Penetration of a selected antibiotic and antiseptic into a biofilm formed on orthopedic steel implants.

BACKGROUND The aim of the study was to determine the impact of octenidine hydrochloride and gentamicin on bacterial survival and reduction of biofilms formed on orthopaedic metal implants. MATERIAL AND METHODS We studied metal orthopaedic components (screws, nails, fragments of wires used in Ilizarov devices) and a bone sequester. The presence and intensity of biofilm formation on the medical biomaterials was determined using the method of Richards et al. by visual evaluation of 2,3,5-triphenyl tetrazolium chloride (TTC) reduction by viable bacteria. The presence and structure of the biofilm on the components of the Ilizarov device, screws and bone sequester was also studied by electron microscopy. Bacterial survival in the biofilm following exposure to the antibiotic and antiseptic was studied by CLSI microdilution method in microtitre plates using TTC. Results. Most of the 16 strains (S. aureus, S. epidermidis, E. coli, Enterobacter) isolated from orthopaedic implants were able to form a biofilm. Established biofilms were resistant to gentamicin and octenidine hydrochloride but demonstrated greater susceptibility to octenidine. CONCLUSIONS The results of the study indicate that octenidine hydrochloride is more effective than gentamicin in the treatment of infections associated with the formation of a biofilm on orthopaedic implants.