TABLE 5.
Variations resulting in serious discords in the categorization of susceptibility (susceptible versus resistant)a
| Antimicrobial agent | No. of serious discords by:
|
|||||
|---|---|---|---|---|---|---|
| Participating laboratory
|
Organism groupb
|
|||||
| A | B | C | Nonmucoid | Mucoid | Non-CF | |
| Amikacin | 1 | 1 | 3 | 3 | 2 | 0 |
| Gentamicin | 4 | 0 | 2 | 2 | 2 | 2 |
| Tobramycin | 3 | 1 | 1 | 1 | 3 | 1 |
| Ciprofloxacin | 6 | 6 | 4 | 10 | 3 | 3 |
| Piperacillin | 15 | 4 | 6 | 6 | 9 | 10 |
| Ticarcillin | 12 | 4 | 7 | 5 | 10 | 8 |
| Piperacillin-tazobactam | 11 | 13 | 6 | 9 | 12 | 9 |
| Ticarcillin-clavulanate | 9 | 3 | 5 | 5 | 7 | 5 |
| Ceftazidime | 5 | 3 | 3 | 0 | 5 | 6 |
| Aztreonam | 9 | 5 | 4 | 5 | 7 | 6 |
| Imipenem | 5 | 5 | 8 | 9 | 2 | 7 |
| Meropenem | 7 | 2 | 4 | 3 | 2 | 8 |
| No. of observations | 4,704 | 4,704 | 4,704 | 3,312 | 3,600 | 7,200 |
| Total no. (%) | 87 (1.8) | 47 (1.0) | 53 (1.1) | 58 (1.8) | 64 (1.8) | 65 (0.9) |
a
Analysis includes the number of variations for agar dilutions and broth microdilutions read at 24 and 48 h.
b
Nonmucoid and mucoid strains are from CF patients.