Formation rule of Staphylococcus aureus biofilm and effect of Qingkailing granules on this biofilm

Objective To observe the formation rule of Staphylococcus( S.) aureus biofilm and the inhibitory and damage effects of Qingkailing granules on this biofilm. Methods Double dilution method for the determination of minimum inhibitory concentration( MIC) of Qingkailing granules. The inhibitory effect on biofilm was examined by crystal violet assay,while bacteria and sample liquid were joined in the biofilm at the same time. The damage effect on biofilm was also examined by crystal violet assay,while Qingkailing granules was added after S. aureus biofilm formation. Results The biofilms formed better in 15 hours.Qingkailing granules showed a good effect with 3. 9 to 62. 4 mg · m L-1concentration proved by biofilm inhibition test and destruction test( P 0. 05). Conclusion Qingkailing granules exhibits a good antibacterial effect on S. aureus,it also has a inhibitory and damage effect on S. aureus biofilm in a concentration-dependent manner.