Staphylococcus epidermidis RP62A adhesion to chemically modified cellulosederivatives

The adhesion of coagulase negative Staphylococcus epidermidis expressing ca psular polysaccharide/adhesin (PS/A) to cellulose diacetate (CDA), as well as to primary reference low-density polyethylene, was assessed in vitro. At tached bacteria were released by gentle sonication and quantified as colony forming units. Surface free energy of cells and materials and the free ene rgy of interaction between cells, each type of material and water molecules was calculated through contact angle measurement, also enabling the determ ination of materials surface hydrophobicity. The influence of CDA surface m odification by deacetylation and phosphorylation on bacterial adhesion was studied. Chemical modifications of CDA by deacetylation and by phosphorylat ion were effective in lowering bacterial adhesion. (C) 2001 Kluwer Academic Publishers.