The Effect of Honeybee Propolis on Escherichia coli Biofilm Formation in vitro

Background: Colibacillosis is an infectious disease that affects livestock such as cattle, pigs, goats, sheep, horses and poultry caused by the bacterium Escherichia coli. E. coli can form biofilms when environmental conditions are unfavorable. The purpose of this research is to determine the effect of honeybee propolis on the formation of E. coli biofilm in vitro. Methods: The research began with the dilution of propolis using the microdilution technique and determination of concentration values with a modified minimum inhibitory concentration (MIC). Biofilm inhibition assays were conducted in microplates with five propolis concentration treatments: 0.39 mg/mL, 0.78 mg/mL, 1.56 mg/mL, 3.125 mg/mL and 6.25 mg/mL, along with negative and positive controls, with eight replications. Subsequently, crystal violet quantification and absorbance value readings were done using an ELISA reader with a wavelength of 595 nm. Result: The results showed that between concentrations of 3.125 mg/mL, 6.25 mg/mL and the negative control, there was no significant difference with mean values of 0.09963, 0.078857 and 0.079375, respectively. Honeybee propolis extract has the potential to act as an antibiofilm against E. coli in vitro, with the minimum concentrations capable of inhibiting biofilm formation being 3.125 mg/mL and 6.25 mg/mL.