The purpose of these experiments was to investigate methods and materials that could lead to a reduction in the number of nosocomial infections associated with indwelling medical devices. Using the viable count technique, we examined these proposed methods and materials with clinical organisms commonly found in nosocomial infections: Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans individually and a mixture of the four organisms.
First, polyvinyl chloride (PVC), commonly used for catheters, was physically changed by stamping an impression into the surface in the hopes of deterring microbial adhesion. Regrettably, several trials yielded no statistical difference in microbial adhesion between stamped and unstamped PVC.
Second, studies were continued in the investigation of the biocompatibility of zirconium alloys used in prosthetic devices. Oxidized Zircadyne-705 (Zr-705), oxidized Zircaloy-2 (Zry-2), and un-oxidized Zr-705 were evaluated for their microbial resistance and endotoxin resistance under turbulent-like growing conditions as previous studies had been done under laminar growing conditions. Statistical analysis showed biofilm formation to be greater under the turbulent-like conditions as well as endotoxin presence. Analysis did not show one materials to be more resistant to biofilm formation or endotoxin production under turbulent-like conditions. Results of this study, while not definitive, provide important considerations for experimental design for future research with oxidized zirconium alloys and their use in hemiarthroplasty.