Direct detection and identification of mycobacteria in bovine samples by PCR assay

Document Type : Original Article


1 Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 6511, Egypt.

2 Department of Tuberculosis, Bacterial Diagnostic Products Veterinary Serum and Vaccine Research Institute, Cairo, Egypt.

3 General Authorities for Veterinary Services.


Bovine tuberculosis, caused by Mycobacterium bovis, is a zoonotic disease causing
approximately 6% of total human deaths. Its economic losses are not only a
reduction of 10-20% in milk production and weight, but also infertility and
condemnation of meat. Many serological tests are applied for detection of
tuberculosis. ELISA test has the highest sensitivity and specificity than the other
serological tests for the diagnosis of tuberculosis. Several forms of new technology
were brought into the diagnostic approach to mycobacterial infection. The aim of
this work was to detect bovine tuberculosis by application of different traditional
tests and PCR. Tuberculin skin test was applied on 2650 cattle, only 63(2.4%) were
positive. Forty eight (76.2%) of the slaughtered positive animals showed visible
lesions (VL) while the other 15 (23.8%) had non-visible lesions (NVL).
Bacteriological examination of 10 selected tuberculin positive samples revealed M.
bovis from 6 processed samples (60%) while PCR and ELISA assays revealed
positive in 8 cases (80%) and 7 cases (70%), respectively. It was concluded that PCR
test is more sensitive and specific test to confirm the infection with tuberculosis.


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