Comparison of Efficacy of the Rapid Mycobacteria Growth Indicator Tube (MGIT) Culture Method (Manual System) and Conventional Culture Method in Mycobacterial Detection

Overview

Diagnosis of tuberculosis is based on clinical symptoms, lung X-ray, skin tuberculin test and primarily on the detection of the causative agent Mycobacterium tuberculosis by direct microscopy of biological specimens and culture on solid egg media and in liquid media (Ogawa, Löwenstein-Jensen, Šula). Slow growth of most mycobacterial species is a limiting factor in both the confirmation of etiology and subsequent drug susceptibility tests and species identification that are of crucial relevance to early institution of treatment, selection of treatment regimen and implementation of antiepidemic measures. One of the methods proposed for more rapid detection of mycobacteria and suitable for use in routine diagnostic laboratories is the BD BBL MGIT culture system (Becton Dickinson, 1 Becton Drive, Franklin Lakes, NJ 07417, USA) based on fluorescence detection of the initial phase of mycobacterial multiplication at which macrocolony growth is still not visible. The fluorescent compound Tris, 4,7-diphenyl-1,10-phenalthroline ruthenium chloride pentahydrate is embedded in silicone on the bottom of tubes with liquid culture medium in which growing, actively respiring mycobacteria consume the oxygen and allow the fluorescence to be detected and visualized using a UV transluminator.

Key words:
MGIT – Mycobacterium tubercilosis – NTM.