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Petty NK, Feltwell T, Pickard D, Clare S, Toribio AL, Fookes M, Roberts K, Monson R, Nair S, Kingsley RA, Bulgin R, Wiles S, Goulding D, Keane T, Corton C, Lennard N, Harris D, Willey D, Rance R, Yu L, Choudhary JS, Churcher C, Quail MA, Parkhill J, Frankel G, Dougan G, Salmond GPC, Thomson NR. Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux. PLoS Pathog 2011; 7:e1002018. [PMID: 21490962 PMCID: PMC3072379 DOI: 10.1371/journal.ppat.1002018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/18/2011] [Indexed: 11/18/2022] Open
Abstract
Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E) lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease.
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Affiliation(s)
- Nicola K. Petty
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Theresa Feltwell
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Derek Pickard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Simon Clare
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Ana L. Toribio
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Maria Fookes
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Kevin Roberts
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Rita Monson
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Satheesh Nair
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Robert A. Kingsley
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Bulgin
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Siouxsie Wiles
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - David Goulding
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Thomas Keane
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Craig Corton
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nicola Lennard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Harris
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Willey
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Rance
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Jyoti S. Choudhary
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Carol Churcher
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Michael A. Quail
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Gad Frankel
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | | | - Nicholas R. Thomson
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
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Nagai T, Abe A, Sasakawa C. Targeting of enteropathogenic Escherichia coli EspF to host mitochondria is essential for bacterial pathogenesis: critical role of the 16th leucine residue in EspF. J Biol Chem 2004; 280:2998-3011. [PMID: 15533930 DOI: 10.1074/jbc.m411550200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The attachment of enteropathogenic Escherichia coli (EPEC) to host cells and the induction of attaching and effacing (A/E) lesions are prominent pathogenic features. EPEC infection also leads to host cell death and damage to the intestinal mucosa, which is partly dependent upon EspF, one of the effectors. In this study, we demonstrate that EspF is a mitochondrial import protein with a functional mitochondrial targeting signal (MTS), because EspF activity for importing into the mitochondria was abrogated by MTS deletion mutants. Substitution of the 16th leucine with glutamic acid (EspF(L16E)) completely abolished EspF activity. Infection of HeLa cells with wild type but not the espF mutant (DeltaespF) decreased mitochondrial membrane potential (DeltaPsi(m)), leading to cell death. The DeltaPsi(m) decrease and cell death were restored in cells infected with DeltaespF/pEspF but not DeltaespF/pEspF(L16E), suggesting that the 16th leucine in the MTS is a critical amino acid for EspF function. To demonstrate the impact of EspF in vivo, we exploited Citrobacter rodentium by infecting C3H/HeJ mice with DeltaespF(CR), DeltaespF(CR)/pEspF(CR), or DeltaespF(CR)/pEspF(L16E)(CR). These results indicate that EspF activity contributes to bacterial pathogenesis, as judged by murine lethality and intestinal histopathology, and promotion of bacterial colonization of the intestinal mucosa.
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Affiliation(s)
- Takeshi Nagai
- Department of Microbiology and Immunity, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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