Table 1.
Most common antimicrobial resistance patterns in commensal E. coli (n = 3007) isolated from cecal swine samples at slaughter across the United States, 2013–2019.
| Antimicrobial Resistance Pattern a | N (%) | Number of Classes | MDR b (Yes/No) |
|---|---|---|---|
| Susceptible | 905 (27.95) | - | - |
| TET | 1109 (34.26) | 1 | N |
| STR | 30 (0.92) | 1 | N |
| AMP | 33 (1.02) | 1 | N |
| AMP-TET | 180 (5.56) | 2 | N |
| CHL-TET | 27 (0.83) | 2 | N |
| COT-TET | 19 (0.58) | 2 | N |
| CIP-TET | 22 (0.68) | 2 | N |
| STR-TET | 307 (9.48) | 2 | N |
| AMP-CHL-TET | 9 (0.28) | 3 | Y |
| AMP-COT-STR | 13 (0.4) | 3 | Y |
| AMP-STR-TET | 165 (5.09) | 3 | Y |
| GEN-STR-TET | 9 (0.28) | 2 | N |
| COT-STR-TET | 17 (0.52) | 3 | Y |
| CIP-STR-TET | 9 (0.28) | 3 | Y |
| CHL-STR-TET | 31 (0.95) | 3 | Y |
| AMP-CHL-STR-TET | 20 (0.62) | 4 | Y |
| AMP-COT-STR-TET | 16 (0.49) | 4 | Y |
| AMC-AMP-AXO-FOX | 16 (0.49) | 1 | N |
| AMC-AMP-AXO-FOX-TET | 34 (1.05) | 2 | N |
| AMP-CHL-COT-STR-TET | 12 (0.37) | 5 | Y |
| AMC-AMP-AXO-FOX-STR-TET | 15 (0.46) | 3 | Y |
| AMC-AMP-AXO-COT-FOX-STR-TET | 9 (0.27) | 4 | Y |
a AMC—Amoxicillin-Clavulanic acid; AMP—Ampicillin; AXO—Ceftriaxone; AZI—Azithromycin; CHL—Chloramphenicol; CIP—Ciprofloxacin; COT—Trimethoprim-Sulfamethoxazole; FOX—Cefoxitin; GEN—Gentamicin; NAL—Nalidixic Acid; STR—Streptomycin; TET—Tetracycline. b MDR: Multidrug-resistant (Resistant to three or more antimicrobial classes).