Abstract
The in vitro activity of rosoxacin, a pyridyl quinolone derivative against Neisseria gonorrhoeae is compared with that of penicillin, cefuroxime and tetracycline. Three groups of gonococci comprising of β-lactamase-positive and negative strains and gonococci with high penicillin MICs are studied. Rosoxacin was the most active against the entire spectrum of gonococci tested in vitro and its activity is not affected by the production off β-lactamase by some gonococci.