Pretreatment With Vancomycin Prevents Staphylococcal Biofilm Formation on Marlex Mesh

Background Polypropylene (PPE) mesh is a popular surgical treatment for extensor mechanism disruption in revision knee arthroplasty, but development of infection can be catastrophic. Pretreating orthopedic materials with antibiotics has precedence, but has not yet been described for PPE mesh. The purpose of the current study is to determine if mesh pretreatment with vancomycin could effectively prevent biofilm formation. Methods Sterile PPE mesh was cut into 10-mm diameter circles. PPE circles were soaked in saline for 20 minutes with one of the following vancomycin concentrations: 1) 0.625 mg/ml, 2) 1.25 mg/ml, 3) 2.5 mg/ml, 4) 5.0 mg/ml, and 5) 10.0 mg/ml. To simulate surgical irrigation prior to closure, samples were rinsed with saline 0, 1, 2, or 3 times. Each group had 9 samples. Rinsed PPE circles were placed in a 48-well plate, inoculated with 10 6 colony-forming units (CFUs) of methicillin-sensitive Staphylococcus aureus , cultured in tryptic soy broth for 24 hours, rinsed to remove planktonic bacteria, and sonicated in fresh media for 30 minutes. Sonicated fluid was serially diluted and plated for CFUs. Infection prevention was defined as 0 CFUs. PPE circles were imaged with scanning electron microscopy to visualize vancomycin crystals and biofilm. Results Pretreatment of PPE mesh with 10 mg/mL of vancomycin was the only condition that prevented S aureus biofilm formation in all conditions. Scanning electron microscopy confirmed that vancomycin pretreatment deposited antibiotic crystals on the mesh surface and that biofilm was not present. Conclusions Vancomycin pretreatment of PPE mesh can prevent biofilm formation even after rinsing.