TABLE 2.
Distributions of disk diffusion zones of 951 fecal isolates to 12 antimicrobial agents
| Agent | Overall
|
Lower peak
|
Upper peak
|
CLSI breakpointa | |||
|---|---|---|---|---|---|---|---|
| Mean | Median | Range | Median | Range | Median | ||
| Neomycin | 17.7 | 16.3 | 6.0-18.7 | 15.4 | 19.0-26.2 | 22.0 | 12 |
| Streptomycin | 15.2 | 14.5 | 3.2-16.7 | 13.5 | 17.0-26.0 | 20.0 | 17 |
| Tetracycline | 18.6 | 21.7 | 6.0-13.9 | 6.0 | 15.0-35.0 | 23.7 | 14 |
| Ampicillinb | 19.3 | 19.0 | 13 | ||||
| TMP/SMZc | 26.7 | 26.1 | 6.0-29.9 | 24.5 | 30.0-38.0 | 33.0 | 10 |
| Cephalothin | 17.6 | 16.1 | 6.0-17.9 | 14.4 | 18.0-32.0 | 22.0 | 14 |
| Sulfisoxazole | 20.6 | 22.1 | 6.0-7.8 | 6.0 | 12.0-35.0 | 22.8 | 12 |
| Gentamicin | 21.0 | 19.6 | 6.0-20.9 | 18.3 | 21.0-30.0 | 25.0 | 12 |
| Chloramphenicol | 25.6 | 25.4 | 6.0-26.9 | 24.3 | 27.0-35.0 | 28.0 | 12 |
| Ofloxacinb | 29.3 | 29.4 | 12 | ||||
| Nalidixic acid | 24.2 | 22.9 | 6.0-25.9 | 21.0 | 26.0-36.0 | 29.0 | 13 |
| Nitrofurantoin | 21.0 | 19.5 | 6.0-20.8 | 18.1 | 21.0-30.0 | 25.0 | 14 |
a
Maximum diffusion zone (mm) breakpoint for the determination of antimicrobial resistance (17).
b
Not bimodally distributed; lower and upper peak ranges and medians not reported.
c
TMP/SMZ, trimethoprim-sulfamethoxazole.