The prevalence of virulence-related genes, eaeA, aggR and astA, of localized and aggregative-adherent Escherichia coli (EPEC and EAggEC) in healthy children and age-matched patients with diarrhea

Abstract

The prevalence of virulence-related genes of localized- and aggregated-adherent Escherichia coli (EPEC and EAggEC), such as eaeA, aggR and astA was compared between E. coli isolated from 0 to 5 year old children with and without diarrhea in Saga Prefecture. In the case of eaeA, 233 cases in Aichi Prefecture were included. The subjects were 74 diarrheal patients from which no diarrheagenic bacteria were detected besides E. coli. The control subjects were 304 nursery school children without diarrhea, and E. coli was isolated from 278 children in which 105 strains were of 0-serotype. EaeA-positive E. coli was isolated from nine (12.2%) Saga cases, 19 (8.2%) Aichi cases and 6 (5.7%) control subjects; aggR-positive E. coli was isolated from 10 (13.5%) cases and 6 (5.7%) control subjects and astA-positive E. coli from 10 (13.5%) cases and 14 (13.3%) control subjects. No significant difference (p > 0.05) was observed in the prevalence of eaeA, aggR and astA between healthy and diarrheal children, even in age-matched and 0-serotypable E. coli limited comparisons. The pathogenicity of EPEC and EAggEC should be investigated, considering other known or unidentified factors.