Distribution of espM and espT among enteropathogenic and enterohaemorrhagic Escherichia coli
1 Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK 2 Laboratorio de Referencia de E. coli , Departamento de Microbiología y Parasitología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain 3...
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| Published in: | Journal of medical microbiology Vol. 58; no. 8; pp. 988 - 995 |
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| Main Authors: | , , , , , , , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
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Soc General Microbiol
01-08-2009
Society for General Microbiology |
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| Online Access: | Get full text |
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| Summary: | 1 Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK
2 Laboratorio de Referencia de E. coli , Departamento de Microbiología y Parasitología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain
3 Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
4 Unidade de Microbioloxía Clínica, Complexo Hospitalario Xeral-Calde, Lugo, Spain
Correspondence Jorge Blanco jorge.blanco{at}usc.es
Received February 12, 2009
Accepted April 7, 2009
Enterohaemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) translocate dozens of type III secretion system effectors, including the WxxxE effectors Map, EspM and EspT that activate Rho GTPases. While map , which is carried on the LEE pathogenicity island, is absolutely conserved among EPEC and EHEC strains, the prevalence of espM and espT is not known. Here we report the results of a large screen aimed at determining the prevalence of espM and espT among clinical EPEC and EHEC isolates. The results suggest that espM , detected in 51 % of the tested strains, is more commonly found in EPEC and EHEC serogroups that are linked to severe human infections. In contrast, espT was absent from all the EHEC isolates and was found in only 1.8 % of the tested EPEC strains. Further characterization of the virulence gene repertoire of the espT -positive strains led to the identification of a new 2 intimin variant. All the espT -positive strains but two contained the tccP gene. espT was first found in Citrobacter rodentium and later in silico in EPEC E110019 , which is of particular interest as this strain was responsible for a particularly severe diarrhoeal outbreak in Finland in 1987 that affected 650 individuals in a school complex and an additional 137 associated household members. Comparing the protein sequences of EspT to that of E110019 showed a high level of conservation, with only three strains encoding EspT that differed in 6 amino acids. At present, it is not clear why espT is so rare, and what impact EspM and EspT have on EPEC and EHEC infection.
These authors contributed equally to this work.
The GenBank/EMBL/DDBJ accession numbers for the eae - 2 variant gene sequences of E110019 and T2381-8 are FM872419 and FM872420, respectively. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 These authors contributed equally to this work. |
| ISSN: | 0022-2615 1473-5644 |
| DOI: | 10.1099/jmm.0.010231-0 |