Detección y aislamiento de cepas presuntivas de E.coli O157:H7 en ensaladas de lechuga listas para el consumo

Abstract

Escherichia coli O157: H7 shiga toxin-producing (STEC) is considering an emerging foodborne pathogen, which has recently been linked to infectious outbreaks associated with intake of minimally processed vegetables. Given this background the present study aimed to determine the prevalence of presumptive strains of E. coli O157: H7 isolated lettuce salad ready for consumption. In total 15 samples of three types of lettuce salad ready to consume, which were enriched broth with novobiocin E. coli modified (0.02g / L) and then seeded in SMAC agar for isolation of presumptive colonies were analyzed crops They were purified to obtain colonies of E. coli O157 typical: H7 were then cryopreserved at -80 ° C. According to regulations el93.3 reference% (14) did not meet the allowable limits being presumptive serotype E. coli O157: H7, due to the presence of the pathogen in this type of food should be considered vegetables study as potential risk factors in the transmission of foodborne illness, until further validation by serological or molecular techniques.