Evaluation of a PCR based method for identification of mycobacterial isolates.

In recent years an increasing number of mycobacterial species have been described as causing disease in humans. Identification of isolates to the species level is essential for evaluation of the significance of an isolate. Conventional methods for identification based on selective inhibitors of growth and biochemical reactions are slow. We have evaluated a novel method, PCR restriction enzyme pattern analysis (PRA), for identification of mycobacterial isolates. Fifty three cultures including a mixed culture of M. tuberculosis and M. avium and four mycobacterial cultures contaminated with rapidly growing organisms of other genera were studied. The method permits identification of most isolates within 1 to 2 days, including some contaminated cultures, and results were generally in accordance with those obtained by conventional methods.