Study of the growth activity of Mycobacterium avium subspecies paratuberculosis cultures isolated from cows with latent and clinical forms of paratuberculosis

Abstract

Article presents results of bacteriological study of intestine samples collected from cattle which have clinical and subclinical form of Johne’s disease. Mycobacterium avium subspecies paratuberculosis (MAP) cultures were isolated from collected biomaterial samples. It was established that clinical signs and anatomopathological lesions were characteristic for Johne’s disease. Positive bacterioscopic examination of smears from internal organs shows high contagious activity of MAP cultures in vivo and in vitro. MAP isolates have ability to high speed replication of bacterial cells and intensive growth on nutrient media. In case of latent MAP infection bacterial cells have low level of microbiological activity and slow adaptation ability to growth on selective nutrient media. Cell wall deficient forms cause low microbiological activity of MAP to replication and adaptation to the nutrient medium in the latent form of paratuberculosis disease. It is necessary to conduct multiple reinoculations of MAR cultures on selective nutrient media for reversion and recovery of their activity.