Detección y aislamiento de cepas presuntivas de E.coli productor de toxina shiga en vegetales (zanahoria, tomate y manzana) listos para el consumo

Abstract

Escherichia coli is a bacterium that lives in the gastrointestinal tract of animals and humans. Sometimes strains of this pathogen may be the cause of some intestinal diseases that can be transmitted by water, contaminated food and close contact with animals.The objective of this research work to detect the presence of Escherichia coli strains which allegedly generate Shiga toxin in vegetables that are ready to eat such as: apple, tomato baby and carrot baby; which are sold in supermarkets in the city of Loja. It was performed five samples of each product, that correspond to five different production lands, in each sampling it was taken by random three packages of each product to form the unit of the analyzed sample. The detection of E. coli O157:H7 was performed by enrichment broth EC (Escherichia coli) modified with novobiocin (ECM+n) and isolation on SMAC agar (MacConkey sorbitol). The results demonstrate that 80% of the samples contained characteristic colonies of E.coli O157:H7, Shiga toxin-producing; failing the normative requirement of this kind of products and becoming a risk to the consumer’s health