IN VITRO ANTIBACTERIAL ACTIVITY OF CINOXACIN

• Published in: CHEMOTHERAPY Vol. 28; no. Supplement4; pp. 46 - 65
• Main Authors: TAWARA, KATSUYA, YOSHIDA, TADASHI, TAKEMA, MORIO, MOTOKAWA, KIYOSHI
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Chemotherapy 1980
• ISSN: 0009-3165; 1884-5894
• DOI: 10.11250/chemotherapy1953.28.Supplement4_46

The in vitro activity of cinoxacin, a new synthetic organic acid with a cinnoline as its basic ring structure, was compared with that of nalidixic acid and pipemidic acid. Cinoxacin showed effective in vitro activity against members of the family Enterobacteriaceae, but negligible activity against Pseudomonas aeruginosa and gram-positive cocci. The antibacterial activity of cinoxacin was similar to that of nalidixic acid, but slightly lower than that of pipemidic acid. Minimal inhibitory concentrations of cinoxacin were determined by agar dilution method for 734 clinical isolates of 11 species of pathogenic bacteria. Escherichia coli was the most susceptible group of organisms. Eighty percent of the isolates were inhibited by 6.25μg/ml of cinoxacin with inoculum of 108 cells per ml. Seventy percent of Proteus vulgaris, Klebsiella pneumoniae and Citrobacter freundii were inhibited by 12.5 μg/ml. Most strains of Escherichia coli, Proteus mirabilis, Proteus vulgaris and Proteus inconstans were found to be more susceptible to cinoxacin in Nutrient agar than in other media. Cinoxacin showed bactericidal effect at minimal inhibitory concentration against E. coli in broth dilution test. Relative to nalidixic acid, cinoxacin showed slightly greater bactericidal activity.