Environmental mycobacteria: Clinical and environmental significance, 10 years’ experience in Iran

In developing countries where tuberculosis is still a health challenge, the prevalence of nontuberculous mycobacterial diseases is expected to rise as medical conditions that compromise the immune system become more widespread. In the current study, we aimed to determine the presence and diversity of nontuberculous Mycobacteria (NTM) potentially caused infections in Iranian patients from clinical and environmental sample.Material and methods: From a comprehensive study among ten years in 2004 - 2014, which was performed on clinical and environmental samples, more than 300 water samples were collected in Isfahan, transferred and subjected to decontamination. Then subcultured onto Lowenstein Jensen media and incubated at various temperatures for 60 day. After appearance of colony A set of phenotypic tests were then applied to identify the isolates based on Runyon classification. The chromosomal DNA was extracted with pitcher method and the amplification and direct sequence analysis of almost full length of 16S rDNA was carried out. The obtained sequences were aligned manually with all existing sequences of the mycobacteria retrieved.Results : 137 NTM isolates were identified using conventional and molecular methods,. Out of 137 NTM isolates, 67 isolates had associated with immunosuppressive patients, 40 and 30 isolates retained from water and soil sample respectively. We obtained the following results: M. fortuitum, M.kansasii, M.gordonae, M.porcinum, M.conceptionense, M.phlei, M.austroafricanum, M. avium,.elephantis, M.intracellulare, M.lentiflavum, M.monacense, M.parascrofulaceum, M. thermoresistibile, M.phocaiecum, M. setense, M.abcesuss, M. simiae, M, massiliense, M. frederiksbergense, M.canariesense and M. novocastrense and 3 potentially novel mycobacterial species Conclusion: The increasing rates of NTM infections have engendered substantial interest to identify the source of the NTM transmission as have the number of species identified in both clinical and system environments. The number of NTM infections has increased in immunocompetent individuals, but the exact cause is unknown. Our results show that there is a sizable diversity of NTM in polluted environment, and many of the species identified in this study are potentially pathogenic. With regard to the complexity of identification, it is recommended that laboratory diagnosis of NTM diseases be centralized by strengthening or setting up quality national and regional infrastructure.