A technique for the purification of Mycobacterium paratuberculosis from the ileal mucosa of infected cattle.

Mycobacterium paratuberculosis, the causative agent of paratuberculosis, produces considerable economic loss in the cattle industry in many countries. The slow growth of M. paratuberculosis has hindered investigations of the antigenic composition of the organism and the development of species-specific antigen for serological detection of this disease. This paper describes a simple method for the isolation of large quantities of viable M. paratuberculosis from the intestinal mucosa of infected cattle by a combination of trypsin digestion, deoxyribonuclease/lysozyme treatment and differential centrifugation. Purity was about 99% and yield between 10(5)-10(9) bacteria/g tissue.