Background and Aim: Nowadays, the importance of pathogenicity of non-tuberculosis mycobacteria is well known. Generally, this group, in addition to the respiratory system can cause lymph nodes, skin, soft tissue and bone disorders. Identification of Mycobacterium by culture and biochemical tests may take several weeks and may not be useful for definitive diagnosis. PCR-RFLP (PRA) technique of the hsp65 gene using HaeIII and BstEII enzymes is a precise method for species differentiation, in comparison to phenotypic methods. It is a quick and inexpensive method for detection of mycobacterial species. This study aimed to assess the prevalence of non-tuberculous mycobacteria isolated from the patients referring to tuberculosis center (TB) of Kashan University of Medical Sciences.

Material and Method: The study included 106 patients who had been referring to TB Center of Kashan University of Medical Sciences, from 1391 to 1394. The samples were tested by biochemical diagnostic tests. At the same time identification of the strains was made by use of PRA. Amplification of 441-bp fragment was performed by PRA for detection of hsp65 gene. The PCR products were digested with HaeIII and BsteII enzymes and analysis was performed on the basis of electrophoresis.

Results: Molecular analysis showed non-tuberculosis mycobacteria in 4(8.3%) sputum samples,i.e. one positive sample (o.9 %)  for every one of the following strains: M. abscessus, M. senegalense, M. fortuitum and M.kansasii.  

Conclusion: The results of this study showed that some cases of tuberculosis in Kashan are due to non-tuberculosis mycobacteria. Also use of PRA analysis of hsp65 gene for clinical specimens is a rapid and useful tool for identification of species of mycobacterium which is helpful for early diagnosis, treatment and control of tuberculosis.  

Keywords: Mycobacterium tuberculosis complex, Non-tuberculosis mycobacteria, PCR-RFLP ، hsp65.

Received: Jul 31, 2016      Accepted: Sep 5, 2016