TABLE 3.
Results of susceptibility tests for 24 clinical isolates of M. tuberculosis exposed to RIFa
| Isolate | Susceptibility to RIF (1.0 μg/ml)
|
|
|---|---|---|
| Proportion method | Flow cytometry | |
| 072 | S | S |
| 126 | S | S |
| 204 | R | R |
| 212 | R | R |
| 231 | R | S |
| 243 | S | S |
| 246 | S | S |
| 253 | S | S |
| 289 | R | R |
| 292 | R | R |
| 299 | R | R |
| 322 | S | R |
| 497 | S | S |
| 498 | S | S |
| 508 | S | S |
| 509 | S | R |
| 514 | S | S |
| 531 | R | R |
| 705 | S | S |
| 710 | S | S |
| 813 | R | R |
| 843 | S | R |
| 863 | S | S |
| 982 | S | S |
a
Isolates of M. tuberculosis were exposed to 1.0 μg of RIF/ml. The isolates marked S for the proportion method showed less than 1% of the growth seen on drug-free control plates. The isolates marked S for flow cytometry had a susceptibility index of 0.75 or less after exposure to RIF for 24 h. Isolates marked R for both methods were considered resistant.