Detection of Non-Tuberculosis Mycobacteria Infection due to Mycobacterium leprae and Mycobacterium kansasii in Patients Suspected of Tuberculosis in Isfahan, Iran

Several reports have indicated that infection with Non-Tuberculosis Mycobacteria (NTM) is increasing worldwide. Therefore, monitoring species causing micobacterial infection in any region is of great importance. This study was going to detect, differentiate, and identify pathogenic mycobacteria in primary clinical samples. Eighty samples collected from tuberculosis suspected patients in Isfahan/Iran were included in this study. The clinical samples were processed for Acid Fast Bacilli (AFB), culture and PCR-PFLP procedures. A 342 bp fragment of rpoB gene was PCR amplified and the products were digested with HindII restriction enzyme to discriminate between tuberculosis and non-tuberculosis mycobacteria. The PCR products were then digested with HaeIII restriction enzyme to identify the species. Of 80 studied samples, 8 showed AFB on microscopy, 9 were cultured positive for mycobacteria, and 32 (40%) were shown positive by PCR. Moreover, 2 specimens were infected with mycobacterium other than tuberculosis. Further digestion with the enzyme HaeIII showed that one of these samples was Mycobacterium leprae and the other one was Mycobacterium kansasii. The results obtained by this study show that similar to many other regions, nontuberclusis mycobaceria infection is increasing in the studied region, although its prevalence in Isfahan is yet lower than the southern parts of Iran.