TABLE 1.

 Comparative activities of the test antibiotics against the ciprofloxacin-susceptible control strain MRSA P8 and two ciprofloxacin-resistant MRSA strains used in experiments with animals

Drug	MIC (mg/liter)
	MRSA P8	MRSA P8/128a	MRSA CR1b
Ciprofloxacin	0.25	>128	128
Y-688	0.006	0.25	0.5
Sparfloxacin	0.06	2	16
Vancomycin	2	2	2

^aStrain P8/128 is a ciprofloxacin-resistant derivative generated by serial exposures of the ciprofloxacin-susceptible parent MRSA P8 to the drug. 

^bStrain CR1 is a ciprofloxacin-resistant clinical isolate of MRSA.