Frequency of Enteropathogenic Escherichia coli strains isolated from children with diarrhea in Bushehr

BACKGROUND AND OBJECTIVESEnteropathogenic E. coli (EPEC) is associated with outbreaks of infantile diarrhea, and is a contributor to diarrheagenic diseases in human populations around the world. All EPEC strains contain the eaeA gene that encodes intimin for attachment to epithelial cells, differentiate from STEC by absence of the shiga toxin (stx) gene, and also classified into typical and atypical strains based on the presence or absence of bundle-forming pilus (bfpA) gene. Purpose of the current study was to find out the frequency of EPEC strains by PCR molecular method in Bushehr.MATERIALS AND METHODSA total of ۱۶۵ E. coli strains isolated from diarrheic children less than ۱۰ years were examined. The specimens collected from two hospitals from November ۲۰۲۱ to April ۲۰۲۲ in Bushehr province. All E. coli isolates were identified by Gram stain and standard biochemical tests such as TSI, motility, indole, simmon citrate and urease. Total DNA was extracted by boiling method. E. coli isolates were confirmed by detection of uidA gene using PCR. Determination of EPEC isolates was analyzed using by PCR for the eaeA, stx۱, stx۲ and bfpA genes.RESULTS AND DISCUSSION Out of these isolates, EPEC were detected in ۹ (۵.۴۵%) of children by PCR, which harbored both uidA and eaeA genes. Additionally, all isolates have been checked for Stx۱ and Stx۲ genes. Males in this study constituted ۵۸.۲%, and females were ۴۱.۸%. EPEC isolates were then tested by PCR-based targeting of bfpA gene to differentiate typical and atypical EPEC. All EPEC strains displayed eaeA+, stx۱/stx۲−, bfpA−genotype as atypical EPEC isolates. Any isolate wasn’t determined as typical EPEC strain with eaeA+, stx۱/stx۲−, bfpA+ genotype in present study.CONCLUSIONThe findings of current study indicated atypical EPEC to be dominant subtype and should be considered in diagnosis of diarrhea among children. PCR method can be a reliable, fast and sensitive alternative applied to identify the EPEC strains, and it is recommended that these strains are detected by this molecular method.