ADHERENCE OF STAPHYLOCOCCUS-AUREUS SLIME-PRODUCING STRAIN VARIANTS TOBIOMATERIALS USED IN ORTHOPEDIC-SURGERY

The adherence of Staphylococcus aureus to biomaterials used in orthopa edic surgery (polymethylmethacrylate, fresh bone, steel and titanium a lloys) and to glass was studied in vitro at 1, 2, 6, 24 and 48 h of in cubation. Nonslime-producing strains (72, 80 and 510) and slime-produc ing variants of these strains were used. An automated and fast method of ATP-bioluminiscence was applied to determine bacterial viability. T he lowest adherence corresponded to polymethylmethacrylate and bone, a nd the highest to metals. Significant adherence was detected in all ca ses after 6 h and was strain dependent, being lowest for strain 72. In most cases, adherence of nonslime-producing variants was not signific ant compared with controls, and slime-producing were more adherent tha n nonslime-producing variants. These differences were maximal at 6 h o r 48 h, depending on the strain and the material. The findings suggest that the appearance of slime-producing cells within a given nonslime- producing bacterial population may jeopardise postoperative immune sys tems and antibiotic efficacy as a consequence of biofilm formation on implants and prostheses.