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Mycobacterial infection is an important problem of zoonosis. O-
pportunistic infections with atypical mycobacteria in the
course of AIDS gained importance in the past decade. There
have been c- ontinuous occurrences of tuberculosis in bovine
and wild animals. We describe here a assay based on PCR
amplification with 2 gro- ups of primers followed by Southern
blot hybridization with AP- labelled DNA probe to detect and to
group mycobacterial infection in formalin-fixed and tissues of
zoo animal. A 383 bp fragment e- ncoding for the 65 kD Ag of M.
tuberculosis, M. bovis, M. avium, M. paratuberculosis and M.
fortuitum was dectected by PCR with 1- st group of primers. The
specificity of PCR products was confirm- ed by Southern blot
using a region-specific DNA probe. Using the 2nd group of
primers, we achieved specific amplification of a 419 bp
fragment of M. tuberculosis and M. bovis. The product was also
confirmed by Southern blot with DNA probe. Serial dilution
studi- es showed that our PCR method could detect DNA amplified
from 1 pg DNA and the nucleic acid probe we used could detect
DNA ampli- fied from 100 fg DNA. Fifty-three formalin-fixed
tissue blocks of suspecious mycobac- terial infection cases
were collected from Taipei City Zoo. The ratio of positive
reaction for acid-fast staining was 60.4％. Th- e positive
ratio of PCR-TB and Probe-TB were 69.8％ and 77.4％； the
positive ratios of PCR-MT and Probe-MT were 60.4％ and Within
the 32 cases showing positive result, there were 23 and 25
cases are belonged to the typical mycobacterial infection
detect- ed by PCR and confirmed by Southern blot with AP-
labelled nucleic acid probe. The result indicated that the
methods of PCR and Sou- thern blot hybridization described
above should be a important di agnostic method in detecting and
grouping mycobacterial infection in formalin-fixed tissues.
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