title: Evaluation of rapid techniques for the detection of mycobacteria in sputum with scanty bacilli or clinically evident, smear negative cases of pulmonary and extra-pulmonary tuberculosis.
abstract: The objective of the current study was to compare two rapid methods, the BBL Mycobacteria Growth Indicator Tube (MGIT TM) and Biotec FASTPlaque TB TM (FPTB) assays, with the conventional Löwenstein-Jensen (LJ) media assay to diagnose mycobacterial infections from paucibacillary clinical specimens. For evaluation of the clinical utility of the BBL MGIT TM and FPTB assays, respiratory tract specimens (n = 208), with scanty bacilli or clinically evident, smear negative cases and non-respiratory tract specimens (n = 119) were analyzed and the performance of each assay was compared with LJ media. MGIT and FPTB demonstrated a greater sensitivity (95.92% and 87.68%), specificity (94.59% and 98.78%), positive predictive value (94.91% and 99.16%) and negative predictive value (96.56% and 90.92%), respectively, compared to LJ culture for both respiratory tract and non-respiratory tract specimens. However, the FPTB assay was unable to detect nontuberculous mycobacteria and few Mycobacterium tuberculosis complex cases from paucibacillary clinical specimens. It is likely that the analytical sensitivity of FPTB is moderately low and may not be useful for the direct detection of tuberculosis in paucibacillary specimens. The current study concluded that MGIT was a dependable, highly efficient system for recovery of M. tuberculosis complexes and nontuberculous mycobacteria from both respiratory and non-respiratory tract specimens in combination with LJ media.
authors: Department of Microbiology, M.M. Institute of Medical Sciences and Research, Mullana, Ambala, India. shinup1983@gmail.com
authors: Pottathil
authors: P
authors: Shinu
authors: Anroop
authors: A
authors: Nair
authors: Varsha
authors: V
authors: Singh
authors: Surinder
authors: S
authors: Kumar
authors: Rajesh
authors: R
authors: Bareja
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D006801:Humans; D009161:Mycobacterium / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000382:microbiology
chemical_list: D011933:Reagent Kits, Diagnostic