Interleukin-1, interleukin-6, and interleukin-10 responses after antibiotic treatment in experimental chronic Staphylococcus aureus osteomyelitis.

BACKGROUND

Staphylococcal implant infections' response to treatment may be correlated with cytokine production. We investigated the effect of certain antibiotics on the cytokine response in experimental osteomyelitis.

METHODS

A stainless steel needle with an adherent slime-producing Staphylococcus aureus was implanted intramedullarly in the left tibia of 40 adult male Wistar rats. At 42 days after implantation, cefuroxime, vancomycin, tobramycin, and ciprofloxacin were administered intramuscularly every 12 h for 21 days. The control group was given no antibiotic. At the end of the treatment, implants and tibias were retrieved, and the bacterial numbers were estimated. Cytokines [interleukin-1alpha (IL-1alpha), IL-6, and IL-10] were determined (ELISA) in the tibial extract.

RESULTS

Vancomycin and cefuroxime inhibited bone colonization in all tibias, and tobramycin and ciprofloxacin inhibited it only partially. Cefuroxime reduced the number of bacteria that adhered to the implants more than the other antibiotics. IL-1alpha and IL-6 showed higher levels in the ciprofloxacin-treated group than in the cefuroxime-treated and control groups. IL-6 levels in rats treated with cefuroxime were lower than in rats treated with tobramycin or vancomycin and the control group. Cefuroxime decreased IL-10 levels more than ciprofloxacin or vancomycin or those seen in the control group.

CONCLUSIONS

The cefuroxime group showed the greatest decrease of pro-inflammatory cytokines. Different antibiotics produce different cytokine reactions that should be studied to choose the best treatment.