Table 1.
Percentages of E. coli isolates from avian and human sources susceptible (S), intermediate (I) and resistant (R) to antimicrobial agents by NCCLS disc diffusion methods.
| Antimicrobial agent (μg) | Diffusion zone breakpoint (mm) | Avian isolates (n = 34) | Human isolates (n = 48) | ||||
| S | I | R | S | I | R | ||
| Aminoglycosides | |||||||
| Gentamicin (10) | ≤ 12 | 100 | 0 | 0 | 60.4 | 6.3 | 33.3 |
| Kanamycin (30) | ≤ 13 | 2.9 | 5.9 | 91.2 | 8.3 | 18.8 | 43.8 |
| β-lactams | |||||||
| Ampicillin (10) | ≤ 13 | 73.5 | 5.9 | 20.6 | 58.3 | 6.3 | 35.4 |
| Amoxicillin/clavulanate (20) | ≤ 13 | 85.3 | 11.8 | 2.9 | 79.2 | 18.8 | 2.1 |
| Phenicols | |||||||
| Chloramphenicol (30) | ≤ 12 | 88.2 | 8.8 | 2.9 | 68.8 | 6.3 | 25 |
| Quinolones | |||||||
| Ciprofloxacin (5) | ≤ 15 | 64.7 | 26.5 | 8.8 | 89.6 | 0 | 10.4 |
| Enrofloxacin (5) | ≤ 17 | 32.4 | 38.2 | 29.4 | 89.6 | 0 | 10.4 |
| Nalidixic acid (30) | ≤ 13 | 11.8 | 2.9 | 85.3 | 89.6 | 0 | 10.4 |
| Norfloxacin (5) | ≤ 12 | 64.7 | 14.7 | 20.6 | 91.7 | 2.1 | 6.3 |
| Ofloxacin (5) | ≤ 12 | 85.3 | 2.9 | 11.8 | 91.7 | 0 | 8.3 |
| Tetracyclines | |||||||
| Tetracycline (30) | ≤ 14 | 17.6 | 0 | 82.4 | 39.6 | 16.7 | 43.8 |