In vitro activity of the two new 4-quinolones A56619 and A56620 againstNeisseria gonorrhoeae,Chlamydia trachomatis,Mycoplasma hominis,Ureaplasma urealyticum andGardnerella vaginalis

The in vitro activity of tetracycline, ciprofloxacin and two recently developed 1-aryl-fluoro-quinolones, A56610 and A56620, was tested against 65 beta-lactamase-negative and 35 betalactamase-positiveNeisseria gonorrhoeaestrains, 12Chlamydia trachomatis,50Mycoplasma hominis,28Ureaplasma urealyticumand 50Gardnerella vaginalisstrains. In the case ofChlamydia trachomatisandMycoplasma hominisboth the MIC and the MBC were determined. The MIC90 of ciprofloxacin forNeisseria gonorrhoeaewas 0.008g/mland of A56619 and A56620 0.03g/ml.No difference was observed between the activity against beta-lactamase-negative and beta-lactamase-positive strains. The MIC90 values of ciprofloxacin and A56620 forChlamydia trachomatis, Mycoplasma hominisandUreaplasma urealyticumwere identical, the values being 2g/ml, 1g/mland 4g/mlrespectively. The MIC90 of A56619 forChlamydia trachomatisandUreaplasma urealyticumwas 0.5g/mland 1g/mlrespectively. The MBC90 values of the three quinolones forChlamydia trachomatisandMycoplasma hominiswere 2g/ml.The activity of the quinolones againstGardnerella vaginaliswas rather low, the MIC90 being 4g/ml.It is concluded that A56619 and A56620 might be useful for single-dose therapy of gonococcal infections.