Can Curcumin Prevent the Formation of Pseudomonas aeruginosa Biofilm on the Surface of Tympanostomy Tubes?

Abstract

Formation of bacterial biofilm on the surface of tympanostomy tubes are held responsible in the pathogenesis of post-tympanostomy tube otorrhea. To prevent the formation of biofilm, various methods were employed and varying degrees of success have been achieved. In some recent studies curcumin, which is the fenolic form of Curcuma longa (turmeric), has been pointed out to have inhibitory effects on virulence factors of Pseudomonas aeruginosa. The aim of this study was to investigate whether the administration of curcumin is able to prevent the formation of P.aeruginosa biofilm on the surface of silicone tympanostomy tubes in vitro conditions. For this purpose, qualitative and quantitative analysis of P.aeruginosa biofilm created on the surface of the tympanostomy tubes were performed following a period of 48 hours incubation in microplate wells that contained decreasing concentrations of curcumin. For qualitative analysis, specimens were evaluated with an environmental scanning electron microscope for the existence of biofilm. For the quantitative analysis, bacteria attached to the tube surface was detached using a combination of vortexing and sonication. Following serial dilutions, the obtained solution was then inoculated on the sheep blood agar plates using calibrated loop, incubated for 24 hours and the colony forming unit (CFU) per mL were recorded. Environmental scanning electron microscope analysis revealed that 100 mu g/mL of curcumin could prevent formation of the biofilm. Lower concentrations of curcumin could not prevent the biofilm formation. Qualitative analysis also revealed that when the concentrations of curcumin in the wells were decreased, the number of CFU/mL was increased significantly. Mean number of CFU in 100 mu g/mL and 12.5 mu g/mL groups were 35 +/- 7.07 and 650 +/- 494, respectively. Curcumin could prevent formation of P.aeruginosa biofilm on the surface of tympanostomy tubes in vitro with concentrations lower than the MIC value. The results of the present study show that local administration of curcumin may prevent suppurative otitis media following tympanostomy tube insertion, keep the patency of the tube and decrease the rate of treatment failure. In vivo studies are needed to support the in vitro anti-biofilm action of curcumin on tympanostomy tubes.