The Frequency of Diarrheagenic Escherichia coli Isolates in Children with Acute Diarrhea

Objective: This study aimed to detect the frequency of diarrheagenic Escherichia coli pathotypes [enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) Shiga toxin-producing E. coli (STEC), enterohemorrhagic E. coli (EHEC), enteroaggregative E. coli (EAEC) and diffuse adherence E. coli (DAEC)] in children with acute diarrhea under five years in Konya, Türkiye. Material and Methods: Three thousand and sixty-four stool samples taken from children with acute diarrhea under the age of five years sent to the Medical Microbiology Laboratory of the Medical Faculty Hospital, Selçuk University between 1 January and 31 December 2019 were scanned. E. coli isolates were included in the study that predominantly growing in the feces of 312 children. E. coli was defined by conventional methods and VITEK® 2, compact automated system. DNA isolation was performed with a commercial kit. The primers of eae, pEAF, daaC, aatA, elt, est, ipaH, stx1 and stx2 genes were studied by real-time multiplex polymerase chain reaction (PCR) method. Detection of eae plus pEAF genes was accepted typical EPEC (tEPEC), only eae atypical EPEC (aEPEC), stx1 and/or stx2 genes STEC, eae plus stx1 and/or stx2 genes EHEC, elt and/or est genes ETEC, ipaH gene EIEC, aatA gene EAEC and daaC gene DAEC. Results were confirmed by monoplex PCR and gel electrophoresis. Results: Of the 312 E. coli isolates, 56 had single pathotype, 254 had mixed pathotypes and two isolates could not be typed. Two hundred and eighty-one DAEC, 187 EPEC, 159 EAEC, 43 EIEC, 31 EHEC, four ETEC and two STEC were detected in 312 samples. The most frequently detected single pathotypes were DAEC (47) and EAEC (7), while mixed pathotypes were DAEC+EPEC+EAEC (108), DAEC+EPEC (58) and DAEC+EIEC (24) respectively. Conclusion: DAEC was single and also DAEC plus tEPEC/aEPEC plus EAEC were mixed predominant pathotypes in the diarrheagenic E. coli isolates in children with acute diarrhea under five years in Konya, Türkiye. This is the first study to investigate all diarrheagenic E. coli pathotypes in Türkiye. The most important limitation of our study is that single-centered. Multicentre studies are needed to determine which pathotypes are common in Türkiye.