Resistance to pyrazinamide

Mutations in the kcUG gene result in the underproduction of mycobacterial catalase, an enzyme that bioactivates INH. facilitating its interaction with its target, keto-acyl carrier protein synthetase. The result is high-level resistance to isoniazid but without cross-resistance to pyrazinamide. Mutations in the inhA gene result in low-level resistance, with cross-resistance to pyrazinamide. The answer is (B). 

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