TABLE 3.
Proposed criteria for differentiating hVISA/VISA from non-VISA isolates
| Category | Vancomycin MIC (μg/ml) (macrodilution) | And/or | Agar testing |
|
|---|---|---|---|---|
| Growth on BHIV2a | Growth on BHIT4b | |||
| Non-VISA | ≤2 | And | <103 CFU | <103 CFU |
| Potential VISA | ≥4 | Or | SC2c or C2d | SC4 or C4 |
| Proven VISA | ≥4 | And | SC2 or C2 | SC4 or C4 |
a
Number of CFU/plate from 200-μl inocula (106 CFU/plate) on BHI agar supplemented with 2 μg of vancomycin (BHIV2) per ml.
b
Number of CFU/plate from 200-μl inocula (106 CFU/plate) on BHI agar supplemented with 4 μg of teicoplanin (BHIT4) per ml.
c
Semiconfluent growth on BHIV2 (SC2) or BHIT4 (SC4).
d
Confluent growth on BHIV2 (C2) or BHIT4 (C4).