Survey of ground beef for the detection of Mycobacterium avium paratuberculosis.

Mycobacterium avium paratuberculosis (MAP) is thought to be associated with Crohn's disease in humans. Since Johne's disease affects dairy and beef cattle, meat may be a possible route of transmission of MAP to humans. In this study, we compared a rapid multiplex real time PCR assay and conventional culture to detect MAP in ground beef. The real time PCR assay amplifies both an internal sequence of the IS900 gene and an internal control targeting the ruminant-specific mt-cyt-b gene, in order to control for any false negative results. The sensitivity of this multiplex real time PCR assay on ground beef is 10(1) CFU/g and the sensitivity of conventional culture at 10(3) CFU/g. Furthermore, we conducted a survey of 200 retail ground beef samples using this system and did not detect the presence of MAP.