合成化学療法剤Pipemidic acidに関する細菌学的研究

抄録

Pipemidic acid is a new synthetic antibacterial agent structurally related to nalidixic acid. Pipemidic acid was inherently similar to nalidixic acid in antibacterial spectrum, though the former was generally more potent than the latter in in vitro antibacterial activity.
Nalidixic acid-resistant bacteria and Pseudomonas aeruginosa were also inhibited by pipemidic acid. Pipemidic acid was stable when dissolved in water and kept at 37°C for 1 month. Its antibacterial activity tended to become higher when medium pH was alkaline, but serum addition and high inocula caused a descent in the activity of pipemidic acid as well as nalidixic acid. Pipemidic acid was generally bactericidal above its minimal inhibitory concentrations. Frequencies of mutants resistant to pipemidic acid were lower than those of mutants resistant to nalidixic acid, streptomycin and rifampicin.
Scanning and transmission electron microscopy revealed that pipemidic acid caused damage to the cell surface of Pseudomonas aeruginosa.
In the experimental infections with various bacteria in mice, pipemidic acid was always more effective than nalidixic acid. The infection due to Pseudomonas aeruginosa or nalidixic acid-resistant organism was also succesfully treated with pipemidic acid by the oral route.