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Table 1 Susceptibility of urine-(SaU) isolate and blood isolates obtained before (SaB1) and during (SaB2) vancomycin therapy

From: Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

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 +
  1. 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.