The proportion of nontuberculous mycobacteria infection is increasing, but identifying mycobacteria species by conventional methods requires at least 2 or 4 weeks because of their slow groupwth rate. Two-step assay combining polymerase chain
reaction
(PCR) and restriction enzyme analysis was developed to differentiate the mycobacteria species. These species were M. avium, M. bovis, M. fortuitum, M. gordonae., M. intracellulare, M. kansasii, M. phlei, M. scrofulaceum, M. segmatic, M. terrae,
M.
tuberculosis, and M. vaccae. With PCR, 439-bp portion of the gene coding for the 65 kDa protein was amplified. 65 kDa protein contains epitope unique as wlll as common to various species of mycobacteria. The PCR product was digested with 4
restriction
enzymes : Sma I, Alu I, Msp I, and Hae III. The restriction enzyme analysis patterns of standard mycobacteria were analyzed. The method was applied to 31 clinical isolates.
@ES The results and conclusions were as follows:
@EN 1. Diagnostic algorithm could be made with Msp I and Hae III restriction analysis patterns that had a higher discrimination capacity.
2. All of 31 clinical isolates could be identified to the species within 2 days except 4 cases of complex form mycobacteria.
This method is so simple and rapid that it can be used as a routine test in clinical laboratory. Early identification of mycobacteria can help physician to decide the therapeutic regimen and the prognosis of patient.
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