TABLE 2.
Comparison of genotypic testing by rpoB PCR-sequencing to the agar proportion method for 286 M. tuberculosis culture-positive respiratory specimens and 352 purified isolates
| Sample for genotypic testing and result (n) | No. of isolates (no. of individual patient strainsa) with the indicated result as determined by the agar proportion method
|
|
|---|---|---|
| Susceptible | Resistant | |
| M. tuberculosis culture-positive respiratory specimens (286)a | ||
| RRDR mutation absent (230) | 230 (184) | 0 |
| RRDR mutation present (5) | 0 | 5 (4) |
| PCR negative (51) | 51 (45) | 0 |
| Purified nonduplicate isolates (352) | ||
| RRDR mutation absent (313) | 313 | 0 |
| RRDR mutation present (39) | 0 | 39b |
a
The 286 culture-positive specimens were obtained from 233 patients. The numbers of individual patient strains, as defined by a unique genotype, are shown in parentheses.
b
The 39 RIF-resistant strains included four from the tested respiratory specimens and 35 from the 119 purified isolates.