Isolation and identification of Mycobacterium bovis and Mycobacterium tuberculosis from animal tissues by conventional and molecular method

Tuberculosis is a worldwide contagious and chronic disease of human as well as domestic animals with zoonotic potential. The Mycobacterium bovis and Mycobacterium tuberculosis are the main cause of tuberculosis. It has worldwide distribution with significant effect on animals and has public health importance. Therefore the present study was conducted to determine the prevalence of Mycobacterium bovis and Mycobacterium tuberculosis among the ruminant of district Kohat, Khyber PakhtunKhwa and also to evaluate the sensitivity and specificity of Microscopy and PCR. A total 200 tissue samples of lungs, lymph nodes and liver from cattle, buffaloes, sheep and goats were collected from Abattoir Kohat. All the tissue were first examined by direct smear microscopy by Ziehl Neelsen staining and then subjected to the PCR for the detection of M. bovis and M. tuberculosis. The overall prevalence of tuberculosis was 6.5% by PCR. Prevalence of tuberculosis was recorded in 7.87% of lungs samples followed by 5.26% lymph node. Moreover the prevalence was found 5.2%, 4%, 10.6% and 6.5% in cattle, buffalos, Goats and sheep respectively. Furthermore the sensitivity and specificity of PCR and microscopy in term of detection of TB was determined that PCR was found less sensitive then microscopy because of other species which was not amplified due to non availability of specific primer and were found positive in microscopy.In conclusion PCR is more reliable diagnostic tool for diagnosis of bovine tuberculosis. It is recommended that PCR based diagnostic reference laboratory may be established at district level and Tuberculosis awareness campaign must be arranged.