Table 2.
Percent resistance by E. coli to a panel of different antibiotics and across different water sources.
| E. coli source | |||||||
|---|---|---|---|---|---|---|---|
| Drug class | Antibiotics | Sewer water (n=17) (%) | WWTP influent (n=10) (%) | Wastewater (sewer + influent) (n=27) (%) | WWTP effluent (n=2) (%) | Surface water (n=5) (%) | Ambient water (effluent + surface) (n=7) (%) |
| Aminoglycoside | Amikacin | 0 | 0 | 0 | 0 | 0 | 0 |
| Gentamicin | 11.7 | 0 | 7.40 | 50.0 | 0 | 14.2 | |
| Tobramycin | 5.88 | 0 | 3.70 | 50.0 | 0 | 14.2 | |
|
| |||||||
| Beta-lactam | Amoxicillin/clavulanic acid | 29.4 | 40.0 | 33.3 | 50.0 | 0 | 14.2 |
| Ampicillin | 41.1 | 50.0 | 44.4 | 50.0 | 0 | 14.2 | |
| Cefalexin | 35.2 | 40.0 | 37.0 | 50.0 | 0 | 14.2 | |
| Cefovecin | 35.2 | 40.0 | 37.0 | 50.0 | 0 | 14.2 | |
| Cefpodoxine | 35.2 | 40.0 | 37.0 | 50.0 | 0 | 14.2 | |
| Ceftiofur | 23.5 | 40.0 | 29.6 | 50.0 | 0 | 14.2 | |
| Imipenem | 29.4 | 40.0 | 33.3 | 50.0 | 0 | 14.2 | |
| Piperacillin | 41.1 | 50.0 | 44.4 | 50.0 | 0 | 14.2 | |
|
| |||||||
| Chloramphenicol | Chloramphenicol | 5.88 | 10.0 | 7.40 | 0 | 0 | 0 |
|
| |||||||
| Fluoroquinolone | Marbofloxacin | 11.7 | 0 | 7.40 | 0 | 0 | 0 |
| Enrofloxacin | 11.7 | 10.0 | 11.1 | 0 | 0 | 0 | |
|
| |||||||
| Nitrofuran | Nitrofurantoin | 0 | 0 | 0 | 0 | 0 | 0 |
| Tetracycline | Tetracycline | 23.5 | 10.0 | 18.5 | 50.0 | 0 | 14.2 |
| Sulfonamide | Trimethoprim/sulfamethoxazide | 0 | 20.0 | 7.40 | 0 | 0 | 0 |
Percentage of E. coli isolates resistant to 17 drugs (5 drug classes) was calculated by dividing total E. coli resistant for a given drug by total E. coli examined in a source type. WWTP: wastewater treatment plant.