Table 4.
Prevalence of antimicrobial resistances among the 65 mcr-1 diarrheagenic E. coli.
| Antimicrobial agent | No. of resistant isolates (%)a |
|---|---|
| Colistin | 65 (100) |
| Ampicillin | 49 (75.4) |
| Ticarcillin | 48 (73.8) |
| Ampicillin-sulbactam | 42 (64.6) |
| Aztreonam | 5 (7.7) |
| Ceftazidime | 1 (1.5) |
| Cefepime | 6 (9.2) |
| Cefotaxime | 7 (10.8) |
| Gentamicin | 31 (47.7) |
| Tobramycin | 31 (47.7) |
| Minocycline | 27 (41.5) |
| Fosfomycin | 3 (4.6)b |
| Chloramphenicol | 38 (58.5) |
| Trimethoprim-sulfamethoxazole | 47 (72.3) |
| Nalidixic acid | 39 (60.0) |
| Ciprofloxacin | 8 (12.3) |
| Levofloxacin | 7 (10.8) |
aIsolates showing intermediate resistance were considered as resistant. None of the 65 mcr-1-positive E. coli isolates showed resistance to piperacillin-tazobactam, imipenem, meropenem, amikacin, or tigecycline. bAdditionally, eight isolates showed a MIC value = 64. According to EUCAST, the cut-off point is 32 mg/L and higher values are considered resistant, while for CLSI it is 64.