Table 2.
Prevalence of class 1 and 2 integrons among multidrug-resistant E. coli isolated from groups of pigs.
| Source of isolates | No. (%) E. coli with class 1 integrons | Class 1 integron elements | No. (%) E. coli with class 2 integrons | Class 2 integron elements | |||
|---|---|---|---|---|---|---|---|
| 5′CS* | variable region with gene cassettes | 3′ CS* | 5′CS* | variable region with gene cassettes | |||
| Piglets (n=34) | Typical 20 (59) | int1 |
dfrA1-aadA1 dfrA12-aadA2 dfrA7 |
sul1-qacEΔ1 | Typical 7 (20) | int2 | dfrA1-sat2-aadA1; estX-sat2-aadA1 |
| Atypical 5 (15) | int1 | aadA1 | — | Atypical 3 (9) | int2 | — | |
| int1 | — | — | |||||
| Sows (n=22) | Typical 5 (27) | int1 |
dfrA1-aadA1 aadA1 dfrA7 |
sul1-qacEΔ1 | Typical 9 (41) | int2 | dfr1-sat2-aadA1; estX-sat2-aadA1 |
| Atypical 14 (64) | int1 | — | — | Atypical 3 (14) | int2 | — | |
| Total (n=56) | Typical class 1 integrons 25 (45) | Typical class 2 integrons 16 (28) | |||||
| Atypical class 1 integrons 19 (34) | Atypical class 2 integrons 6 (11) | ||||||
*
5′CS and 3′CS-conserved segments of integrons.