[Comparative in vitro activity of 10 new 4-quinolones against enteropathogenic bacteria]

The susceptibility has been determined of 169 Shigella spp., 93 Salmonella spp., 68 Yersinia enterocolitica, 34 Vibrio cholerae 0:1, and 34 Campylobacter jejuni, isolated in Central Africa and in Belgium, to ten fluoroquinolones: ciprofloxacin, ofloxacin, norfloxacin, pefloxacin, enoxacin, amifloxacin, CI-934, A-56619, A-56620 and RO 23-6240. All quinolones were active against the strains tested, showing an MIC90 between 0.004 mg/l and 2 mg/l for strains susceptible to nalidixic acid and an MIC90 between 0.12 and 4 mg/l for resistant strains. Ciprofloxacin was the most active compound against Shigella spp., Salmonella spp. and Y. enterocolitica. A-56620 was the most active against C. jejuni; and both compounds were equal in activity against V. cholerae. The MBCs of all ten compounds were either similar to the MIC or one concentration higher. Killing curves show that the quinolones are bactericidal for the strains tested within 2 to 8 h of contact with concentrations corresponding to 2 or 8 times the MIC.