Association between the presence of class 1 integrons, virulence genes, and phylogenetic groups of Escherichia coli isolates from river water.

Ninety-six class 1 integron-positive and 96 integron-negative Escherichia coli isolates cultured from the water of the Warta River, Poland, were characterized for their phylogenetic group affiliation and for the presence of genes associated with virulence. Most strains belonged to phylogenetic group A, but phylogenetic group affiliation was not related with the presence of integrons. The occurrence of heat-stable toxin gene of enterotoxigenic E.