Mycobacterial 70 kD heat-shock protein is an effective subunit vaccine against bovine paratuberculosis.

Paratuberculosis is a chronic granulomatous inflammation of the small intestine of cattle and other ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). The disease can be found in ruminant herds worldwide, causing substantial economic losses at farm level due to premature culling and production losses. In previous studies, it has been shown that immune responses to recombinant MAP Hsp70 proteins were predominantly cell mediated. As protective immunity to the intracellular mycobacterial pathogens is thought to be cell-mediated in origin, we have studied the use of a recombinant MAP Hsp70 as a subunit vaccine in cattle experimentally infected with MAP. The results of the current study demonstrate that recombinant MAP Hsp70 can be successfully used as a subunit vaccine against bovine paratuberculosis, significantly reducing shedding of bacteria in feces during the first 2 years following experimental infection.