High discrimination of Mycobacterium bovis isolates in Brazilian herds by spoligotyping.

ABSTRACT

Bovine tuberculosis is an infectious disease caused by Mycobacterium bovis (M. bovis), that leads to economic losses in infected herds and it is also considered an important zoonosis. The molecular typing methods of M. bovis isolates are fundamental for the bovine tuberculosis surveillance system, and spoligotyping is the standard genotyping technique for this species. Thus, the aim of the present study is to analyze the spatial and cluster distribution of M. bovis strains from several regions of Brazil through molecular typing. Spoligotyping technique was applied on 422 isolates identified as M. bovis, and Ripley's K function was used to perform the spatial and cluster analysis of each identified profile. Forty-three (43) different profiles were identified and spoligotype SB0121 was the most frequent and showed a uniform pattern in the spatial distribution while spoligotypes SB0295, SB1380 and SB1050 formed clusters. In addition, three novel spoligotype profiles (SB2361, SB2362, SB2364) were identified in different herds. In this perspective, it is believed that molecular identification and typing can significantly improve the performance of surveillance systems for bovine tuberculosis in Brazil.