[PROBLEMS] To provide a novel quinolonecarboxylic acid compound which is safe,has potent antibacterial activity, and is effective against resistant bacteriawhich are less controlled by conventional antibacterials. [MEANS FOR SOLVINGPROBLEMS] It is a 7-(4-substituted 3-cyclopropylaminomethylpyrrolidinyl)quinolonecarboxylic acid derivativerepresented by the general formula (I)(typical example: 1-cyclopropyl-7-[(3S,4S)-3-cyclopropyl~aminomethyl-4-fluoro-1-pyrrolidinyl]-6-fluoro-1,4-dihydro~8-methoxy-4-oxo-3-quinolinecarboxylic acid). The derivative has potentantibacterial activity against gram-positive bacteria, in particular,resistant bacteria such as MRSA, PRSP, and VRE, and is highly safe.
