Use of plasmid profiles to differentiate strains withi9n specific serotypes of classical enteropathogenic Escherichia coli

ABSTRACT

The usefulness of plasmid profile analysis to differentiate strains of enteropathogenic Escherichia coli (EPEC) was evaluated by studying 123 strains of the most prevalent serotypes causing infant diarrhea in the city of Säo Paulo, Brazil, i. e.,0111abH-, 0111abH2 and 0119H6. No common profiles were found among strains of distinct serotypes. However, within each serotype, most of the strains were grouped within a few major profiles. More than 68% of the strainsof serotypes 0111abH- and 0111abH2 were included in 6 and 9 major profiles, respectively. In 0119H6, abouth 48% of the strainswere included in 3 major profiles. This analysis suggewsts that only a few EPEC clones are causing infant diarrhea in Säo Paulo and revealed that the distribution of serotypes 0111 abH- and 0111abH2 during the one-year study was at least partly determined by small outbreaks of the most common profiles. We conclude that plasmid profile analysis is very useful to differentiate strasins within specific EPEC serotypes