TABLE 2.
Viable M. tuberculosis in lungs and spleens of BALB/c mice 3 months after cessation of treatment with three-drug regimens via the HDA, LDA, and i.v. infection modelsa
| Infection route | Regimen | Lungs |
Spleens |
Relapse rate (%) | ||
|---|---|---|---|---|---|---|
| Log10 CFU ± SEM | n/N (%) | Log10 CFU ± SEM | n/N (%) | |||
| HDA | 2MRZ/2MR | 0.48 ± 0.27 | 3/19 (16) | 0.16 ± 0.16 | 1/19 (5) | 3/19 (16) |
| HDA | 2HRZ/3HR | 0.75 ± 0.27 | 6/20 (30) | 0.13 ± 0.13 | 1/20 (5) | 6/20 (30) |
| HDA | 2HRZ/4HR | 0.13 ± 0.13 | 1/22 (5) | 0.08 ± 0.08 | 1/22 (5) | 1/22 (5) |
| i.v. | 2MRZ/2MR | 1.27 ± 0.30 | 10/19 (53) | 1.00 ± 0.30 | 9/19 (47) | 12/19 (63) |
| i.v. | 2HRZ/3HR | 3.14 ± 0.13 | 20/20 (100) | 1.70 ± 0.31 | 13/20 (65) | 20/20 (100) |
| i.v. | 2HRZ/4HR | 1.62 ± 0.35 | 11/20 (55) | 0.64 ± 0.26 | 5/20 (25) | 11/20 (55) |
| LDA | 2MRZ/1MR | 0 ± 0 | 0/21 (0) | 0 ± 0 | 0/19 (0) | 0/21 (0) |
| LDA | 2MRZ/2MR | 0 ± 0 | 0/21 (0) | 0.15 ± 0.15 | 1/21 (5) | 1/21 (5) |
| LDA | 2HRZ/1HR | 0.53 ± 0.25 | 4/21 (19) | 0.22 ± 0.15 | 2/21 (10) | 5/21 (24) |
| LDA | 2HRZ/2HR | 0.36 ± 0.25 | 2/21 (10) | 0.10 ± 0.10 | 1/21 (5) | 2/21 (10) |
a
Bacterial numbers are presented as the log10 CFU with standard errors of the means. Drug treatments included 2 months of MXF, RIF, and PZA followed by 2 months of MXF and RIF (2MRZ/2MR), 2 months of INH, RIF, and PZA followed by 2 to 4 months of INH and RIF (2HRZ/2HR), etc. Relapse rates include all lung and spleens positive for bacilli. N, total number of mice/group; n, number of mice with detectable CFU.