TENTATIVE INTERPRETIVE CRITERIA AND QUALITY-CONTROL PARAMETERS FOR IN-VITRO SUSCEPTIBILITY TESTING OF NEISSERIA-GONORRHOEAE TO 2 FLUOROQUINOLONES (PD-131628 AND GREPAFLOXACIN (OPC-17116))

The susceptibility of Neisseria gonorrhoeae to PD 131628 and grepaflox acin (OPC 17116) was evaluated by agar dilution and disc diffusion met hods. A tentative susceptibility category for both fluoroquinolones in cluded strains for which the MICs are equal to or less than 0.06 mg/L and the zones of inhibition are equal to or greater than 38 mm for PD 131628 and equal to or greater than 37 mm for grepafloxacin. Quality c ontrol studies with N. gonorrhoeae ATCC 49226 suggested that agar dilu tion MIC limits were 0.002-0.008 mg/L and 0.004-0.03 mg/L for PD 13162 8 and grepafloxacin, respectively. The zone size limits were 50-58 mm for PD 131628 and 44-52 mm for grepafloxacin.