Mechanisms of pyrazinamide resistance in mycobacteria: importance of lack of uptake in addition to lack of pyrazinamidase activity

A study was conducted to analyze the uptake mechanism of the antituberculosis drug, pyrazinamide, in Mycobacterium tuberculosis. Results indicated that one of the mechanisms of resistance to pyrazinamide resides in the failure of strains to take up the drug. Findings also showed that susceptibility to the drug in mycobacteria requires the presence of a functional PZase and a PZA transport system.