Isolation and identification of non-tuberculosis mycobacterium (atypic) from water in Isfahan

Study of nontuberculous Mycobacteria is pivotal due to their undisputable impact on human health and environment. Among ecosystem factors Surface water plays an important role in the circulation of mycobacteria throughout the environment and transmission of some pathogens to a human. In addition, there are increasing evidence showing the correlation of mycobacteria isolated from water resources and nosocomial infections. Therefore, the main aim of the current study was to isolate and identify the nontuberculous mycobacteria from surface water resources. A total of 70 water samples were collected from the surface water resources in Isfahan, transferred to the research laboratory and subjected to filtration and decontamination. They were then subcultured onto Lowenstein Jensen medium and incubated at various temperatures and inspected weekly for the appearance of Mycobacterium-like colonies. A battery of biochemical and molecular tests including hsp65 based PCR were then applied to identify the isolates up to genus level. Out of 70 water samples a total of 24 (36%) mycobacteria were isolated. Among these, 5 stains isolated from water resources in local parks, 6 from urban water resources, 1 and 2 from the countryside springs and wells respectively, 1 from household tap water, 3 from agriculture and farms, 3 from rivers and 1 from water resources in hospitals. The results of the current study showed that a noticeable rate of water resources are contaminated with mycobacteria which could be considered as a potential hazardous source of infection for the people exposed to them, in particular those with immunocompromised immune systems such as the aged, the children and the patients with immunodeficiency conditions.