TABLE 7.
Sensitivities and specificities of SNPs for predicting phenotypic resistance to kanamycin in M. tuberculosis isolates from India, Moldova, the Philippines, and South Africaa
| Observed mutation(s) by gene location | No. of KANr isolates with mutation (n = 276)b | No. of KANs isolates with mutation (n = 117) | Estimated sensitivity (% [95% CI]) | Estimated specificity (% [95% CI]) |
|---|---|---|---|---|
| rrs only | ||||
| 1401A→G | 188 | 0 | 68.1 (62.2–73.5) | 100 (96–100) |
| 1484G→T | 4 | 0 | 1.4 (0.5–3.9) | 100 (96–100) |
| 1401A→G/1462A→T/1486A→T | 1 | 0 | 0.4 (0–2.3) | 100 (96–100) |
| eis only | ||||
| −12C→T | 38 | 1 | 13.8 (10–18.5) | 99.1 (94.6–100) |
| −14C→T | 11 | 0 | 4 (2.1–7.2) | 100 (96–100) |
| −10G→A | 5 | 0 | 1.8 (0.7–4.4) | 100 (96–100) |
| rrs and eis | ||||
| 1401A→G/−12C→T | 2 | 0 | 0.7 (0.1–2.9) | 100 (96–100) |
| 1401A→G/−43A→T | 1 | 0 | 0.4 (0–2.3) | 100 (96–100) |
| Other rrs/eis mutations | 2 | 3 | 0.7 (0.1–2.9) | 97.4 (92.1–99.3) |
| No rrs or eis | 24 | 113 |
a
Phenotypic resistance determined by MGIT 960 drug susceptibility testing (DST) and WHO-recommended critical concentrations. SNPs, single nucleotide polymorphisms.
b
KAN, kanamycin.