Submitted to: World Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/1999
Publication Date: N/A
Technical Abstract: Tuberculosis caused by Mycobacterium bovis was recently discovered in wild, white-tailed deer (WTD) in northeast Michigan (MI). Several wildlife surveys have been conducted since 1994 and M. bovis has been isolated from over 145 wild WTD, five coyotes, two raccoons, and one bear harvested from a six-county region. In 1997, M. bovis was isolated from several captive WTD in a herd located within one of the affected counties. In addition, M. bovis has been isolated from cattle originating from three herds in northeast MI and from a heifer from Wisconsin (WI). The DNA fingerprints of the M. bovis isolates were determined by restriction fragment length polymorphism (RFLP) analysis and spoligotyping. For RFLP analysis, DNA was extracted and digested with restriction endonucleases PvuII and AluI. The following DNA probes were used: 1) an IS6110 123-bp sequence; 2) an IS6110 445-bp sequence; 3) the direct repeat sequence; and 4) the polymorphic GC-rich repetitive sequence. RFLP types were designated for each isolate b combining results of the 4 different probes. Spoligotyping was done as previously described. About 95% of the wild deer isolates had a single copy of IS6110. RFLP patterns for 81% of the wild deer isolates were identical to the patterns for isolates from the captive deer, coyotes, raccoons, bear, MI cattle, and WI heifer. The only difference in the RFLP patterns for an additional 14% of wild deer isolates was the presence of an extra band when DNA was probed with the IS6110 445-bp sequence. The remaining deer isolates had other minor differences. Results of spoligotyping were identical for all isolates except one deer isolate, which varied by one sequence. We conclude that most animals with tuberculosis in northeast MI are infected with a common strain of M. bovis.