Memorias do Instituto Oswaldo Cruz (Nov 2007)

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

  • Vanessa Bueris,
  • Marcelo Palma Sircili,
  • Carla Romano Taddei,
  • Maurilio Fernandes dos Santos,
  • Marcia Regina Franzolin,
  • Marina Baquerizo Martinez,
  • Suzana Ramos Ferrer,
  • Mauricio Lima Barreto,
  • Luiz Rachid Trabulsi

Journal volume & issue
Vol. 102, no. 7
pp. 839 – 844

Abstract

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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.

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