Table 3.
Clofazimine MICs of 20 isolates tested on 7H11 agar with the 1% proportion method, showing number of isolates that have genetically wild-type Rv0678 and those with Rv0678 variants
| 0·12 μg/mL | 0·25 μg/mL | 0·5 μg/mL | 1·0 μg/mL | 2·0 μg/mL | 4·0 μg/mL | ||
|---|---|---|---|---|---|---|---|
| H37Rv | 1 | 2 | .. | .. | .. | .. | |
| Clinical isolates | |||||||
| Wild type | 2 | 4 | 1 | .. | .. | .. | |
| Val1Ala/Gly37fs/Arg89Trp | .. | .. | 1 | ... | .. | .. | |
| Val20Gly | .. | .. | .. | .. | .. | 1 | |
| Gln22Pro/Asp47fs | .. | .. | .. | .. | 2* | .. | |
| Cys46fs | .. | .. | .. | .. | 1 | .. | |
| Cys46fs/Asp47fs | .. | .. | .. | .. | 2 | .. | |
| Asp47fs | .. | .. | .. | .. | 2 | .. | |
| Asp47fs/Ile67fs/Leu136Arg | .. | .. | .. | .. | 1 | .. | |
| Glu49fs | .. | 1 | .. | .. | 1 | .. | |
| Ile67fs | .. | .. | .. | .. | 1 | 1 | |
| Phe93Ser | .. | .. | .. | 2 | .. | .. | |
| Arg109Leu/Arg156fs | .. | .. | .. | 1 | 1 | .. | |
| Ala118Thr | .. | .. | 1 | .. | .. | .. | |
| Glu147fs | .. | .. | 1 | .. | .. | .. | |
Mycobacterium tuberculosis strain H37Rv was included in each batch for quality control. WHO has not yet determined a critical concentration for clofazimine on 7H11 agar. MIC measurement failed for one (P0121, carrying the Phe93Leu RAV; appendix p 8, 19) of the 21 clinical isolates with Rv0678 variants we included in our analysis. MIC=minimum inhibitory concentration.
*
One isolate had an additional six Rv0678 mutations below 15% allele frequency.