversity. Here, we take a broad view of bacterial and archaeal symbioses with protist hosts, focusing on their evolution, ecology, and cell biology, and also explore what functions (if any) the symbionts provide to their hosts. With the immense diversity of protist symbioses starting to come into focus, we can now begin to see how these systems will impact symbiosis theory more broadly.
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Affiliation(s)
- Filip Husnik
- Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan; Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Daria Tashyreva
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Vittorio Boscaro
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Emma E George
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czech Republic
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
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26
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Oren A, Garrity GM. Candidatus List No. 2. Lists of names of prokaryotic Candidatus taxa. Int J Syst Evol Microbiol 2021; 71. [PMID: 33881984 DOI: 10.1099/ijsem.0.004671] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Aharon Oren
- The Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, 9190401 Jerusalem, Israel
| | - George M Garrity
- Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences, Michigan State University, East Lansing, MI 48824-4320, USA
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27
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Stavru F, Riemer J, Jex A, Sassera D. When bacteria meet mitochondria: The strange case of the tick symbiont Midichloria mitochondrii †. Cell Microbiol 2021; 22:e13189. [PMID: 32185904 DOI: 10.1111/cmi.13189] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 12/28/2022]
Abstract
Mitochondria are key eukaryotic organelles that perform several essential functions. Not surprisingly, many intracellular bacteria directly or indirectly target mitochondria, interfering with innate immunity, energy production or apoptosis, to make the host cell a more hospitable niche for bacterial replication. The alphaproteobacterium Midichloria mitochondrii has taken mitochondrial targeting to another level by physically colonising mitochondria, as shown by transmission electron micrographs of bacteria residing in the mitochondrial intermembrane space. This unique localization provokes a number of questions around the mechanisms allowing, and reasons driving intramitochondrial tropism. We suggest possible scenarios that could lead to this peculiar localization and hypothesize potential costs and benefits of mitochondrial colonisation for the bacterium and its host.
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Affiliation(s)
- Fabrizia Stavru
- Unité de Biologie Evolutive de la Cellule Microbienne, Institut Pasteur, Paris, France.,CNRS ERL6002, Paris, France
| | - Jan Riemer
- Department for Chemistry, Institute for Biochemistry, University of Cologne, Cologne, Germany
| | - Aaron Jex
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia.,Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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28
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Multidisciplinary integrated characterization of a native Chlorella-like microalgal strain isolated from a municipal landfill leachate. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Castelli M, Lanzoni O, Nardi T, Lometto S, Modeo L, Potekhin A, Sassera D, Petroni G. 'Candidatus Sarmatiella mevalonica' endosymbiont of the ciliate Paramecium provides insights on evolutionary plasticity among Rickettsiales. Environ Microbiol 2021; 23:1684-1701. [PMID: 33470507 DOI: 10.1111/1462-2920.15396] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/14/2022]
Abstract
Members of the bacterial order Rickettsiales are obligatorily associated with a wide range of eukaryotic hosts. Their evolutionary trajectories, in particular concerning the origin of shared or differential traits among distant sub-lineages, are still poorly understood. Here, we characterized a novel Rickettsiales bacterium associated with the ciliate Paramecium tredecaurelia and phylogenetically related to the Rickettsia genus. Its genome encodes significant lineage-specific features, chiefly the mevalonate pathway gene repertoire, involved in isoprenoid precursor biosynthesis. Not only this pathway has never been described in Rickettsiales, it also is very rare among bacteria, though typical in eukaryotes, thus likely representing a horizontally acquired trait. The presence of these genes could enable an efficient exploitation of host-derived intermediates for isoprenoid synthesis. Moreover, we hypothesize the reversed reactions could have replaced canonical pathways for producing acetyl-CoA, essential for phospholipid biosynthesis. Additionally, we detected phylogenetically unrelated mevalonate pathway genes in metagenome-derived Rickettsiales sequences, likely indicating evolutionary convergent effects of independent horizontal gene transfer events. Accordingly, convergence, involving both gene acquisitions and losses, is highlighted as a relevant evolutionary phenomenon in Rickettsiales, possibly favoured by plasticity and comparable lifestyles, representing a potentially hidden origin of other more nuanced similarities among sub-lineages.
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Affiliation(s)
- Michele Castelli
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Olivia Lanzoni
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy.,Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
| | - Tiago Nardi
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Stefano Lometto
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Letizia Modeo
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione dell'Università di Pisa, Pisa, Italy
| | - Alexey Potekhin
- Department of Microbiology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Davide Sassera
- Dipartimento di Biologia e Biotecnologie, Università degli studi di Pavia, Pavia, Italy
| | - Giulio Petroni
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
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30
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Nardi T, Olivieri E, Kariuki E, Sassera D, Castelli M. Sequence of a Coxiella Endosymbiont of the Tick Amblyomma nuttalli Suggests a Pattern of Convergent Genome Reduction in the Coxiella Genus. Genome Biol Evol 2021; 13:evaa253. [PMID: 33275132 PMCID: PMC7851586 DOI: 10.1093/gbe/evaa253] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2020] [Indexed: 12/20/2022] Open
Abstract
Ticks require bacterial symbionts for the provision of necessary compounds that are absent in their hematophagous diet. Such symbionts are frequently vertically transmitted and, most commonly, belong to the Coxiella genus, which also includes the human pathogen Coxiella burnetii. This genus can be divided in four main clades, presenting partial but incomplete cocladogenesis with the tick hosts. Here, we report the genome sequence of a novel Coxiella, endosymbiont of the African tick Amblyomma nuttalli, and the ensuing comparative analyses. Its size (∼1 Mb) is intermediate between symbionts of Rhipicephalus species and other Amblyomma species. Phylogenetic analyses show that the novel sequence is the first genome of the B clade, the only one for which no genomes were previously available. Accordingly, it allows to draw an enhanced scenario of the evolution of the genus, one of parallel genome reduction of different endosymbiont lineages, which are now at different stages of reduction from a more versatile ancestor. Gene content comparison allows to infer that the ancestor could be reminiscent of C. burnetii. Interestingly, the convergent loss of mismatch repair could have been a major driver of such reductive evolution. Predicted metabolic profiles are rather homogenous among Coxiella endosymbionts, in particular vitamin biosynthesis, consistently with a host-supportive role. Concurrently, similarities among Coxiella endosymbionts according to host genus and despite phylogenetic unrelatedness hint at possible host-dependent effects.
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Affiliation(s)
- Tiago Nardi
- Department of Biology and Biotechnology, University of Pavia, Italy
| | | | - Edward Kariuki
- Veterinary and Capture Service Department, Kenya Wildlife Service, Kenya
| | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Italy
| | - Michele Castelli
- Department of Biology and Biotechnology, University of Pavia, Italy
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31
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Driscoll TP, Verhoeve VI, Brockway C, Shrewsberry DL, Plumer M, Sevdalis SE, Beckmann JF, Krueger LM, Macaluso KR, Azad AF, Gillespie JJ. Evolution of Wolbachia mutualism and reproductive parasitism: insight from two novel strains that co-infect cat fleas. PeerJ 2020; 8:e10646. [PMID: 33362982 PMCID: PMC7750005 DOI: 10.7717/peerj.10646] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/03/2020] [Indexed: 12/26/2022] Open
Abstract
Wolbachiae are obligate intracellular bacteria that infect arthropods and certain nematodes. Usually maternally inherited, they may provision nutrients to (mutualism) or alter sexual biology of (reproductive parasitism) their invertebrate hosts. We report the assembly of closed genomes for two novel wolbachiae, wCfeT and wCfeJ, found co-infecting cat fleas (Ctenocephalides felis) of the Elward Laboratory colony (Soquel, CA, USA). wCfeT is basal to nearly all described Wolbachia supergroups, while wCfeJ is related to supergroups C, D and F. Both genomes contain laterally transferred genes that inform on the evolution of Wolbachia host associations. wCfeT carries the Biotin synthesis Operon of Obligate intracellular Microbes (BOOM); our analyses reveal five independent acquisitions of BOOM across the Wolbachia tree, indicating parallel evolution towards mutualism. Alternately, wCfeJ harbors a toxin-antidote operon analogous to the wPip cinAB operon recently characterized as an inducer of cytoplasmic incompatibility (CI) in flies. wCfeJ cinB and three adjacent genes are collectively similar to large modular toxins encoded in CI-like operons of certain Wolbachia strains and Rickettsia species, signifying that CI toxins streamline by fission of large modular toxins. Remarkably, the C. felis genome itself contains two CI-like antidote genes, divergent from wCfeJ cinA, revealing episodic reproductive parasitism in cat fleas and evidencing mobility of CI loci independent of WO-phage. Additional screening revealed predominant co-infection (wCfeT/wCfeJ) amongst C. felis colonies, though fleas in wild populations mostly harbor wCfeT alone. Collectively, genomes of wCfeT, wCfeJ, and their cat flea host supply instances of lateral gene transfers that could drive transitions between parasitism and mutualism.
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Affiliation(s)
| | - Victoria I Verhoeve
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | | | | | - Mariah Plumer
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Spiridon E Sevdalis
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - John F Beckmann
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Laura M Krueger
- Orange County Mosquito and Vector Control District, Garden Grove, CA, USA
| | - Kevin R Macaluso
- Microbiology and Immunology, University of South Alabama, Mobile, AL, USA
| | - Abdu F Azad
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Joseph J Gillespie
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
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32
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Phylogenetic analyses with systematic taxon sampling show that mitochondria branch within Alphaproteobacteria. Nat Ecol Evol 2020; 4:1213-1219. [PMID: 32661403 DOI: 10.1038/s41559-020-1239-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 05/29/2020] [Indexed: 12/15/2022]
Abstract
Though it is well accepted that mitochondria originated from an alphaproteobacteria-like ancestor, the phylogenetic relationship of the mitochondrial endosymbiont to extant Alphaproteobacteria is yet unresolved. The focus of much debate is whether the affinity between mitochondria and fast-evolving alphaproteobacterial lineages reflects true homology or artefacts. Approaches such as site exclusion have been claimed to mitigate compositional heterogeneity between taxa, but this comes at the cost of information loss, and the reliability of such methods is so far unproven. Here we demonstrate that site-exclusion methods produce erratic phylogenetic estimates of mitochondrial origin. Thus, previous phylogenetic hypotheses on the origin of mitochondria based on pretreated datasets should be re-evaluated. We applied alternative strategies to reduce phylogenetic noise by systematic taxon sampling while keeping site substitution information intact. Cross-validation based on a series of trees placed mitochondria robustly within Alphaproteobacteria, sharing an ancient common ancestor with Rickettsiales and currently unclassified marine lineages.
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33
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Kashkouli M, Castelli M, Floriano AM, Bandi C, Epis S, Fathipour Y, Mehrabadi M, Sassera D. Characterization of a novel Pantoea symbiont allows inference of a pattern of convergent genome reduction in bacteria associated with Pentatomidae. Environ Microbiol 2020; 23:36-50. [PMID: 32686279 DOI: 10.1111/1462-2920.15169] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/15/2020] [Indexed: 11/29/2022]
Abstract
Phytophagous stink bugs typically harbor nutritional symbiotic bacteria in their midgut, to integrate their unbalanced diet. In the Pentatomidae, most symbionts are affiliated to the genus Pantoea, and are polyphyletic. This suggests a scenario of an ancestral establishment of symbiosis, followed by multiple symbiont replacement events by akin environmental bacteria in different host lineages. In this study, a novel Pantoeaspecies ('CandidatusPantoea persica') was characterized from the gut of the pentatomid Acrosternum arabicum, and shown to be highly abundant in a specific portion of the gut and necessary for the host development. The genome of the symbiont (2.9 Mb), while presenting putative host-supportive metabolic pathways, including those for amino acids and vitamin synthesis, showed a high level of pseudogenization, indicating ongoing genome reduction. Comparative analyses with other free-living and symbiotic Pantoea highlighted a convergent pattern of genome reduction in symbionts of pentatomids, putatively following the typical phases modelized in obligate nutritional symbionts of insects. Additionally, this system has distinctive traits, as hosts are closely related, and symbionts originated multiple independent times from closely related free-living bacteria, displaying convergent and independent conspicuous genome reduction. Due to such peculiarities, this may become an ideal model to study genome evolutionary processes in insect symbionts.
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Affiliation(s)
- Marzieh Kashkouli
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, 14115-336, Iran
| | - Michele Castelli
- Department of Biosciences and Pediatric Clinical Research Center, University of Milan, Milan, 20133, Italy.,Department of Biology and Biotechnology, University of Pavia, 27100, Italy
| | - Anna M Floriano
- Department of Biology and Biotechnology, University of Pavia, 27100, Italy
| | - Claudio Bandi
- Department of Biosciences and Pediatric Clinical Research Center, University of Milan, Milan, 20133, Italy
| | - Sara Epis
- Department of Biosciences and Pediatric Clinical Research Center, University of Milan, Milan, 20133, Italy
| | - Yaghoub Fathipour
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, 14115-336, Iran
| | - Mohammad Mehrabadi
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, 14115-336, Iran
| | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, 27100, Italy
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34
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Pasqualetti C, Szokoli F, Rindi L, Petroni G, Schrallhammer M. The Obligate Symbiont " Candidatus Megaira polyxenophila" Has Variable Effects on the Growth of Different Host Species. Front Microbiol 2020; 11:1425. [PMID: 32733401 PMCID: PMC7360802 DOI: 10.3389/fmicb.2020.01425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/02/2020] [Indexed: 12/18/2022] Open
Abstract
"Candidatus Megaira polyxenophila" is a recently described member of Rickettsiaceae which comprises exclusively obligate intracellular bacteria. Interestingly, these bacteria can be found in a huge diversity of eukaryotic hosts (protist, green algae, metazoa) living in marine, brackish or freshwater habitats. Screening of amplicon datasets revealed a high frequency of these bacteria especially in freshwater environments, most likely associated to eukaryotic hosts. The relationship of "Ca. Megaira polyxenophila" with their hosts and their impact on host fitness have not been studied so far. Even less is known regarding the responses of these intracellular bacteria to potential stressors. In this study, we used two phylogenetically close species of the freshwater ciliate Paramecium, Paramecium primaurelia and Paramecium pentaurelia (Ciliophora, Oligohymenophorea) naturally infected by "Ca. Megaira polyxenophila". In order to analyze the effect of the symbiont on the fitness of these two species, we compared the growth performance of both infected and aposymbiotic paramecia at different salinity levels in the range of freshwater and oligohaline brackish water i.e., at 0, 2, and 4.5 ppt. For the elimination of "Ca. Megaira polyxenophila" we established an antibiotic treatment to obtain symbiont-free lines and confirmed its success by fluorescence in situ hybridization (FISH). The population and infection dynamics during the growth experiment were observed by cell density counts and FISH. Paramecia fitness was compared applying generalized additive mixed models. Surprisingly, both infected Paramecium species showed higher densities under all salinity concentrations. The tested salinity concentrations did not significantly affect the growth of any of the two species directly, but we observed the loss of the endosymbiont after prolonged exposure to higher salinity levels. This experimental data might explain the higher frequency of "Ca. M. polyxenophila" in freshwater habitats as observed from amplicon data.
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Affiliation(s)
- Chiara Pasqualetti
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy.,Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Franziska Szokoli
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy.,Institut für Hydrobiologie, Technische Universität Dresden, Dresden, Germany
| | - Luca Rindi
- Dipartimento di Biologia, CoNISMa, Università di Pisa, Pisa, Italy
| | - Giulio Petroni
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
| | - Martina Schrallhammer
- Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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35
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“Candidatus Mystax nordicus” Aggregates with Mitochondria of Its Host, the Ciliate Paramecium nephridiatum. DIVERSITY 2020. [DOI: 10.3390/d12060251] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Extensive search for new endosymbiotic systems in ciliates occasionally reverts us to the endosymbiotic bacteria described in the pre-molecular biology era and, hence, lacking molecular characterization. A pool of these endosymbionts has been referred to as a hidden bacterial biodiversity from the past. Here, we provide a description of one of such endosymbionts, retrieved from the ciliate Paramecium nephridiatum. This curve-shaped endosymbiont (CS), which shared the host cytoplasm with recently described “Candidatus Megaira venefica”, was found in the same host and in the same geographic location as one of the formerly reported endosymbiotic bacteria and demonstrated similar morphology. Based on morphological data obtained with DIC, TEM and AFM and molecular characterization by means of sequencing 16S rRNA gene, we propose a novel genus, “Candidatus Mystax”, with a single species “Ca. Mystax nordicus”. Phylogenetic analysis placed this species in Holosporales, among Holospora-like bacteria. Contrary to all Holospora species and many other Holospora-like bacteria, such as “Candidatus Gortzia”, “Candidatus Paraholospora” or “Candidatus Hafkinia”, “Ca. Mystax nordicus” was never observed inside the host nucleus. “Ca. Mystax nordicus” lacked infectivity and killer effect. The striking peculiarity of this endosymbiont was its ability to form aggregates with the host mitochondria, which distinguishes it from Holospora and Holospora-like bacteria inhabiting paramecia.
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Pirritano M, Zaburannyi N, Grosser K, Gasparoni G, Müller R, Simon M, Schrallhammer M. Dual-Seq reveals genome and transcriptome of Caedibacter taeniospiralis, obligate endosymbiont of Paramecium. Sci Rep 2020; 10:9727. [PMID: 32546745 PMCID: PMC7297999 DOI: 10.1038/s41598-020-65894-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
Interest in host-symbiont interactions is continuously increasing, not only due to the growing recognition of the importance of microbiomes. Starting with the detection and description of novel symbionts, attention moves to the molecular consequences and innovations of symbioses. However, molecular analysis requires genomic data which is difficult to obtain from obligate intracellular and uncultivated bacteria. We report the identification of the Caedibacter genome, an obligate symbiont of the ciliate Paramecium. The infection does not only confer the host with the ability to kill other cells but also renders them immune against this effect. We obtained the C. taeniospiralis genome and transcriptome by dual-Seq of DNA and RNA from infected paramecia. Comparison of codon usage and expression level indicates that genes necessary for a specific trait of this symbiosis, i.e. the delivery of an unknown toxin, result from horizontal gene transfer hinting to the relevance of DNA transfer for acquiring new characters. Prediction of secreted proteins of Caedibacter as major agents of contact with the host implies, next to several toxin candidates, a rather uncharacterized secretome which appears to be highly adapted to this symbiosis. Our data provides new insights into the molecular establishment and evolution of this obligate symbiosis and for the pathway characterization of toxicity and immunity.
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Affiliation(s)
- Marcello Pirritano
- Molecular Cell Biology and Microbiology, University of Wuppertal, Wuppertal, Germany.,Molecular Cell Dynamics Saarland University, Saarbrücken, Germany
| | - Nestor Zaburannyi
- Department of Microbial Natural Products, Helmholtz Centre for Infection Research and Department of Pharmacy, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Saarbrücken and German Centre for Infection Research (DZIF), Hannover, Germany
| | - Katrin Grosser
- Microbiology, Institute of Biology II, Albert Ludwig University of Freiburg, Freiburg, Germany.,Deep Sequencing Unit, Max-Planck-Institute for Immunobiology and Epigenetics, Freiburg, Germany
| | - Gilles Gasparoni
- Genetics, Centre for Human and Molecular Biology, Saarland University, Saarbruecken, Germany
| | - Rolf Müller
- Department of Microbial Natural Products, Helmholtz Centre for Infection Research and Department of Pharmacy, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Saarbrücken and German Centre for Infection Research (DZIF), Hannover, Germany
| | - Martin Simon
- Molecular Cell Biology and Microbiology, University of Wuppertal, Wuppertal, Germany. .,Molecular Cell Dynamics Saarland University, Saarbrücken, Germany.
| | - Martina Schrallhammer
- Microbiology, Institute of Biology II, Albert Ludwig University of Freiburg, Freiburg, Germany.
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37
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Origin and diversification of the cardiolipin biosynthetic pathway in the Eukarya domain. Biochem Soc Trans 2020; 48:1035-1046. [DOI: 10.1042/bst20190967] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/07/2020] [Accepted: 05/14/2020] [Indexed: 12/19/2022]
Abstract
Cardiolipin (CL) and its precursor phosphatidylglycerol (PG) are important anionic phospholipids widely distributed throughout all domains of life. They have key roles in several cellular processes by shaping membranes and modulating the activity of the proteins inserted into those membranes. They are synthesized by two main pathways, the so-called eukaryotic pathway, exclusively found in mitochondria, and the prokaryotic pathway, present in most bacteria and archaea. In the prokaryotic pathway, the first and the third reactions are catalyzed by phosphatidylglycerol phosphate synthase (Pgps) belonging to the transferase family and cardiolipin synthase (Cls) belonging to the hydrolase family, while in the eukaryotic pathway, those same reactions are catalyzed by unrelated homonymous enzymes: Pgps of the hydrolase family and Cls of the transferase family. Because of the enzymatic arrangement found in both pathways, it seems that the eukaryotic pathway evolved by convergence to the prokaryotic pathway. However, since mitochondria evolved from a bacterial endosymbiont, it would suggest that the eukaryotic pathway arose from the prokaryotic pathway. In this review, it is proposed that the eukaryote pathway evolved directly from a prokaryotic pathway by the neofunctionalization of the bacterial enzymes. Moreover, after the eukaryotic radiation, this pathway was reshaped by horizontal gene transfers or subsequent endosymbiotic processes.
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Modeo L, Salvetti A, Rossi L, Castelli M, Szokoli F, Krenek S, Serra V, Sabaneyeva E, Di Giuseppe G, Fokin SI, Verni F, Petroni G. "Candidatus Trichorickettsia mobilis", a Rickettsiales bacterium, can be transiently transferred from the unicellular eukaryote Paramecium to the planarian Dugesia japonica. PeerJ 2020; 8:e8977. [PMID: 32351785 PMCID: PMC7183750 DOI: 10.7717/peerj.8977] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 03/24/2020] [Indexed: 01/10/2023] Open
Abstract
Most of the microorganisms responsible for vector-borne diseases (VBD) have hematophagous arthropods as vector/reservoir. Recently, many new species of microorganisms phylogenetically related to agents of VBD were found in a variety of aquatic eukaryotic hosts; in particular, numerous new bacterial species related to the genus Rickettsia (Alphaproteobacteria, Rickettsiales) were discovered in protist ciliates and other unicellular eukaryotes. Although their pathogenicity for humans and terrestrial animals is not known, several indirect indications exist that these bacteria might act as etiological agents of possible VBD of aquatic organisms, with protists as vectors. In the present study, a novel strain of the Rickettsia-Like Organism (RLO) endosymbiont "Candidatus (Ca.) Trichorickettsia mobilis" was identified in the macronucleus of the ciliate Paramecium multimicronucleatum. We performed transfection experiments of this RLO to planarians (Dugesia japonica) per os. Indeed, the latter is a widely used model system for studying bacteria pathogenic to humans and other Metazoa. In transfection experiments, homogenized paramecia were added to food of antibiotic-treated planarians. Treated and non-treated (i.e. control) planarians were investigated at day 1, 3, and 7 after feeding for endosymbiont presence by means of PCR and ultrastructural analyses. Obtained results were fully concordant and suggest that this RLO endosymbiont can be transiently transferred from ciliates to metazoans, being detected up to day 7 in treated planarians' enterocytes. Our findings might offer insights into the potential role of ciliates or other protists as putative vectors for diseases caused by Rickettsiales or other RLOs and occurring in fish farms or in the wild.
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Affiliation(s)
- Letizia Modeo
- Department of Biology, University of Pisa, Pisa, Italy.,CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione, University of Pisa, Pisa, Italy
| | - Alessandra Salvetti
- CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione, University of Pisa, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Leonardo Rossi
- CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione, University of Pisa, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Michele Castelli
- Centro Romeo ed Enrica Invernizzi Ricerca Pediatrica, Department of Biosciences, University of Milan, Milan, Italy
| | - Franziska Szokoli
- Institute of Hydrobiology, Dresden University of Technology, Dresden, Germany
| | - Sascha Krenek
- Institute of Hydrobiology, Dresden University of Technology, Dresden, Germany.,Department of River Ecology, Helmholtz Center for Environmental Research-UFZ, Magdeburg, Germany
| | | | - Elena Sabaneyeva
- Department of Cytology and Histology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | | | - Sergei I Fokin
- Department of Biology, University of Pisa, Pisa, Italy.,CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,Department of Invertebrate Zoology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Franco Verni
- Department of Biology, University of Pisa, Pisa, Italy.,CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione, University of Pisa, Pisa, Italy
| | - Giulio Petroni
- Department of Biology, University of Pisa, Pisa, Italy.,CIME, Centro Interdipartimentale di Microscopia Elettronica, University of Pisa, Pisa, Italy.,CISUP, Centro per l'Integrazione della Strumentazione, University of Pisa, Pisa, Italy
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Campello-Nunes PH, Fernandes NM, Szokoli F, Fokin SI, Serra V, Modeo L, Petroni G, Soares CA, Paiva TDS, Silva-Neto IDD. Parablepharisma (Ciliophora) is not a Heterotrich: A Phylogenetic and Morphological Study with the Proposal of New Taxa. Protist 2020; 171:125716. [DOI: 10.1016/j.protis.2020.125716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/30/2020] [Accepted: 02/02/2020] [Indexed: 12/13/2022]
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40
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Kaczmarek Ł, Roszkowska M, Poprawa I, Janelt K, Kmita H, Gawlak M, Fiałkowska E, Mioduchowska M. Integrative description of bisexual Paramacrobiotus experimentalis sp. nov. (Macrobiotidae) from republic of Madagascar (Africa) with microbiome analysis. Mol Phylogenet Evol 2020; 145:106730. [PMID: 31904510 DOI: 10.1016/j.ympev.2019.106730] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 12/31/2019] [Accepted: 12/31/2019] [Indexed: 12/26/2022]
Abstract
In a moss samples collected on Madagascar two populations of Paramacrobiotus experimentalis sp. nov. were found. Paramacrobiotus experimentalis sp. nov. with the presence of a microplacoid and areolatus type of eggs is similar to Pam. danielae, Pam. garynahi, Pam. hapukuensis, Pam. peteri, Pam. rioplatensis and Pam. savai, but it differs from them by some morphological and morphometric characters of the eggs. The p-distance between two COI haplotypes of Pam. experimentalis sp. nov. was 0.17%. In turn, the ranges of uncorrected genetic p-distances of all Paramacrobiotus species available in GenBank was from 18.27% (for Pam. lachowskae) to 25.26% (for Pam. arduus) with an average distance of 20.67%. We also found that Pam. experimentalis sp. nov. is bisexual. This observation was congruent on three levels: (i) morphological - specimen size dimorphism; (ii) structural (primary sexual characteristics) - females have an unpaired ovary while males have an unpaired testis and (iii) molecular - heterozygous and homozygous strains of the ITS-2 marker. Although symbiotic associations of hosts with bacteria (including endosymbiotic bacteria) are common in nature and these interactions exert various effects on the evolution, biology and reproductive ecology of hosts, there is still very little information on the bacterial community associated with tardigrades. To fill this gap and characterise the bacterial community of Pam. experimentalis sp. nov. populations and microbiome of its microhabitat, high throughput sequencing of the V3-V4 hypervariable regions in the bacterial 16S rRNA gene fragment was performed. The obtained 16S rRNA gene sequences ranged from 92,665 to 131,163. In total, 135 operational taxonomic units (OTUs) were identified across the rarefied dataset. Overall, both Pam. experimentalis sp. nov. populations were dominated by OTUs ascribed to the phylum Proteobacteria (89-92%) and Firmicutes (6-7%). In the case of samples from tardigrades' laboratory habitat, the most abundant bacterial phylum was Proteobacteria (51-90%) and Bacteroides (9-48%). In all compared microbiome profiles, only 16 of 137 OTUs were shared. We found also significant differences in beta diversity between the partly species-specific microbiome of Pam. experimentalis sp. nov. and its culturing environment. Two OTUs belonging to a putative bacterial endosymbiont were identified - Rickettsiales and Polynucleobacter. We also demonstrated that each bacterial community was rich in genes involved in membrane transport, amino acid metabolism, and carbohydrate metabolism.
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Affiliation(s)
- Łukasz Kaczmarek
- Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University, Poznan, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland.
| | - Milena Roszkowska
- Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University, Poznan, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland; Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Poznan, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland.
| | - Izabela Poprawa
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Bankowa 9, 40-007 Katowice, Poland.
| | - Kamil Janelt
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Bankowa 9, 40-007 Katowice, Poland
| | - Hanna Kmita
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Poznan, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland.
| | - Magdalena Gawlak
- The Institute of Plant Protection-National Research Institute, Węgorka 20, 60-318 Poznań, Poland.
| | - Edyta Fiałkowska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - Monika Mioduchowska
- Department of Genetics and Biosystematics, Faculty of Biology, University of Gdańsk, Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
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Epidemiology of Nucleus-Dwelling Holospora: Infection, Transmission, Adaptation, and Interaction with Paramecium. Results Probl Cell Differ 2020; 69:105-135. [PMID: 33263870 DOI: 10.1007/978-3-030-51849-3_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The chapter describes the exceptional symbiotic associations formed between the ciliate Paramecium and Holospora, highly infectious bacteria residing in the host nuclei. Holospora and Holospora-like bacteria (Alphaproteobacteria) are characterized by their ability for vertical and horizontal transmission in host populations, a complex biphasic life cycle, and pronounced preference for host species and colonized cell compartment. These bacteria are obligate intracellular parasites; thus, their metabolic repertoire is dramatically reduced. Nevertheless, they perform complex interactions with the host ciliate. We review ongoing efforts to unravel the molecular adaptations of these bacteria to their unusual lifestyle and the host's employment in the symbiosis. Furthermore, we summarize current knowledge on the genetic and genomic background of Paramecium-Holospora symbiosis and provide insights into the ecological and evolutionary consequences of this interaction. The diversity and occurrence of symbioses between ciliates and Holospora-like bacteria in nature is discussed in connection with transmission modes of symbionts, host specificity and compatibility of the partners. We aim to summarize 50 years of research devoted to these symbiotic systems and conclude trying to predict some perspectives for further studies.
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Chiodi A, Comandatore F, Sassera D, Petroni G, Bandi C, Brilli M. SeqDeχ: A Sequence Deconvolution Tool for Genome Separation of Endosymbionts From Mixed Sequencing Samples. Front Genet 2019; 10:853. [PMID: 31608107 PMCID: PMC6761303 DOI: 10.3389/fgene.2019.00853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 08/15/2019] [Indexed: 12/04/2022] Open
Abstract
In recent years, the advent of NGS technology has made genome sequencing much cheaper than in the past; the high parallelization capability and the possibility to sequence more than one organism at once have opened the door to processing whole symbiotic consortia. However, this approach needs the development of specific bioinformatics tools able to analyze these data. In this work, we describe SeqDex, a tool that starts from a preliminary assembly obtained from sequencing a mixture of DNA from different organisms, to identify the contigs coming from one organism of interest. SeqDex is a fully automated machine learning–based tool exploiting partial taxonomic affiliations and compositional analysis to predict the taxonomic affiliations of contigs in an assembly. In literature, there are few methods able to deconvolve host–symbiont datasets, and most of them heavily rely on user curation and are therefore time consuming. The problem has strong similarities with metagenomic studies, where mixed samples are sequenced and the bioinformatics challenge is trying to separate contigs on the basis of their source organism; however, in symbiotic systems, additional information can be exploited to improve the output. To assess the ability of SeqDex to deconvolve host–symbiont datasets, we compared it to state-of-the-art methods for metagenomic binning and for host–symbiont deconvolution on three study cases. The results point out the good performances of the presented tool that, in addition to the ease of use and customization potential, make SeqDex a useful tool for rapid identification of endosymbiont sequences.
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Affiliation(s)
- Alice Chiodi
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy.,Department of Biosciences, University of Milan, Milan, Italy
| | - Francesco Comandatore
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi", University of Milan, Milan, Italy.,Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | | | - Claudio Bandi
- Department of Biosciences, University of Milan, Milan, Italy.,Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi", University of Milan, Milan, Italy
| | - Matteo Brilli
- Department of Biosciences, University of Milan, Milan, Italy.,Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi", University of Milan, Milan, Italy
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43
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Lanzoni O, Plotnikov A, Khlopko Y, Munz G, Petroni G, Potekhin A. The core microbiome of sessile ciliate Stentor coeruleus is not shaped by the environment. Sci Rep 2019; 9:11356. [PMID: 31388025 PMCID: PMC6684585 DOI: 10.1038/s41598-019-47701-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/22/2019] [Indexed: 12/29/2022] Open
Abstract
Microbiomes of multicellular organisms are one of the hottest topics in microbiology and physiology, while only few studies addressed bacterial communities associated with protists. Protists are widespread in all environments and can be colonized by plethora of different bacteria, including also human pathogens. The aim of this study was to characterize the prokaryotic community associated with the sessile ciliate Stentor coeruleus. 16S rRNA gene metabarcoding was performed on single cells of S. coeruleus and on their environment, water from the sewage stream. Our results showed that the prokaryotic community composition differed significantly between Stentor cells and their environment. The core microbiome common for all ciliate specimens analyzed could be defined, and it was composed mainly by representatives of bacterial genera which include also potential human pathogens and commensals, such as Neisseria, Streptococcus, Capnocytophaga, Porphyromonas. Numerous 16S rRNA gene contigs belonged to endosymbiont “Candidatus Megaira polyxenophila”. Our data suggest that each ciliate cell can be considered as an ecological microniche harboring diverse prokaryotic organisms. Possible benefits for persistence and transmission in nature for bacteria associated with protists are discussed. Our results support the hypothesis that ciliates attract potentially pathogenic bacteria and play the role of natural reservoirs for them.
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Affiliation(s)
| | - Andrey Plotnikov
- Center of Shared Scientific Equipment, Institute for Cellular and Intracellular Symbiosis, Ural Division of RAS, Orenburg, Russia
| | - Yuri Khlopko
- Center of Shared Scientific Equipment, Institute for Cellular and Intracellular Symbiosis, Ural Division of RAS, Orenburg, Russia
| | - Giulio Munz
- Department of Civil and Environmental Engineering, University of Florence, Florence, Italy
| | | | - Alexey Potekhin
- Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia.
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