DNA restriction endonuclease analysis of Mycobacterium bovis and other members of the tuberculosis complex

Abstract

DNA preparations from 24 New Zealand isolates, 2 reference strains of M. bovis, and 1 reference strain each of M. microti, M. africanum and M. tuberculosis were characterized by restriction endonuclease analysis. Twenty-five restriction enzymes were investigated. The clearest differences in M. bovis patterns were obtained with the enzymes BstEII and BclI. These produced 4 and 5 different patterns, respectively, for the 24 local isolates. When the results from both enzymes were considered, 7 different combinations were obtained. The patterns produced for the 2 reference strains of M. bovis could be distinguished from each other and also from the patterns produced for the local isolates. All patterns were reproducible and are now being used for typing M. bovis isolates. With either enzyme, the patterns produced for the M. tuberculosis, M. bovis and M. africanum strains had many features in common, but all the M. bovis patterns were clearly more similar to each other than to the M. tuberculosis patterns. The patterns produced for the M. microti strain were markedly different from those produced for the other species. Restriction endonuclease analysis is clearly a useful method for inter- and intraspecific classifications of the tuberculosis complex.