Table 4 Interpretive criteria for M haemolytica using disk diffusion susceptibility testing reported as inhibition zone diameters in (mm)
From: Methodological comparisons for antimicrobial resistance surveillance in feedlot cattle
Antimicrobial | [Disk] (μg) | Susceptible | Intermediate | Resistant | Reference |
|---|---|---|---|---|---|
Ampicillin | 10 | ≥27 | - | - | CLSI M45-A2, 2010 |
Amoxicillin- Clavulanate | 20/10 | ≥27 | - | - | CLSI M45-A2, 2010 |
Ceftiofur | 30 | ≥21 | 18-20 | ≤17 | CLSI M31-A3, 2008 |
Danofloxacin | 5 | ≥22 | - | - | CLSI M31-A3, 2008 |
Enrofloxacin | 5 | ≥21 | 17-20 | ≤16 | CLSI M31-A4, 2013 |
Florfenicol | 30 | ≥19 | 15-18 | ≤14 | CLSI M31-A4, 2013 |
Gentamicin | 10 | ≥15 | - | ≤12 | Catry et al., 2007 |
Spectinomycin | 100 | ≥14 | 11-13 | ≤10 | CLSI M31-A3, 2008 |
Sulfisoxazole | 300 | ≥17 | 13-16 | ≤12 | CLSI M31-A3, 2008 |
Tetracycline | 30 | ≥23 | - | - | CLSI M45-A2, 2010 |
Tilmicosin | 15 | ≥14 | 11-13 | ≤10 | CLSI M31-A4, 2013 |
Trimethoprim-Sulfamethoxazole | 1.25/23.75 | ≥24 | - | - | CLSI M45-A2, 2010 |
Tulathromycin | 30 | ≥18 | 15-17 | ≤14 | CLSI M31-A4, 2013 |