DIFFERENTIATION BETWEEN MYCOBACTERIUM-TUBERCULOSIS AND MYCOBACTERIUM-BOVIS BY A MULTIPLEX-POLYMERASE CHAIN-REACTION

A multiplex-polymerase chain reaction (PCR) assay, based on one-step a mplification and detection of three different mycobacterial genomic fr agments, was designed for differentiation between Mycobacterium bovis and Mycobacterium tuberculosis. The oligonucleotide primers were chose n from the groEL gene, present in the genus Mycobacterium sp., from th e IS6110 insertion sequence, present in Myco. tuberculosis complex and from the mtp40 gene, identified as a specific-species Myco. tuberculo sis genomic fragment. This amplification method allowed the detection of two fragments of 576 and 317 base pairs in Myco. bovis and three fr agments of 576, 396 and 317 base pairs in Myco. tuberculosis strains, including atypical strains of Myco. tuberculosis where the copy number of the IS6110 element is low. The multiplex-PCR assay described may b e a very useful tool for the rapid and specific differentiation of the se related mycobacteria and easy to use in medical and veterinary micr obiology laboratories.