Table 3. MICs for 13 antimicrobial agents against 45 strains of P. multocida.
| Antimicrobial | No. of isolates showing an MIC of agent (µg/ml) | Breakpoint (µg/ml) |
Resistance (%) |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | ≥1,024 | |||
| Amoxicillin | 2 | 1 | 2 | 3 | 10 | 6 | 7 | 6 | 5 | 3 | 32 | 82.2 | ||||||
| Ciprofloxacin | 8 | 2 | 18 | 5 | 10 | 2 | 4a) | 0.0 | ||||||||||
| Florfenicol | 6 | 8 | 10 | 13 | 2 | 3 | 3 | 8 | 46.7 | |||||||||
| Tetracycline | 8 | 11 | 2 | 9 | 6 | 3 | 3 | 1 | 2 | 16 | 53.3 | |||||||
| Tilmicosin | 5 | 2 | 4 | 13 | 3 | 8 | 5 | 2 | 3 | 32 | 22.2 | |||||||
| Doxycycline | 3 | 7 | 4 | 9 | 10 | 3 | 7 | 2 | 16b) | 48.9 | ||||||||
| Amikacin | 3 | 5 | 2 | 17 | 5 | 2 | 7 | 3 | 1 | 64 | 24.4 | |||||||
| Sulfamethazine | 3 | 3 | 7 | 21 | 11 | 512 | 71.1 | |||||||||||
| Spectinomycin | 17 | 2 | 9 | 8 | 5 | 1 | 3 | 128 | 6.7 | |||||||||
| Lincomycin | 1 | 5 | 13 | 9 | 5 | 2 | 10 | 4 | 37.8 | |||||||||
| Erythromycin | 17 | 5 | 7 | 6 | 3 | 5 | 2 | 8 | 22.2 | |||||||||
| Gentamicin | 7 | 3 | 10 | 16 | 2 | 1 | 5 | 1 | 16 | 20.0 | ||||||||
| Streptomycin | 1 | 9 | 15 | 13 | 7 | 512c) | 44.4 | |||||||||||
a) The value is based on Tang et al. standards [37]. b) The value is based on CLSI-2017 standards. c) The value is based on EUCAST standards.