Contamination with Enterococcus spp., strains of lettuces of different species acquired in Cumaná

Abstract

Lettuce is one of the most common crops in the world, with high index of vitamins, minerals and fiber. Raw food consumption is closely related to foodborne illness, of which Escherichia coli O157:H7, seems to be the prime perpetrator leading to undesirable consequences. However, E. coli is not the only microorganism that can be transmitted, as reports validating the involvement of Aeromonas, Yersinia, Listeria, Staphylococcus, Campylobacter, and Salmonella have surfaced. The objective of this work was to detect the contamination of lettuces of different species acquired in several places of Cumaná, with Enterococcus strains. Of 52 lettuces acquired in food retail centers, 38% were contaminated with Enterococcus spp., strains. The best-selling lettuce was Lactuca sativa L. (25/52), but the most contaminated was Lactuca sativa var. capitata (89%). The highest average for Enterococcus was obtained in lettuces from Municipal Market. The dominant species of Enterococcus were E. faecalis (40%), and E. casseliflavus (30%); and to a lesser extent E. faecium (15%), E. gallinarum (10%), and E. avium (5%). The susceptibility profile showed that there are strains resistant to glycopeptides, fluoroquinolones, ansamycins, macrolides, phenols and tetracyclines. The clonal dissemination of two strains of E. faecalis and one strain of E. faecium by antibiotyping was demonstrated in lettuces from the municipal market. These results demonstrate that the food chain is a route of dissemination of multidrug resistant Enterococcus to the human intestinal microbiota, turning the gastrointestinal tract into a reservoir of intractable bacteria with the available antibiotics.