Initial adhesion and surface growth of Staphylococcus epidermidis and Pseudomonas aeruginosa on biomedical polymers

The infection risk of biomaterials implants varies between different materi als and is determined by an interplay of adhesion and surface growth of the infecting organisms. In this study, we compared initial adhesion and surfa ce growth of Staphylococcus epidermidis HBH2 102 and Pseudomonas aeruginosa AK1 on poly(dimethylsiloxane), Teflon, polyethylene, polypropylene, polyur ethane, poly(ethylene terephthalate), poly(methyl methacrylate), and glass. Initial adhesion was measured in situ in a parallel plate now chamber with microorganisms suspended in phosphate-buffered saline, while subsequent su rface growth was followed in full and in 20 times diluted growth medium, in itial adhesion of both bacterial strains was similar to all biomaterials in full growth medium, generation times of surface growing S. epidermidis ran ged from 17 to 38 min with no relation to wettability, while in diluted gro wth medium generation times increased from 44 to 98 min with increasing sur face wettability. For P. aeruginosa no influence of surface wettability on generation times was observed, but generation times increased with decreasi ng desorption rates, maximal generation times being 47 min and minimal valu es down to 30 min. Generally, generation times of adhering bacteria were sh orter than of planktonic bacteria. In conclusion, surface grow th of initia lly adhering bacteria is influenced by biomaterials surface properties to a greater extent than initial adhesion. (C) 2000 John Wiley & Sons, Inc.