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Seth-Smith H, Bommana S, Dean D, Read TD, Marti H. Chlamydia suis undergoes interclade recombination promoting Tet-island exchange. BMC Genomics 2024; 25:724. [PMID: 39060998 PMCID: PMC11282597 DOI: 10.1186/s12864-024-10606-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND The obligate intracellular bacterial family Chlamydiaceae comprises a number of different species that cause disease in various vertebrate hosts including humans. Chlamydia suis, primarily found in the gastrointestinal tract of pigs, is the only species of the Chlamydiaceae family to have naturally gained tetracycline resistance (TetR), through a genomic island (Tet-island), integrated into the middle of chromosomal invasin-like gene inv. Previous studies have hypothesised that the uptake of the Tet-island from a host outside the Chlamydiaceae family was a unique event, followed by spread among C. suis through homologous recombination. In vitro recombination studies have shown that Tet-island exchange between C. suis strains is possible. Our aim in this study was to gain a deeper understanding of the interclade recombination of the Tet-island, among currently circulating C. suis field strains compared to in vitro-generated recombinants, using published whole genome sequences of C. suis field strains (n = 35) and in vitro-generated recombinants (n = 63). RESULTS We found that the phylogeny of inv better reflected the phylogeny of the Tet-island than that of the whole genome, supporting recombination rather than site-specific insertion as the means of transfer. There were considerable differences between the distribution of recombinations within in vitro-generated strains compared to that within the field strains. These differences are likely because in vitro-generated recombinants were selected for a tetracycline and rifamycin/rifampicin resistant background, leading to the largest peak of recombination across the Tet-island. Finally, we found that interclade recombinations across the Tet-island were more variable in length downstream of the Tet-island than upstream. CONCLUSIONS Our study supports the hypothesis that the occurrence of TetR strains in both clades of C. suis came about through interclade recombination after a single ancestral horizontal gene transfer event.
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Affiliation(s)
- Helena Seth-Smith
- Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Sankhya Bommana
- Division of Infectious Diseases and Global Health, Departments of Medicine and Pediatrics, University of California San Francisco School of Medicine, San Francisco, CA, USA
| | - Deborah Dean
- Division of Infectious Diseases and Global Health, Departments of Medicine and Pediatrics, University of California San Francisco School of Medicine, San Francisco, CA, USA
- Joint Graduate Program in Bioengineering, University of California Berkeley, University of California San Francisco, Berkeley and San Francisco, CA, USA
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Hanna Marti
- Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland.
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2
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Diallo A, Overman G, Sah P, Liechti GW. Recognition of Chlamydia trachomatis by Toll-like receptor 9 is altered during persistence. Infect Immun 2024; 92:e0006324. [PMID: 38899879 PMCID: PMC11238561 DOI: 10.1128/iai.00063-24] [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: 02/05/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Toll-like receptor 9 (TLR9) is an innate immune receptor that localizes to endosomes in antigen presenting cells and recognizes single stranded unmethylated CpG sites on bacterial genomic DNA (gDNA). Previous bioinformatic studies have demonstrated that the genome of the human pathogen Chlamydia trachomatis contains TLR9 stimulatory motifs, and correlative studies have implied a link between human TLR9 (hTLR9) genotype variants and susceptibility to infection. Here, we present our evaluation of the stimulatory potential of C. trachomatis gDNA and its recognition by hTLR9- and murine TLR9 (mTLR9)-expressing cells. Utilizing reporter cell lines, we demonstrate that purified gDNA from C. trachomatis can stimulate hTLR9 signaling, albeit at lower levels than gDNA prepared from other Gram-negative bacteria. Interestingly, we found that while C. trachomatis is capable of signaling through hTLR9 and mTLR9 during live infections in HEK293 reporter cell lines, signaling only occurs at later developmental time points. Chlamydia-specific induction of hTLR9 is blocked when protein synthesis is inhibited prior to the RB-to-EB conversion, exacerbated by the inhibition of lipooligosaccharide biosynthesis, and is significantly altered during the induction of aberrance/persistence. Our observations support the hypothesis that chlamydial gDNA is released during the conversion between the pathogen's replicative and infectious forms and during treatment with antibiotics targeting peptidoglycan assembly. Given that C. trachomatis inclusions do not co-localize with TLR9-containing vacuoles in the pro-monocytic cell line U937, our findings also hint that chlamydial gDNA is capable of egress from the inclusion, and traffics to TLR9-containing vacuoles via an as yet unknown pathway.
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Affiliation(s)
- Aissata Diallo
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Grace Overman
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Prakash Sah
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - George W Liechti
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
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3
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Fernandez MC, Sweeney YC, Suchland RJ, Carrell SJ, Soge OO, Phan IQ, Rockey DD, Patton DL, Hybiske K. CT135 mediates the resistance of Chlamydia trachomatis to primate interferon gamma stimulated immune defenses. iScience 2024; 27:110143. [PMID: 38947519 PMCID: PMC11214326 DOI: 10.1016/j.isci.2024.110143] [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: 01/31/2024] [Revised: 04/19/2024] [Accepted: 05/27/2024] [Indexed: 07/02/2024] Open
Abstract
Evading host innate immune defenses is a critical feature of Chlamydia trachomatis infections, and the mechanisms used by C. trachomatis to subvert these pathways are incompletely understood. We screened a library of chimeric C. trachomatis mutants for genetic factors important for interference with cell-autonomous immune defenses. Mutant strains with predicted truncations of the inclusion membrane protein CT135 were susceptible to interferon gamma-activated immunity in human cells. CT135 functions to prevent host-driven recruitment of ubiquitin and p62/SQSTM to the inclusion membrane. In a nonhuman primate model of C. trachomatis infection, a CT135-deficient strain was rapidly cleared, highlighting the importance of this virulence factor for C. trachomatis pathogenesis. Analysis of CT135 phenotypes in primary macaque cells revealed that cell-autonomous immune defenses against C. trachomatis are conserved between humans and nonhuman primates and connects mechanistic findings with in vivo infection outcomes.
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Affiliation(s)
- Mark C. Fernandez
- Department of Global Health, University of Washington, Seattle, WA 98109, USA
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | | | - Robert J. Suchland
- Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Steven J. Carrell
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Olusegun O. Soge
- Department of Global Health, University of Washington, Seattle, WA 98109, USA
- Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Isabelle Q. Phan
- Seattle Structural Genomics Center for Infectious Disease, Seattle, WA 98109, USA
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA 98109, USA
| | - Daniel D. Rockey
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Dorothy L. Patton
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98109, USA
| | - Kevin Hybiske
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA 98109, USA
- Department of Medicine, University of Washington, Seattle, WA 98109, USA
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4
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Diallo A, Overman G, Sah P, Liechti GW. Recognition of Chlamydia trachomatis by Toll-Like Receptor 9 is altered during persistence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579186. [PMID: 38370826 PMCID: PMC10871208 DOI: 10.1101/2024.02.06.579186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Toll-like receptor 9 (TLR9) is an innate immune receptor that localizes to endosomes in antigen presenting cells and recognizes single stranded unmethylated CpG sites on bacterial genomic DNA. Previous bioinformatic studies have indicated that the genome of the human pathogen Chlamydia trachomatis contains TLR9 stimulatory motifs, and correlative studies have implied a link between human TLR9 (hTLR9) genotype variants and susceptibility to infection. Here we present our evaluation of the stimulatory potential of C. trachomatis gDNA and its recognition by hTLR9- and murine TLR9 (mTLR9)-expressing cells. We confirm that hTLR9 colocalizes with chlamydial inclusions in the pro-monocytic cell line, U937. Utilizing HEK293 reporter cell lines, we demonstrate that purified genomic DNA from C. trachomatis can stimulate hTLR9 signaling, albeit at lower levels than gDNA prepared from other Gram-negative bacteria. Interestingly, we found that while C. trachomatis is capable of signaling through hTLR9 and mTLR9 during live infections in non-phagocytic HEK293 reporter cell lines, signaling only occurs at later developmental time points. Chlamydia-specific induction of hTLR9 is blocked when protein synthesis is inhibited prior to the RB-to-EB conversion and exacerbated by the inhibition of lipooligosaccharide biosynthesis. The induction of aberrance / persistence also significantly alters Chlamydia-specific TLR9 signaling. Our observations support the hypothesis that chlamydial gDNA is released at appreciable levels by the bacterium during the conversion between its replicative and infectious forms and during treatment with antibiotics targeting peptidoglycan assembly.
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Affiliation(s)
- Aissata Diallo
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Grace Overman
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Prakash Sah
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - George W. Liechti
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
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5
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Marti H, Biggel M, Shima K, Onorini D, Rupp J, Charette SJ, Borel N. Chlamydia suis displays high transformation capacity with complete cloning vector integration into the chromosomal rrn-nqrF plasticity zone. Microbiol Spectr 2023; 11:e0237823. [PMID: 37882558 PMCID: PMC10715202 DOI: 10.1128/spectrum.02378-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/19/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE The obligate intracellular Chlamydia genus contains many pathogens with a negative impact on global health and economy. Despite recent progress, there is still a lack of genetic tools limiting our understanding of these complex bacteria. This study provides new insights into genetic manipulation of Chlamydia with the opportunistic porcine pathogen Chlamydia suis, the only chlamydial species naturally harboring an antibiotic resistance gene, originally obtained by horizontal gene transfer. C. suis is transmissible to humans, posing a potential public health concern. We report that C. suis can take up vectors that lack the native plasmid, a requirement for most chlamydial transformation systems described to date. Additionally, we show that C. trachomatis, the most common cause for bacterial sexually transmitted infections and infectious blindness worldwide, can be transformed with C. suis vectors. Finally, the chromosomal region that harbors the resistance gene of C. suis is highly susceptible to complete vector integration.
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Affiliation(s)
- Hanna Marti
- Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Michael Biggel
- Institute for Food Safety and Hygiene, University of Zurich, Zurich, Switzerland
| | - Kensuke Shima
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Delia Onorini
- Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Jan Rupp
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Steve J. Charette
- Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Quebec City, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Quebec City, Canada
- Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec City, Canada
| | - Nicole Borel
- Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
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6
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Fisher DJ, Beare PA. Recent advances in genetic systems in obligate intracellular human-pathogenic bacteria. Front Cell Infect Microbiol 2023; 13:1202245. [PMID: 37404720 PMCID: PMC10315504 DOI: 10.3389/fcimb.2023.1202245] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/22/2023] [Indexed: 07/06/2023] Open
Abstract
The ability to genetically manipulate a pathogen is fundamental to discovering factors governing host-pathogen interactions at the molecular level and is critical for devising treatment and prevention strategies. While the genetic "toolbox" for many important bacterial pathogens is extensive, approaches for modifying obligate intracellular bacterial pathogens were classically limited due in part to the uniqueness of their obligatory lifestyles. Many researchers have confronted these challenges over the past two and a half decades leading to the development of multiple approaches to construct plasmid-bearing recombinant strains and chromosomal gene inactivation and deletion mutants, along with gene-silencing methods enabling the study of essential genes. This review will highlight seminal genetic achievements and recent developments (past 5 years) for Anaplasma spp., Rickettsia spp., Chlamydia spp., and Coxiella burnetii including progress being made for the still intractable Orientia tsutsugamushi. Alongside commentary of the strengths and weaknesses of the various approaches, future research directions will be discussed to include methods for C. burnetii that should have utility in the other obligate intracellular bacteria. Collectively, the future appears bright for unraveling the molecular pathogenic mechanisms of these significant pathogens.
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Affiliation(s)
- Derek J. Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, United States
| | - Paul A. Beare
- Rocky Mountain Laboratory, National Institute of Health, Hamilton, MT, United States
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7
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Luu LDW, Kasimov V, Phillips S, Myers GSA, Jelocnik M. Genome organization and genomics in Chlamydia: whole genome sequencing increases understanding of chlamydial virulence, evolution, and phylogeny. Front Cell Infect Microbiol 2023; 13:1178736. [PMID: 37287464 PMCID: PMC10242142 DOI: 10.3389/fcimb.2023.1178736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/10/2023] [Indexed: 06/09/2023] Open
Abstract
The genus Chlamydia contains important obligate intracellular bacterial pathogens to humans and animals, including C. trachomatis and C. pneumoniae. Since 1998, when the first Chlamydia genome was published, our understanding of how these microbes interact, evolved and adapted to different intracellular host environments has been transformed due to the expansion of chlamydial genomes. This review explores the current state of knowledge in Chlamydia genomics and how whole genome sequencing has revolutionised our understanding of Chlamydia virulence, evolution, and phylogeny over the past two and a half decades. This review will also highlight developments in multi-omics and other approaches that have complemented whole genome sequencing to advance knowledge of Chlamydia pathogenesis and future directions for chlamydial genomics.
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Affiliation(s)
- Laurence Don Wai Luu
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Vasilli Kasimov
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Samuel Phillips
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Garry S. A. Myers
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Martina Jelocnik
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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8
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Marti H, Suchland RJ, Rockey DD. The Impact of Lateral Gene Transfer in Chlamydia. Front Cell Infect Microbiol 2022; 12:861899. [PMID: 35321311 PMCID: PMC8936141 DOI: 10.3389/fcimb.2022.861899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 02/07/2022] [Indexed: 11/24/2022] Open
Abstract
Lateral gene transfer (LGT) facilitates many processes in bacterial ecology and pathogenesis, especially regarding pathogen evolution and the spread of antibiotic resistance across species. The obligate intracellular chlamydiae, which cause a range of diseases in humans and animals, were historically thought to be highly deficient in this process. However, research over the past few decades has demonstrated that this was not the case. The first reports of homologous recombination in the Chlamydiaceae family were published in the early 1990s. Later, the advent of whole-genome sequencing uncovered clear evidence for LGT in the evolution of the Chlamydiaceae, although the acquisition of tetracycline resistance in Chlamydia (C.) suis is the only recent instance of interphylum LGT. In contrast, genome and in vitro studies have shown that intraspecies DNA exchange occurs frequently and can even cross species barriers between closely related chlamydiae, such as between C. trachomatis, C. muridarum, and C. suis. Additionally, whole-genome analysis led to the identification of various DNA repair and recombination systems in C. trachomatis, but the exact machinery of DNA uptake and homologous recombination in the chlamydiae has yet to be fully elucidated. Here, we reviewed the current state of knowledge concerning LGT in Chlamydia by focusing on the effect of homologous recombination on the chlamydial genome, the recombination machinery, and its potential as a genetic tool for Chlamydia.
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Affiliation(s)
- Hanna Marti
- Institute of Veterinary Pathology, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
- *Correspondence: Hanna Marti,
| | - Robert J. Suchland
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Daniel D. Rockey
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
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9
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Garvin L, Vande Voorde R, Dickinson M, Carrell S, Hybiske K, Rockey D. A broad-spectrum cloning vector that exists as both an integrated element and a free plasmid in Chlamydia trachomatis. PLoS One 2021; 16:e0261088. [PMID: 34914750 PMCID: PMC8675754 DOI: 10.1371/journal.pone.0261088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/23/2021] [Indexed: 12/23/2022] Open
Abstract
Plasmid transformation of chlamydiae has created new opportunities to investigate host-microbe interactions during chlamydial infections; however, there are still limitations. Plasmid transformation requires a replicon derived from the native Chlamydia plasmid, and these transformations are species-specific. We explored the utility of a broad host-range plasmid, pBBR1MCS-4, to transform chlamydiae, with a goal of simplifying the transformation process. The plasmid was modified to contain chromosomal DNA from C. trachomatis to facilitate homologous recombination. Sequences flanking incA were cloned into the pBBR1MCS-4 vector along with the GFP:CAT cassette from the pSW2-GFP chlamydial shuttle vector. The final plasmid construct, pBVR2, was successfully transformed into C. trachomatis strain L2-434. Chlamydial transformants were analyzed by immunofluorescence microscopy and positive clones were sequentially purified using limiting dilution. PCR and PacBio-based whole genome sequencing were used to determine if the plasmid was maintained within the chromosome or as an episome. PacBio sequencing of the cloned transformants revealed allelic exchange events between the chromosome and plasmid pBVR2 that replaced chromosomal incA with the plasmid GFP:CAT cassette. The data also showed evidence of full integration of the plasmid into the bacterial chromosome. While some plasmids were fully integrated, some were maintained as episomes and could be purified and retransformed into E. coli. Thus, the plasmid can be successfully transformed into chlamydia without a chlamydial origin of replication and can exist in multiple states within a transformed population.
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Affiliation(s)
- Lotisha Garvin
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Rebecca Vande Voorde
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Mary Dickinson
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA, United States of America
| | - Steven Carrell
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Kevin Hybiske
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA, United States of America
| | - Daniel Rockey
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
- * E-mail:
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Dimond ZE, Suchland RJ, Baid S, LaBrie SD, Soules KR, Stanley J, Carrell S, Kwong F, Wang Y, Rockey DD, Hybiske K, Hefty PS. Inter-species lateral gene transfer focused on the Chlamydia plasticity zone identifies loci associated with immediate cytotoxicity and inclusion stability. Mol Microbiol 2021; 116:1433-1448. [PMID: 34738268 PMCID: PMC9119408 DOI: 10.1111/mmi.14832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/20/2022]
Abstract
Chlamydia muridarum actively grows in murine mucosae and is a representative model of human chlamydial genital tract disease. In contrast, C. trachomatis infections in mice are limited and rarely cause disease. The factors that contribute to these differences in host adaptation and specificity remain elusive. Overall genomic similarity leads to challenges in the understanding of these significant differences in tropism. A region of major genetic divergence termed the plasticity zone (PZ) has been hypothesized to contribute to the host specificity. To evaluate this hypothesis, lateral gene transfer was used to generate multiple hetero-genomic strains that are predominately C. trachomatis but have replaced regions of the PZ with those from C. muridarum. In vitro analysis of these chimeras revealed C. trachomatis-like growth as well as poor mouse infection capabilities. Growth-independent cytotoxicity phenotypes have been ascribed to three large putative cytotoxins (LCT) encoded in the C. muridarum PZ. However, analysis of PZ chimeras supported that gene products other than the LCTs are responsible for cytopathic and cytotoxic phenotypes. Growth analysis of associated chimeras also led to the discovery of an inclusion protein, CTL0402 (CT147), and homolog TC0424, which was critical for the integrity of the inclusion and preventing apoptosis.
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Affiliation(s)
- Zoe E. Dimond
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Robert J. Suchland
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Srishti Baid
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Scott D. LaBrie
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Katelyn R. Soules
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Jacob Stanley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Steven Carrell
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Forrest Kwong
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Yibing Wang
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Daniel D. Rockey
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Kevin Hybiske
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - P. Scott Hefty
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
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11
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Marti H, Bommana S, Read TD, Pesch T, Prähauser B, Dean D, Borel N. Generation of Tetracycline and Rifamycin Resistant Chlamydia Suis Recombinants. Front Microbiol 2021; 12:630293. [PMID: 34276577 PMCID: PMC8278220 DOI: 10.3389/fmicb.2021.630293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 06/03/2021] [Indexed: 01/01/2023] Open
Abstract
The Chlamydiaceae are a family of obligate intracellular, gram-negative bacteria known to readily exchange DNA by homologous recombination upon co-culture in vitro, allowing the transfer of antibiotic resistance residing on the chlamydial chromosome. Among all the obligate intracellular bacteria, only Chlamydia (C.) suis naturally integrated a tetracycline resistance gene into its chromosome. Therefore, in order to further investigate the readiness of Chlamydia to exchange DNA and especially antibiotic resistance, C. suis is an excellent model to advance existing co-culture protocols allowing the identification of factors crucial to promote homologous recombination in vitro. With this strategy, we co-cultured tetracycline-resistant with rifamycin group-resistant C. suis, which resulted in an allover recombination efficiency of 28%. We found that simultaneous selection is crucial to increase the number of recombinants, that sub-inhibitory concentrations of tetracycline inhibit rather than promote the selection of double-resistant recombinants, and identified a recombination-deficient C. suis field isolate, strain SWA-110 (1-28b). While tetracycline resistance was detected in field isolates, rifampicin/rifamycin resistance (RifR) had to be induced in vitro. Here, we describe the protocol with which RifR C. suis strains were generated and confirmed. Subsequent whole-genome sequencing then revealed that G530E and D461A mutations in rpoB, a gene encoding for the β-subunit of the bacterial RNA polymerase (RNAP), was likely responsible for rifampicin and rifamycin resistance, respectively. Finally, whole-genome sequencing of recombinants obtained by co-culture revealed that recombinants picked from the same plate may be sibling clones and confirmed C. suis genome plasticity by revealing variable, apparently non-specific areas of recombination.
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Affiliation(s)
- Hanna Marti
- Vetsuisse Faculty, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Sankhya Bommana
- Division of Infectious Diseases, Departments of Medicine and Pediatrics, University of California San Francisco School of Medicine, San Francisco, CA, United States
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States.,Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States
| | - Theresa Pesch
- Vetsuisse Faculty, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Barbara Prähauser
- Vetsuisse Faculty, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Deborah Dean
- Division of Infectious Diseases, Departments of Medicine and Pediatrics, University of California San Francisco School of Medicine, San Francisco, CA, United States.,Joint Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, CA, United States.,Joint Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Nicole Borel
- Vetsuisse Faculty, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
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Banerjee A, Nelson DE. The growing repertoire of genetic tools for dissecting chlamydial pathogenesis. Pathog Dis 2021; 79:ftab025. [PMID: 33930127 PMCID: PMC8112481 DOI: 10.1093/femspd/ftab025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/28/2021] [Indexed: 01/29/2023] Open
Abstract
Multiple species of obligate intracellular bacteria in the genus Chlamydia are important veterinary and/or human pathogens. These pathogens all share similar biphasic developmental cycles and transition between intracellular vegetative reticulate bodies and infectious elementary forms, but vary substantially in their host preferences and pathogenic potential. A lack of tools for genetic engineering of these organisms has long been an impediment to the study of their biology and pathogenesis. However, the refinement of approaches developed in C. trachomatis over the last 10 years, and adaptation of some of these approaches to other Chlamydia spp. in just the last few years, has opened exciting new possibilities for studying this ubiquitous group of important pathogens.
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Affiliation(s)
- Arkaprabha Banerjee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David E Nelson
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Köstlbacher S, Collingro A, Halter T, Domman D, Horn M. Coevolving Plasmids Drive Gene Flow and Genome Plasticity in Host-Associated Intracellular Bacteria. Curr Biol 2021; 31:346-357.e3. [PMID: 33157023 PMCID: PMC7846284 DOI: 10.1016/j.cub.2020.10.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/30/2020] [Accepted: 10/09/2020] [Indexed: 12/30/2022]
Abstract
Plasmids are important in microbial evolution and adaptation to new environments. Yet, carrying a plasmid can be costly, and long-term association of plasmids with their hosts is poorly understood. Here, we provide evidence that the Chlamydiae, a phylum of strictly host-associated intracellular bacteria, have coevolved with their plasmids since their last common ancestor. Current chlamydial plasmids are amalgamations of at least one ancestral plasmid and a bacteriophage. We show that the majority of plasmid genes are also found on chromosomes of extant chlamydiae. The most conserved plasmid gene families are predominantly vertically inherited, while accessory plasmid gene families show significantly increased mobility. We reconstructed the evolutionary history of plasmid gene content of an entire bacterial phylum over a period of around one billion years. Frequent horizontal gene transfer and chromosomal integration events illustrate the pronounced impact of coevolution with these extrachromosomal elements on bacterial genome dynamics in host-dependent microbes.
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Affiliation(s)
- Stephan Köstlbacher
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Astrid Collingro
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Tamara Halter
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Daryl Domman
- Wellcome Sanger Institute, Parasites and Microbes Programme, Hinxton, Cambridge CB10 1SA, UK; Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Matthias Horn
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria.
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Collingro A, Köstlbacher S, Horn M. Chlamydiae in the Environment. Trends Microbiol 2020; 28:877-888. [PMID: 32591108 DOI: 10.1016/j.tim.2020.05.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 12/19/2022]
Abstract
Chlamydiae have been known for more than a century as major pathogens of humans. Yet they are also found ubiquitously in the environment where they thrive within protists and in an unmatched wide range of animals. This review summarizes recent advances in understanding chlamydial diversity and distribution in nature. Studying these environmental chlamydiae provides a novel perspective on basic chlamydial biology and evolution. A picture is beginning to emerge with chlamydiae representing one of the evolutionarily most ancient and successful groups of obligate intracellular bacteria.
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Affiliation(s)
- Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
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