Identification and Characterization of Non-Tuberculous Mycobacteria Isolated from Extrapulmonary Tuberculosis Suspects by Heat Shock Protein 65 by PCR-RFLP

Abstract

The genus Mycobacteria contains more than 170 officially recognized species. In the last decades, the reports of nontuberculous mycobacteria (NTM) associated with extrapulmonary diseases are increasing. The aim of this study is to know the prevalence of NTM among extrapulmonary tuberculosis cases in a tertiary care hospital in south India. This study was conducted from Mar 2017 to December 2017. Diagnosis was performed by Ziehl-Neelsen staining followed by culture in BacT/ALERT and Lowenstein Jensen culture medium. We applied conventional biochemical test like growth on the LJ medium containing PNBA (para nitro benzoic acid) to differentiate M.tuberculosis and NTM and PCR-restriction fragment length polymorphism analysis (PRA) of the hsp65 gene for species identification. We identified 96 non-tuberculous infection cases from 1138 (AFB)-Positive tuberculosis suspects. The diversity of NTM species were Mycobacterium abscessus 17(45.9%) followed by Mycobacterium fortuitum 10(27%), Mycobacterium chelonae 8(21.6%) and Mycobacterium simiae 2(5.4%). Regular documentation and reporting of these NTMs from clinical settings along with their sensitivity profile is essential to be aware of the clinical spectrum of disease associated and preferred treatment options.