Detection of diarrheagenic Escherichia coli from children with and without diarrhea in Salvador, Bahia, Brazil

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 102; no. 7
• Main Authors: Bueris, Vanessa, Sircili, Marcelo Palma, Taddei, Carla Romano, dos Santos, Maurilio Fernandes, Franzolin, Marcia Regina, Martinez, Marina Baquerizo, Ferrer, Suzana Ramos, Barreto, Mauricio Lima, Trabulsi, Luiz Rachid
• Format: Journal Article
• Published: Brazil Fundação Oswaldo Cruz, Fiocruz 05.03.2008
• Subjects: diarrheagenic Escherichia coli; Multiplex PCR; virulence
• ISSN: 1678-8060

We identified different diarrheagenic (DEC) Escherichia coli pathotypes isolated from 1,207 children with and without acute endemic diarrhea in Salvador, Bahia, Brazil collected as part of a case-control study. Since the identification of DEC cannot be based on only biochemical and culture criteria, we used a multiplex polymerase chain reaction developed by combining five specific primer pairs for Enteropathogenic Escherichia coli (EPEC), Shiga toxin-producing E. coli/ Enterohaemorrhagic E. coli (STEC/EHEC), Enterotoxigenic E. coli (ETEC) and Enteroaggregative E. coli (EAEC) to detect these pathotypes simultaneously in a single-step reaction. In order to distinguish typical and atypical EPEC strains, these were tested for the presence of EAF plasmid. The prevalence of diarrheagenic E. coli in this sample of a global case-control study was 25.4% (259 patients) and 18.7% (35 patients) in the diarrhea group (1,020 patients) and the control group (187 patients), respectively. The most frequently isolated pathotype was EAEC (10.7%), followed by atypical EPEC (9.4%), ETEC (3.7%), and STEC (0.6%). Typical EPEC was detected only in one sample. The prevalence of the pathotypes studied in children with diarrhea was not significantly different from that in children without diarrhea.