Short communication: Characterization of microflora in Mexican Chihuahua cheese

This work was performed to identify the bacterial species present in 10 Chihuahua cheeses obtained from commercial producers in Mexico using 16S rRNA gene analysis. As expected, some of the agar media initially used for isolation were not very selective, supporting the growth of several unrelated bacterial species. Sequence analysis identified potential pathogens, including Escherichia coli and Staphylococcus aureus, in all raw milk samples and 2 pasteurized milk samples. Streptococcus thermophilus and Lactococcus lactis ssp. lactis were identified in 9 and 6 samples, respectively, and would serve as acidifying agents during cheese production. Lactobacilli were identified in all cheeses, with the most prevalent being Lactobacillus plantarum identified in 7 raw milk and 1 pasteurized milk cheeses. Leuconostoc mesenteroides and Streptococcus macedonicus were identified in 4 raw milk cheeses and both were present in all pasteurized milk samples, suggesting that they may play a role in the development of traditional Chihuahua cheese attributes.