TABLE 3.
CFU counts in mouse lungs after 2 weeks and 6 months of treatment and after 3 months of follow-up without treatmenta
| Treatment groupb | Log10 CFU at 2 wk | % of positive culture atc:
|
|
|---|---|---|---|
| 6 mo | 9 mo | ||
| B: 6 mo of P alone 1/7 | 7/10* | ||
| C: 2 mo of HRZ 5/7 + 4 mo of HR 5/7 | 5.60 ± 0.34 | 0/20 | 1/16 |
| D: 2 wk of SHRZ 5/7 + 5.5 mo of SHP 1/7 | 4.94 ± 0.32** | 2/16d | 11/18 |
| E: 2 wk of SHRZ 5/7 + 5.5 mo of HP 1/7 | 0/16 | 10/18 | |
| F: 2 wk of MHRZ 5/7 + 5.5 mo of MHP 1/7 | 5.30 ± 0.45 | 0/19 | 2/13 |
| G: 2 wk of MHRZ 5/7 + 5.5 mo of HP 1/7 | 0/18 | 7/14 | |
| H: 6 mo of SHPM 1/7 | 5.56 ± 0.25 | 1/19d | 7/12 |
Mice were infected intravenously with 1.6 × 107 CFU of M. tuberculosis H37Rv. The next day after infection, the mean CFU count (log10) in the lungs of 10 mice was 5.01 ± 0.17, and at 2 weeks after infection, or the day treatment began, the mean value for 29 mice was 6.46 ± 0.33. A culture was considered positive if any number of colonies was detected. *, five of 7 mice harbored rifampin-resistant mutants; **, significantly different (P < 0.01) from groups C, F, and H.
H, isoniazid; R, rifampin; Z, pyrazinamide; P, rifapentine; S, streptomycin; M, moxifloxacin; 1/7, once weekly; 5/7, five times weekly.
Positive cultures yielded highly variable numbers of colonies ranging from one colony to a few hundred colonies.
The positive cultures of lungs yielded a single colony of M. tuberculosis, and the organisms from each colony were drug susceptible