Use of the polymerase chain reaction for diagnosing bovine tuberculosis in Panama.

In addition to causing large losses to the cattle industry, Mycobacterium bovis, the causative agent for bovine tuberculosis, is a serious public health issue because it can potentially infect humans. Diagnosis based on isolation and identification of the bacillus is tedious and may take weeks. The diagnosis of M. bovis by polymerase chain reaction (PCR), using species-specific primers, is fast, highly sensitive and of great value in epidemiological studies. In this study, deoxyribonucleic acid (DNA) was extracted from 60 nasal mucus samples collected from three different farms, all located in an area where M. bovis is endemic. Two farms tested negative for an antibody response to the M. tuberculosis purified protein derivative (PPD) antigen, whereas the other farm gave a positive result. The amplified fragment of DNA was 460 base pairs with a sequence similar to that previously reported. Only 5% of the samples from the third farm tested positive for the presence of antibodies against PPD, whereas 65% of samples (from all three farms) gave a positive result when PCR was used. Thus, the authors suggest the use of the PCR species-specific primers test to support the programme against bovine tuberculosis in Panama.