TABLE 3.

Comparison of susceptibility testing methods to mecA gene analysis for 41 S. aureus isolates

Method	Medium	Incubation temp (°C)	Incubation time (h)	No. of isolates					Sensitivity (%)	Specificity (%)
				mecA positive	mecA negative	Susceptible	Intermediate	Resistant
Agar dilution	0% NaCl	30	24	17	24	24		17	100	100
			48	17	24	24		17	94.1	95.8
		35	24	17	24	24		17	100	100
			48	17	24	24		17	100	100
	2% NaCl	30	24	17	24	24		17	100	100
			48	17	24	23		18	100	95.8
		35	24	17	24	24		17	100	100
			48	17	24	24		17	100	100
	4% NaCl	30	24	17	24	22		19	100	95.8
			48	17	24	24		17	100	100
		35	24	17	24	24		17	100	91.7
			48	17	24	20		21	100	83.3
Disk diffusion	Difco	35	24	17	24	24	0	17	100	100
			48	17	24	12	2	27	100	41.7
	BBL	35	24	17	24	24	0	17	100	100
			48	17	24	14	4	23	100	58.3
Agar screen
Swab inoculation	Remel	35	24	17	23	23a		17	100	100
			48	17	23	23a		17	100	100
	Difco	35	24	17	24	24		17	100	100
			48	17	24	24		17	100	100
Spot inoculation	Remel	30	24	17	24	24		17	100	100
			48	17	24	23		18	100	95.8
		35	24	17	24	24		17	100	100
			48	17	24	24		17	100	100
	Difco	30	24	17	24	24		17	100	100
			48	17	24	24		17	100	100
		35	24	17	24	24		17	100	100
			48	17	24	24		17	100	100

^aOne isolate not tested.