Antimicrobial activity against clinical isolates of staphylococcus aureus and therapeutic effect on acute bronchitis of AM-715

Antimicrobial activity of AM-715, which is a new quinoline derivative structually related to nalidixic acid, against clinical isolates of Staphylococcus aureus was examined and compared with that of β-lactam antibiotics. Against these isolates of Staphylococci, CER was shown to be most effective among antimicrobial agents tested, followed by MCIPC and AM-715. AM-715 inhibited all the strains tested at a narrow range of the concentrations ranging from 0.2 to 6.25 μg/ml, while β-lactam antibiotics need higher concentrations, 25 μg/ml or more, for the inhibition of all of these strains. Eight patients with acute bronchitis, mild or moderate in severity, were treated with oral administration of 600mg a day of AM-715. Of these patients, seven were associated with underlying diseases; one with healed pulmonary tuberculosis, one with chronic pulmonary emphysema, one with bronchiectasis, one with cerebral vascular disorder and three with lung cancer. For these patients AM-715 was given for five to ten days. An excellent and a good clinical response was obtained in three and five patients respectively. No adverse symptom and sign was noted during adminstration of AM-715.