Detection of Mycobacterium bovis in artisanal cheese in the state of Pernambuco, Brazil.

OBJECTIVE/BACKGROUND: The present study was aimed at detecting Mycobacterium bovis in artisanal cheese using real-time quantitative polymerase chain reaction.

METHODS: One hundred seven cheese samples (250g) were purchased in 107 commercial establishments including neighborhood grocery stores, bakeries, and open-air markets from 19 municipalities of the state of Pernambuco, Brazil. Ten grams of each cheese sample were macerated with sterile saline solution in a sterile bag and DNA was extracted from 20mg of the macerated material using the Wizard SV Genomic DNA Purification System. The quantitative polymerase chain reaction amplified a fragment corresponding to the region of difference 4 of M. bovis.

RESULTS: Of the 107 samples analyzed, three (2.8%) were positive for M. bovis and their identities were confirmed by sequencing. This is perhaps the first report of the presence of M. bovis in artisanal cheese in the state of Pernambuco, Brazil.

CONCLUSION: The results of the present study highlight the need for improving sanitary measures during the production of artisanal cheese to prevent zoonotic tuberculosis in humans, resulting from the consumption of food contaminated with M. bovis.