TABLE 1.

Vancomycin resistance of S. capitis isolates

Isolate or strain no.	Result bya:
	PAP-AUCb		Vancomycin screen (4 μg/ml)c		CLSI standard		Etest
							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

^aI, intermediate; S, susceptible; H, possibly heteroresistant; R, potentially resistant; V, variable results; CG, confluent growth on at least three of four replicates.

^bMean (standard error) AUC determined by PAP. An AUC_test/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.

^cNumber of colonies on BHIA containing 4 μg/ml vancomycin after 48 h.

^dIsolates 8a and 8b were collected on different occasions from the same infant.