PCR amplification for the diagnosis of Mycobacterium tuberculosis in clinical practice

Abstract

Recently Polymerase Chain Reaction (PCR) technique has gained wide acceptance for the rapid-diagnosis of Myocobacterium tuberculosis. In this study, we tested 137 clinical specimens (sputum, gastric aspirate, pleural fluid and paracentesis fluid) from 46 patients suspected of having tuberculosis in pretreatment period. Each sample was processed by direct microscopy, culture and PCR methods. For PCR, the method of heating in a boiling water was used to break down the bacterial cell wall and to release the DNA. Primers specific for the 35 kD protein Antigen b (Pab) of Mycobacterium tuberculosis for PCR procedure were used. The sensibility, specificity, positive predictive value and negative predictive value of our PCR results were 78.5%, 84.3%, 68.7% and 90% respectively. The method was proved to be a useful technique for the diagnosis of Mycobacterium tuberculosis in clinical practice.