TABLE 2.

Effect of medium source on oxacillin MICs expressed as dilution difference of MICs

Organism group and media	No. of results with a dilution difference of:							% of results within a dilution difference of ±1
	≥−3	−2	−1a	0	+1b	+2	≥+3
mecA negative
S. epidermidis
CDC Difco vs. MicroScan Difco			5	76	16			100
CDC Difco vs. CDC Acumedia			13	77	9		1	99.0
MicroScan Difco vs. MicroScan BDMS		1	37	58	2			99.0
Other species
CDC Difco vs. MicroScan Difco		8	32	71	18			93.8
CDC Difco vs. CDC Acumedia		19	38	54	6			83.8
MicroScan Difco vs. MicroScan BDMS		8	44	77	1			93.8
mecA positive
S. epidermidis
CDC Difco vs. MicroScan Difco	29	50	77	29	5	1		58.1
CDC Difco vs. CDC Acumedia	1	7	18	45	54	46	11	64.3
MicroScan Difco vs. MicroScan BDMS	2	3	12	45	91	33	11	75.1
Other species
CDC Difco vs. MicroScan Difco	2	18	20	24	15	2		76.5
CDC Difco vs. CDC Acumedia	26	12	9	22	6			49.3
MicroScan Difco vs. MicroScan BDMS	1	6	21	39	12	3		87.8

^aThe second parameter in the comparison is lower. 

^bThe second parameter in the comparison is higher.