Isolates | Broth dilution μg/ml | Agar dilution μg/ml |
E-test
μg/ml | VITEK 2 μg/ml | MET μg/ml | GRD strip μg/ml | MHA5T |
---|
 |
VAN
|
TEIC
|
VAN
|
TEIC
|
VAN
|
TEIC
|
VAN
|
TEIC
|
VAN
|
TEIC
|
VAN
24 h/48 h
|
TEIC
24 h/48 h
|
TEIC
|
SaU | 1 | 1 | 1 | 1 | 1 | 1 | 1 | ≤ 05 | 4 | 8 | 1/1 | 2/2 | - |
SaB1 | 1 (1)* | 1 | 1 | 1 | 1 (1.5)* | 1 (1)* | 1 | ≤ 05 | 4 | 8 | 1/1 | 2/2 | - |
SaB2
|
2 (2)*
|
4
|
2
|
4
|
2 (2)*
|
2 (1.5)*
|
2
|
4
|
12
|
12
|
4/4
|
12/16
| + |
- MIC: Minimum inhibitory concentration, VAN: vancomycin, TEIC: teicoplanin, MET: Macromethod E-test, 200 μl of inoculum at 2 McFarland standard suspensions onto BHI Agar, positive result: VAN MIC of ≥8 and TEIC MIC of ≥8 μg/ml or TEIC MIC of ≥12 μg/ml; GRD strip, Etest Glycopeptide-resistance (AB bioMérieux) detection strip were used as described by the manufacture:GRD positive (GISA o h-GISA): VAN o TEIC ≥ 8 μg/ml; MHA5T screening, Mueller Hinton Agar with 5 μg/ml of TEIC, 10 μl of inoculum at 0.5 McFarland-standard direct-colony suspensions. Any growth was considered positive. All screening methods were read at 24 and 48 h and incubated at 35°C. (MIC)*: MIC results from the Instituto Nacional de Enfermedades Infecciosas Dr. Carlos G. Malbran. The strains h-VISA-Mu3 and VISA-Mu50 and the vancomycin-susceptible S. aureus strain ATCC 29213 were tested for all methods in parallel, as positive and negative controls, respectively.