Evaluating the effect of cationic peptide K16ApoE against Staphylococcus epidermidis biofilms

Purpose Staphylococcus epidermidis is one of the most common causative pathogens of nosocomial-related infections. It is known to form biofilms on indwelling medical devices. The negatively charged extracellular matrix of the biofilm can entrap bacteria, thus limiting the diffusion of therapeutic agents and contributing to the ineffectiveness of therapeutic agents against the bacteria. To combat this, we investigated the effectiveness of a cationic peptide, K16ApoE, with bioadhesive properties to serve as an anti-adhesion agent. Methods The ability of K16ApoE to serve as an anti-adhesive agent was evaluated using crystal violet staining to quantify the degree of inhibition of biofilm formation. The minimum inhibitory concentration was determined by concurrently incubating the S. epidermidis inoculum with K16ApoE (0-250 mu g/mL) for 24 h, after which a relative biofilm density assay was performed. Inhibition of the surface adhesion of biofilms to various matrices was also evaluated by coating K16ApoE on ceramic discs as well as polyvinyl chloride (PVC) or silicone catheter extension tubing. Bovine serum albumin (BSA), pure unconjugated ApoE or K16 peptide were used as controls. Results K16ApoE (250 mu g/mL) was very effective at reducing biofilm integrity by 99.92%. ApoE or K16 alone was largely ineffective compared to K16ApoE. In addition, catheter tubing pretreated with K16ApoE showed a significant (83 +/- 12.7%) reduction in the formation of adherent biofilms. Conclusion These results demonstrate that K16ApoE can serve as an effective anti-adhesive agent to prevent the formation of an adherent bacterial biofilm on matrices with different surface properties.

Automated summary

The study found that K16ApoE as an anti-adhesive agent has a significant inhibitory effect on the formation of Staphylococcus epidermidis biofilms, effectively preventing bacteria from forming adherent biofilms on different surfaces.