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Marquis B, Pillonel T, Carrara A, Bertelli C. zDB: bacterial comparative genomics made easy. mSystems 2024; 9:e0047324. [PMID: 38940522 PMCID: PMC11264898 DOI: 10.1128/msystems.00473-24] [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: 04/02/2024] [Accepted: 05/31/2024] [Indexed: 06/29/2024] Open
Abstract
The analysis and comparison of genomes rely on different tools for tasks such as annotation, orthology prediction, and phylogenetic inference. Most tools are specialized for a single task, and additional efforts are necessary to integrate and visualize the results. To fill this gap, we developed zDB, an application integrating a Nextflow analysis pipeline and a Python visualization platform built on the Django framework. The application is available on GitHub (https://github.com/metagenlab/zDB) and from the bioconda channel. Starting from annotated Genbank files, zDB identifies orthologs and infers a phylogeny for each orthogroup. A species phylogeny is also constructed from shared single-copy orthologs. The results can be enriched with Pfam protein domain prediction, Cluster of Orthologs Genes and Kyoto Encyclopedia of Genes and Genomes annotations, and Swissprot homologs. The web application allows searching for specific genes or annotations, running Blast queries, and comparing genomic regions and whole genomes. The metabolic capacities of organisms can be compared at either the module or pathway levels. Finally, users can run queries to examine the conservation of specific genes or annotations across a chosen subset of genomes and display the results as a list of genes, Venn diagram, or heatmaps. Those features make zDB useful for both bioinformaticians and researchers more accustomed to laboratory research.IMPORTANCEGenome comparison and analysis rely on many independent tools, leaving to scientists the burden to integrate and visualize their results for interpretation. To alleviate this burden, we have built zDB, a comparative genomics tool that includes both an analysis pipeline and a visualization platform. The analysis pipeline automates gene annotation, orthology prediction, and phylogenetic inference, while the visualization platform allows scientists to easily explore the results in a web browser. Among other features, the interface allows users to visually compare whole genomes and targeted regions, assess the conservation of genes or metabolic pathways, perform Blast searches, or look for specific annotations. Altogether, this tool will be useful for a broad range of applications in comparative studies between two and hundred genomes. Furthermore, it is designed to allow sharing of data sets easily at a local or international scale, thereby supporting exploratory analyses for non-bioinformaticians on the genome of their favorite organisms.
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Affiliation(s)
- Bastian Marquis
- Lausanne University Hospital and University of Lausanne, Institute of Microbiology, Lausanne, Switzerland
| | - Trestan Pillonel
- Lausanne University Hospital and University of Lausanne, Institute of Microbiology, Lausanne, Switzerland
| | - Alessia Carrara
- Lausanne University Hospital and University of Lausanne, Institute of Microbiology, Lausanne, Switzerland
| | - Claire Bertelli
- Lausanne University Hospital and University of Lausanne, Institute of Microbiology, Lausanne, Switzerland
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Ardissone S, Greub G. The Chlamydia-related Waddlia chondrophila encodes functional type II toxin-antitoxin systems. Appl Environ Microbiol 2024; 90:e0068123. [PMID: 38214519 PMCID: PMC10880633 DOI: 10.1128/aem.00681-23] [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: 04/25/2023] [Accepted: 11/13/2023] [Indexed: 01/13/2024] Open
Abstract
Bacterial toxin-antitoxin (TA) systems are widespread in chromosomes and plasmids of free-living microorganisms, but only a few have been identified in obligate intracellular species. We found seven putative type II TA modules in Waddlia chondrophila, a Chlamydia-related species that is able to infect a very broad series of eukaryotic hosts, ranging from protists to mammalian cells. The RNA levels of Waddlia TA systems are significantly upregulated by iron starvation and novobiocin, but they are not affected by antibiotics such as β-lactams and glycopeptides, which suggests different mechanisms underlying stress responses. Five of the identified TA modules, including HigBA1 and MazEF1, encoded on the Waddlia cryptic plasmid, proved to be functional when expressed in a heterologous host. TA systems have been associated with the maintenance of mobile genetic elements, bacterial defense against bacteriophages, and persistence upon exposure to adverse conditions. As their RNA levels are upregulated upon exposure to adverse conditions, Waddlia TA modules may be involved in survival to stress. Moreover, as Waddlia can infect a wide range of hosts including free-living amoebae, TA modules could also represent an innate immunity system to fight against bacteriophages and other microorganisms with which Waddlia has to share its replicative niche.IMPORTANCEThe response to adverse conditions, such as exposure to antibiotics, nutrient starvation and competition with other microorganisms, is essential for the survival of a bacterial population. TA systems are modules composed of two elements, a toxic protein and an antitoxin (protein or RNA) that counteracts the toxin. Although many aspects of TA biological functions still await to be elucidated, TAs have often been implicated in bacterial response to stress, including the response to nutrient starvation, antibiotic treatment and bacteriophage infection. TAs are ubiquitous in free-living bacteria but rare in obligate intracellular species such as chlamydiae. We identified functional TA systems in Waddlia chondrophila, a chlamydial species with a strikingly broad host range compared to other chlamydiae. Our work contributes to understand how obligate intracellular bacteria react to adverse conditions that might arise from competition with other viruses/bacteria for the same replicative niche and would threaten their ability to replicate.
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Affiliation(s)
- Silvia Ardissone
- Institute of Microbiology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Gilbert Greub
- Institute of Microbiology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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Greub G, Pillonel T, Bavoil PM, Borel N, Campbell LA, Dean D, Hefty S, Horn M, Morré SA, Ouellette SP, Pannekoek Y, Puolakkainen M, Timms P, Valdivia R, Vanrompay D. Use of gene sequences as type for naming prokaryotes: Recommendations of the international committee on the taxonomy of chlamydiae. New Microbes New Infect 2023; 54:101158. [PMID: 37416863 PMCID: PMC10320375 DOI: 10.1016/j.nmni.2023.101158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 06/01/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023] Open
Abstract
The International Committee on Systematics of Prokaryotes (ICSP) discussed and rejected in 2020 a proposal to modify the International Code of Nomenclature of Prokaryotes to allow the use of gene sequences as type for naming prokaryotes. An alternative nomenclatural code, the Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode), which considers genome sequences as type material for naming species, was published in 2022. Members of the ICSP subcommittee for the taxonomy of the phylum Chlamydiae (Chlamydiota) consider that the use of gene sequences as type would benefit the taxonomy of microorganisms that are difficult to culture such as the chlamydiae and other strictly intracellular bacteria. We recommend the registration of new names of uncultured prokaryotes in the SeqCode registry.
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Affiliation(s)
- Gilbert Greub
- Centre for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Centre and University of Lausanne, Bugnon 48, 1011, Lausanne, Switzerland
| | - Trestan Pillonel
- Centre for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Centre and University of Lausanne, Bugnon 48, 1011, Lausanne, Switzerland
| | - Patrik M. Bavoil
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Nicole Borel
- Department of Pathobiology, Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 268, CH-8057, Zurich, Switzerland
| | - Lee Ann Campbell
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Deborah Dean
- Departments of Medicine and Pediatrics, University of California San Francisco School of Medicine, Oakland, CA, USA
| | - Scott Hefty
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, 1090, Vienna, Austria
| | - Servaas A. Morré
- Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, the Netherlands
- Institute for Public Health Genomics (IPHG), Department of Genetics and Cell Biology, Research School GROW (School for Oncology & Developmental Biology), Faculty of Health, Medicine & Life Sciences, University of Maastricht, Maastricht, the Netherlands
- Dutch Chlamydia Trachomatis Reference Laboratory, Department of Medical Microbiology & Infection Control, VU University Medical Centre, Amsterdam, the Netherlands
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Yvonne Pannekoek
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Mirja Puolakkainen
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Peter Timms
- Genecology Research Center, University of Sunshine Coast, Queensland, Australia
| | - Raphael Valdivia
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, 27710, USA
| | - Daisy Vanrompay
- Department of Animal Science and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
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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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Huang Y, Wurihan W, Lu B, Zou Y, Wang Y, Weldon K, Fondell JD, Lai Z, Wu X, Fan H. Robust Heat Shock Response in Chlamydia Lacking a Typical Heat Shock Sigma Factor. Front Microbiol 2022; 12:812448. [PMID: 35046926 PMCID: PMC8762339 DOI: 10.3389/fmicb.2021.812448] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/02/2021] [Indexed: 11/13/2022] Open
Abstract
Cells reprogram their transcriptome in response to stress, such as heat shock. In free-living bacteria, the transcriptomic reprogramming is mediated by increased DNA-binding activity of heat shock sigma factors and activation of genes normally repressed by heat-induced transcription factors. In this study, we performed transcriptomic analyses to investigate heat shock response in the obligate intracellular bacterium Chlamydia trachomatis, whose genome encodes only three sigma factors and a single heat-induced transcription factor. Nearly one-third of C. trachomatis genes showed statistically significant (≥1.5-fold) expression changes 30 min after shifting from 37 to 45°C. Notably, chromosomal genes encoding chaperones, energy metabolism enzymes, type III secretion proteins, as well as most plasmid-encoded genes, were differentially upregulated. In contrast, genes with functions in protein synthesis were disproportionately downregulated. These findings suggest that facilitating protein folding, increasing energy production, manipulating host activities, upregulating plasmid-encoded gene expression, and decreasing general protein synthesis helps facilitate C. trachomatis survival under stress. In addition to relieving negative regulation by the heat-inducible transcriptional repressor HrcA, heat shock upregulated the chlamydial primary sigma factor σ66 and an alternative sigma factor σ28. Interestingly, we show for the first time that heat shock downregulates the other alternative sigma factor σ54 in a bacterium. Downregulation of σ54 was accompanied by increased expression of the σ54 RNA polymerase activator AtoC, thus suggesting a unique regulatory mechanism for reestablishing normal expression of select σ54 target genes. Taken together, our findings reveal that C. trachomatis utilizes multiple novel survival strategies to cope with environmental stress and even to replicate. Future strategies that can specifically target and disrupt Chlamydia’s heat shock response will likely be of therapeutic value.
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Affiliation(s)
- Yehong Huang
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China.,Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
| | - Wurihan Wurihan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
| | - Bin Lu
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China.,Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
| | - Yi Zou
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Yuxuan Wang
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
| | - Korri Weldon
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Joseph D Fondell
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
| | - Zhao Lai
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX, United States.,Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Xiang Wu
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Huizhou Fan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States
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Colpaert M, Kadouche D, Ducatez M, Pillonel T, Kebbi-Beghdadi C, Cenci U, Huang B, Chabi M, Maes E, Coddeville B, Couderc L, Touzet H, Bray F, Tirtiaux C, Ball S, Greub G, Colleoni C. Conservation of the glycogen metabolism pathway underlines a pivotal function of storage polysaccharides in Chlamydiae. Commun Biol 2021; 4:296. [PMID: 33674787 PMCID: PMC7935935 DOI: 10.1038/s42003-021-01794-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/03/2021] [Indexed: 01/31/2023] Open
Abstract
The order Chlamydiales includes obligate intracellular pathogens capable of infecting mammals, fishes and amoeba. Unlike other intracellular bacteria for which intracellular adaptation led to the loss of glycogen metabolism pathway, all chlamydial families maintained the nucleotide-sugar dependent glycogen metabolism pathway i.e. the GlgC-pathway with the notable exception of both Criblamydiaceae and Waddliaceae families. Through detailed genome analysis and biochemical investigations, we have shown that genome rearrangement events have resulted in a defective GlgC-pathway and more importantly we have evidenced a distinct trehalose-dependent GlgE-pathway in both Criblamydiaceae and Waddliaceae families. Altogether, this study strongly indicates that the glycogen metabolism is retained in all Chlamydiales without exception, highlighting the pivotal function of storage polysaccharides, which has been underestimated to date. We propose that glycogen degradation is a mandatory process for fueling essential metabolic pathways that ensure the survival and virulence of extracellular forms i.e. elementary bodies of Chlamydiales.
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Affiliation(s)
- Matthieu Colpaert
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Derifa Kadouche
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Mathieu Ducatez
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Trestan Pillonel
- Institute of Microbiology, University of Lausanne and University Hospital Center, Lausanne, Switzerland
| | - Carole Kebbi-Beghdadi
- Institute of Microbiology, University of Lausanne and University Hospital Center, Lausanne, Switzerland
| | - Ugo Cenci
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Binquan Huang
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan/School of Agriculture, Yunnan University, Kunming, China
| | - Malika Chabi
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Emmanuel Maes
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, US 41 - UMS 2014 - PLBS, Lille, France
| | - Bernadette Coddeville
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Loïc Couderc
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, US 41 - UMS 2014 - PLBS, Lille, France
| | - Hélène Touzet
- University of Lille, CNRS, Centrale Lille, UMR 9189 - CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille, Lille, France
| | - Fabrice Bray
- University of Lille, CNRS, USR 3290-MSAP-Miniaturisation pour la Synthèse, l'Analyse et la Protéomique, Lille, France
| | - Catherine Tirtiaux
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Steven Ball
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Gilbert Greub
- Institute of Microbiology, University of Lausanne and University Hospital Center, Lausanne, Switzerland
| | - Christophe Colleoni
- University of Lille, CNRS, UMR8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France.
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Galperin MY, Wolf YI, Makarova KS, Vera Alvarez R, Landsman D, Koonin EV. COG database update: focus on microbial diversity, model organisms, and widespread pathogens. Nucleic Acids Res 2021; 49:D274-D281. [PMID: 33167031 DOI: 10.1093/nar/gkaa1018] [Citation(s) in RCA: 378] [Impact Index Per Article: 126.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/20/2022] Open
Abstract
The Clusters of Orthologous Genes (COG) database, also referred to as the Clusters of Orthologous Groups of proteins, was created in 1997 and went through several rounds of updates, most recently, in 2014. The current update, available at https://www.ncbi.nlm.nih.gov/research/COG, substantially expands the scope of the database to include complete genomes of 1187 bacteria and 122 archaea, typically, with a single genome per genus. In addition, the current version of the COGs includes the following new features: (i) the recently deprecated NCBI's gene index (gi) numbers for the encoded proteins are replaced with stable RefSeq or GenBank\ENA\DDBJ coding sequence (CDS) accession numbers; (ii) COG annotations are updated for >200 newly characterized protein families with corresponding references and PDB links, where available; (iii) lists of COGs grouped by pathways and functional systems are added; (iv) 266 new COGs for proteins involved in CRISPR-Cas immunity, sporulation in Firmicutes and photosynthesis in cyanobacteria are included; and (v) the database is made available as a web page, in addition to FTP. The current release includes 4877 COGs. Future plans include further expansion of the COG collection by adding archaeal COGs (arCOGs), splitting the COGs containing multiple paralogs, and continued refinement of COG annotations.
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Affiliation(s)
- Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Roberto Vera Alvarez
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - David Landsman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
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Transcriptional Landscape of Waddlia chondrophila Aberrant Bodies Induced by Iron Starvation. Microorganisms 2020; 8:microorganisms8121848. [PMID: 33255276 PMCID: PMC7760296 DOI: 10.3390/microorganisms8121848] [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: 10/22/2020] [Revised: 11/05/2020] [Accepted: 11/20/2020] [Indexed: 11/17/2022] Open
Abstract
Chronic infections caused by obligate intracellular bacteria belonging to the Chlamydiales order are related to the formation of persistent developmental forms called aberrant bodies (ABs), which undergo DNA replication without cell division. These enlarged bacteria develop and persist upon exposure to different stressful conditions such as β-lactam antibiotics, iron deprivation and interferon-γ. However, the mechanisms behind ABs biogenesis remain uncharted. Using an RNA-sequencing approach, we compared the transcriptional profile of ABs induced by iron starvation to untreated bacteria in the Chlamydia-related species Waddliachondrophila, a potential agent of abortion in ruminants and miscarriage in humans. Consistent with the growth arrest observed following iron depletion, our results indicate a significant reduction in the expression of genes related to energy production, carbohydrate and amino acid metabolism and cell wall/envelope biogenesis, compared to untreated, actively replicating bacteria. Conversely, three putative toxin-antitoxin modules were among the most up-regulated genes upon iron starvation, suggesting that their activation might be involved in growth arrest in adverse conditions, an uncommon feature in obligate intracellular bacteria. Our work represents the first complete transcriptomic profile of a Chlamydia-related species in stressful conditions and sets the grounds for further investigations on the mechanisms underlying chlamydial persistence.
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Kebbi-Beghdadi C, Pilloux L, Martin V, Greub G. Eukaryotic Cell Permeabilisation to Identify New Putative Chlamydial Type III Secretion System Effectors Secreted within Host Cell Cytoplasm. Microorganisms 2020; 8:microorganisms8030361. [PMID: 32138376 PMCID: PMC7143554 DOI: 10.3390/microorganisms8030361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/08/2023] Open
Abstract
Chlamydia trachomatis and Waddlia chondrophila are strict intracellular bacteria belonging to the Chlamydiales order. C. trachomatis is the most frequent bacterial cause of genital and ocular infections whereas W. chondrophila is an opportunistic pathogen associated with adverse pregnancy outcomes and respiratory infections. Being strictly intracellular, these bacteria are engaged in a complex interplay with their hosts to modulate their environment and create optimal conditions for completing their life cycle. For this purpose, they possess several secretion pathways and, in particular, a Type III Secretion System (T3SS) devoted to the delivery of effector proteins in the host cell cytosol. Identifying these effectors is a crucial step in understanding the molecular basis of bacterial pathogenesis. Following incubation of infected cells with perfringolysin O, a pore-forming toxin that binds cholesterol present in plasma membranes, we analysed by mass spectrometry the protein content of the host cell cytoplasm. We identified 13 putative effectors secreted by C. trachomatis and 19 secreted by W. chondrophila. Using Y. enterocolitica as a heterologous expression and secretion system, we confirmed that four of these identified proteins are secreted by the T3SS. Two W. chondrophila T3SS effectors (hypothetical proteins Wcw_0499 and Wcw_1706) were further characterised and demonstrated to be early/mid-cycle effectors. In addition, Wcw_1706 is associated with a tetratricopeptide domain-containing protein homologous to C. trachomatis class II chaperone. Furthermore, we identified a novel C. trachomatis effector, CT460 that localises in the eukaryotic nucleus when ectopically expressed in 293 T cells.
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Affiliation(s)
| | | | | | - Gilbert Greub
- Correspondence: ; Tel.: +41-21-314-4979; Fax: +41-21-314-4060
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A predation assay using amoebae to screen for virulence factors unearthed the first W. chondrophila inclusion membrane protein. Sci Rep 2019; 9:19485. [PMID: 31862969 PMCID: PMC6925127 DOI: 10.1038/s41598-019-55511-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 11/11/2019] [Indexed: 01/21/2023] Open
Abstract
Waddlia chondrophila is an intracellular bacterium phylogenetically related to the well-studied human and animal pathogens of the Chlamydiaceae family. In the last decade, W. chondrophila was convincingly demonstrated to be associated with adverse pregnancy outcomes in humans and abortions in animals. All members of the phylum Chlamydiae possess a Type Three Secretion System that they use for delivering virulence proteins into the host cell cytosol to modulate their environment and create optimal conditions to complete their life cycle. To identify W. chondrophila virulence proteins, we used an original screening approach that combines a cosmid library with an assay monitoring resistance to predation by phagocytic amoebae. This technique combined with bioinformatic data allowed the identification of 28 candidate virulence proteins, including Wimp1, the first identified inclusion membrane protein of W. chondrophila.
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11
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Interactions Screenings Unearth Potential New Divisome Components in the Chlamydia-Related Bacterium, Waddlia chondrophila. Microorganisms 2019; 7:microorganisms7120617. [PMID: 31779160 PMCID: PMC6956297 DOI: 10.3390/microorganisms7120617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/23/2022] Open
Abstract
Chlamydiales order members are obligate intracellular bacteria, dividing by binary fission. However, Chlamydiales lack the otherwise conserved homologue of the bacterial division organizer FtsZ and certain division protein homologues. FtsZ might be functionally replaced in Chlamydiales by the actin homologue MreB. RodZ, the membrane anchor of MreB, localizes early at the division septum. In order to better characterize the organization of the chlamydial divisome, we performed co-immunoprecipitations and yeast-two hybrid assays to study the interactome of RodZ, using Waddlia chondrophila, a potentially pathogenic Chlamydia-related bacterium, as a model organism. Three potential interactors were further investigated: SecA, FtsH, and SufD. The gene and protein expression profiles of these three genes were measured and are comparable with recently described division proteins. Moreover, SecA, FtsH, and SufD all showed a peripheral localization, consistent with putative inner membrane localization and interaction with RodZ. Notably, heterologous overexpression of the abovementioned proteins could not complement E. coli mutants, indicating that these proteins might play different functions in these two bacteria or that important regulators are not conserved. Altogether, this study brings new insights to the composition of the chlamydial divisome and points to links between protein secretion, degradation, iron homeostasis, and chlamydial division.
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