TABLE 5.
Comparison of MICs generated by the VITEK 2 method (P534 cards) with MICs generated by the reference microbroth dilution method for 121 enterococcia
| Species | Drug | No. of VITEK 2 MICs that differed from reference MICs by the following dilution
|
EA (no. [%]) | No. of errors
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| −3 | −2 | −1 | Concordant | +1 | +2 | +3 | Minor | Major | Very major | |||
| E. faecium wild type (n = 1) | Vancomycin | 0 | 1 | 1 | ||||||||
| Teicoplanin | 0 | 1 | ||||||||||
| E. faecium vanA (n = 66) | Vancomycin | 66 | 66 (100) | |||||||||
| Teicoplanin | 1 | 1 | 5 | 52 | 7 | 64 (97) | 11 | |||||
| Quin-dalfo | 40 | 26 | 66 (100) | |||||||||
| Linezolid | 1 | 54 | 11 | 65 (98.5) | 4 | |||||||
| Moxifloxacin | 9 | 56 | 1 | 66 (100) | 6 | |||||||
| E. faecium vanB (n = 14) | Vancomycin | 2 | 10 | 2 | 12 (85.7) | |||||||
| Teicoplanin | 2 | 4 | 8 | 12 (85.7) | ||||||||
| Quinu-dalfo | 10 | 4 | 14 (100) | |||||||||
| Linezolid | 12 | 2 | 14 (100) | |||||||||
| Moxifloxacin | 14 | 14 (100) | ||||||||||
| E. gallinarum vanC1 (n = 30) | Vancomycin | 19 | 7 | 4 | 26 (86.7) | 5 | ||||||
| Teicoplanin | 30 | 30 (100) | ||||||||||
| Quinu-dalfo | 2 | 25 | 3 | 30 (100) | 4 | |||||||
| Linezolid | 27 | 1 | 2 | 28 (93) | 1 | |||||||
| Moxifloxacin | 30 | 30 (100) | ||||||||||
| E. casseliflavus vanC2 (n = 10) | Vancomycin | 1 | 9 | 10 (100) | 1 | |||||||
| Teicoplanin | 1 | 9 | 10 (100) | |||||||||
| Quinu-dalfo | 2 | 8 | 10 (100) | 2 | ||||||||
| Linezolid | 3 | 7 | 10 (100) | 1 | ||||||||
| Moxifloxacin | 2 | 8 | 10 (100) | |||||||||
a
Dilutions indicate the number of VITEK 2 MIC dilutions compared to reference microbroth dilution MICs. EA, essential agreement (present VITEK 2 MICs within 1 dilution of reference MICs); minor error, intermediate by either the VITEK 2 or reference method and either susceptible or resistant by the other method. Quin-dalfo, quinupristin-dalfopristin.