TABLE 1.
Isolate or strain no. | Result bya:
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---|---|---|---|---|---|---|---|---|---|
PAP-AUCb
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Vancomycin screen (4 μg/ml)c
|
CLSI standard
|
Etest
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MIC (μg/ml)
|
Interpretation | ||||||||
Mean (SE) AUCtest/Mu3 ratio | Interpretation | No. of colonies | Interpretation | MIC μg/ml | Interpretation | Vancomycin | Teicoplanin | ||
S. capitis 6 | 1.7 (0.15) | I | 7, 86, CG | V | 2 | S | 6 | 2 | S |
S. capitis 22 | 1.7 (0.12) | I | CG | R | 4 | S | 12 | 16 | H |
S. capitis 15 | 1.3 (0.08) | I | CG | R | 4 | S | 12 | 16 | H |
S. aureus Mu50 | 1.6 (0.05) | I | CG | R | 8 | R | 16 | 12 | H |
S. capitis 17 | 1.2 (0.04) | H | 4 | H | 2 | S | 3 | 4 | S |
S. capitis 8ad | 1.1 (0.03) | H | 2 | H | 1 | S | 4 | 3 | S |
S. capitis 9 | 1.1 (0.03) | H | 0, 2, CG | V | 1 | S | 4 | 2 | S |
S. capitis 16 | 1.1 (0.03) | H | 1 | H | 1 | S | 3 | 2 | S |
S. capitis 8bd | 1.0 (0.04) | H | 12 | H | 1 | S | 8 | 3 | S |
S. capitis 18 | 1.0 (0.05) | H | 0, 36, CG | V | 2 | S | 4 | 4 | S |
S. capitis ATCC 27840 | 1.0 (0.01) | H | 1 | H | 1 | S | 2 | 0.2 | S |
S. aureus Mu3 | 1 | H | 14 | H | 2 | 8 | 16 | H |
I, intermediate; S, susceptible; H, possibly heteroresistant; R, potentially resistant; V, variable results; CG, confluent growth on at least three of four replicates.
Mean (standard error) AUC determined by PAP. An AUCtest/Mu3 ratio of ≤0.90 was interpreted as susceptible, a ratio of 0.90 to 1.3 was interpreted as heteroresistant, and a ratio of ≥1.3 was interpreted as intermediate.
Number of colonies on BHIA containing 4 μg/ml vancomycin after 48 h.
Isolates 8a and 8b were collected on different occasions from the same infant.