Phase IIB, 12-week, open-label, single-site, randomized clinical trial with three treatment groups. Patients with drug-sensitive TB will all receive once daily isoniazid and pyrazinamide for 8 weeks followed by 4 weeks of daily isoniazid. In addition, Arm 1 participants will receive PA-824 200 mg daily and rifampin 600 mg daily for 12 weeks. Arm 2 participants will receive PA-824 200 mg daily and rifabutin 300 mg daily for 12 weeks. Arm 3 participants (control group) will receive rifampin for 12 weeks and ethambutol for 8 weeks. Patients will be screened within 1 week of TB diagnosis, will receive 12 weeks of study treatment and will return for follow-up visits at 4, 12, and 36 weeks after study treatment completion. All patients will be referred to the local TB treatment program after completion of study treatment to finish their 24-week TB treatment course.