Polymerase chain reaction for the differentiation of Mycobacterium intracellulare and Mycobacterium avium

Polymerase chain reaction (PCR) amplification was performed using DNA purified from 15 mycobacterial type strains and from 21 specimens isolated from patients suspected to have non-tuberculous mycobacterial diseases. Using a primer set of MTB1-MTB2, 11 specimens out of 21 were Mycobacterium avium and 8 were M. intracellulare, which were verified by the Gen Probe Rapid Diagnostic System for the M. avium complex (MAC). One of the remaining 2 specimens which did not hybridize with the probe for the MAC was identified as M. kansasii and the other was not specifically identified by the conventional culture method. PCR amplification, using a primer set of TB1-TB3, was also performed for the specific identification of M. tuberculosis complex.