Table 4.
Comparison of predicted to actual MGIT PZA susceptibility test results stratified by inoculation method. Cumulative results of 9 laboratoriesa each testing 20 isolates in duplicate.
| Isolate numberb |
Predicted resultc (category) |
Actual number of results by inoculation methodd |
|||||
|---|---|---|---|---|---|---|---|
| BD | A | C | |||||
| S | R | S | R | S | R | ||
| 1 | S (A) | 18 | 0 | 18 | 0 | 18 | 0 |
| 4 | R (A) | 0 | 18 | 0 | 18 | 0 | 18 |
| 7 | S (A) | 17 | 1 | 17 | 0 | 16 | 1 |
| 8 | S (A) | 18 | 0 | 18 | 0 | 18 | 0 |
| 11 | S (A) | 18 | 0 | 14 | 0 | 12 | 0 |
| 12 | S (P) | 1 | 16 | 13 | 5 | 15 | 3 |
| 13 | S (P) | 12 | 6 | 18 | 0 | 17 | 0 |
| 14 | R (A) | 0 | 18 | 2e | 15 | 2e | 16 |
| 16 | S (P) | 9 | 9 | 15 | 2 | 18 | 0 |
| 17 | R (P) | 2 | 16 | 9 | 9 | 7 | 8 |
| 18 | S (A) | 14 | 4 | 18 | 0 | 18 | 0 |
| 19 | INC | 13 | 5 | 18 | 0 | 18 | 0 |
| 20 | S (A) | 17 | 1 | 18 | 0 | 18 | 0 |
| 21 | INC | 6 | 12 | 13 | 5 | 14 | 4 |
| 22 | S (A) | 18 | 0 | 18 | 0 | 18 | 0 |
| 23 | S (A) | 17 | 0 | 16 | 0 | 12 | 0 |
| 24 | S (P) | 3 | 15 | 11 | 7 | 15 | 3 |
| 25 | S (P) | 12 | 6 | 18 | 0 | 17 | 0 |
| 26 | S (P) | 12 | 6 | 15 | 3 | 17 | 1 |
| 27 | INC | 7 | 11 | 14 | 4 | 13 | 5 |
aResults for one laboratory excluded due to <70% reproducibility. bIsolate numbers correspond to those in Table 1. cS: susceptible; R: resistant; INC: inconclusive; A: always; P: predominately. dTotal results by method less than 18 (9 laboratories × 2 tests per isolate) indicate that some tests “Timed-Out” prior to a result. eAll 4 false-susceptible results occurred in the same laboratory.