Evaluation of the effect of curcumin-ciprofloxacin encapsulated chitosan nanoparticles on Pseudomonas aeruginosa motility

BACKGROUND AND OBJECTIVESP. aeruginosa is a gram-negative opportunistic bacterial pathogen. The ability of P. aeruginosa to cause chronic infection is attributed to several factors such as biofilm formation, intrinsic resistance to antibiotics, and QS-dependent virulence traits. Curcumin is a polyphenol compound with anti-tumor, antioxidant, anti-inflammatory, antimicrobial, and anti-biofilm properties. Therefore, the current work was performed to evaluate the effect of curcumin-ciprofloxacin encapsulated chitosan nanoparticles (Cur-Cip chitosan NPs) on P. aeruginosa motility.MATERIALS AND METHODSTo evaluate the swarming motility, a nutrient agar medium containing ۵% agar and Cur-Cip chitosan NPs (۶۴۰ mg/mL) was prepared in ۶ cm Petri dishes. Then, ۲ μL of bacterial suspension was placed on the surface of the medium. After incubation, the swarming zone diameter was measured. The effect of the NPs on twitching motility in a nutrient agar medium (۱.۵% agar) containing Cur-Cip chitosan NPs was evaluated. The bacterial suspension was inoculated at the bottom of the plates and after incubation, the medium was removed and the plates were stained with crystal violet and the twitching motility zone was measured. To evaluate bacterial swimming, nutrient broth containing ۰.۳% agar and the NPs was prepared in Petri dishes and the bacterial suspension was inoculated in the center of the agar layer. After incubation, the swimming zone was measured.RESULTS AND DISCUSSIONCur-Cip chitosan NPs significantly reduced the swarming, swimming, and twitching motility of P. aeruginosa. The swimming and swarming motility zones in the presence of the NPs reduced by ۶۵% and ۴۵%, respectively. Also, bacterial twitching was almost completely inhibited in nanoparticles-treated bacteria.CONCLUSIONCur-Cip chitosan NPs exhibited considerable inhibitory effects on the motility of P. aeruginosa strains. Due to the role of bacterial motility in the pathogenesis of P. aeruginosa, Cur-Cip chitosan NPs can be considered a potent anti-virulence compound against pathogenic P. aeruginosa strains.

کلیدواژه ها:

Curcumin ، Chitosan ، Ciprofloxacin ، Twitching.