TABLE 1.
Susceptibility of M. catarrhalis to four antimicrobial agents
| Antimicrobial agent and phenotype (no. of isolates) | MIC (μg/ml)a
|
||
|---|---|---|---|
| 50% | 90% | Range | |
| Amoxicillin | |||
| β-Lactamase negative (34) | ≤0.06 | 0.25 | ≤0.06-0.5 |
| β-Lactamase positive; BRO-1 (363) | 2 | 8 | ≤0.06->8 |
| β-Lactamase positive; BRO-2 (22) | 0.25 | 8 | ≤0.06->8 |
| Penicillin | |||
| β-Lactamase negative | ≤0.03 | 0.25 | ≤0.03-0.5 |
| β-Lactamase positive; BRO-1 | 4 | >4 | ≤0.03->4 |
| β-Lactamase positive; BRO-2 | 1 | >4 | 0.25->4 |
| Cefepime | |||
| β-Lactamase negative | 0.12 | 0.5 | ≤0.06-2 |
| β-Lactamase positive; BRO-1 | 0.5 | 2 | ≤0.06-4 |
| β-Lactamase positive; BRO-2 | 0.25 | 1 | 0.12-4 |
| Cefixime | |||
| β-Lactamase negative | ≤0.03 | 0.03 | ≤0.03-0.5 |
| β-Lactamase positive; BRO-1 | 0.12 | 0.5 | ≤0.03-2 |
| β-Lactamase positive; BRO-2 | 0.06 | 0.25 | ≤0.03-0.5 |
a
50% and 90%, MICs at which 50 and 90% of isolates were inhibited, respectively.