Evaluation of colorimetric methods using nicotinamide for rapid detection of pyrazinamide resistance in Mycobacterium tuberculosis Institute of Tropical Medicine
The direct detection of pyrazinamide resistance in Mycobacterium tuberculosis is sufficiently difficult so that many laboratories don't attempt it. Most pyrazinamide resistance is caused by mutations that inactivate the pyrazinamidase enzyme needed to convert the prodrug pyrazinamide to its active form. We evaluated two newer and simpler methods to assess pyrazinamidase activity - the nitrate reductase and malachite green microtube assays - ...