Genetic diversity based on MIRU-VNTR profile of isolates of Mycobacterium bovis from Mexican cattle

Bovine tuberculosis (bTB) is a disease caused by Mycobacterium bovis (M. bovis), which affects cattle, animal species and humans. To determinate the genetic structure of strains of M. bovis in mexican cattle, 467 isolates obtained from 2009 to 2010 from different regions of Mexico with known spoligotype were included in the study. The isolates were genotyped by interspersed repeated mycobacterial units-variable number tandem repeats (MIRU-VNTR) obtaining 13 MIRU-VNTR groups. When combining MIRU-VNTR patterns with its spolygotypes, the Hunter genetic discrimination index (HGDI), we obtained 421 genetic patterns distributed in 17 groups. The HGDI for the total loci was 0.99. The locus that presented the higher HGDI was 2461 (0.857), while the locus with the lowest HGDI was 2686 (0.239). When we analyzed our results, using just 6 or 8 MIRU-VNTR we obtained an discriminatory power of 0.8499 and 0.8875 respectively indicating lower HGDI than 12 MIRU-VNTR locus.