A case-control study on diarrheagenic E. coli infection in children

Abstract

Objective To understand the regional epidemiology and antibiotic resistance pattern of diarrheagenic E. coli infection in children, and to clarify the pathogenic association between diarrheagenic E. coli infection and childhood diarrhea. Methods Totally 680 diarrheal children in the outpatient setting and 680 non-diarrheal control children were enrolled prospectively. The stool samples were collected and the potential enteric pathogens were detected. Minimal inhibitory concentration (MIC) method was used to determine the antimicrobial susceptibility for diarrheagenic E. coli isolates. Results The isolation rates of diarrheagenic E. coli in diarrhea group and control group were 15.6% and 13.1%, respecitvely, and diarrheagenic E. coli was the most commonly detected enteric bacteria. Multivariate logistic regression analysis adjusted for age suggested no clinical association between diarrhea and infection with enteropathogenic E. coli (EPEC) (aOR=1.2, 95%CI: 0.8-1.8), enteroadhesive E. coli (EAEC) (aOR=1.1, 95%CI: 0.7-1.6) and enterotoxigenic E. coli (ETEC) (aOR=1.8, 95%CI: 0.5-6.2). Among 199 diarrheagenic E. coli strains, the rates of resistance to ampicillin, tetracycline, trimethoprim-sulfamethoxazole, azithromycin, and ceftriaxone were 63.8%, 55.8%, 48.2%, 34.2% and 26.6%, respectively, while the rates of resistance to ciprofloxacin, amoxicillin-clavulanate and cefoxitin were 4.5%, 1.5% and 0.5%, respectively. Conclusions Diarrheagenic E. coli is the most common enteric bacteria detected in the stool samples from children with and without diarrhea in this study. The pathogenic role of infections with EPEC, EAEC and ETEC in childhood diarrhea is not determined. EHEC and EIEC are rarely detected and further studies are needed to clarify the pathogenic association between infection with EHEC, EIEC and childhood diarrhea. Key words: Child; Diarrhea; Drug resistance, microbial; Diarrheagenic E. coli