Table 2. Isolates were classified as susceptible (S) or resistant (R) based on the zones of inhibition (mm) observed; isolates that were resistant to at least one antimicrobial from three or more antimicrobial categories were classified as MDR [52].
| Antibiotic | Antimicrobial category | Mode of action | Disc content (µg) | Zone diameter breakpoint (mm) [52] |
|
| S | R | ||||
| Ampicillin | Beta-lactams | Bacterial cell wall synthesis inhibitor | 10 | ≥16 | <16 |
| Chloramphenicol* | Phenicols | Inhibits protein synthesis (prevents growth) | 30 | ≥18 | <18 |
| Erythromycin | Macrolides | Inhibits protein synthesis (bacteriostatic) | 15 | ≥25 | <25 |
| Gentamicin* | Aminoglycoside | Inhibits protein synthesis (leads to cell death) | 10 | ≥18 | <18 |
| Tetracycline* | Tetracycline | Inhibits protein synthesis (ribosomal inhibitor) | 30 | ≥22 | <19 |