| Área: Microbiologia Clinica ( Divisão A ) PREVALENCE OF DIARRHEAGENIC ESCHERICHIA COLI IN CHILDREN FROM NORTHEASTERN BRAZIL Ila Fernanda Nunes Lima (UFC); Josiane da Silva Quetz (UFC); Alexandre Havt (UFC); Lourrany Borges Costa (UFC); Jones Barbosa Lima Neto (UFC); Rosa Maria Salani Mota (UFC); James Nataro (UMMC); Aldo Ângelo Moreira Lima (UFC)
ResumoINTRODUCTION: Among bacteria, diarrheagenic Escherichia coli (DEC) are some of the most frequently detected intestinal pathogens. We aimed to determine the prevalence of four DEC types in children with and without diarrhea in Fortaleza, Ceara, Brazil.
MATERIAL AND METHODS: A total of 325 fecal samples from children (83 with and 242 without diarrhea) aged 2-36 months from poor-resource urban area in Fortaleza were collected. Of those 242 control samples, 166 were randomly selected and analyzed together with the 83 case samples (n=249). Fecal DNA was obtained by QIAamp DNA Stool Mini Kit (Qiagen, Valencia, CA, USA). Molecular identification of DEC was based on the presence of different chromossomal and/or plasmid-encoded virulence genes of enteroaggregative E. coli (EAEC, aaiC and aatA genes), enteropathogenic E. coli (EPEC, eae and bfpA genes), shiga-toxin producing E. coli (STEC, Stx1 and Stx2 genes), and enteroinvasive E. coli (EIEC, ipaH gene). Samples were considered positive for DEC when they were positive for at least one of the researched diagnostic gene.
RESULTS: At least one DEC was detected in 98.8% (82/83) stool samples of the diarrhea group and in 96.4% (160/166) in the control group. EPEC was the pathotype more frequent in the population under study (79.1%, 197/249), followed by STEC (77.5%, 193/249), EAEC (37.3%, 93/249), and EIEC (26,9%, 67/249). EPEC was found significantly more often in children with diarrhea (89.2%, 74/83) than in children without the disease (74.1%, 123/166) (p=0.008). EAEC and EIEC were detected with slightly higher frequencies in children with diarrhea, 41.0% (34/83) and 30.1% (25/83), respectively, when compared to children without diarrhea, 35.5% (59/166) and 25.3% (42/166), respectively, but with no significant difference. The prevalence of STEC was also similar among control children (78.3%, 130/166) and cases (75.9%, 63/83). None of the genes used for DEC diagnosis was exclusively found in children with diarrhea.
CONCLUSION: EPEC continues to be an important agent associated with diarrhea in poor-resource children from FortaIeza. High rates of children with and without diarrhea presented at least one DEC pathotype, indicating a wide spread of these pathotypes in the study population and a high carriage percentage after primary infection.
FINANCIAL SUPPORT: FIC/NIH (USA) and CNPq (Brazil)
Palavras-chave: CHILDHOOD DIARRHEA, Escherichia coli, PCR DETECTION |