TABLE 2.

Antimicrobial susceptibility testing methods used by participating laboratories by organism^a

Strain	No. of results	No. of participating laboratories that used method
		Disk diffusion	Broth microdilutiona	MIC 2000a	MicroScana	Sceptora	Sensititrea	Viteka	MIC method not identified
WHO-1	130	83	2	7	23	9	2	3	1
WHO-2	127	75	3	7	25	9	2	5	1
WHO-3	122	72	4	7	23	8	2	5	1
WHO-4	128b	109	2	4	1	5	1	0	6
WHO-5	130	106	2	3	12	1	2	3	1
WHO-6	130	105	2	0	19	1	1	2	0

^aManufacturers: Broth microdilution, no manufacturer or method specified; MIC 2000, Eiken Ltd., Tokyo, Japan; MicroScan, Dade Behring, West Sacramento, Calif.; Sceptor, Becton Dickinson Microbiology Systems, Cockeysville, Md.; Sensititre, Trek Diagnostics, Westlake, Ohio; Vitek, bioMérieux, Hazelwood, Mo. 

^bForty laboratories performed the oxacillin screen test and determined the penicillin MIC of the organism using the Etest method.