Study Of Biofilm In Bacterial Adhesion To Biomaterials In Vitro

Objective: To investigate bacterial biofilm (BF) in the pathogenesis of biomaterial centered infection (BCI). We observe that bacterial biofilm forming on cardiovascular biomaterials in vitro. So this trial could provide a novel method for anti-bacterial adhesion, and prevent the rate of biomaterial centered infection.Methods: We observe the BF formation of Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) in the bacterial adhesive trial in vitro, by using scanning electron microscopy (SEM) and Spectrophotometric method for the optical densities (ODs) of adherent biofilm. We compare the ODs of the various bacterial biofilm on the same material surface. Results:一, Scanning electron microscopy (SEM) results: Our studies show three phases are involved in biofilm formation: the first phase is characterized by the rapid adherence of bacterial to the biomaterial surface, and is followed by a second, more prolonged accumulation phase that involves cell proliferation, enclosed in a self-produced extracellular slime substance (ESS) matrix and adhere to another formed microcolony. After these microcolonies developed into organized communities with functional heterogeneity, a mature biofilm has been formed in the third phase.二, Adhesive trial results:1. The ESS production of Staphylococcus epidermidis(SE)and Staphylococcus aureus(SA) in TSBD more than in0.9%N.S(P<0.01).2.The ESS production of Staphylococcus epidermidis(SE)onpolyvinylchloride(PVC)surface at 0, 3, 6, 9, 12, 15,18hours, compared with 21 , 24hours, the difference issignificant P<0.05).3.The ESS production of Staphylococcus aureus(SA) onpolyvinylchloride(PVC)surface at 0, 3, 6, 9, 12 , 15, 18,21 hours, compared with 24hours,the difference issignificant P<0.05).4.The ESS production of Staphylococcus epidermidis(SE) tothe same biomaterial surface is more than Staphylococcusaureus(SA) (P<0.05).Conclusion:1. Bacterial biofilm are composed of multilayered cell clusters that are embedded in an extracellular slime substance (ESS).2. The multilayered cell clusters of bacterial biofilm and ESS are the main cause of antibiotic resistance of bacteria in biofilms.3. The ESS plays an critical role in initial bacterial adherence and the later accumulative phases of adherence, in which organisms adhere to one another and elaborate biofilm. It is required for biofilm formation.