[Genetic determinants of Escherichia coli pathogenicity isolated from urine and feces of children with different clinical variants of urinary system infection].

In the process of examination of 156 children of different age groups 176 E. coli cultures were isolated; of these, 98 cultures were isolated from acute cystitis and pyelonephritis patients, 28--from urine in cases of aysmptomatic bacteriuria, 30--from feces in cases of asymtomatc bacteriuria and intestinal dysbacteriosis, while 20 cultures--from feces of healthy children. In these bacteria the presence of genes associated with pathogenicity islets (PI) hlyA, hlyB, cnf-1, papC, sfaG and gene irp-2 (iron-regulated protein) was established with PCR. The detection rate of PI determinants in uropathogenic E. coli (UPEC) was shown to depend on the variants of the clinical manifestation of urinary tract infection. The total detection rate of PI gene fragments in UPEC cultures of different origin was indicative of their definitely less frequent occurrence in asymptomatic bacteriuria, observed simultaneously with intestinal dysbacteriosis, in comparison with acute urological infection. Practically the same detection rate of PI determinants in E. coli, isolated in asymptomatic bacteriuria in children, reflected high probability of genetic exchange in the above-mentioned fragments and made it possible to presume the existence of DNA sites, characteristic mainly of pathogenic clones. The established heterogeneity of the detection rate of PI determinants in E. coli clinical isolates requires further study.