Detection and identification of multiple mycobacterial pathogens by DNA amplification in a single tube.

A comparison of the DNA sequence of the 16S rRNA revealed a region in which there was a minor variation between the species of mycobacteria. This information was used to develop a multiplex amplification system that could identify the genus Mycobacterium and then distinguish between M. avium and M. intracellulare, two commonly encountered mycobacteria other than tuberculosis. The combination of these rRNA gene primers together with primers aimed at the MPB70 gene of M. tuberculosis complex organisms permits the detection and identification of clinically significant mycobacteria in a single tube. An amplification product of 1030 bp is indicative of the genus Mycobacterium and smaller fragments of 850, 372, and 180 bp are the positive signals for M. intracellulare, M. tuberculosis complex, and M. avium, respectively.