TABLE 4.
MICs of tetracycline antimicrobials for E. coli isolates with different tetracycline resistance genes
| Antimicrobial | Gene profile | No. of strains | Avg MIC (μg/ml) | No. of isolates for which the MIC (μg/ml) was: |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | 1,024 | 2,048 | ||||
| Tetracycline | tet(A) | 72 | 200.0 | 3 | 27 | 42 | |||||||||
| tet(B) | 70 | 245.9 | 1 | 4 | 65 | ||||||||||
| tet(C) | 9 | 23.1 | 5 | 4 | |||||||||||
| tet(A) and tet(B) | 2 | 256.0 | 2 | ||||||||||||
| tet(B) and tet(C) | 2 | 256.0 | 2 | ||||||||||||
| Chlortetracycline | tet(A) | 72 | 1,365.3 | 48 | 24 | ||||||||||
| tet(B) | 70 | 1,682.3 | 25 | 45 | |||||||||||
| tet(C) | 9 | 170.7 | 6 | 3 | |||||||||||
| tet(A) and tet(B) | 2 | 1,536 | 1 | 1 | |||||||||||
| tet(B) and tet(C) | 2 | 1,536 | 1 | 1 | |||||||||||
| Oxytetracycline | tet(A) | 72 | 384.0 | 36 | 36 | ||||||||||
| tet(B) | 70 | 479.1 | 9 | 61 | |||||||||||
| tet(C) | 9 | 49.8 | 4 | 5 | |||||||||||
| tet(A) and tet(B) | 2 | 512.0 | 2 | ||||||||||||
| tet(B) and tet(C) | 2 | 384.0 | 1 | 1 | |||||||||||
| Doxycycline | tet(A) | 72 | 17.3 | 1 | 7 | 54 | 10 | ||||||||
| tet(B) | 70 | 42.5 | 4 | 41 | 25 | ||||||||||
| tet(C) | 9 | 5.8 | 6 | 2 | 1 | ||||||||||
| tet(A) and tet(B) | 2 | 32.0 | 2 | ||||||||||||
| tet(B) and tet(C) | 2 | 32.0 | 2 | ||||||||||||
| Minocycline | tet(A) | 72 | 3.3 | 39 | 28 | 4 | 1 | ||||||||
| tet(B) | 70 | 13.7 | 1 | 6 | 29 | 24 | 10 | ||||||||
| tet(C) | 9 | 1.1 | 8 | 1 | |||||||||||
| tet(A) and tet(B) | 2 | 6.0 | 1 | 1 | |||||||||||
| tet(B) and tet(C) | 2 | 8.0 | 2 | ||||||||||||