Virulence determinants of uropathogenic Escherichia coli in fecal strains from intestinal infections and healthy individuals.

Twenty-five fecal Escherichia coli strains of serogroups O6 and O18 from patients with and without intestinal infections were analyzed for fimbrial adhesins pap, prs and sfa, hemolysin, cytonecrotic factor, colicins, capsules, antibiotic resistances, plasmid content and some plasmid encoded characteristics. A high percentage of strains expressing P fimbriae was found with an even higher percentage in strains isolated from intestinal infections. A correlation was found between colicinogenicity and P fimbriae production. None of the strains produced hemolysin while 28% had cytonecrotic factor type 1 sequences, demonstrating that cytonecrotic factor type 1 is not always associated with hemolysin production and indicating that the examined strains do not harbor a larger pathogenicity island. Plasmids and plasmid associated characteristics were more frequently associated with the O18 serogroup and chromosomal colicin V genes were found independently of plasmids.