TYPING OF BOVINE ATTACHING AND EFFACING ESCHERICHIA-COLI BY MULTIPLEXIN-VITRO AMPLIFICATION OF VIRULENCE-ASSOCIATED GENES

Attaching and effacing Escherichia coli is a new causal agent of diarr hea in calves. Its major virulence factors are the intimin protein, en coded by the eaeA gene, and the Shiga-like toxins, encoded by sit gene s, Because the sequences of these genes are available, we selected spe cific primers to amplify each virulence gene so as to develop a new id entification test based on multiplex amplification of virulence-associ ated genes. Of 30 tested strains, 14 were eaeA(+), 15 were eneA(+) slt -I+, 1 was eneA(+) slt-I+ slt-II+, and 1 was eaeA(+) slt-II+. The meth od proved in our hands to be fast and specific and in perfect correlat ion with the hybridization method.