Bactericidal action of lomefloxacin a new pyridonecarboxylic acid derivative

: Lomefloxacin (NY-198) [(+/-)-1-ethyl-6,8-difluoro-1,4-dihydro-7-(3-methyl-1-piperazinyl)-4-oxo -3- quinolinecarboxylic acid hydrochloride] strongly inhibited the growths of not only Gram-negative Escherichia coli but Gram-positive Staphylococcus aureus. In vivo and in vitro experiments showed deoxyribonucleic acid (DNA) synthesis was specifically inhibited by this drug in E. coli.