Resumen

GALLEGOS, Miguel et al. Characterization of Escherichia coli O157:H7 Isolates Obtained from Bovine and Porcine Carcasses.. Rev. Cient. (Maracaibo) [online]. 2009, vol.19, n.2, pp.139-146. ISSN 0798-2259.

Many Escherichia coli O157:H7 outbreaks have been associated to consumption of undercooked beef, but the presence has also been reported in the meat of other domestic animals. In Mexico, little information exists on the presence of this pathogen in bovine and pork carcasses. The objective of this study was to determine the presence and/or absence of E. coli serotype O157:H7 in bovine and pork carcasses and their characterization by means of PCR. Of 18 isolates, 12 were positive by PCR to rfbE and fliC genes, which determine O157:H7 serotype. Of these 12, one from bovine carcass and three of pork carcasses were positive by PCR to stx1, stx2 and eaeA genes, therefore, they were considered enterohemorrhagic strains. The differences found in the positive carcass number to any of the genes were not statistically significant. The results show that E. coli O157:H7 could be found in both carcasses types, representing a risk for the health, so strict hygienic and handling measures should be taken in order to avoid that carcasses which do not fulfill the food safety aspect might arrive to the final consumers.

Palabras clave : Bovine and pork carcasses; E. coli O157:H7; enterohemorrhagic; molecular characterization; PCR.