TABLE 1.
In vitro susceptibility to vancomycin and detection of hVISA in MRSA isolates obtained in surveillance done by the CNISP, 1995 to 2006
| Yr | No. (%) of isolatesa with vancomycin MIC (μg/ml) of: |
No. screened for hVISA phenotype | No. (%) of hVISA strains | ||
|---|---|---|---|---|---|
| ≤0.5 | 1.0 | 2.0 | |||
| 1995 | 94 (47) | 101 (50) | 7 (8) | 19 | 1 (5.3) |
| 1996 | 53 (19) | 222 (76) | 16 (5) | 28 | 2 (7.1) |
| 1997 | 80 (13) | 502 (84) | 16 (3) | 30 | 4 (13.3) |
| 1998 | 303 (40) | 453 (59) | 6 (1) | 20 | 2 (10.0) |
| 1999 | 263 (27) | 684 (69) | 44 (4) | 58 | 5 (8.6) |
| 2000 | 174 (50) | 166 (47) | 11 (3) | 25 | 1 (4.0) |
| 2001 | 187 (49) | 197 (51) | 4 (1) | 18 | 1 (5.6) |
| 2002 | 32 (8) | 324 (82) | 40 (10) | 61 | 2 (3.3) |
| 2003 | 15 (4) | 376 (86) | 45 (10) | 66 | 2 (3.0) |
| 2004 | 78 (13) | 524 (85) | 12 (2) | 33 | 4 (12.1) |
| 2005 | 342 (58) | 239 (41) | 6 (1) | 27 | 0 |
| 2006 | 329 (42) | 388 (50) | 64 (8) | 90 | 1 (1.1) |
| Total | 1,951 (31) | 4,192 (65) | 271 (4) | 475 | 25 (5.3) |
a
Antimicrobial susceptibility testing was done by the by broth microdilution method (4).