Biofilm formation ability of homologous Staphylococcus aureus strains:a comparative study

OBJECTIVE To compare the adhesion and the abilities of biofilm formation of the homologous clinical isolates of Staphylococcus aureus.METHODS Congo red plate method was used to detect strains The in vitro biofilm model of S.aureus was established,and the crystal violet staining biofilm semi-quantitative method was employed to compare the adhesion and biofilm formation abilities of the homologous S.aureus.RESULTS Totally 10 strains of homologous S.aureus were biofilm formation-positive,which were isolated from the clinic.The ability of adhesion and early biofilm formation of S.aureus 17546 was the strongest(P0.001),but S.aureus 17422′s was the weakest(P0.001).As for the formation ability of the mature biofilm,S.aureus 17546 was the most powerful(P0.001),S.aureus 17642 was extremely similar to strain 17546(P=0.495).the biofilm formation ability of S.aureus 17422 was the weakest,but as compared with S.aureus 17431,S.aureus 18541-2,S.aureus 18558,S.aureus 18565 and S.aureus 18719,the difference was not statistically significant.CONCLUSION Congo red plate method can detect the S.aureus strains of BF formation.All the homologous S.aureus strains vary in the adhesion and biofilm formation ability.