Table 7.
Transfer of sul and dfr genes and integrons from resistant strains to Escherichia coli K-12.
| Donor | Transconjugant |
Frequency of transfer∗ | |||
|---|---|---|---|---|---|
| Integron | Cassette | Genes out of VZ | Resistance pattern | ||
| FB98 | 1 | dfrA12, orfF, aadA2 | – | S-CM-FFC-OT-NA-SFX-TMP-NaN3 | 7.4 × 10−3 |
| FM4 | 1 | – | – | S-CM-FFC-OT-NA-SFX-NaN3 | 1.4 × 10−3 |
| FM7 | 1 | – | – | NA-TMP-NaN3 | 5.4 × 10−3 |
| FM22 | – | – | sul1, dfrA14 | S-CM-FFC-OT-NA-SFX-TMP-NaN3 | 2.6 × 10−5 |
| FP45 | 1 | aadA2, cmlA | – | S-CM-NA-TMP-NaN3 | 4.1 × 10−3 |
| FP75 | 1 | dfrA12, orfF, aadA2 | sul2 | S-CM-FFC-OT-NA-SFX-TMP-NaN3 | 9.8 × 10−4 |
| OP29 | 1 | dfrA12, orfF, aadA2 | sul2 | S-CM-FFC-OT-NA-SFX-TMP-NaN3 | 8.4 × 10−3 |
| SX52 | 1 | aadA9 | dfrA12 | S-NA-TMP-NaN3 | 5.0 × 10−4 |
| OT42 | – | – | sul1 | S-NA-TMP-NaN3 | 1.7 × 10−3 |
| FR27 | 1 | aadA2, cmlA | dfrA12 | S-CM-FFC-NA-TMP-NaN3 | 3.1 × 10−5 |
| FE3 | NT | ||||
| FM2 | NT | ||||
| FM3 | NT | ||||
| Q20 | NT | ||||
| Q64 | NT | ||||
| Q67 | NT | ||||
| Q75 | NT | ||||
| 0233 | NT | ||||
| FB13 | NT | ||||
| FB15 | NT | ||||
| FR34 | NT | ||||
| SR72 | NT | ||||
VZ, variable zone; ∗transconjugant per recipient cell; S, streptomycin; CM, chloramphenicol; FFC, florfenicol, OT, oxytetracycline; NA, nalidixic acid; SFX, sulfisoxazole; TMP, trimethoprim; NaN3, sodium azide; NT, not transfer detected.