Effect of Ciprofloxacin, Levofloxacin, and Ofloxacin on Pseudomonas aeruginosa: A case control study with time kill curve analysis

Background: Antibiotic resistance is closely related to therapy failure. Most antibiotic resistance is caused by delays in determining antibiotic agents, low administration doses, long periods between doses (inadequate pharmacokinetics) and single drug administration in infections caused by more than one pathogen. Treatment of Pseudomonas aeruginosa (P. aeruginosa) with ciprofloxacin, levofloxacin, and ofloxacin as monotherapy can lead to drug resistance, although combination therapy also does not provide a better outcome. Objective: To analyze the time-kill curve for P. aeruginosa and Multidrug resistance (MDR) P. aeruginosa. Methods: This research is a case control study using isolates of P. aeruginosa ATCC 27853, clinical isolates of P. aeruginosa and MDR P. aeruginosa. Exposure of ciprofloxacin, levofloxacin, and ofloxacin to isolates with 1MIC, 2MIC, and 4MIC were then cultured at 0, 2, 4, 6, 8, 24 h of testing, then counting the number of colonies that grew and then analyzed by time-kill curve and statistical tests. The statistical test used in this study was the ANOVA and Mann-Whitney test with p < 0.05. Results: Ciprofloxacin and ofloxacin achieved bactericidal activity, especially at a concentration of 4MIC. Levofloxacin ultimately achieved bactericidal activity at all concentrations. Statistical analysis showed there were significant differences in the number of colonies p < 0.001 in the second, fourth, sixth, and eighth hour between the three isolates, p < 0.001 in the sixth and second 4 h between 1MIC and 4MIC, p = 0.012 in the second 4 h between levofloxacin and ofloxacin antibiotics. Conclusion: Levofloxacin has shown to have better bactericidal activity than ciprofloxacin, and ciprofloxacin has almost the same bactericidal activity as ofloxacin in vitro tests seen from the time-kill curve.