[Genetic determinants of pathogenicity of opportunistic enterobacteria isolated from children with acute intestinal infections].
OBJECTIVE
Detection of nucleotide sequences of genes controlling synthesis of pathogenicity factors in clinical strains of opportunistic enterobacteria isolated from children with acute intestinal infections (AII), as well as their association with resistance to antibiotics and the course of the infectious process.


METHODS
175 clinical strains obtained from children with AII undergoing treatment in Irkutsk state infectious diseases hospital (2007-2010) were studied. Primers to a number of genes detected in Escherichia coli pathogenicity islands, controlling type S and type 1 adhesion; formation of hemolysins; iron-regulatory protein synthesis; capsule formation were used in the study. PCR products analysis was performed by agar gel electrophoresis.


RESULTS
Genetic determinants of pathogenicity were detected in bacteria genera Klebsiella, Citrobacter, Enterobacter, Proteus, Kluyvera, Morganella, Pantoea, Serratia. Fragments of hlyA and hlyB genes (hemolysin production) were detected more frequently; less frequently--sfaA, sfaG, fimA (adhesion), as well as irp-2 gene (synthesis of iron-regulatory protein). The largest set of genetic determinants of pathogenicity was noted in clinical strains of Klebsiella spp. Cultures with DNA fragments specific to genes of E. coli pathogenicity clusters were obtained predominately from children aged up to 3 years, had multiple antibiotic resistance and were isolated significantly more frequently in severe forms of AII when compared with strains in which these determinants were not detected.


CONCLUSIONS
The studies performed showed that clinical strains of opportunistic bacteria isolated from patients with AII have a certain pathogenic potential, as evidenced by the presence of genetic pathogenicity markers in them.
E V
EV
Anganova
A V
AV
Dukhanina
E D
ED
Savilov
D000208:Acute Disease; D001426:Bacterial Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics*; D004755:Enterobacteriaceae / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D004756:Enterobacteriaceae Infections / Q000235:genetics* / Q000382:microbiology; D005260:Female; D006801:Humans; D007410:Intestinal Diseases; D008297:Male
D001426:Bacterial Proteins; D004269:DNA, Bacterial