J Med Microbiol 56 (2007), 1431-1439; DOI: 10.1099/jmm.0.47311-0
© 2007 Society for General Microbiology
ISSN 1473-5644
Influence of geographical origin, host animal and stx gene on the virulence characteristics of Escherichia coli O26 strains
Ilknur Aktan1,2,
Ben Carter2,
Hendrik Wilking3,
Roberto M. La Ragione2,
Lothar Wieler3,
Martin J. Woodward2 and
Muna F. Anjum2
1 Department of Veterinary Clinical Science and Animal Husbandry, University of Liverpool, Neston, South Wirral CH64 7TE, UK
2 Department of Food and Environmental Safety, Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
3 Institute of Microbiology and Epizootics, Free University Berlin, D-10115 Berlin, Germany
Correspondence
Muna F. Anjum
m.anjum{at}vla.defra.gsi.gov.uk
Received 26 March 2007
Accepted 11 July 2007
The influence of geographical origin, host animal and presence of the stx gene on the virulence of Escherichia coli O26 strains from ruminants was determined in this study. A clear association was found between the virulence profile and geographical origin of Shiga-toxigenic E. coli (STEC) O26 strains, with UK STEC O26 strains harbouring virtually identical profiles, whilst central European strains showed considerable heterogeneity in plasmid-encoded genes. The former group were also more likely to be non-motile and katP gene positive. Comparison of UK STEC and atypical enteropathogenic E. coli (aEPEC) O26 strains showed that the presence of the stx1 gene was positively correlated with the presence of espP and katP genes and negatively associated with the presence of the yagP–yagT region and with rhamnose fermentation. In contrast to the uniform profiles of STEC O26 strains from ruminants in the UK, aEPEC O26 strains of bovine and ovine origin showed diverse profiles both within and between groups, and could not be separated into discrete groups. These results indicate that the characteristics of UK O26 strains from ruminants are distinct from those of O26 strains from ruminants and humans in other regions in central Europe. Such differences are expected to influence the zoonotic potential of this pathogen and the subsequent incidence of O26-associated human disease.
Abbreviations: aEPEC, atypical enteropathogenic E. coli; EHEC, enterohaemorrhagic E. coli; HPI, high-pathogenicity island; HUS, haemolytic uraemic syndrome; STEC, Shiga toxin-producing E. coli; Stx, Shiga toxin.
Copyright © 2007 Society for General Microbiology.