Molecular Characterization and Antibiotic Susceptibility of Diarrheagenic Escherichia coli from Children

Abstract

In Thi Qar there are relatively few studies have been done to reveal and classify diarrheagenic Escherichia coli (DEC) strains among children with diarrhea. This study focused genetically at investigating DEC among hospitalized children under 2 years in Thi Qar city.A total of 200 children (Below 12 years) with diarrhea and 75 without diarrhea were their stools investigated using culture on Mac¬Conkey and EMB agar, and E. coli isolates were examined for detection of diarrheagenic E. coli types, antimicrobial susceptibility pattern. Virulence genes detected using PCR. A multiplex PCR system method was used to detect a species specific gene for E.coli and ten different virulence genes for detection of five pathogroups of DEC namely enteroaggregative- (EAEC), enteropathogenic- (EPEC), enterotoxigenic- (ETEC), enteroinvasive- (EIEC) and enterohemorghagic- Escherichia coli (EHEC).The study has indicated that diarrheagenic E. coli isolates were found mostly in stools of children with diarrhea. DEC diarrhoeagenic E. coli was significantly detected among diarrheic children (44.8%) compared with control children (16.4%). Of the DEC pathotypes examined, EAEC was found in (64.73%), ETEC in (19.5%), EPEC in (10.5%) and EHEC in (5.27%) of diarrheic. Virulence-gene factors in DEC isolated from children with diarrhea and from controls. The distribution of virulence gene was; pCVD432 93.6%, 87.3%; eaeA 64.2%, 8.5%; bfpA 59.1%, 2.05%; stx1 22.8%, 0.8%; stx2 18.6%, 0%; estA1 heat-stable (ST) 8.14%, 1.3%; estA2-4 heat-stable (ST) 14.6%, 0.2%; eltB heat-labile (LT) 43.1%, 0.4% in DEC and control children respectively. This study revealed high incidence of diarrheagenic E. coli isolates and high prevalence of antimicrobial resistance among normal intestinal E. coli with typical EAEC and typical EPEC predominating. The use of primers for both variants of ST useful to detect the sensitivity for detection of ETEC strains of hospitalized children in Thi Qar.