TABLE 1.
Antimicrobial susceptibility of mcr-1-positive Salmonella strains isolated from different sources
| Antibiotic | Breakpoint (μg/ml) | % of resistancea |
|
|---|---|---|---|
| WT (n = 28) | TC (n = 21) | ||
| Ampicillin | ≥32 | 89 | 52 |
| Amoxicillin-clavulanic acid | ≥32/16 | 50 | 14 |
| Ceftriaxone | ≥4 | 64 | 62 |
| Chloramphenicol | ≥32 | 64 | 19 |
| Gentamicin | ≥16 | 54 | 24 |
| Nalidixic acid | 32 | 68 | 24 |
| Ciprofloxacin | ≥1 | 25 | 0 |
| Trimethoprim-sulfamethoxazole | ≥4/76 | 39 | 14 |
| Tetracycline | ≥16 | 79 | 0 |
| Colistin | >2 | 100 | 100 |
| Azithromycin | ≥16 | 14 | 0 |
a
“% of resistance” refers to the no. of resistant strains/no. of total strains (n). WT, wild type; TC, transconjugant.