Table 1. Antimicrobial susceptibility of E. coli isolates from chickens obtained from Southeast Asian countries.
| Antimicrobial | Break point (mg/l)a) |
MIC range (mg/l) |
MIC50 (mg/l) | MIC90 (mg/l) | % of antimicrobial resistance |
||
|---|---|---|---|---|---|---|---|
| Vietnam (n=47) |
Indonesia (n=78) |
Total (n=125) |
|||||
| Ampicillin | 32 | 1–>512 | 256 | >512 | 83.0b) | 43.6 | 58.4 |
| Cefazolin | 8 | 0.25–512 | 2 | 8 | 4.3 | 5.1 | 4.8 |
| Cefpodoxime | 8 | <0.125–128 | 0.25 | 1 | 4.3 | 5.1 | 4.8 |
| Kanamycin | 64 | 2–>512 | 2 | >512 | 48.9b) | 16.7 | 28.8 |
| Gentamicin | 16 | 0.3–>512 | 1 | 32 | 44.7b) | 0 | 16.8 |
| Dihydrostreptomycin | 32 | 1–>512 | 8 | 512 | 82.9b) | 24.4 | 46.4 |
| Oxytetracycline | 16 | 0.5–>512 | 128 | 512 | 93.6b) | 61.5 | 73.6 |
| Chloramphenicol | 32 | 0.25–>512 | 8 | 256 | 51.1b) | 25.6 | 35.2 |
| Nalidixic acid | 32 | 2–>512 | 128 | >512 | 80.1b) | 42.3 | 56.8 |
| Enrofloxacin | 2 | <0.125–64 | 1 | 64 | 70.2b) | 35.9 | 48.8 |
MIC: Minimal inhibitory concentration. a) The value was the CLSI break point, b) The percentage of antimicrobial resistance in Vietnam was significantly higher than that in Indonesia (P<0.05).