Caracterización molecular de cepas de escherichia coli aisladas de vegetales frescos expendidos en las ferias libres de la ciudad de Loja

Abstract

Abstract:Foodborne diseases are currently considered one of the most important public health problems worldwide, with vegetables being one of the vehicles of transmission of microorganisms such as Salmonella, Escherichia coli(EHEC O157:H7), Campylobacter,etc. Escherichia coliis a gram-negative bacillus found in the intestinal microbiota of humans and animals. Most are harmless or cause brief diarrhea, however, some strains such as E. coli O157:H7can producebloody diarrhea and hemolytic uremic syndrome. The present work was based on determining the phylogenetic group and shiga toxin in 64 strains of E. coliisolated from fresh vegetables sold in free fairs, using the multiplex PCR technique. Four phylogenetic groups were identified by evaluating the presence and absence of the genes chuaA, yjaA, tspE.4 C2, obtaining for A (1.56%), B1 (25%), B2 (67.19%) and D (6.25%); in relation to shiga toxin, four genes stx1, stx2, eae, exhAwere identified, 20.31% were positive for these genes being presumptive of serotype O157:H7, 79.69% of strains were E. coli not O157:H7, but also associated with intraintestinal and extraintestinal cases in humans.