Quinolinecarboxylic acid derivatives represented by the following general formula (I) and physiologically-acceptable salts thereof.
wherein R' is hydrogen, alkyl, or substituted or unsubstituted phenyl; R2 is hydrogen, alkyl, alkoxy, hydroxy, halogen, nitro or substituted or unsubstituted amino; R3 is hydrogen or optionally-substituted alkyl; R4 and R5 are same or different and are alkyl or hydroxyalkyl or R4 and R5 may be combined and may form a cyclic amino together with the adjacent nitrogen atom and said cyclic amino may also be substituted and may further contain nitrogen, oxygen or sulfur as heteroatoms therein; and X is halogen, have been found to be very effective antibacterial therapeutic agents for systemic and local infectious diseases caused by P. aeruginosa and Gram-positive and negative bacteria.