Microbial quality and prevalence of foodborne pathogens of cheeses commercialized at different retail points in Mexico

Abstract Microbial quality and the prevalence of foodborne pathogens (E. coli 0157:H7, Salmonella spp., Listeria monocytogenes and Campylobacter jejuni) of cheeses sold at three retail points (supermarkets [SM], street markets [ST], and convenience grocery stores [CGS]) in Chihuahua, Mexico, were evaluated (n=90). The most commonly found cheeses in the retail points were Chihuahua (60%) and Ranchero (28.8%). According to Mexican standards, three SM, two CGS, and none of the ST cheeses complied with the regulations. Two cheeses (cheddar and Ranchero) from SM (2.22%) were positive for L. monocytogenes. Eight cheeses (8.88%) were positive for Salmonella spp. (5 from ST and 3 from CGS). E.coli 0157:H7 and Campylobacter jejuni were negative in all samples. In the Ranchero cheese, total coliforms (TC), faecal coliforms (FC), and yeast and moulds (Y&M) showed no significant differences (P > 0.05) among retail points. Nevertheless, in Chihuahua cheese, the numbers of total coliforms, faecal coliforms, and yeast and moulds were statistically different (P