TABLE 6.
Percent agreement by interpretive category among four laboratories for microdilution testing of M. abscessus, M. chelonae, and the M. fortuitum groupa
| Drug | % Agreement (category) forb:
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
M. abscessus
|
M. chelonae
|
M. fortuitum group
|
||||||||
| 1801 | 1802 | 1807 | 1814 | 1831 | 1866 | 1351 | 1352 | 1353 | 1359 | |
| Amikacin | 97.2 (S/I) | 82.3 (S/I) | 100 (S/I) | 97.2 (R) | 55.6 (S/I) | 88.9 (S/I) | 100 (S) | 100 (S) | 100 (S) | 100 (S) |
| Cefoxitinc | 91.7 (S/I) | 77.8 (S/I) | 100 (S/I) | 100 (R) | 100 (R) | 100 (R) | 77.8 (S/I) | 58.3 (S/I) | 100 (S/I) | 100 (S/I) |
| Ciprofloxacin | 100 (R) | 100 (R) | 100 (R) | 94.4 (R) | 83.3 (R) | 97.2 (R) | 100 (S) | 100 (S) | 100 (S) | 100 (S/I) |
| Clarithromycin | 100 (S/I) | 100 (R) | 100 (S) | 100 (S) | 100 (S) | 100 (R) | 61.1 (R) | 58.3 (R) | 100 (S) | 100 (S) |
| Doxycycline | 100 (R) | 100 (R) | 100 (R) | 100 (S/I) | 100 (R) | 100 (R) | 97.2 (R) | 100 (R) | 100 (S) | 100 (S) |
| Imipenem | 55.5 (S/I) | 66.7 (R) | 50d | 80.5 (R) | 72.2 (R) | 77.8 (R) | 91.7 (S/I) | 63.9 (S/I) | 58.3 (S/I) | 100 (S/I) |
| Sulfamethoxazole | 86.1 (R) | 100 (R) | 100 (R) | 91.7 (R) | 97.2 (R) | 97.2 (R) | 100 (S) | 88.9 (S) | 97.2 (S) | 91.7 (S) |
| Tobramycin | 50d | 100 (S/I) | 100 (S/I) | |||||||
a
Interpretive category suggested in the American Society for Microbiology Clinical Procedures Handbook (3).
b
S, susceptible; I, intermediate; R, resistant.
c
Percent agreement based on new recommended breakpoints (≤16 μg/ml, susceptible; 32 to 64 μg/ml, intermediate; ≥128 μg/ml, resistant) is 100% for all isolates except 1802 (97.2%) and 1352 (86.1%).
d
Intermediate, 50%; resistant, 50%.