Nontuberculous Mycobacteria diagnosis using conventional methods compared with INNOLiPA MYCOBACTERIA DNA probe assay

Sumi M. G.; Biljo V Joseph; Sathish Mundayoor

Volume : V, Issue : II, February - 2015

Nontuberculous Mycobacteria diagnosis using conventional methods compared with INNOLiPA MYCOBACTERIA DNA probe assay

Sumi M. G. , Biljo V Joseph, Sathish Mundayoor

Abstract :

The utility of biochemical tests for the diagnosis of nontuberculous mycobacteria (NTM) was evaluated and the results were compared with the newer molecular diagnostic method using INNOLiPA MYCOBACTERIA v2 Amp Kit. A battery of biochemical tests was conducted for the identification and classification of the isolates to species level which included Niacin test, Nitrate Reduction test, Catalase activity (at 37°C and 68°C), Hydrolysis of Tween–80, Tellurite reduction test, test for production of Arylsulphatase, Pyrazinamidase and Urease activity. INNOLiPA MYCOBACTERIA v2 Amp Kit, a DNA probe based kit designed for the detection and identification of genus mycobacterium and 16 different mycobacterial species was used for the molecular diagnosis. On compå the results of the ten samples studied, 8 results matched perfectly and the organisms were identified as M. scrofulaceum, M. fortuitum, M. gordonae, 2 strains as M. avium, 3 strains as M. chelonei. INNOLiPA MYCOBACTERIA v2 Amp Kit it is very costly. It cannot be used for routine identification as it a tedious process which requires expertise, time and also sophisticated equipments. So this method is not feasible in an ordinary lab and is not affordable for an ordinary patient. It was noted that activity of catalase at 68°C was one biochemical test that could be used to differentiate NTMs from M. tuberculosis and could be used as a presumptive diagnosis of NTM.