TABLE 4.
Class 1 and class 2 integrons found among E. coli isolates from clinical specimens (ESBL and non-ESBL) and from healthy volunteers
| RFLP type | Length of variable region (bp) | Gene cassettes and order | Resistance phenotypea | No. of isolates | C-ESBL (n = 52)
|
C-nESBL (n = 43) | V-nESBL (n = 38) | Isolation date | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
| TEM | SHV | CT-X-M-9/14 | CTX-M-10 | ||||||||
| Class 1 integrons | |||||||||||
| I1 | 1,000 | aadA1 | Sm Sp | 15 | 0 | 4 | 3 | 0 | 6 | 2 | 1988-2001 |
| II1 | 1,500 | dhfrA1-aadA1 | Tmp Sm Sp | 12 | 1 | 2 | 2 | 0 | 5 | 2 | 1997-2001 |
| III1 | 1,800 | dhfrA12-orfF-aadA2 | Tmp Sm Sp | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1997 |
| IV1 | 1,500 | dhfrA16-aadA2 | Tp Sm Sp | 13 | 0 | 0 | 13 | 0 | 0 | 0 | 1996-2000 |
| V1 | 950 | aadA2 | Sm Sp | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1998 |
| VI1 | 1,500 | dhfrA17-aadA5 | Tp Sm Spc | 5 | 1 | 0 | 0 | 0 | 3 | 1 | 1997-2001 |
| VII1 | 800 | aac(6′)-Ib" | Km Ak Tb Nt Gm | 2 | 1 | 0 | 0 | 0 | 0 | 1 | 2000-2001 |
| Class 2 integrons | |||||||||||
| I2 | 1,600 | sat-aadA1-orfX | Str Sm Sp | 2 | 0 | 0 | 0 | 0 | 0 | 2 | 2001 |
| II2 | 1,900 | dhfrA1-sat-aadA1-orfX | Tp Str Sm Sp | 15 | 3 | 0 | 3 | 0 | 5 | 4 | 1991-2001 |
| III2 | 2,300 | orf-sat-aadA1-orfX | Str Sm Sp | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 2000 |
a
Sm, streptomycin; Sp, spectinomycin; Tp, trimethoprim; Km, kanamycin; Ak, amikacin; Tb, tobramycin; Nt, netilmicin; Gm, gentamicin; Str, streptotricin.