Qom University of Medical Sciences Journal

Background and Objectives: Pseudomonas aeruginosa is one of the most common causes of secondary infections. Considering the indiscriminate use of antibiotics and the risk of antibiotic resistance, studies on identification of new antibacterial agents, have increased. The aim of this study was to evaluate the antibacterial effect of silver nanoparticles, ciprofloxacin, and their combination on P. aeruginosa PAO1. 

Methods: Inhibitory effect of silver nanoparticles and ciprofloxacin alone and their combination, was investigated on P. aeruginosa PAO1 using disk diffusion method. Also, using broth macrodilution method, MIC and MBC of each agent were determined. Data statistical analysis was performed using one-way ANOVA test. Significance level was considered to be p<0.05.

Results: Investigation of the effect of silver nanoparticles and ciprofloxacin alone on Pseudomonas aeruginosa showed that dilutions above 15.26mg/ml and 5.85g/ml inhibit the bacterial growth. Also, evaluation of combined effect of silver nanoparticles and ciprofloxacin showed that the plates containing combined disks of ciprofloxacin and silver nanoparticles with dilutions of 1.46µg/ml and 1.95mg/ml caused inhibition zone, respectively.

Conclusion: It seems that silver nanoparticles in combination with ciprofloxacin have synergistic effect against Pseudomonas aeruginosa. Therefore, this issue reduces the risk of incidence of genetic mutations in bacteria and consequently reduces the risk of developing resistant strains.