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.