DNA amplification assay for rapid detection of bovine tubercle bacilli in semen

摘要

The efficacy of a DNA amplification technique by polymerase chain reaction (PCR) for the detection of tubercle bacilli was evaluated using fresh and frozen semen spiked with the pathogen. The test was based on insertion sequence IS 1081 and could detect as few as 10-100 bacterium cells per ml of spiked semen. The specificity of the test was 100%. The method was applied to semen samples from known and suspected tuberculous bulls. Each of 20 semen samples (fresh and frozen diluted) from 1 of 3 breeding bulls included in the study was positive while the remaining 40 samples from the other 2 bulls failed to generate any detectable signal. PCR products were confirmed with Southern blot hybridization to an alpha 32P labelled-PCR product of the target sequence from the IS 1081 element of the Mycobacterium tuberculosis complex.