Caracterização dos genes de virulência de infecção por Escherichia coli enterotoxigênica em crianças com e sem diarreia no semiárido brasileiro

• Ano de defesa: 2019
• Autor(a) principal: Melo, Natália Kelly Fernandes de Menezes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Escherichia coli Enterotoxigênica; Diarreia; Criança
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/53907

Introduction: Enterotoxigenic Escherichia coli (ETEC) infections are important causes of diarrhea in children in developing countries. Therefore, a greater understanding of its pathobiology, virulence factors and clinical impact is necessary. Objective: The present study aims to characterize genes related to the virulence of ETEC infection in children with and without diarrhea in the Brazilian semiarid. Material and Methods: A case-control study was conducted in six cities of the Brazilian semiarid region, which analyzed data / samples from 113 children aged 2 to 36 months infected with and without diarrhea. The diagnosis of ETEC was made by the Luminex technique (Bioplex 200), based on the estA (thermostable toxin-ST) and eltB (thermo labile toxin-LT) genes. The identified ETEC positive samples were analyzed by polymerase chain reactions (PCR) for seven virulence genes.Results: Among the study population, 56 children were collected from diarrheal stool samples (cases) and 57 children provided stool samples without diarrhea (controls), with a higher prevalence of eltB-producing ETEC than estA-producing ETEC (70.8% - 80 / 113 vs 10.6% - 12/113). The age group from 2 to 3 years old was associated with controls, absence of diarrhea, (P = 0.001), while non-exclusive breastfeeding was more prevalent among cases, children with diarrhea (P = 0.004). Children with ETEC-LT infections had lower WAZ values (weight-for-age z score) compared to children with ETEC-ST infections (P = 0.02) when analyzed in control children. Exclusive ETEC-ST samples did not show the virulence genes researched, characterizations occurred in exclusive ST / LT or LT samples. The most frequently detected virulence genes were eatA (31.8% - 36/113) and csuA (24.8% - 28/113), and the highest prevalence of co-infection was enteropathogenic E. coli (EPEC) and enteroaggregative. (EAEC).