TABLE 3.

Performance of the VITEK 2 system for AST of gram-positive cocci compared to that of the reference method

Microorganism(s) and antimicrobial agent	No. of isolates with susceptibilitya			No. of errors			CA (%)
	S	I	R	VME	ME	mE
S. aureus (n = 100)
Clindamycin	50	0	50	0	0	0	100
Erythromycin	40	1	59	0	0	0	100
Gentamicin	50	0	50	0	0	0	100
Norfloxacin	38	7	55	0	0	6	94
Oxacillin	39	0	61	0	0	0	100
Rifampin	92	2	6	0	0	2	98
Teicoplanin	100	0	0	0	0	0	100
Vancomycin	100	0	0	0	0	0	100
CNS (n = 100)
Clindamycin	59	6	35	0	0	6	94
Erythromycin	40	7	53	1	0	9	90
Gentamicin	38	3	59	0	0	9	91
Norfloxacin	46	9	45	0	0	8	92
Oxacillin	32	0	68	1	2	0	97
Rifampin	74	7	19	0	0	3	97
Teicoplanin	95	5	0	0	0	7	93
Vancomycin	100	0	0	0	0	0	100
Enterococcus spp. (n = 89)
Ampicillin	69	1	19	0	0	1	99
Teicoplanin	67	0	22	4	0	4	91
Vancomycin	67	0	22	0	0	1	99
HC Gentamicin	69		20	1	0	0	99
HC Streptomycin	44		45	0	0	0	100
S. agalactiae (n = 29)
Ampicillin	29	0	0	0	0	0	100
Clindamycin	28	0	1	0	0	0	100
Erythromycin	28	0	1	0	0	0	100
Tetracycline	12	0	17	0	1	0	96
Teicoplanin	29	0	0	0	0	0	100
Vancomycin	29	0	0	0	0	0	100
S. pneumoniae (n = 66)
Penicillin	60	5	1	0	0	6	91
Cefotaxime	65	1	0	0	0	2	97
Erythromycin	49	0	17	0	0	0	100
Ofloxacin	66	4	0	0	0	3	95
% for all individual         species testedb				0.24	0.12	2.7	97
% according to FDA-        NCCLS criteriac				0.82	0.17	2.7	96

^aAbbreviations; S, susceptible; I, intermediate; R, resistant.\

^bCalculated from results for 2,483 drug-organism combinations.\

^cPercent VME = number of VME × 100/total number of resistant strains (730); percent ME = number of ME × 100/total number of susceptible strains (1,753); percent mE = number of mE × 100/total number of strain tested (2,483). FDA, Food and Drug Administration.