Clinical and etiologic features of diarrheagenic Escherichia coli-associated diarrhea in children

Abstract

Objective To investigate the pathotypes, epidemiological characteristics and antimicrobial resistance of diarrheagenic Escherichia coli (DEC) in children with acute bacterial diarrhea in Shanghai. Methods A total of 2 071 outpatient children with probable acute bacterial diarrhea referred to the enteric clinic of Children′s Hospital of Fudan University during June 2012 to June 2014 were enrolled in our study. The stool samples were processed for routine microbiologic and biochemistry tests to identify enteric bacteria, including enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enteroinvasive Escherichia coli(EIEC) and enterohemorrhagic Escherichia coli (EHEC). Kirby-Bauer method was used to identify the antibiotic sensitivity. Difference of means between groups was compared by chi-square test. Results Of 2 071 enrolled children, DEC were identified in 145 (7.0%) cases. 148 strains were isolated with three of mix infection strains. All DEC isolates in this study included 106 (71.6%) EPEC, 24 (16.2%) ETEC, 16(10.8%) EIEC and 2(1.4%) EHEC. The median ages of diarrheal children with DEC infections were 14 months (range: 3 months to 13 years) and 62.8% of them were <2 years. Among 125 DEC isolates tested for antimicrobial susceptibility, the rates of resistance to ampicillin, trimethoprim-sulfamethoxazole, cefotaxime, cefepime, gentamicin, ceftazidime, amoxicillin-clavulanate, ciprofloxacin, and ofloxacin in a descending order were 55.2%, 35.2%, 28.0%, 27.2%, 23.2%, 8.8%, 5.6%, 4.0% and 4.0%, respectively. Resistance rates of EIEC to cefotaxime, cefepime and ceftazidime were 50.0%, 43.8% and 25.0%, respectively, which were higher than those of EPEC, ETEC and EHEC. Conclusion DEC is the important enteric bacteria that causes bacterial diarrhea in children in this study. Key words: Diarrhea; Diarrheagenic Escherichia coli; Epidemiology; Child; Drug resistance, microbial