Production of cytolethal distending toxin and other virulence characteristics of Escherichia coli strains of serogroup O86

RESUMO

Genetic and phenotypic virulence markers of different categories of diarrhoeagenic Escherichia coli were investigated in 106 strains of enteropathogenic E. coli (EPEC) serogroup O86. The most frequent serotype found was O86H34 (86 percent). Strains of this serotype and the non motile ones behaved as EPEC i.e., carried eae, bfpA and EAF DNA sequences and presented localised adherence to HeLa cells. Serotypes O86H2, O86H6, O86H10, O86H18, O86H27 and O86H non determined, belonged to other categories. The majority of the strains of serotype O86H34 and non motile strains produced cytolethal-distending toxin (CDT). The ribotyping analysis showed a correlation among ribotypes, virulence markers and serotypes, thus suggesting that CDT production might be a property associated with a universal clone represented by the O86H34 serotype