[Relation between P-fimbriae and resistance to amoxicillin, carbenicillin and tetracycline in uropathogenic strains of Escherichia coli].

Escherichia coli is the most common cause of uncomplicated urinary tract infections. The ability of adherence enables E. coli colonization of mucosal surfaces of the urinary tract, and strains which express P-fimbriae significantly more often cause unobstructive pyelonephritis. The relationship between adhesin type and susceptibility to 13 antimicrobial agents of 160 E. coli strains isolated from urine from individuals with acute pyelonephritis, chronic pyelonephritis, acute cystitis and asymptomatic bacteriuria was investigated. The adhesins of investigated strains of E. coli were determined by hemagglutination, and susceptibility to antimicrobial agents by Kirby-Bauer disk diffusion method. P-fimbriated strains were more frequently resistant to tetracycline and carbenicillin than strains in which P-fimbriae were not detected, and they all were resistant to amoxicillin, in contrast with non P-fimbriated strains (p < 0.01). The observed relationship between P-fimbriae and antimicrobial resistance among strains in which different serogroups were detected suggest the possibility of horizontal gene transfer of these properties. It can be concluded that in patients with symptoms of acute upper urinary tract infection amoxicillin should not be used empirically because there is a great possibility that infection is caused by P-fimbriated and amoxicillin resistant strain of E. coli.