Novel pyridonecarboxylic acids of the formula :
 or the pharmaceutically acceptable salts thereof having a more potent and longer lasting antibacterial activites against gram-positive and gram-negative bacteria than known analogues, useful for antibacterial agents at an oral dose of 1-500 mg, preferably 50-100 mg per day to an adult.  
                            式.的新型
吡啶羧酸或其药物可接受盐对革兰氏阳性和阴性细菌的抗菌活性比已知类似物更强、更持久:
 或其药学上可接受的盐类,对革兰氏阳性菌和革兰氏阴性菌的抗菌活性比已知类似物更强、更持久,可用作抗菌剂,成人每天口服剂量为 1-500 毫克,最好为 50-100 毫克。