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Pyrazinamide (PZA) is often used for treatment of tuberculosis (TB) and PZA in combination with isoniazid (INH) is rapidly bactericidal for replicating and non-replicating forms of Mycobacterium tuberculosis (MTB) strains. MTB produces a pyrazinamidase (PZase) enzyme and most PZA resistant strains lack this enzyme. The lack of PZase activity and it's correlation with PZA resistance has been associated with mutations in the pncA gene which encodes the PZase. The enzymatic pyrazinamidase assay by Wayne's method for determining PZase activity can be used as a screening method for PZA drug susceptibility testing (DST), since resistant strains are PZase negative. The gold standard for detection of PZA resistance is PCR mediated direct DNA sequencing using Sanger method. In this study, 343 strains of MTB were tested by both Wayne's method and Sanger method. The sensitivity and specificity of Wayne's was 28.37 % and 37.78 %, respectively, with PPV of 41.26 % and NPV of 25.50 %. Our findings suggest that Wayne's method can be used as a screening test for the detection of PZA resistance.

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