Schematic representation of our study of MAC-infected mice. The mice were infected intravenously with 1.0 × 107 to 3.0 × 107 CFU of MAC strain N016, N018, or N084 or one of two reference strains. After 21 days, treatment was initiated with CLR alone (200 mg/kg/day), FQ alone (MXF, 100 mg/kg/day; GAT, 100 mg/kg/day; or LVX, 200 mg/kg/day), or FQ-CLR combinations at the same doses described above. Control mice were treated with distilled water. All agents were administered daily by gavage for 28 days. Viable bacterial counts in organs and histopathological examination were carried out 2 days after completion of treatment.