Isolation and Identification of Nontuberculous Mycobacteria from Environmental Water Samples in the Northeast of Iran

Abstract

Introduction: The importance of nontuberculous mycobacteria (NTM), a group including over 150 species, has recently received increased attention as an environmental source of human infection. This study aimed to isolate and identify NTM species in the environment in the northeast of Iran. Materials and Methods: A total of 344 water samples were obtained from water resources and drinking water distribution networks in 73 cities in the Khorasan Razavi province and were examined using culture. Nontuberculous mycobacteria identification was also accomplished by polymerase chain reaction amplification of the hsp65 gene, sequencing and data analysis. Statistical analysis was performed by Pearson’s correlation coefficient test and two-sample T-test using SPSS 16.0. Statistical significance was determined at a significance level of 0.05. Results: Nontuberculous mycobacteria were identified in 10.46% of the water samples (36/344) by culture. The most frequent NTM species was Mycobacterium gordonae (13/36). Other Mycobacterium species detected included M. mucogenicum, M. senegalense, M. gadium, M. genavense, M. simiae, M. frederiksbergense, M. flouranthenivorans, M. neoaurum, and M. pallens. Statistically significant correlations were observed between the presence of NTM in water and nitrate level, turbidity, pH, and age of water resource (p0.05). Conclusion: It was concluded that NTM water contamination was not very high in this area, but further studies are needed to investigate the sources of contamination and origins of these species.

Keywords

• nontuberculous mycobacteria
• environment
• water resources
• iran