RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM ANALYSIS OF MYCOBACTERIUM-BOVIS ISOLATES FROM CAPTIVE AND FREE-RANGING ANIMALS

Mycobacterium bovis isolates from cattle, captive elk, and free-rangin g mule deer and coyotes were examined by restriction fragment length p olymorphism (RFLP) analysis. DNA extracted from each isolate was diges ted with restriction endonucleases AluI and PVuII. DNA probes used for Southern hybridizations were a 37-base oligonucleotide and a 123-base -pair sequence specific for the insertion sequence IS6110 and a plasmi d, pTBN12, which contains a polymorphic GC-rich repetitive sequence pr esent in several species of mycobacteria. Generally, M. bovis isolates originating from a single herd of either cattle or captive elk had id entical RFLP patterns, whereas isolates from unrelated sources had dis tinct patterns. The RFLP patterns for M. bovis isolates from free-rang ing mule deer and coyotes were identical to patterns observed for isol ates from a captive elk herd that was located in the area where the fr ee-ranging animals were found. These results indicate that the captive elk herd may have been the source of M. bovis that infected the free- ranging animals. Results of this study show that RFLP analysis is a us eful tool for differentiation of M. bovis isolates and for molecular e pidemiology studies to determine possible sources of infection in outb reaks of tuberculosis in animals.