TABLE 4.
Sensitivities and specificities of SNPs for predicting phenotypic resistance to rifampin in M. tuberculosis isolates from India, Moldova, the Philippines, and South Africaa
| Observed mutation(s) by gene location | No. of RIFr isolates with mutation (n = 336)b | No. of RIFs isolates with mutation (n = 55) | Estimated sensitivity (% [95% CI]) | Estimated specificity (% [95% CI]) |
|---|---|---|---|---|
| rpoB | ||||
| 531TCG→TTG | 231 | 1 | 68.8 (63.5–73.6) | 98.2 (89–99.9) |
| 516GAC→GGC/533CTG→CCG | 27 | 0 | 8 (5.5–11.6) | 100 (91.9–100) |
| 516GAC→GTC | 23 | 0 | 6.8 (4.5–10.2) | 100 (91.9–100) |
| 526CAC→TAC | 18 | 0 | 5.4 (3.3–8.5) | 100 (91.9–100) |
| 531TCG→TGG | 7 | 0 | 2.1 (0.9–4.4) | 100 (91.9–100) |
| 526CAC→CGC | 6 | 0 | 1.8 (0.7–4) | 100 (91.9–100) |
| 513CAA→AAA | 4 | 0 | 1.2 (0.4–3.2) | 100 (91.9–100) |
| 526CAC→GAC | 3 | 0 | 0.9 (0.2–2.8) | 100 (91.9–100) |
| 522TCG→TTG | 2 | 0 | 0.6 (0.1–2.4) | 100 (91.9–100) |
| 526CAC→TAC/526CAC→CGC | 2 | 1 | 0.6 (0.1–2.4) | 98.2 (89–99.9) |
| 511CTG→CCG/512AGC→ACC/516GAC→TAC | 1 | 0 | 0.3 (0–1.9) | 100 (91.9–100) |
| 513CAA→AAA/526CAC→GAC | 1 | 0 | 0.3 (0–1.9) | 100 (91.9–100) |
| 526CAC→CTC | 1 | 3 | 0.3 (0–1.9) | 94.5 (83.9–98.6) |
| 526CAC→TAC/509AGC→CGC | 1 | 0 | 0.3 (0–1.9) | 100 (91.9–100) |
| 531TCG→TTG/515ATG→ATA | 1 | 0 | 0.3 (0–1.9) | 100 (91.9–100) |
| 516GAC→TAC | 0 | 4 | 0 (0–1.4) | 92.7 (81.6–97.6) |
| 526CAC→AAC/526CAC→CGC | 0 | 1 | 0 (0–1.4) | 98.2 (89–99.9) |
| 526CAC→AAC | 0 | 1 | 0 (0–1.4) | 98.2 (89–99.9) |
| No mutations in rpoB | 8 | 44 |
a
Phenotypic resistance determined by MGIT 960 drug susceptibility testing (DST) and WHO-recommended critical concentrations. SNPs, single nucleotide polymorphisms.
b
RIF, rifampin.