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Aracil-Gisbert S, Fernández-De-Bobadilla MD, Guerra-Pinto N, Serrano-Calleja S, Pérez-Cobas AE, Soriano C, de Pablo R, Lanza VF, Pérez-Viso B, Reuters S, Hasman H, Cantón R, Baquero F, Coque TM. The ICU environment contributes to the endemicity of the " Serratia marcescens complex" in the hospital setting. mBio 2024; 15:e0305423. [PMID: 38564701 PMCID: PMC11077947 DOI: 10.1128/mbio.03054-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Serratia marcescens is an opportunistic pathogen historically associated with sudden outbreaks in intensive care units (ICUs) and the spread of carbapenem-resistant genes. However, the ecology of S. marcescens populations in the hospital ecosystem remains largely unknown. We combined epidemiological information of 1,432 Serratia spp. isolates collected from sinks of a large ICU that underwent demographic and operational changes (2019-2021) and 99 non-redundant outbreak/non-outbreak isolates from the same hospital (2003-2019) with 165 genomic data. These genomes were grouped into clades (1-4) and subclades (A and B) associated with distinct species: Serratia nematodiphila (1A), S. marcescens (1B), Serratia bockelmannii (2A), Serratia ureilytica (2B), S. marcescens/Serratia nevei (3), and S. nevei (4A and 4B). They may be classified into an S. marcescens complex (SMC) due to the similarity between/within subclades (average nucleotide identity >95%-98%), with clades 3 and 4 predominating in our study and publicly available databases. Chromosomal AmpC β-lactamase with unusual basal-like expression and prodigiosin-lacking species contrasted classical features of Serratia. We found persistent and coexisting clones in sinks of subclades 4A (ST92 and ST490) and 4B (ST424), clonally related to outbreak isolates carrying blaVIM-1 or blaOXA-48 on prevalent IncL/pB77-CPsm plasmids from our hospital since 2017. The distribution of SMC populations in ICU sinks and patients reflects how Serratia species acquire, maintain, and enable plasmid evolution in both "source" (permanent, sinks) and "sink" (transient, patients) hospital patches. The results contribute to understanding how water sinks serve as reservoirs of Enterobacterales clones and plasmids that enable the persistence of carbapenemase genes in healthcare settings, potentially leading to outbreaks and/or hospital-acquired infections.IMPORTANCEThe "hospital environment," including sinks and surfaces, is increasingly recognized as a reservoir for bacterial species, clones, and plasmids of high epidemiological concern. Available studies on Serratia epidemiology have focused mainly on outbreaks of multidrug-resistant species, overlooking local longitudinal analyses necessary for understanding the dynamics of opportunistic pathogens and antibiotic-resistant genes within the hospital setting. This long-term genomic comparative analysis of Serratia isolated from the ICU environment with isolates causing nosocomial infections and/or outbreaks within the same hospital revealed the coexistence and persistence of Serratia populations in water reservoirs. Moreover, predominant sink strains may acquire highly conserved and widely distributed plasmids carrying carbapenemase genes, such as the prevalent IncL-pB77-CPsm (pOXA48), persisting in ICU sinks for years. The work highlights the relevance of ICU environmental reservoirs in the endemicity of certain opportunistic pathogens and resistance mechanisms mainly confined to hospitals.
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Affiliation(s)
- Sonia Aracil-Gisbert
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
| | - Miguel D. Fernández-De-Bobadilla
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
| | - Natalia Guerra-Pinto
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
| | - Silvia Serrano-Calleja
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
| | - Ana Elena Pérez-Cobas
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
- Biomedical Research Center Network of Infectious Diseases (CIBERINFEC), Madrid, Spain
| | - Cruz Soriano
- Intensive Medicine, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- University of Alcalá (UAH), Madrid, Spain
| | - Raúl de Pablo
- Intensive Medicine, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- University of Alcalá (UAH), Madrid, Spain
| | - Val F. Lanza
- Biomedical Research Center Network of Infectious Diseases (CIBERINFEC), Madrid, Spain
- Bioinformatics Unit, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
| | - Blanca Pérez-Viso
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
| | - Sandra Reuters
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Institute for Infection Prevention and Control, Medical Center–University of Freiburg, Freiburg, Germany
| | - Henrik Hasman
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
- Statens Serum Institut, Copenhagen, Denmark
| | - Rafael Cantón
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Biomedical Research Center Network of Infectious Diseases (CIBERINFEC), Madrid, Spain
| | - Fernando Baquero
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Biomedical Research Center Network of Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Teresa M. Coque
- Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Member of the ESCMID Study Group for Epidemiological Markers (ESGEM), Basel, Switzerland
- Member of the ESCMID Food- and Water-borne Infections Study Group (EFWISG), Basel, Switzerland
- Biomedical Research Center Network of Infectious Diseases (CIBERINFEC), Madrid, Spain
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Sterzi L, Nodari R, Di Marco F, Ferrando ML, Saluzzo F, Spitaleri A, Allahverdi H, Papaleo S, Panelli S, Rimoldi SG, Batisti Biffignandi G, Corbella M, Cavallero A, Prati P, Farina C, Cirillo DM, Zuccotti G, Bandi C, Comandatore F. Genetic barriers more than environmental associations explain Serratia marcescens population structure. Commun Biol 2024; 7:468. [PMID: 38632370 PMCID: PMC11023947 DOI: 10.1038/s42003-024-06069-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
Bacterial species often comprise well-separated lineages, likely emerged and maintained by genetic isolation and/or ecological divergence. How these two evolutionary actors interact in the shaping of bacterial population structure is currently not fully understood. In this study, we investigate the genetic and ecological drivers underlying the evolution of Serratia marcescens, an opportunistic pathogen with high genomic flexibility and able to colonise diverse environments. Comparative genomic analyses reveal a population structure composed of five deeply-demarcated genetic clusters with open pan-genome but limited inter-cluster gene flow, partially explained by Restriction-Modification (R-M) systems incompatibility. Furthermore, a large-scale research on hundred-thousands metagenomic datasets reveals only a partial habitat separation of the clusters. Globally, two clusters only show a separate gene composition coherent with ecological adaptations. These results suggest that genetic isolation has preceded ecological adaptations in the shaping of the species diversity, an evolutionary scenario coherent with the Evolutionary Extended Synthesis.
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Affiliation(s)
- Lodovico Sterzi
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
| | - Riccardo Nodari
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
| | - Federico Di Marco
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Laura Ferrando
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesca Saluzzo
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Hamed Allahverdi
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
| | - Stella Papaleo
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
| | - Simona Panelli
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
| | - Sara Giordana Rimoldi
- Laboratorio di Microbiologia Clinica, Virologia e Diagnostica delle Bioemergenze, ASST Fatebenefratelli Sacco, Milan, Italy
| | | | - Marta Corbella
- Department of Microbiology & Virology, Fondazione IRCCS Policlinico San Matteo, Viale Camillo Golgi 19, 27100, Pavia, Italy
| | | | - Paola Prati
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna (IZSLER), Pavia, Italy
| | - Claudio Farina
- Laboratory of Microbiology and Virology, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy
| | - Daniela Maria Cirillo
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Gianvincenzo Zuccotti
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy
- Department of Paediatrics, Children's Hospital "V. Buzzi", Milano, Italy
| | - Claudio Bandi
- Department of Biosciences and Pediatric Clinical Research Center "Romeo Ed Enrica Invernizzi", University of Milan, 20133, Milan, Italy
| | - Francesco Comandatore
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center "Romeo and Enrica Invernizzi", Università Di Milano, 20157, Milan, Italy.
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Nagano DS, Taniguchi I, Ono T, Nakamura K, Gotoh Y, Hayashi T. Systematic analysis of plasmids of the Serratia marcescens complex using 142 closed genomes. Microb Genom 2023; 9. [PMID: 37966169 DOI: 10.1099/mgen.0.001135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023] Open
Abstract
Plasmids play important roles in bacterial genome diversification. In the Serratia marcescens complex (SMC), a notable contribution of plasmids to genome diversification was also suggested by our recent analysis of >600 draft genomes. As accurate analyses of plasmids in draft genomes are difficult, in this study we analysed 142 closed genomes covering the entire complex, 67 of which were obtained in this study, and identified 132 plasmids (1.9-244.4 kb in length) in 77 strains. While the average numbers of plasmids in clinical and non-clinical strains showed no significant difference, strains belonging to clade 2 (one of the two hospital-adapted lineages) contained more plasmids than the others. Pangenome analysis revealed that of the 28 954 genes identified, 12.8 % were plasmid-specific, and 1.4 % were present in plasmids or chromosomes depending on the strain. In the latter group, while transposon-related genes were most prevalent (31.4 % of the function-predicted genes), genes related to antimicrobial resistance and heavy metal resistance accounted for a notable proportion (22.7 %). Mash distance-based clustering separated the 132 plasmids into 23 clusters and 50 singletons. Most clusters/singletons showed notably different GC contents compared to those of host chromosomes, suggesting their recent or relatively recent appearance in the SMC. Among the 23 clusters, 17 were found in only clinical or only non-clinical strains, suggesting the possible preference of their distribution on the environmental niches of host strains. Regarding the host strain phylogeny, 16 clusters were distributed in two or more clades, suggesting their interclade transmission. Moreover, for many plasmids, highly homologous plasmids were found in other species, indicating the broadness of their potential host ranges, beyond the genus, family, order, class or even phylum level. Importantly, highly homologous plasmids were most frequently found in Klebsiella pneumoniae and other species in the family Enterobacteriaceae, suggesting that this family, particularly K. pneumoniae, is the main source for plasmid exchanges with the SMC. These results highlight the power of closed genome-based analysis in the investigation of plasmids and provide important insights into the nature of plasmids distributed in the SMC.
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Affiliation(s)
- Debora Satie Nagano
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Itsuki Taniguchi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tomoyuki Ono
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
- Department of Cardiovascular Surgery, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Keiji Nakamura
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yasuhiro Gotoh
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, 812-8582, Japan
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Shikov AE, Merkushova AV, Savina IA, Nizhnikov AA, Antonets KS. The man, the plant, and the insect: shooting host specificity determinants in Serratia marcescens pangenome. Front Microbiol 2023; 14:1211999. [PMID: 38029097 PMCID: PMC10656689 DOI: 10.3389/fmicb.2023.1211999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/21/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Serratia marcescens is most commonly known as an opportunistic pathogen causing nosocomial infections. It, however, was shown to infect a wide range of hosts apart from vertebrates such as insects or plants as well, being either pathogenic or growth-promoting for the latter. Despite being extensively studied in terms of virulence mechanisms during human infections, there has been little evidence of which factors determine S. marcescens host specificity. On that account, we analyzed S. marcescens pangenome to reveal possible specificity factors. Methods We selected 73 high-quality genome assemblies of complete level and reconstructed the respective pangenome and reference phylogeny based on core genes alignment. To find an optimal pipeline, we tested current pangenomic tools and obtained several phylogenetic inferences. The pangenome was rich in its accessory component and was considered open according to the Heaps' law. We then applied the pangenome-wide associating method (pan-GWAS) and predicted positively associated gene clusters attributed to three host groups, namely, humans, insects, and plants. Results According to the results, significant factors relating to human infections included transcriptional regulators, lipoproteins, ABC transporters, and membrane proteins. Host preference toward insects, in its turn, was associated with diverse enzymes, such as hydrolases, isochorismatase, and N-acetyltransferase with the latter possibly exerting a neurotoxic effect. Finally, plant infection may be conducted through type VI secretion systems and modulation of plant cell wall synthesis. Interestingly, factors associated with plants also included putative growth-promoting proteins like enzymes performing xenobiotic degradation and releasing ammonium irons. We also identified overrepresented functional annotations within the sets of specificity factors and found that their functional characteristics fell into separate clusters, thus, implying that host adaptation is represented by diverse functional pathways. Finally, we found that mobile genetic elements bore specificity determinants. In particular, prophages were mainly associated with factors related to humans, while genetic islands-with insects and plants, respectively. Discussion In summary, functional enrichments coupled with pangenomic inferences allowed us to hypothesize that the respective host preference is carried out through distinct molecular mechanisms of virulence. To the best of our knowledge, the presented research is the first to identify specific genomic features of S. marcescens assemblies isolated from different hosts at the pangenomic level.
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Affiliation(s)
- Anton E. Shikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russia
- Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Anastasiya V. Merkushova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russia
| | - Iuliia A. Savina
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russia
| | - Anton A. Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russia
- Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Kirill S. Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russia
- Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
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Reglinski M, Monlezun L, Coulthurst SJ. The accessory protein TagV is required for full Type VI secretion system activity in Serratia marcescens. Mol Microbiol 2023; 119:326-339. [PMID: 36627840 PMCID: PMC7614798 DOI: 10.1111/mmi.15027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 12/21/2022] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
The bacterial Type VI secretion system (T6SS) is a dynamic macromolecular structure that promotes inter- and intra-species competition through the delivery of toxic effector proteins into neighbouring cells. The T6SS contains 14 well-characterised core proteins necessary for effector delivery (TssA-M, PAAR). In this study, we have identified a novel accessory component required for optimal T6SS activity in the opportunistic pathogen Serratia marcescens, which we name TagV. Deletion of tagV, which encodes an outer membrane lipoprotein, caused a reduction in the T6SS-dependent antibacterial activity of S. marcescens Db10. Mutants of S. marcescens lacking the core component TssJ, a distinct outer membrane lipoprotein previously considered essential for T6SS firing, retained a modest T6SS activity that could be abolished through deletion of tagV. TagV did not interact with the T6SS membrane complex proteins TssL or TssM, but is proposed to bind to peptidoglycan, indicating that the mechanism by which TagV promotes T6SS firing differs from that of TssJ. Homologues of tagV were identified in several other bacterial genera, suggesting that the accessory function of TagV is not restricted to S. marcescens. Together, our findings support the existence of a second, TssJ-independent mechanism for T6SS firing that is dependent upon the activity of TagV proteins.
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Affiliation(s)
- Mark Reglinski
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Laura Monlezun
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Sarah J Coulthurst
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
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Li P, He S, Zhang X, Gao Q, Liu Y, Liu L. Structures, biosynthesis, and bioactivities of prodiginine natural products. Appl Microbiol Biotechnol 2022; 106:7721-7735. [DOI: 10.1007/s00253-022-12245-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/06/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022]
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Hayashi T. [Genome analysis-based studies on bacterial genetic diversity]. Nihon Saikingaku Zasshi 2022; 77:145-160. [PMID: 36418109 DOI: 10.3412/jsb.77.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
There are a huge number of bacterial species on earth, and a huge intra-species genomic diversity are also observed in many bacteria. The high ability of bacteria to acquire foreign DNA and the presence of various mobile genetic elements contribute the generation of such genomic diversity. During the biochemical and genetic analysis of a Pseudomonas aeruginosa toxin, called cytotoxin, and its converting phage, which I first engaged in my research carrier, I became very interested in the genetic diversity of bacteria and mobile genetic elements such as bacteriophages, and realized the usefulness and power of genome analysis. Since then, I have been involved in genome analyses of various pathogenic bacteria such as enterohemorrhagic Escherichia coli (EHEC), commensal bacteria of human and other animals, and bacteria or bacterial communities in natural environments. I was so lucky that I jumped in this research field at the very begging of genome analyses and experienced a very exciting time of surprisingly rapid advance in genome sequencing technologies which revolutionized a wide range of biology. In this article, I first review the main findings which our group obtained from the genome analyses on the P. aeruginosa cytotoxin converting phage and those on the evolution and genomic diversity of EHEC and related bacteria. The results of our analyses of Rickettsiaceae family genomes, which show surprisingly very low genomic diversity, and genome sequence-based analyses of an intrahospital bacterial outbreak and within-host genomic diversity are also summarized.
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Affiliation(s)
- Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University
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