[Genetic markers of pathogenicity of conditionally pathogenic enterobacteria isolated from children with diarrheal diseases].

In the process of examination of 89 children from different age groups with diarrheal disease caused by bacteria from Enterobacteriaceae family 89 microorganisms were isolated including Klebsiella spp. (37 isolates), Citrobacter spp. (9 isolates), Enterobacter spp. (17 isolates), Hafnia alvei (1 isolate), Morganella morganii (11 isolates), Proteus spp. (14 isolates). Presence of genes associated with pathogenicity islands (PAIS): hlyA, hlyB (hemolysin), sfaG (fimbria antigen type S), cnf1 (cytotoxic necrotizing factor 1), estB (heat-stable enterotoxin B)were studied in these cultures by PCR. It was found that 32.6% of examined isolates had fragments of PAIS's genes--hlyA was detected in 9 cases (10.1%), hlyB--in 10 cases (11.2%), sfaG --in 8 cases (9%), cnf1--in 9 cases (10.1%), and estB--in 3 cases (3.4%). Positive correlation between genetic determinants hlyB and cnf1 as well as hlyA and sfaG was found while estB was not associated with other genes. Weak positive correlation between presence of sfaG and resistance to tetracycline and chloramphenicol was detected. Factors coded by revealed determinants of PAIS can play a role in the development of diarrheal syndrome.