Incidence of infection in implanted polyurethane tubing segments serially injected with staphylococci

• Published in: Journal of materials science. Materials in medicine 1994-09, Vol.5 (9-10), p.628-634
• Main Authors: Van Wachem, P. B., Van Luyn, M. J. A., Blaauw, E. H., Raatjes, D., Cahalan, P. T., Hendriks, M.
• Format: Article
• Language: English
• ISSN: 0957-4530; 1573-4838
• DOI: 10.1007/BF00120344

One of the major clinical complications in the biomedical application of synthetic materials is the incidence of implant-associated infections. Such infections are very often induced by Staphylococcus aureus. To obtain information on tissue reactions and minimal bacterial challenge needed to create an infection related to untreated implant surfaces, we injected polyurethane tubing segments with a series of Staphylococcus aureus. The semgents were subcutaneously implanted in rats. Implantation periods varied from two, five and ten days to three weeks. Specimen were evaluated using light and transmission electron microscopy. At least 0.25x10 exp 4 of Staphylococci aureus were needed to clearly recognize that bacteria had been injected in the polyurethane tubing segments. The evidence was indirect, showing high infiltation and activation of neutrophils and macrophages, but not bacteria. Furthermore, 0.25x10 exp 6 S. aureus were needed to induce a persistent specific inflammatory reaction with high concentrations of lymphocytes, i.e. mainly plasma-cells, at three weeks. The results indicate that this model functioned well to obtain the wanted information. Results are discussed with respect to (a-) specific inflammatory reactions occurring with (bacterial-challenged) biomaterials. Ultimately, our goal is to develop infection-resistant materials, for which the in vivo model developed may be used to quality the processed materials.