Table 4.
Distribution of β-lactamase gene-carrying β-lactam-resistant E. coli in 5 integrated broiler chicken operations.
| Enzyme | β-Lactamase gene | No. of isolates carrying each gene (%) |
|||||
|---|---|---|---|---|---|---|---|
| A (n = 79) |
B (n = 156) |
C (n = 102) |
D (n = 87) |
E (n = 42) |
Total (n = 466) |
||
| Narrow-spectrum β-lactamase | blaTEM-1 | 62 (78.5) | 127 (81.4) | 82 (80.4) | 71 (81.6) | 39 (92.9) | 381 (81.8)A |
| blaTEM-135 | 3 (3.8) | 6 (3.8) | 9 (8.8) | 12 (13.8) | 0 (0.0) | 30 (6.4)B | |
| Extended-spectrum β-lactamase | blaSHV-12 | 2 (2.5) | 4 (2.6) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 6 (1.3)C,D |
| blaOXA-1 | 0 (0.0) | 3 (1.9) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 3 (0.6)D | |
| blaCTX-M-27 | 1 (1.3) | 5 (3.2) | 3 (2.9) | 0 (0.0) | 0 (0.0) | 9 (1.9)C,D | |
| blaCTX-M-55 | 7 (8.9) | 12 (7.7) | 6 (5.9) | 2 (2.3) | 1 (2.4) | 28 (6.0)B | |
| blaCTX-M-65 | 0 (0.0) | 1 (0.6) | 2 (2.0) | 0 (0.0) | 1 (2.4) | 4 (0.9)C,D | |
| Plasmidic class C β-lactamase | blaCMY-2 | 6 (7.6) | 4 (2.6) | 4 (3.9) | 3 (3.4) | 0 (0.0) | 17 (3.6)B,C |
| No. of isolates carrying 1 or more β-Lactamase gene (%) |
71 (89.9) | 143 (91.7) | 95 (93.1) | 83 (95.4) | 40 (95.2) | 432 (92.7) | |
Values with different uppercase superscript letters represent significant difference among β-lactamase gene (P < 0.05).