Salmonella and E. coli O157:H7 Prevalence and Generic E. coli and Coliform Quantitative Baseline in Raw Pork and Beef in Retail Channels in Mexico

This project was designed to determine the prevalence of Salmonella and E. coli O157:H7 and to quantify generic E. coli and coliforms in fresh whole beef, whole pork, ground beef and ground pork from various retail channels (supermarkets, city markets, street vendors, and butcher shops) in three major cities in Mexico (Mexico City, Guadalajara and Monterrey). The overall prevalence of Salmonella was found to be 4.4, 7.8, 7.3, and 13.9% in whole beef, whole pork, ground beef, and ground pork, respectively. With regard to retail channels, supermarkets had the lowest Salmonella prevalence in the samples collected (1.3%), followed by butcher shops (8.4%), whereas street vendors and city markets had the highest (13.6 and 22.3%, respectively). Analysis by city indicated that Monterrey had the lowest prevalence, followed by Mexico City, while Guadalajara showed the highest prevalence. E. coli O157:H7 was not detected in any of the samples; however, coliforms ranged from 0.60 to 7.30 log CFU/g. This baseline for the prevalence of Salmonella and E. coli O157:H7 in various cities and retail venues will help in the establishment of controls during the processing of these types of products and serve as a starting point to create trend analyses, performance criteria, and microbial risk assessments in Mexico.