Table 4.
Minimum inhibitory concentration (MIC) of 12 antibiotics against bacteria isolates obtained from WW, WTP and RW.
| Activity against the Isolates | ||||
|---|---|---|---|---|
| Antibiotics | Resistance Prevalence (%) | MIC (mg L−1) | ||
| Range | 50% | 90% | ||
| Ampicillin (AMP) | 100.0 | 64 to ≥1024 | 1024 | 1024 |
| Amoxicillin (AMO) | 100.0 | 1 to ≥1024 | 1024 | 1024 |
| Streptomycin Sulfate (STR) | 92.3 | 1 to ≥1024 | 128 | 512 |
| Trimethoprim (TRI) | 98.0 | 8 to ≥1024 | 1024 | 1024 |
| Chloramphenicol (CHL) | 100.0 | 256 to ≥1024 | 1024 | 1024 |
| Sulfonamide (SUL) | 100.0 | 512 to ≥1024 | 1024 | 1024 |
| Tetracycline (TET) | 90.6 | 2 to ≥512 | 128 | 256 |
| Oxytetracycline (OXY) | 90.6 | 1 to ≥1024 | 256 | 512 |
| Nalidixic Acid (NAL) | 73.6 | 1 to ≥1024 | 512 | 1024 |
| Erythromycin (ERY) | 92.5 | 4 to ≥1024 | 128 | 512 |
| Spiramycin (SPIRA) | 90.6 | 2 to ≥1024 | 512 | 1024 |
| Kanamycin (KAN) | 54.7 | 1 to ≥1024 | 128 | 1024 |
WW, wastewater effluent; WTP, wastewater treatment plant; RW, river water; 50%, MIC50; 90%, MIC90. The MICs for each antibiotic for all tested isolates in WW, WTP, and RW, which represent MICs required for the inhibition of 50% and 90% of bacterial strains respectively.