SENSITIVITY AND SPECIFICITY OF CONVENTIONAL CULTURE, LIGHT MICROSCOPY, SEROLOGICAL AND MOLECULAR METHODS FOR IDENTIFYING Mycobacterium tuberculosis COMPLEX

Abstract

In this study, some different tools, i.e., conventional culture, light microscopy, serological and molecular methods were evaluated for their sensitivities to detect the Mycobacterium tuberculosis complex in forty specimens from animal and human sources. To achieve such goal 20 samples from each of raw milk, animal tissues, and human CSF were collected. Enzyme-linked immunosorbent assay (ELISA) was compared to conventional culture, light microscopy for its sensitivity and specificity to detect the presence of TB pathogen in these samples. Results showed that sensitivity and specificity of 10% &100% for IS6110-targed PCR, 30 and 90% for ELISA, 16.25% and 100% for conventional culturing and 17.5% and 87.0% for light microscopy were recorded. In other mean, the IS6110-targed PCR was relatively more useful in TB diagnosis followed by ELISA. Furthermore, the DNA fingerprinting of three standards TB strains using random amplified polymorphic of DNA-PCR (RAPD-PCR) was carried out in the hope of generating some DNA molecular marker for TB identification. RAPD-PCR finding showed some molecular DNA markers that could be very useful in the identification of tuberculosis strains.