Identification of Mycobacterium tuberculosis complex by polymerase chain reaction of Exact Tandem Repeat-D fragment from mycobacterial cultures

Abstract

This study evaluated an in-house polymerase chain reaction (PCR) for rapid identification of the Mycobacterium tuberculosis complex (MTBC) using the MTBC-specific Exact Tandem Repeat D (ETR-D) as the amplification target. In a prospective study, 801 clinical isolates identified as MTBC and 15 nontuberculous mycobacteria were analyzed. Mycobacterial DNA was extracted from automated broth cultures or from egg-based media. The amplification of the ETR-D showed to a sensitivity of 99.6% and a specificity of 100% for the correct identification of MTBC; improved extractions protocols led to 100% sensitivity. The main utility of this technique is the simplicity, rapidity, low cost and accuracy.