Effectiveness of once-weekly rifapentine and moxifloxacin regimens againstMycobacterium tuberculosis in mice

Mice infected with 1.6 x 10(7) CFU of Mycobacterium tuberculosis were treat ed 14 days later for 6 months with a regimen of once-weekly 10 mg of rifape ntine and 75 mg of isoniazid per kg of body weight supplemented with either 150 mg of streptomycin per kg or 100 mg of moxifloxacin per kg during eith er both the 2-week daily initial and once-weekly continuation phases or onl y in the daily 2-week initial phase. On completion of treatment, all lung c ultures were negative, except for three mice, each with a single colony: tw o whose rifapentine-isoniazid regimen was supplemented with streptomycin du ring the whole course of therapy and one whose rifapentine-isoniazid regime n had no initial daily phase, but was supplemented with streptomycin and mo xifloxacin during the whole course of therapy. After 3 months of follow-up, positive lung cultures were obtained from 61 and 56% of mice supplemented with streptomycin during either the full course of therapy or only the dail y 2-week initial phase, respectively, and 15 and 50% of mice supplemented w ith moxifloxacin during either the full course of therapy or only the daily 2-week initial phase, respectively. These results suggest that moxifloxaci n has sterilizing activity against M. tuberculosis.