Tuberculosis (TB) is a global public health concern and developing new treatment regimens is an important research priority. PA-824 is an experimental TB medication. This study will evaluate the safety and tolerability of PA-824 when combined with efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r), which are medications used to treat HIV infection, or rifampin (RIF), which is a medication used to treat TB. Study researchers will examine the safety and tolerability of these drug combinations and how the medications affect the levels of PA-824 in the blood.