RESUMO
Diarrheagenics Escherichia coli are the major agents involved in diarrheal disease in developing countries. The aim of this study was to evaluate the time of appearance of the first asymptomatic infection by the different categories of diarrheagenic E. coli in 44 children since their birth and during the first 20 months of their lives. In all of the children studied, we detected at least one category of diarrheagenic E. coli through the 20 months of the study. 510 diarrheagenic E. coli (33.5%) were obtained from the 1,524 samples collected from the 44 children during the time of the study (31.4% EAggEC, 28.8% EPEC, 27.1% DAEC, and 12.7% ETEC). Neither EHEC nor EIEC were identified. The median age for diarrheagenic E. coli colonization was 7.5 months. The mean weaning period was 12.8 months and the mean age for introduction of mixed feeding (breast fed supplemented) was 3.8 months. A significantly lower incidence of diarrheal disease and asymptomatic infections was recorded among the exclusively breast-fed rather than in the supplemented and non breast-fed infants. For ETEC, EPEC and EAggEC the introduction of weaning foods and complete termination of breast-feeding were associated with an increase of asymptomatic infections.
Assuntos
Diarreia Infantil/microbiologia , Infecções por Escherichia coli/microbiologia , Argentina , Aleitamento Materno , Sondas de DNA , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Seguimentos , Humanos , Lactente , Recém-Nascido , Fatores de Risco , Fatores de TempoRESUMO
Forty-nine patients with a diagnosis of idiopathic haemolytic uraemic syndrome (HUS) were investigated to determine evidence of infection by verotoxin-producing Escherichia coli (VTEC). Free faecal cytotoxin active on Vero cells (VT) was detected in 15 out of 49 patients (31%). Seroconversion or high titres of VT-neutralizing antibodies were detected in 11 out of 18 patients (61%). The results of the present study suggest an association between HUS and infection by VTEC.