• 1 January 1985
    • journal article
    • research article
    • Vol. 11  (5) , 335-338
Abstract
The influence of pH on the antibacterial activity of ciprofloxacin, norfloxacin and ofloxacin was studied in broth and pooled human urine by microdilution susceptibility tests. Selected strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used as test organisms. Cultivation at pH 5.7 in urine increased the MIC [minimal inhibitory concentration] values for all 3 quinolones 8, 16 and 32-fold compared with broth at pH 7.1. Killing curves show that in urine with 10 mcg/ml ciprofloxacin, rapid killing of E. coli and P. aeruginosa occurred, whereas ofloxacin and especially norfloxacin were less effective.