TABLE 1.
Prevalence of aac(6′)-Ib-cr and qnr genes in Enterobacteriaceae from the United States
| Year | Variant | No. of isolates with aac(6′)-Ib variant/total no. of isolates (%)
|
||
|---|---|---|---|---|
| K. pneumoniae | Enterobacter spp. | E. coli | ||
| 1999 | cr | 5/21 (23.8) | 9/45 (20.0) | 3/9 (33.3) |
| Any | 9/21 (42.9) | 28/45 (62.2) | 4/9 (44.4) | |
| 2000 | cr | 4/33 (12.1) | 1/38 (2.6) | 4/8 (50.0) |
| Any | 19/33 (57.6) | 15/38 (39.5) | 7/8 (87.5) | |
| 2001 | cr | 5/20 (25.0) | 0/39 (0.0) | 2/5 (40.0) |
| Any | 13/20 (65.0) | 12/39 (30.8) | 3/5 (60.0) | |
| 2004 | cr | 3/32 (9.3) | 2/38 (5.2) | 6/25 (24.0) |
| Any | 23/32 (71.9) | 13/38 (34.2) | 12/25 (48.0) | |
| Total | cr | 17/106 (16.0) | 12/160 (7.5) | 15/47 (31.9) |
| No. of isolates with qnr/total no. of isolates (%) | 21/106 (20) | 50/160 (31) | 2/47 (4) | |