title: Frequency and characteristics of diarrhoeagenic Escherichia coli strains isolated from children with and without diarrhoea in Rio de Janeiro, Brazil.
abstract: The frequency of diarrhoeagenic Escherichia coli (DEC) strains was investigated in 253 children up to 3 years old, with (patient group, PG, 199 children) and without (control group, CG, 54 children) diarrhoea, living in Rio de Janeiro, Brazil. DEC strains were detected in 70 (27.6%) children, including 54 (27.1%) with diarrhoea and 16 (29.6%) without diarrhoea. Enteroaggregative E. coli (EAEC) was the most frequent DEC category, accounting for 14.6% of the isolates in the PG and for 11.1% in the CG. E. coli strains carrying enteropathogenic E. coli (EPEC) virulence markers showed higher incidence in the CG (12.9%) than in the PG (8.0%). E. coli strains belonging to non-classical EPEC groups that carried eae only or eae and bfpA, designated as attaching-effacing E. coli (AEEC) were the most frequent (79.1%). Simultaneous presence of multiple EPEC virulence factors (EAF/eae/bfpA) were only detected among strains isolated from the PG. Enterotoxigenic E. coli (ETEC) strains were isolated from 5.5% of the children in the CG and from 3.5% of those in the PG. Most of the ETEC isolates were LT-probe positive (70%) and none carried both LT-I and ST-I probe sequences. One enteroinvasive E. coli (EIEC) strain was recovered from a child with diarrhoea. No stx-probe positive E. coli strains were detected. Overall, DEC strains were not found to be significantly associated with diarrhoea (p>0.05). However, the higher incidence of EAEC, the most frequent DEC category, among children with diarrhoea, suggests a potential role of EAEC as an important enteric pathogen in the community investigated.
authors.affiliation: Fundação Oswaldo Cruz, Escola Nacional de Saúde Pública, Laboratório de Epidemiologia Molecular, Rua Leopoldo Bulhões, 1480-60 andar, Rio de Janeiro, RJ, Brazil. regua@ensp.fiocruz.br
authors.forename: A H
authors.initials: AH
authors.lastname: Regua-Mangia
authors.forename: T A T
authors.initials: TA
authors.lastname: Gomes
authors.forename: M A M
authors.initials: MA
authors.lastname: Vieira
authors.forename: J R C
authors.initials: JR
authors.lastname: Andrade
authors.forename: K
authors.initials: K
authors.lastname: Irino
authors.forename: L M
authors.initials: LM
authors.lastname: Teixeira
mesh_terms: D000372:Agglutination Tests; D001427:Bacterial Toxins / Q000235:genetics / Q000302:isolation & purification; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D004768:Enterotoxins / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009693:Nucleic Acid Hybridization; D014774:Virulence
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins