Highly efficient imidazolium-containing oligomers for preventing MRSA biofilm and postoperative spinal infection

Abstract Surgical site infections (SSIs) after spinal surgery are one of the serious complications of spinal surgery, which can lead to failure of spinal surgery, central nervous system infection, and even threaten patient lives. Although existing antibiotics can effectively control and treat postoperative infections in the spine, bacterial resistance continues to rise each year due to irrational use of antibiotics. Meanwhile, bacteria can easily form biofilms on the surface of the spinal instruments. The biofilm matrix can restrict the penetration of antibiotics. Nowadays, more patients are infected with drug-resistant bacteria after spinal surgery. However, current treatments and preventions for SSIs are becoming more difficult. Therefore, novel antimicrobial materials for SSIs are urgently needed. Previous studies have shown that imidazolium salts can kill bacteria quickly, and they are less likely to induce resistance. In this study, the antibacterial potency of linear main-chain imidazolium oligomers in postoperative spinal infections was evaluated by in vitro and in vivo experiments. In vitro results showed that imidazolium oligomers had broad-spectrum antibacterial effects, which can inhibit the formation of methicillin-resistant Staphylococcus aureus (MRSA) biofilms and destroy the mature biofilms. Moreover, by establishing a mouse spinal infection model, we confirmed that linear imidazolium salts had comparable in vivo efficacy as vancomycin.