Fluoroquinolone (Lomefloxacin) International Surveillance Trial: a report of 30 months of monitoring in vitro activity.

The antimicrobial activity and spectrum of lomefloxacin were assessed by standardized disk diffusion methods in 36 countries. More than 500,000 facultative organisms were tested during the first 30 months of a 3-year monitoring interval. Lomefloxacin demonstrated inhibition (zones greater than or equal to 19 mm) of greater than 90% of Enterobacteriaceae, greater than 99% of Moraxella (Branhamella) catarrhalis, greater than 98% of Haemophilus spp., and 91% of Staphylococcus aureus strains. Pseudomonas spp., especially Pseudomonas aeruginosa (18% resistance), were considered moderately susceptible, as were most strains of streptococci and enterococci. Some variation of national/regional fluoroquinolone resistance rates was observed, using lomefloxacin as an index or indicator drug, with the highest numbers of resistant strains being isolated in France. However, these data demonstrated a wide spectrum of lomefloxacin activity in all nations monitored.