SUSCEPTIBILITIES OF 123 XANTHOMONAS-MALTOPHILIA STRAINS TO CLINAFLOXACIN, PD-131628, PD-138312, PD-140248, CIPROFLOXACIN, AND OFLOXACIN

The susceptibilities of 123 clinically isolated strains of Xanthomonas maltophilia to six fluoroquinolones (clinafloxacin, PD 131628, PD 138312, PD 140248, ciprofloxacin, and ofloxacin) were examined py microdilution MIC methodology. Clinafloxacin and PD 131628 were the most active compounds tested (MICs for 50% of the strains tested [MIC(50)s] of 0.5 and 1.0 mu g/ml and MIC(90)s of 2.0 and 4.0 mu g/ml, respectively). PD 138312, PD 140248, ciprofloxacin, and ofloxacin were less active, with MIC(50)s ranging from 4.0 to 8.0 mu g/ml and MIC(90)s of 16.0 mu g/ml for all four compounds. Only clinafloxacin and PD 131628 were active against ciprofloxacin-resistant strains, with MIC(50)s of 0.5 and 1.0 mu g/ml and MIC(90)s of 2.0 and 4.0 mu g/ml, respectively.