Increasing Annual Prevalence of Non-tuberculosis Mycobacteria (NTM) in Clinical Isolates: a New Threat to Human Health

Background and Objectives:Non-tuberculosis mycobacteria (NTM) are one of the most important pathogenic mycobacteria that are also found in immunocompromised patients and healthy individuals. The present study is the most important report of the prevalence of non- tuberculosis mycobacteria (NTM) from clinical isolates.Materials and Methods: This descriptive study was performed on 17118 specimens isolated from pulmonary patients during the years 2011-2018 at the Mycobacteriology Research Center, Tehran, Iran. Samples were analyzed for non-tuberculosis mycobacteria (NTM) using hsp65 gene by PCR-RFLP. Results: From 17118 samples, 7984 (7984/17118;46.64%) were positive for mycobacterial infections. Of the 7984 (7984/17118;46.64%) positive samples, 677 (677/7984;8.47%) strains of non-tuberculosis Mycobacterium (NTM) were identified. The most common species identified in this study included Mycobacterium simiae (369/677;54.50%), Mycobacterium intracellular (69/677;10.19%), Mycobacterium abscessus (67/677;9.89%) and Mycobacterium chelonae (59/677;8.71%). Conclusion: In this study, we observed a high prevalence of Mycobacterium simiae (369/677;54.50%) and Mycobacterium intracellular (69/677;10.19%) among patients. According to the results of this study, the incidence and prevalence of non-tuberculosis mycobacteria (NTM) are on the rise. Since non-tuberculosis mycobacterial treatments differ from mycobacterial tuberculosis, timely detection of these species can be very effective in the treatment process by physicians.