1
|
Price CTD, Hanford HE, Al-Quadan T, Santic M, Shin CJ, Da'as MSJ, Abu Kwaik Y. Amoebae as training grounds for microbial pathogens. mBio 2024:e0082724. [PMID: 38975782 DOI: 10.1128/mbio.00827-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024] Open
Abstract
Grazing of amoebae on microorganisms represents one of the oldest predator-prey dynamic relationships in nature. It represents a genetic "melting pot" for an ancient and continuous multi-directional inter- and intra-kingdom horizontal gene transfer between amoebae and its preys, intracellular microbial residents, endosymbionts, and giant viruses, which has shaped the evolution, selection, and adaptation of microbes that evade degradation by predatory amoeba. Unicellular phagocytic amoebae are thought to be the ancient ancestors of macrophages with highly conserved eukaryotic processes. Selection and evolution of microbes within amoeba through their evolution to target highly conserved eukaryotic processes have facilitated the expansion of their host range to mammals, causing various infectious diseases. Legionella and environmental Chlamydia harbor an immense number of eukaryotic-like proteins that are involved in ubiquitin-related processes or are tandem repeats-containing proteins involved in protein-protein and protein-chromatin interactions. Some of these eukaryotic-like proteins exhibit novel domain architecture and novel enzymatic functions absent in mammalian cells, such as ubiquitin ligases, likely acquired from amoebae. Mammalian cells and amoebae may respond similarly to microbial factors that target highly conserved eukaryotic processes, but mammalian cells may undergo an accidental response to amoeba-adapted microbial factors. We discuss specific examples of microbes that have evolved to evade amoeba predation, including the bacterial pathogens- Legionella, Chlamydia, Coxiella, Rickettssia, Francisella, Mycobacteria, Salmonella, Bartonella, Rhodococcus, Pseudomonas, Vibrio, Helicobacter, Campylobacter, and Aliarcobacter. We also discuss the fungi Cryptococcus, and Asperigillus, as well as amoebae mimiviruses/giant viruses. We propose that amoeba-microbe interactions will continue to be a major "training ground" for the evolution, selection, adaptation, and emergence of microbial pathogens equipped with unique pathogenic tools to infect mammalian hosts. However, our progress will continue to be highly dependent on additional genomic, biochemical, and cellular data of unicellular eukaryotes.
Collapse
Affiliation(s)
- Christopher T D Price
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Hannah E Hanford
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Tasneem Al-Quadan
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | | | - Cheon J Shin
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Manal S J Da'as
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
- Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, Kentucky, USA
| |
Collapse
|
2
|
Lanzoni O, Szokoli F, Schrallhammer M, Sabaneyeva E, Krenek S, Doak TG, Verni F, Berendonk TU, Castelli M, Petroni G. "Candidatus Intestinibacterium parameciiphilum"-member of the "Candidatus Paracaedibacteraceae" family (Alphaproteobacteria, Holosporales) inhabiting the ciliated protist Paramecium. Int Microbiol 2024; 27:659-671. [PMID: 37615902 PMCID: PMC11144129 DOI: 10.1007/s10123-023-00414-5] [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: 05/13/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/25/2023]
Abstract
Protists frequently host diverse bacterial symbionts, in particular those affiliated with the order Holosporales (Alphaproteobacteria). All characterised members of this bacterial lineage have been retrieved in obligate association with a wide range of eukaryotes, especially multiple protist lineages (e.g. amoebozoans, ciliates, cercozoans, euglenids, and nucleariids), as well as some metazoans (especially arthropods and related ecdysozoans). While the genus Paramecium and other ciliates have been deeply investigated for the presence of symbionts, known members of the family "Candidatus Paracaedibacteraceae" (Holosporales) are currently underrepresented in such hosts. Herein, we report the description of "Candidatus Intestinibacterium parameciiphilum" within the family "Candidatus Paracaedibacteraceae", inhabiting the cytoplasm of Paramecium biaurelia. This novel bacterium is almost twice as big as its relative "Candidatus Intestinibacterium nucleariae" from the opisthokont Nuclearia and does not present a surrounding halo. Based on phylogenetic analyses of 16S rRNA gene sequences, we identified six further potential species-level lineages within the genus. Based on the provenance of the respective samples, we investigated the environmental distribution of the representatives of "Candidatus Intestinibacterium" species. Obtained results are consistent with an obligate endosymbiotic lifestyle, with protists, in particular freshwater ones, as hosts. Thus, available data suggest that association with freshwater protists could be the ancestral condition for the members of the "Candidatus Intestinibacterium" genus.
Collapse
Affiliation(s)
| | - Franziska Szokoli
- Department of Biology, University of Pisa, Pisa, Italy
- Institut für Hydrobiologie, Technische Universität Dresden, Dresden, Germany
| | - Martina Schrallhammer
- Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Elena Sabaneyeva
- Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Sascha Krenek
- Institut für Hydrobiologie, Technische Universität Dresden, Dresden, Germany
| | | | - Franco Verni
- Department of Biology, University of Pisa, Pisa, Italy
| | - Thomas U Berendonk
- Institut für Hydrobiologie, Technische Universität Dresden, Dresden, Germany
| | - Michele Castelli
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy.
| | | |
Collapse
|
3
|
Queiroz VF, Tatara JM, Botelho BB, Rodrigues RAL, Almeida GMDF, Abrahao JS. The consequences of viral infection on protists. Commun Biol 2024; 7:306. [PMID: 38462656 PMCID: PMC10925606 DOI: 10.1038/s42003-024-06001-2] [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: 10/28/2023] [Accepted: 02/29/2024] [Indexed: 03/12/2024] Open
Abstract
Protists encompass a vast widely distributed group of organisms, surpassing the diversity observed in metazoans. Their diverse ecological niches and life forms are intriguing characteristics that render them valuable subjects for in-depth cell biology studies. Throughout history, viruses have played a pivotal role in elucidating complex cellular processes, particularly in the context of cellular responses to viral infections. In this comprehensive review, we provide an overview of the cellular alterations that are triggered in specific hosts following different viral infections and explore intricate biological interactions observed in experimental conditions using different host-pathogen groups.
Collapse
Affiliation(s)
- Victoria Fulgencio Queiroz
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana Miranda Tatara
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Bruna Barbosa Botelho
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Rodrigo Araújo Lima Rodrigues
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Gabriel Magno de Freitas Almeida
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway.
| | - Jonatas Santos Abrahao
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| |
Collapse
|
4
|
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.
Collapse
Affiliation(s)
| | | | - Michele Castelli
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Chuvochina M, Mussig AJ, Chaumeil PA, Skarshewski A, Rinke C, Parks DH, Hugenholtz P. Proposal of names for 329 higher rank taxa defined in the Genome Taxonomy Database under two prokaryotic codes. FEMS Microbiol Lett 2023; 370:fnad071. [PMID: 37480240 PMCID: PMC10408702 DOI: 10.1093/femsle/fnad071] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/13/2023] [Accepted: 07/20/2023] [Indexed: 07/23/2023] Open
Abstract
The Genome Taxonomy Database (GTDB) is a taxonomic framework that defines prokaryotic taxa as monophyletic groups in concatenated protein reference trees according to systematic criteria. This has resulted in a substantial number of changes to existing classifications (https://gtdb.ecogenomic.org). In the case of union of taxa, GTDB names were applied based on the priority of publication. The division of taxa or change in rank led to the formation of new Latin names above the rank of genus that were only made publicly available via the GTDB website without associated published taxonomic descriptions. This has sometimes led to confusion in the literature and databases. A number of the provisional GTDB names were later published in other studies, while many still lack authorships. To reduce further confusion, here we propose names and descriptions for 329 GTDB-defined prokaryotic taxa, 223 of which are suitable for validation under the International Code of Nomenclature of Prokaryotes (ICNP) and 49 under the Code of Nomenclature of Prokaryotes described from Sequence Data (SeqCode). For the latter, we designated 23 genomes as type material. An additional 57 taxa that do not currently satisfy the validation criteria of either code are proposed as Candidatus.
Collapse
Affiliation(s)
- Maria Chuvochina
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Aaron J Mussig
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Pierre-Alain Chaumeil
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Adam Skarshewski
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Christian Rinke
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Donovan H Parks
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| | - Philip Hugenholtz
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics,, St Lucia QLD 4072, Brisbane, Australia
| |
Collapse
|
7
|
The inside scoop: Comparative genomics of two intranuclear bacteria, "Candidatus Berkiella cookevillensis" and "Candidatus Berkiella aquae". PLoS One 2022; 17:e0278206. [PMID: 36584052 PMCID: PMC9803151 DOI: 10.1371/journal.pone.0278206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/12/2022] [Indexed: 12/31/2022] Open
Abstract
"Candidatus Berkiella cookevillensis" (strain CC99) and "Candidatus Berkiella aquae" (strain HT99), belonging to the Coxiellaceae family, are gram-negative bacteria isolated from amoebae in biofilms present in human-constructed water systems. Both bacteria are obligately intracellular, requiring host cells for growth and replication. The intracellular bacteria-containing vacuoles of both bacteria closely associate with or enter the nuclei of their host cells. In this study, we analyzed the genome sequences of CC99 and HT99 to better understand their biology and intracellular lifestyles. The CC99 genome has a size of 2.9Mb (37.9% GC) and contains 2,651 protein-encoding genes (PEGs) while the HT99 genome has a size of 3.6Mb (39.4% GC) and contains 3,238 PEGs. Both bacteria encode high proportions of hypothetical proteins (CC99: 46.5%; HT99: 51.3%). The central metabolic pathways of both bacteria appear largely intact. Genes for enzymes involved in the glycolytic pathway, the non-oxidative branch of the phosphate pathway, the tricarboxylic acid pathway, and the respiratory chain were present. Both bacteria, however, are missing genes for the synthesis of several amino acids, suggesting reliance on their host for amino acids and intermediates. Genes for type I and type IV (dot/icm) secretion systems as well as type IV pili were identified in both bacteria. Moreover, both bacteria contain genes encoding large numbers of putative effector proteins, including several with eukaryotic-like domains such as, ankyrin repeats, tetratricopeptide repeats, and leucine-rich repeats, characteristic of other intracellular bacteria.
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Konecka E. Fifty shades of bacterial endosymbionts and some of them still remain a mystery: Wolbachia and Cardinium in oribatid mites (Acari: Oribatida). J Invertebr Pathol 2022; 189:107733. [DOI: 10.1016/j.jip.2022.107733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 11/28/2022]
|
11
|
Wang YJ, Chen CH, Chen JW, Lin WC. Commensals Serve as Natural Barriers to Mammalian Cells during Acanthamoeba castellanii Invasion. Microbiol Spectr 2021; 9:e0051221. [PMID: 34935418 PMCID: PMC8693914 DOI: 10.1128/spectrum.00512-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 11/02/2021] [Indexed: 12/23/2022] Open
Abstract
Acanthamoeba castellanii is a free-living, pathogenic ameba found in the soil and water. It invades the body through ulcerated skin, the nasal passages, and eyes and can cause blinding keratitis and granulomatous encephalitis. However, the mechanisms underlying the opportunistic pathogenesis of A. castellanii remain unclear. In this study, we observed that commensal bacteria significantly reduced the cytotoxicity of the ameba on mammalian cells. This effect occurred in the presence of both Gram-positive and Gram-negative commensals. Additionally, commensals mitigated the disruption of cell junctions. Ex vivo experiments on mouse eyeballs further showed that the commensals protected the corneal epithelial layer. Together, these findings indicate that A. castellanii is pathogenic to individuals with a dysbiosis of the microbiota at infection sites, further highlighting the role of commensals as a natural barrier during parasite invasion. IMPORTANCE Acanthamoeba castellanii, an opportunistic protozoan widely present in the environment, can cause Acanthamoeba keratitis and encephalitis in humans. However, only a few reports describe how the ameba acts as an opportunistic pathogen. Our study showed that the normal microbiota interfered with the cytotoxicity of Acanthamoeba, persevered during Acanthamoeba invasion, and reduced corneal epithelium peeling in the mouse eyeball model. This suggests that commensals may act as a natural barrier against Acanthamoeba invasion. In future, individuals who suffer from Acanthamoeba keratitis should be examined for microbiota absence or dysbiosis to reduce the incidence of Acanthamoeba infection in clinical settings.
Collapse
Affiliation(s)
- Yu-Jen Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Clinical Laboratory, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Chun-Hsien Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jenn-Wei Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Chen Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
12
|
Jansa J, Hodge A. Swimming, gliding, or hyphal riding? On microbial migration along the arbuscular mycorrhizal hyphal highway and functional consequences thereof. THE NEW PHYTOLOGIST 2021; 230:14-16. [PMID: 33600606 DOI: 10.1111/nph.17244] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Jan Jansa
- Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, Praha 4, 14220, Czech Republic
| | - Angela Hodge
- Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| |
Collapse
|
13
|
Piwosz K, Mukherjee I, Salcher MM, Grujčić V, Šimek K. CARD-FISH in the Sequencing Era: Opening a New Universe of Protistan Ecology. Front Microbiol 2021; 12:640066. [PMID: 33746931 PMCID: PMC7970053 DOI: 10.3389/fmicb.2021.640066] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/09/2021] [Indexed: 12/12/2022] Open
Abstract
Phagotrophic protists are key players in aquatic food webs. Although sequencing-based studies have revealed their enormous diversity, ecological information on in situ abundance, feeding modes, grazing preferences, and growth rates of specific lineages can be reliably obtained only using microscopy-based molecular methods, such as Catalyzed Reporter Deposition-Fluorescence in situ Hybridization (CARD-FISH). CARD-FISH is commonly applied to study prokaryotes, but less so to microbial eukaryotes. Application of this technique revealed that Paraphysomonas or Spumella-like chrysophytes, considered to be among the most prominent members of protistan communities in pelagic environments, are omnipresent but actually less abundant than expected, in contrast to little known groups such as heterotrophic cryptophyte lineages (e.g., CRY1), cercozoans, katablepharids, or the MAST lineages. Combination of CARD-FISH with tracer techniques and application of double CARD-FISH allow visualization of food vacuole contents of specific flagellate groups, thus considerably challenging our current, simplistic view that they are predominantly bacterivores. Experimental manipulations with natural communities revealed that larger flagellates are actually omnivores ingesting both prokaryotes and other protists. These new findings justify our proposition of an updated model of microbial food webs in pelagic environments, reflecting more authentically the complex trophic interactions and specific roles of flagellated protists, with inclusion of at least two additional trophic levels in the nanoplankton size fraction. Moreover, we provide a detailed CARD-FISH protocol for protists, exemplified on mixo- and heterotrophic nanoplanktonic flagellates, together with tips on probe design, a troubleshooting guide addressing most frequent obstacles, and an exhaustive list of published probes targeting protists.
Collapse
Affiliation(s)
- Kasia Piwosz
- Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, Gdynia, Poland
- Centre ALGATECH, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - Indranil Mukherjee
- Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, České Budějovice, Czechia
| | - Michaela M. Salcher
- Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, České Budějovice, Czechia
| | - Vesna Grujčić
- Science for Life Laboratory, Department of Gene Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Karel Šimek
- Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, České Budějovice, Czechia
| |
Collapse
|
14
|
Abstract
Amoebae are protists that have complicated relationships with bacteria, covering the whole spectrum of symbiosis. Amoeba-bacterium interactions contribute to the study of predation, symbiosis, pathogenesis, and human health. Given the complexity of their relationships, it is necessary to understand the ecology and evolution of their interactions. In this paper, we provide an updated review of the current understanding of amoeba-bacterium interactions. We start by discussing the diversity of amoebae and their bacterial partners. We also define three types of ecological interactions between amoebae and bacteria and discuss their different outcomes. Finally, we focus on the implications of amoeba-bacterium interactions on human health, horizontal gene transfer, drinking water safety, and the evolution of symbiosis. In conclusion, amoeba-bacterium interactions are excellent model systems to investigate a wide range of scientific questions. Future studies should utilize advanced techniques to address research gaps, such as detecting hidden diversity, lack of amoeba genomes, and the impacts of amoeba predation on the microbiome.
Collapse
|
15
|
Guillonneau R, Baraquet C, Molmeret M. Marine Bacteria Display Different Escape Mechanisms When Facing Their Protozoan Predators. Microorganisms 2020; 8:microorganisms8121982. [PMID: 33322808 PMCID: PMC7763514 DOI: 10.3390/microorganisms8121982] [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: 09/24/2020] [Revised: 11/24/2020] [Accepted: 12/10/2020] [Indexed: 12/20/2022] Open
Abstract
Free-living amoeba are members of microbial communities such as biofilms in terrestrial, fresh, and marine habitats. Although they are known to live in close association with bacteria in many ecosystems such as biofilms, they are considered to be major bacterial predators in many ecosystems. Little is known on the relationship between protozoa and marine bacteria in microbial communities, more precisely on how bacteria are able survive in environmental niches where these bacterial grazers also live. The objective of this work is to study the interaction between the axenized ubiquitous amoeba Acanthamoeba castellanii and four marine bacteria isolated from immersed biofilm, in order to evaluate if they would be all grazed upon by amoeba or if they would be able to survive in the presence of their predator. At a low bacteria-to-amoeba ratio, we show that each bacterium is phagocytized and follows a singular intracellular path within this host cell, which appears to delay or to prevent bacterial digestion. In particular, one of the bacteria was found in the amoeba nucleolar compartment whereas another strain was expelled from the amoeba in vesicles. We then looked at the fate of the bacteria grown in a higher bacteria-to-amoeba ratio, as a preformed mono- or multi-species biofilm in the presence of A. castellanii. We show that all biofilms were subjected to detachment from the surface in the presence of the amoeba or its supernatant. Overall, these results show that bacteria, when facing the same predator, exhibit a variety of escape mechanisms at the cellular and population level, when we could have expected a simple bacterial grazing. Therefore, this study unravels new insights into the survival of environmental bacteria when facing predators that they could encounter in the same microbial communities.
Collapse
Affiliation(s)
- Richard Guillonneau
- Laboratoire MAPIEM, EA4323, Université de Toulon, 83130 La Garde, France; (R.G.); (C.B.)
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Claudine Baraquet
- Laboratoire MAPIEM, EA4323, Université de Toulon, 83130 La Garde, France; (R.G.); (C.B.)
| | - Maëlle Molmeret
- Laboratoire MAPIEM, EA4323, Université de Toulon, 83130 La Garde, France; (R.G.); (C.B.)
- Correspondence:
| |
Collapse
|
16
|
Oren A, Garrity GM, Parker CT, Chuvochina M, Trujillo ME. Lists of names of prokaryotic Candidatus taxa. Int J Syst Evol Microbiol 2020; 70:3956-4042. [DOI: 10.1099/ijsem.0.003789] [Citation(s) in RCA: 782] [Impact Index Per Article: 195.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We here present annotated lists of names of Candidatus taxa of prokaryotes with ranks between subspecies and class, proposed between the mid-1990s, when the provisional status of Candidatus taxa was first established, and the end of 2018. Where necessary, corrected names are proposed that comply with the current provisions of the International Code of Nomenclature of Prokaryotes and its Orthography appendix. These lists, as well as updated lists of newly published names of Candidatus taxa with additions and corrections to the current lists to be published periodically in the International Journal of Systematic and Evolutionary Microbiology, may serve as the basis for the valid publication of the Candidatus names if and when the current proposals to expand the type material for naming of prokaryotes to also include gene sequences of yet-uncultivated taxa is accepted by the International Committee on Systematics of Prokaryotes.
Collapse
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
- NamesforLife, LLC, PO Box 769, Okemos MI 48805-0769, USA
- Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences, Michigan State University, East Lansing, MI 48824-4320, USA
| | | | - Maria Chuvochina
- Australian Centre for Ecogenomics, University of Queensland, St. Lucia QLD 4072, Brisbane, Australia
| | - Martha E. Trujillo
- Departamento de Microbiología y Genética, Campus Miguel de Unamuno, Universidad de Salamanca, 37007, Salamanca, Spain
| |
Collapse
|
17
|
Frank AC. Molecular host mimicry and manipulation in bacterial symbionts. FEMS Microbiol Lett 2019; 366:5342066. [PMID: 30877310 DOI: 10.1093/femsle/fnz038] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/18/2019] [Indexed: 12/17/2022] Open
Abstract
It is common among intracellular bacterial pathogens to use eukaryotic-like proteins that mimic and manipulate host cellular processes to promote colonization and intracellular survival. Eukaryotic-like proteins are bacterial proteins with domains that are rare in bacteria, and known to function in the context of a eukaryotic cell. Such proteins can originate through horizontal gene transfer from eukaryotes or, in the case of simple repeat proteins, through convergent evolution. Recent studies of microbiomes associated with several eukaryotic hosts suggest that similar molecular strategies are deployed by cooperative bacteria that interact closely with eukaryotic cells. Some mimics, like ankyrin repeats, leucine rich repeats and tetratricopeptide repeats are shared across diverse symbiotic systems ranging from amoebae to plants, and may have originated early, or evolved independently in multiple systems. Others, like plant-mimicking domains in members of the plant microbiome are likely to be more recent innovations resulting from horizontal gene transfer from the host, or from microbial eukaryotes occupying the same host. Host protein mimics have only been described in a limited set of symbiotic systems, but are likely to be more widespread. Systematic searches for eukaryote-like proteins in symbiont genomes could lead to the discovery of novel mechanisms underlying host-symbiont interactions.
Collapse
Affiliation(s)
- A Carolin Frank
- Life and Environmental Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA.,Sierra Nevada Research Institute, School of Natural Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA
| |
Collapse
|
18
|
Tsao HF, Scheikl U, Herbold C, Indra A, Walochnik J, Horn M. The cooling tower water microbiota: Seasonal dynamics and co-occurrence of bacterial and protist phylotypes. WATER RESEARCH 2019; 159:464-479. [PMID: 31128471 PMCID: PMC6554697 DOI: 10.1016/j.watres.2019.04.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 04/04/2019] [Accepted: 04/13/2019] [Indexed: 05/30/2023]
Abstract
Cooling towers for heating, ventilation and air conditioning are ubiquitous in the built environment. Often located on rooftops, their semi-open water basins provide a suitable environment for microbial growth. They are recognized as a potential source of bacterial pathogens and have been associated with disease outbreaks such as Legionnaires' disease. While measures to minimize public health risks are in place, the general microbial and protist community structure and dynamics in these systems remain largely elusive. In this study, we analysed the microbiome of the bulk water from the basins of three cooling towers by 16S and 18S rRNA gene amplicon sequencing over the course of one year. Bacterial diversity in all three towers was broadly comparable to other freshwater systems, yet less diverse than natural environments; the most abundant taxa are also frequently found in freshwater or drinking water. While each cooling tower had a pronounced site-specific microbial community, taxa shared among all locations mainly included groups generally associated with biofilm formation. We also detected several groups related to known opportunistic pathogens, such as Legionella, Mycobacterium, and Pseudomonas species, albeit at generally low abundance. Although cooling towers represent a rather stable environment, microbial community composition was highly dynamic and subject to seasonal change. Protists are important members of the cooling tower water microbiome and known reservoirs for bacterial pathogens. Co-occurrence analysis of bacteria and protist taxa successfully captured known interactions between amoeba-associated bacteria and their hosts, and predicted a large number of additional relationships involving ciliates and other protists. Together, this study provides an unbiased and comprehensive overview of microbial diversity of cooling tower water basins, establishing a framework for investigating and assessing public health risks associated with these man-made freshwater environments.
Collapse
Affiliation(s)
- Han-Fei Tsao
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Ute Scheikl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Craig Herbold
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Alexander Indra
- Department of Mycobacteriology and Clinical Molecular Biology, AGES, Vienna, Austria
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
| |
Collapse
|
19
|
Rossi A, Bellone A, Fokin SI, Boscaro V, Vannini C. Detecting Associations Between Ciliated Protists and Prokaryotes with Culture-Independent Single-Cell Microbiomics: a Proof-of-Concept Study. MICROBIAL ECOLOGY 2019; 78:232-242. [PMID: 30411190 DOI: 10.1007/s00248-018-1279-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/22/2018] [Indexed: 06/08/2023]
Abstract
Symbioses between prokaryotes and microbial eukaryotes, particularly ciliated protists, have been studied for a long time. Nevertheless, researchers have focused only on a few host genera and species, mainly due to difficulties in cultivating the hosts, and usually have considered a single symbiont at a time. Here, we present a pilot study using a single-cell microbiomic approach to circumvent these issues. Unicellular ciliate isolation followed by simultaneous amplification of eukaryotic and prokaryotic markers was used. Our preliminary test gave reliable and satisfactory results both on samples collected from different habitats (marine and freshwater) and on ciliates belonging to different taxonomic groups. Results suggest that, as already assessed for many macro-organisms like plants and metazoans, ciliated protists harbor distinct microbiomes. The applied approach detected new potential symbionts as well as new hosts for previously described ones, with relatively low time and cost effort and without culturing. When further developed, single-cell microbiomics for ciliates could be applied to a large number of studies aiming to unravel the evolutionary and ecological meaning of these symbiotic systems.
Collapse
Affiliation(s)
- Alessia Rossi
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Sergei I Fokin
- Department of Biology, University of Pisa, Pisa, Italy
- Department of Invertebrate Zoology, St.-Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch of the S.I. Vavilov Institute of History of Science and Technology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Vittorio Boscaro
- Department of Biology, University of Pisa, Pisa, Italy
- Department of Botany, University of British Columbia, Vancouver, Canada
| | | |
Collapse
|
20
|
Chamberlain NB, Mehari YT, Hayes BJ, Roden CM, Kidane DT, Swehla AJ, Lorenzana-DeWitt MA, Farone AL, Gunderson JH, Berk SG, Farone MB. Infection and nuclear interaction in mammalian cells by 'Candidatus Berkiella cookevillensis', a novel bacterium isolated from amoebae. BMC Microbiol 2019; 19:91. [PMID: 31072343 PMCID: PMC6507137 DOI: 10.1186/s12866-019-1457-z] [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: 09/10/2017] [Accepted: 04/15/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 'Candidatus Berkiella cookevillensis' and 'Ca. Berkiella aquae' have previously been described as intranuclear bacteria of amoebae. Both bacteria were isolated from amoebae and were described as appearing within the nuclei of Acanthamoeba polyphaga and ultimately lysing their host cells within 4 days. Both bacteria are Gammaproteobacteria in the order Legionellales with the greatest similarity to Coxiella burnetii. Neither bacterium grows axenically in artificial culture media. In this study, we further characterized 'Ca. B. cookevillensis' by demonstrating association with nuclei of human phagocytic and nonphagocytic cell lines. RESULTS Transmission electron microscopy (TEM) and confocal microscopy were used to confirm nuclear co-localization of 'Ca. B. cookevillensis' in the amoeba host A. polyphaga with 100% of cells having bacteria co-localized with host nuclei by 48 h. TEM and confocal microscopy demonstrated that the bacterium was also observed to be closely associated with nuclei of human U937 and THP-1 differentiated macrophage cell lines and nonphagocytic HeLa human epithelial-like cells. Immunofluorescent staining revealed that the bacteria-containing vacuole invaginates the nuclear membranes and appears to cross from the cytoplasm into the nucleus as an intact vacuole. CONCLUSION Results of this study indicate that a novel coccoid bacterium isolated from amoebae can infect human cell lines by associating with the host cell nuclei, either by crossing the nuclear membranes or by deeply invaginating the nuclear membranes. When associated with the nuclei, the bacteria appear to be bound within a vacuole and replicate to high numbers by 48 h. We believe this is the first report of such a process involving bacteria and human cell lines.
Collapse
Affiliation(s)
- Nicholas B Chamberlain
- Molecular Biosciences Program, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA.,Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Yohannes T Mehari
- Molecular Biosciences Program, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA.,Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - B Jason Hayes
- Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Colleen M Roden
- Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Destaalem T Kidane
- Molecular Biosciences Program, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA.,Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Andrew J Swehla
- Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Mario A Lorenzana-DeWitt
- Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Anthony L Farone
- Molecular Biosciences Program, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA.,Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - John H Gunderson
- Department of Biology, Tennessee Technological University, 1 William L Jones Dr, Cookeville, TN, 38505, USA
| | - Sharon G Berk
- Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA
| | - Mary B Farone
- Molecular Biosciences Program, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA. .,Department of Biology, Middle Tennessee State University, 1301 E. Main St, Murfreesboro, TN, 37130, USA.
| |
Collapse
|
21
|
Abstract
Microbial symbioses exhibit astounding adaptations, yet all symbionts face the problem of how to reliably associate with host offspring every generation. A common strategy is vertical transmission, in which symbionts are directly transmitted from the female to her offspring. The diversity of symbionts and vertical transmission mechanisms is as expansive as the diversity of eukaryotic host taxa that house them. However, there are several common themes among these mechanisms based on the degree to which symbionts associate with the host germline during transmission. In this review, we detail three distinct vertical transmission strategies, starting with associations that are transmitted from host somatic cells to offspring somatic cells, either due to lacking a germline or avoiding it. A second strategy involves somatically-localized symbionts that migrate into the germline during host development. The third strategy we discuss is one in which the symbiont maintains continuous association with the germline throughout development. Unexpectedly, the vast majority of documented vertically inherited symbionts rely on the second strategy: soma-to-germline migration. Given that not all eukaryotes contain a sequestered germline and instead produce offspring from somatic stem cell lineages, this soma-to-germline migration is discussed in the context of multicellular evolution. Lastly, as recent genomics data have revealed an abundance of horizontal gene transfer events from symbiotic and non-symbiotic bacteria to host genomes, we discuss their impact on eukaryotic host evolution.
Collapse
Affiliation(s)
- Shelbi L Russell
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA, United States.
| | - Laura Chappell
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA, United States
| | - William Sullivan
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA, United States
| |
Collapse
|
22
|
Samba-Louaka A, Delafont V, Rodier MH, Cateau E, Héchard Y. Free-living amoebae and squatters in the wild: ecological and molecular features. FEMS Microbiol Rev 2019; 43:415-434. [DOI: 10.1093/femsre/fuz011] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/30/2019] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Free-living amoebae are protists frequently found in water and soils. They feed on other microorganisms, mainly bacteria, and digest them through phagocytosis. It is accepted that these amoebae play an important role in the microbial ecology of these environments. There is a renewed interest for the free-living amoebae since the discovery of pathogenic bacteria that can resist phagocytosis and of giant viruses, underlying that amoebae might play a role in the evolution of other microorganisms, including several human pathogens. Recent advances, using molecular methods, allow to bring together new information about free-living amoebae. This review aims to provide a comprehensive overview of the newly gathered insights into (1) the free-living amoeba diversity, assessed with molecular tools, (2) the gene functions described to decipher the biology of the amoebae and (3) their interactions with other microorganisms in the environment.
Collapse
Affiliation(s)
- Ascel Samba-Louaka
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Vincent Delafont
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Marie-Hélène Rodier
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Estelle Cateau
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Yann Héchard
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| |
Collapse
|
23
|
Scheid PL. Vermamoeba vermiformis - A Free-Living Amoeba with Public Health and Environmental Health Significance. ACTA ACUST UNITED AC 2019. [DOI: 10.2174/1874421401907010040] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Many case reports emphasize the fact that Free-Living Amoebae (FLA) can relatively easily get in contact with humans or animals. The presence of several facultative parasitic FLA in habitats related to human activities supports their public health relevance. While some strains of Acanthamoeba,Naegleria fowleri,Balamuthia mandrillarisand several other FLA have been described as facultative human pathogens, it remains controversial whetherVermamoeba vermiformisstrains may have a pathogenic potential, or whether this FLA is just an incidental contaminant in a range of human cases. However, several cases support its role as a human parasite, either as the only etiological agent, or in combination with other pathogens. Additionally, a wide range of FLA is known as vectors of microorganisms (endocytobionts), hereby emphasizing their environmental significance. Among those FLA serving as hosts for and vectors of (pathogenic) endocytobionts, there are also descriptions ofV. vermiformisas a vehicle and a reservoir of those endocytobionts. The involvement in animal and human health, the role as vector of pathogenic microorganisms and the pathogenicity in cell cultures, led to the assumption thatV. vermiformisshould be considered relevant in terms of public health and environmental health.
Collapse
|
24
|
Detection of a new bacterium of the family Holosporaceae (Alphaproteobacteria: Holosporales) associated with the oribatid mite Achipteria coleoptrata. Biologia (Bratisl) 2019. [DOI: 10.2478/s11756-019-00251-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AbstractWe detected an unknown bacterium in Achipteria coleoptrata (Acari: Oribatida). Its 16S rDNA gene sequence showed 89% identity to the endosymbiont “Candidatus Nucleicultrix amoebiphila” from amoebae and “Candidatus Gortzia sp.” from ciliates. Phylogenetic analysis revealed that the microorganism is a member of the family Holosporaceae, order Holosporales of Alphaproteobacteria. Its occurrence in Oribatida is enigmatic. It cannot be excluded that it is a symbiont of Oribatida as well as it is an endosymbiont of a smaller, even unicellular, organisms living inside the mite. The issue of the occurrence of this microorganism is interesting and further research is needed to gain the knowledge of its role and the nature of bacterium-host interaction.
Collapse
|
25
|
Delafont V, Rodier MH, Maisonneuve E, Cateau E. Vermamoeba vermiformis: a Free-Living Amoeba of Interest. MICROBIAL ECOLOGY 2018; 76:991-1001. [PMID: 29737382 DOI: 10.1007/s00248-018-1199-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 04/30/2018] [Indexed: 05/22/2023]
Abstract
Free-living amoebae are protists that are widely distributed in the environment including water, soil, and air. Although the amoebae of the genus Acanthamoeba are still the most studied, other species, such as Vermamoeba vermiformis (formerly Hartmannella vermiformis), are the subject of increased interest. Found in natural or man-made aquatic environments, V. vermiformis can support the multiplication of other microorganisms and is able to harbor and potentially protect pathogenic bacteria or viruses. This feature is to be noted because of the presence of this thermotolerant amoeba in hospital water networks. As a consequence, this protist could be implicated in health concerns and be indirectly responsible for healthcare-related infections. This review highlights, among others, the consequences of V. vermiformis relationships with other microorganisms and shows that this free-living amoeba species is therefore of interest for public health.
Collapse
Affiliation(s)
- Vincent Delafont
- Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, Université de Poitiers, 1 rue Georges Bonnet, 86022, Poitiers Cedex, France
| | - Marie-Helene Rodier
- Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, Université de Poitiers, 1 rue Georges Bonnet, 86022, Poitiers Cedex, France
- Laboratoire de parasitologie et mycologie, CHU La Milètrie, 86021, Poitiers Cedex, France
| | - Elodie Maisonneuve
- Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, Université de Poitiers, 1 rue Georges Bonnet, 86022, Poitiers Cedex, France
| | - Estelle Cateau
- Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, Université de Poitiers, 1 rue Georges Bonnet, 86022, Poitiers Cedex, France.
- Laboratoire de parasitologie et mycologie, CHU La Milètrie, 86021, Poitiers Cedex, France.
| |
Collapse
|
26
|
Chan LL, Mak JW, Ambu S, Chong PY. Identification and ultrastructural characterization of Acanthamoeba bacterial endocytobionts belonging to the Alphaproteobacteria class. PLoS One 2018; 13:e0204732. [PMID: 30356282 PMCID: PMC6200196 DOI: 10.1371/journal.pone.0204732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 09/13/2018] [Indexed: 12/17/2022] Open
Abstract
The detection and identification of two endocytobiotic bacterial strains, one affiliated to the “Candidatus Caedibacter acanthamoebae”/“Ca. Paracaedimonas acanthamoeba”, and another to the endosymbiont of Acanthamoeba UWC8 and “Ca. Jidaibacter acanthamoeba” are described. For endocytobiont screening, we developed a PCR method with a set of broad-range bacterial 16S rRNA primers to substitute the commonly used but technically demanding fluorescent in situ hybridization technique. Our PCR test alone without sequencing failed to discriminate the endocytobiont-containing and endocytobiont-free Acanthamoeba sp. due to the presence of mismatched primers to host mitochondrial DNA. We highlighted the need to perform bacterial primer checking against the Acanthamoeba genome to avoid false positive detection in PCR. Although the genetic aspect of “Ca. Caedibacter acanthamoebae”/“Ca. Paracaedimonas acanthamoeba” and the endosymbiont of Acanthamoeba UWC8/“Ca. Jidaibacter acanthamoeba” are well studied, knowledge pertaining to their morphologies are quite vague. Hence, we used transmission electron microscopy to examine our endocytobionts which are affiliated to previously described intracellular bacteria of Acanthamoeba sp. We used good-quality TEM images for the localization and the fate of the current endocytobionts inside different life stages of the hosts. Furthermore, to the best of our knowledge, our TEM findings are the first to provide morphological evidence for the clearance of defective Acanthamoeba endocytobionts via an autophagic-like process.
Collapse
Affiliation(s)
- Li Li Chan
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- * E-mail:
| | - Joon Wah Mak
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
| | - Stephen Ambu
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
| | - Pei Yee Chong
- Medical Sciences, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| |
Collapse
|
27
|
Shu L, Zhang B, Queller DC, Strassmann JE. Burkholderia bacteria use chemotaxis to find social amoeba Dictyostelium discoideum hosts. THE ISME JOURNAL 2018; 12:1977-1993. [PMID: 29795447 PMCID: PMC6052080 DOI: 10.1038/s41396-018-0147-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/05/2018] [Accepted: 03/28/2018] [Indexed: 12/15/2022]
Abstract
A key question in cooperation is how to find the right partners and maintain cooperative relationships. This is especially challenging for horizontally transferred bacterial symbionts where relationships must be repeatedly established anew. In the social amoeba Dictyostelium discoideum farming symbiosis, two species of inedible Burkholderia bacteria (Burkholderia agricolaris and Burkholderia hayleyella) initiate stable associations with naive D. discoideum hosts and cause carriage of additional bacterial species. However, it is not clear how the association between D. discoideum and its carried Burkholderia is formed and maintained. Here, we look at precisely how Burkholderia finds its hosts. We found that both species of Burkholderia clones isolated from D. discoideum, but not other tested Burkholderia species, are attracted to D. discoideum supernatant, showing that the association is not simply the result of haphazard engulfment by the amoebas. The chemotactic responses are affected by both partners. We find evidence that B. hayleyella prefers D. discoideum clones that currently or previously carried Burkholderia, while B. agricolaris does not show this preference. However, we find no evidence of Burkholderia preference for their own host clone or for other hosts of their own species. We further investigate the chemical differences of D. discoideum supernatants that might explain the patterns shown above using a mass spectrometry based metabolomics approach. These results show that these bacterial symbionts are able to preferentially find and to some extent choose their unicellular partners. In addition, this study also suggests that bacteria can actively search for and target phagocytic cells, which may help us better understand how bacteria interact with immune systems.
Collapse
Affiliation(s)
- Longfei Shu
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Bojie Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - David C Queller
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Joan E Strassmann
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
| |
Collapse
|
28
|
Schrallhammer M, Castelli M, Petroni G. Phylogenetic relationships among endosymbiotic R-body producer: Bacteria providing their host the killer trait. Syst Appl Microbiol 2018; 41:213-220. [PMID: 29426636 DOI: 10.1016/j.syapm.2018.01.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/10/2018] [Accepted: 01/17/2018] [Indexed: 11/28/2022]
Abstract
R-body producing bacterial endosymbionts of Paramecium spp. transform their hosts into "killer" paramecia and provide them a selective advantage. This killer trait is connected to the presence of R-bodies, which are peculiar, tightly coiled protein ribbons capable of rapid unrolling. Based mainly on those two characteristics the respective obligate intracellular bacteria have been comprised in the genus Caedibacter and additional traits such as host species, subcellular localization, and R-body dimensions and mode of unrolling were used for species discrimination. Previous studies applying the full-cycle rRNA approach demonstrated the polyphyly of this assemblage. Following this approach, we obtained new sequences and in situ hybridizations for five strains of Caedibacter taeniospiralis and four strains associated to Caedibacter varicaedens and Caedibacter caryophilus. Detailed phylogenetic reconstructions confirm the association of C. taeniospiralis to Fastidiosibacteraceae and to Holosporales in case of the others. Therefore, we critically revise the taxonomy of the latter group. The high 16S rRNA gene sequence similarity among the type strains of Caedibacter varicaedens and C. caryophilus indicate that they should be classified within a single species for which we propose Caedimonas varicaedens comb. nov. owing to the priority of Caedibacter varicaedens. Moreover, we propose to establish the new family Caedimonadaceae fam. nov. to encompass Caedimonas varicaedens, "Ca. Paracaedimonas acanthamoebae" comb. nov. and "Ca. Nucleicultrix amoebiphila" within the order Holosporales.
Collapse
Affiliation(s)
- Martina Schrallhammer
- Institute of Biology II, Albert-Ludwigs University of Freiburg, 79104 Freiburg, Germany.
| | - Michele Castelli
- Department of Veterinary Medicine, University of Milan, 20133 Milan, Italy; Department of Biosciences, University of Milan, 20133 Milan, Italy
| | - Giulio Petroni
- Department of Biology, University of Pisa, 56126 Pisa, Italy
| |
Collapse
|
29
|
Milanez GD, Masangkay FR, Thomas RC, Ordona MOGO, Bernales GQ, Corpuz VCM, Fortes HSV, Garcia CMS, Nicolas LC, Nissapatorn V. Molecular identification of Vermamoeba vermiformis from freshwater fish in lake Taal, Philippines. Exp Parasitol 2017; 183:201-206. [DOI: 10.1016/j.exppara.2017.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/06/2017] [Accepted: 09/11/2017] [Indexed: 11/28/2022]
|
30
|
Tsao HF, Scheikl U, Volland JM, Köhsler M, Bright M, Walochnik J, Horn M. 'Candidatus Cochliophilus cryoturris' (Coxiellaceae), a symbiont of the testate amoeba Cochliopodium minus. Sci Rep 2017; 7:3394. [PMID: 28611430 PMCID: PMC5469826 DOI: 10.1038/s41598-017-03642-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/02/2017] [Indexed: 11/09/2022] Open
Abstract
Free-living amoebae are well known for their role in controlling microbial community composition through grazing, but some groups, namely Acanthamoeba species, also frequently serve as hosts for bacterial symbionts. Here we report the first identification of a bacterial symbiont in the testate amoeba Cochliopodium. The amoeba was isolated from a cooling tower water sample and identified as C. minus. Fluorescence in situ hybridization and transmission electron microscopy revealed intracellular symbionts located in vacuoles. 16S rRNA-based phylogenetic analysis identified the endosymbiont as member of a monophyletic group within the family Coxiellaceae (Gammaprotebacteria; Legionellales), only moderately related to known amoeba symbionts. We propose to tentatively classify these bacteria as 'Candidatus Cochliophilus cryoturris'. Our findings add both, a novel group of amoeba and a novel group of symbionts, to the growing list of bacteria-amoeba relationships.
Collapse
Affiliation(s)
- Han-Fei Tsao
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Ute Scheikl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Jean-Marie Volland
- Department of Limnology and Oceanography, University of Vienna, Vienna, Austria
| | - Martina Köhsler
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Monika Bright
- Department of Limnology and Oceanography, University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Matthias Horn
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
| |
Collapse
|
31
|
Abstract
Long before bacteria infected humans, they infected amoebas, which remain a potentially important reservoir for human disease. Diverse soil amoebas including Dictyostelium and Acanthamoeba can host intracellular bacteria. Though the internal environment of free-living amoebas is similar in many ways to that of mammalian macrophages, they differ in a number of important ways, including temperature. A new study in PLOS Biology by Taylor-Mulneix et al. demonstrates that Bordetella bronchiseptica has two different gene suites that are activated depending on whether the bacterium finds itself in a hot mammalian or cool amoeba host environment. This study specifically shows that B. bronchiseptica not only inhabits amoebas but can persist and multiply through the social stage of an amoeba host, Dictyostelium discoideum.
Collapse
|
32
|
Disentangling the Taxonomy of Rickettsiales and Description of Two Novel Symbionts ("Candidatus Bealeia paramacronuclearis" and "Candidatus Fokinia cryptica") Sharing the Cytoplasm of the Ciliate Protist Paramecium biaurelia. Appl Environ Microbiol 2016; 82:7236-7247. [PMID: 27742680 PMCID: PMC5118934 DOI: 10.1128/aem.02284-16] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/06/2016] [Indexed: 11/20/2022] Open
Abstract
In the past 10 years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, IN. Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium “Candidatus Bealeia paramacronuclearis” occurs in clumps and is frequently associated with the host macronucleus. With its electron-dense cytoplasm and a distinct halo surrounding the cell, it is easily distinguishable from the second smaller symbiont, “Candidatus Fokinia cryptica,” whose cytoplasm is electron lucid, lacks a halo, and is always surrounded by a symbiontophorous vacuole. For molecular characterization, the small-subunit rRNA genes were sequenced and used for taxonomic assignment as well as the design of species-specific oligonucleotide probes. Phylogenetic analyses revealed that “Candidatus Bealeia paramacronuclearis” clusters with the so-called “basal” Rickettsiales, and “Candidatus Fokinia cryptica” belongs to “Candidatus Midichloriaceae.” We obtained tree topologies showing a separation of Rickettsiales into at least two groups: one represented by the families Rickettsiaceae, Anaplasmataceae, and “Candidatus Midichloriaceae” (RAM clade), and the other represented by “basal Rickettsiales,” including “Candidatus Bealeia paramacronuclearis.” Therefore, and in accordance with recent publications, we propose to limit the order Rickettsiales to the RAM clade and to raise “basal Rickettsiales” to an independent order, Holosporales ord. nov., inside Alphaproteobacteria, which presently includes four family-level clades. Additionally, we define the family “Candidatus Hepatincolaceae” and redefine the family Holosporaceae. IMPORTANCE In this paper, we provide the characterization of two novel bacterial symbionts inhabiting the same Paramecium host (Ciliophora, Alveolata). Both symbionts belong to “traditional” Rickettsiales, one representing a new species of the genus “Candidatus Fokinia” (“Candidatus Midichloriaceae”), and the other representing a new genus of a “basal” Rickettsiales. According to newly characterized sequences and to a critical revision of recent literature, we propose a taxonomic reorganization of “traditional” Rickettsiales that we split into two orders: Rickettsiales sensu stricto and Holosporales ord. nov. This work represents a critical revision, including new records of a group of symbionts frequently occurring in protists and whose biodiversity is still largely underestimated.
Collapse
|
33
|
Delafont V, Samba-Louaka A, Bouchon D, Moulin L, Héchard Y. Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free-living amoeba. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:970-978. [PMID: 26471960 DOI: 10.1111/1758-2229.12343] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 10/06/2015] [Accepted: 10/07/2015] [Indexed: 06/05/2023]
Abstract
The TM6 phylum belongs to the so-called microbial dark matter that gathers uncultivated bacteria detected only via DNA sequencing. Recently, the genome sequence of a TM6 bacterium (TM6SC1) has led to suggest that this bacterium would adopt an endosymbiotic life. In the present paper, free-living amoebae bearing a TM6 strain were isolated from a water network. The amoebae were identified as Vermamoeba vermiformis and the presence of a TM6 strain was detected by polymerase chain reaction and microscopy. The partial sequence of its 16S rRNA gene showed this strain to be closely related to the sequenced TM6SC1 strain. These bacteria displayed a pyriform shape and were found within V. vermiformis. Therefore, these bacteria were named Vermiphilus pyriformis. Interactions studies showed that V. pyriformis was highly infectious and that its relation with V. vermiformis was specific and highly stable. Finally, it was found that V. pyriformis inhibited the encystment of V. vermiformis. Overall, this study describes for the first time an endosymbiotic relationship between a TM6 bacterium and a free-living amoeba in the environment. It suggests that other bacteria of the TM6 phylum might also be endosymbiotic bacteria and may be found in other free-living amoebae or other organisms.
Collapse
Affiliation(s)
- Vincent Delafont
- Microbiologie de l'Eau & Ecologie, Evolution, Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipes, Université de Poitiers, Poitiers, France
- Direction de la Recherche et du Développement pour la Qualité de l'Eau, R&D Biologie, Eau de Paris, 33, avenue Jean Jaurès, 94200, Ivry sur Seine, Paris, France
| | - Ascel Samba-Louaka
- Microbiologie de l'Eau & Ecologie, Evolution, Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipes, Université de Poitiers, Poitiers, France
| | - Didier Bouchon
- Microbiologie de l'Eau & Ecologie, Evolution, Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipes, Université de Poitiers, Poitiers, France
| | - Laurent Moulin
- Direction de la Recherche et du Développement pour la Qualité de l'Eau, R&D Biologie, Eau de Paris, 33, avenue Jean Jaurès, 94200, Ivry sur Seine, Paris, France
| | - Yann Héchard
- Microbiologie de l'Eau & Ecologie, Evolution, Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipes, Université de Poitiers, Poitiers, France
| |
Collapse
|
34
|
"Candidatus Finniella" (Rickettsiales, Alphaproteobacteria), Novel Endosymbionts of Viridiraptorid Amoeboflagellates (Cercozoa, Rhizaria). Appl Environ Microbiol 2015; 82:659-70. [PMID: 26567303 DOI: 10.1128/aem.02680-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/08/2015] [Indexed: 11/20/2022] Open
Abstract
The Rickettsiales (Alphaproteobacteria) are obligate intracellular bacteria that colonize a wide range of eukaryotic hosts, including diverse metazoa and protists. Here, we characterize rickettsial endosymbionts discovered in the cytoplasm of the algivorous amoeboflagellates Viridiraptor invadens and Orciraptor agilis (Viridiraptoridae, Cercozoa, Rhizaria), supplying evidence of free-living, phagotrophic members of the Cercozoa serving as hosts for Rickettsiales. According to 16S rRNA gene phylogenies, the bacteria represent two closely related but distinct genotypes within a deep-branching rickettsial clade, which contains the genera "Candidatus Odyssella," "Candidatus Paracaedibacter," and "Candidatus Captivus." Using the full-cycle rRNA approach, we detected the novel bacteria in four of nine viridiraptorid strains tested. Furthermore, two specific oligonucleotide probes with a single-nucleotide-difference discriminated both bacterial genotypes by fluorescence in situ hybridization (FISH). We establish the candidate species "Candidatus Finniella inopinata" (found in Viridiraptor invadens) and "Candidatus Finniella lucida" (found in Orciraptor agilis) for the novel bacteria and propose a new, provisional family of Rickettsiales, "Candidatus Paracaedibacteraceae."
Collapse
|
35
|
Marine amoebae with cytoplasmic and perinuclear symbionts deeply branching in the Gammaproteobacteria. Sci Rep 2015; 5:13381. [PMID: 26303516 PMCID: PMC4642509 DOI: 10.1038/srep13381] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 07/24/2015] [Indexed: 12/31/2022] Open
Abstract
Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named ‘Candidatus Occultobacter vannellae’ and ‘Candidatus Nucleophilum amoebae’. While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria (85–88% 16S rRNA sequence similarity) but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host-derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts.
Collapse
|
36
|
Schulz F, Martijn J, Wascher F, Lagkouvardos I, Kostanjšek R, Ettema TJG, Horn M. A Rickettsiales symbiont of amoebae with ancient features. Environ Microbiol 2015; 18:2326-42. [PMID: 25908022 DOI: 10.1111/1462-2920.12881] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 03/03/2015] [Accepted: 03/16/2015] [Indexed: 11/28/2022]
Abstract
The Rickettsiae comprise intracellular bacterial symbionts and pathogens infecting diverse eukaryotes. Here, we provide a detailed characterization of 'Candidatus Jidaibacter acanthamoeba', a rickettsial symbiont of Acanthamoeba. The bacterium establishes the infection in its amoeba host within 2 h where it replicates within vacuoles. Higher bacterial loads and accelerated spread of infection at elevated temperatures were observed. The infection had a negative impact on host growth rate, although no increased levels of host cell lysis were seen. Phylogenomic analysis identified this bacterium as member of the Midichloriaceae. Its 2.4 Mb genome represents the largest among Rickettsiales and is characterized by a moderate degree of pseudogenization and a high coding density. We found an unusually large number of genes encoding proteins with eukaryotic-like domains such as ankyrins, leucine-rich repeats and tetratricopeptide repeats, which likely function in host interaction. There are a total of three divergent, independently acquired type IV secretion systems, and 35 flagellar genes representing the most complete set found in an obligate intracellular Alphaproteobacterium. The deeply branching phylogenetic position of 'Candidatus Jidaibacter acanthamoeba' together with its ancient features place it closely to the rickettsial ancestor and helps to better understand the transition from a free-living to an intracellular lifestyle.
Collapse
Affiliation(s)
- Frederik Schulz
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, Vienna, Austria
| | - Joran Martijn
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Husargatan 3, Uppsala, Sweden
| | - Florian Wascher
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, Vienna, Austria
| | - Ilias Lagkouvardos
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, Vienna, Austria
| | - Rok Kostanjšek
- Department of Biology, University of Ljubljana, Večna pot 111, Ljubljana, Slovenia
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Husargatan 3, Uppsala, Sweden
| | - Matthias Horn
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, Vienna, Austria
| |
Collapse
|
37
|
Organelle targeting during bacterial infection: insights from Listeria. Trends Cell Biol 2015; 25:330-8. [DOI: 10.1016/j.tcb.2015.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
|
38
|
The intracellular Scots pine shoot symbiont Methylobacterium extorquens DSM13060 aggregates around the host nucleus and encodes eukaryote-like proteins. mBio 2015; 6:mBio.00039-15. [PMID: 25805725 PMCID: PMC4453540 DOI: 10.1128/mbio.00039-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Endophytes are microbes that inhabit plant tissues without any apparent signs of infection, often fundamentally altering plant phenotypes. While endophytes are typically studied in plant roots, where they colonize the apoplast or dead cells, Methylobacterium extorquens strain DSM13060 is a facultatively intracellular symbiont of the meristematic cells of Scots pine (Pinus sylvestris L.) shoot tips. The bacterium promotes host growth and development without the production of known plant growth-stimulating factors. Our objective was to examine intracellular colonization by M. extorquens DSM13060 of Scots pine and sequence its genome to identify novel molecular mechanisms potentially involved in intracellular colonization and plant growth promotion. Reporter construct analysis of known growth promotion genes demonstrated that these were only weakly active inside the plant or not expressed at all. We found that bacterial cells accumulate near the nucleus in intact, living pine cells, pointing to host nuclear processes as the target of the symbiont’s activity. Genome analysis identified a set of eukaryote-like functions that are common as effectors in intracellular bacterial pathogens, supporting the notion of intracellular bacterial activity. These include ankyrin repeats, transcription factors, and host-defense silencing functions and may be secreted by a recently imported type IV secretion system. Potential factors involved in host growth include three copies of phospholipase A2, an enzyme that is rare in bacteria but implicated in a range of plant cellular processes, and proteins putatively involved in gibberellin biosynthesis. Our results describe a novel endophytic niche and create a foundation for postgenomic studies of a symbiosis with potential applications in forestry and agriculture. All multicellular eukaryotes host communities of essential microbes, but most of these interactions are still poorly understood. In plants, bacterial endophytes are found inside all tissues. M. extorquens DSM13060 occupies an unusual niche inside cells of the dividing shoot tissues of a pine and stimulates seedling growth without producing cytokinin, auxin, or other plant hormones commonly synthesized by plant-associated bacteria. Here, we tracked the bacteria using a fluorescent tag and confocal laser scanning microscopy and found that they localize near the nucleus of the plant cell. This prompted us to sequence the genome and identify proteins that may affect host growth by targeting processes in the host cytoplasm and nucleus. We found many novel genes whose products may modulate plant processes from within the plant cell. Our results open up new avenues to better understand how bacteria assist in plant growth, with broad implications for plant science, forestry, and agriculture.
Collapse
|
39
|
Schulz F, Horn M. Intranuclear bacteria: inside the cellular control center of eukaryotes. Trends Cell Biol 2015; 25:339-46. [PMID: 25680230 DOI: 10.1016/j.tcb.2015.01.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/14/2015] [Accepted: 01/15/2015] [Indexed: 12/17/2022]
Abstract
Intracellular bacteria including major pathogens live in the cytoplasm or in cytoplasmic vacuoles within their host cell. However, some can invade more unusual intracellular niches such as the eukaryotic nucleus. Phylogenetically diverse intranuclear bacteria have been discovered in various protist, arthropod, marine invertebrate, and mammalian hosts. Although targeting the same cellular compartment, they have apparently developed fundamentally-different infection strategies. The nucleus provides a rich pool of nutrients and protection against host cytoplasmic defense mechanisms; intranuclear bacteria can directly manipulate the host by interfering with nuclear processes. The impact on their host cells ranges from stable associations with a neutral or beneficial effect on host fitness to rapid host lysis. The analysis of the intranuclear lifestyle will extend our current framework for understanding host-pathogen interactions.
Collapse
Affiliation(s)
- Frederik Schulz
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Matthias Horn
- Department of Microbiology and Ecosystem Science, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
| |
Collapse
|