title: Inhibitory effects of vancomycin and fosfomycin on methicillin-resistantStaphylococcus aureusfrom antibiotic-impregnated articulating cement spacers.
abstract: OBJECTIVE
  Vancomycin and fosfomycin are antibiotics commonly used to treat methicillin-resistantStaphylococcus aureus(MRSA) infection. This study compares thein vitroinhibitory effects against MRSA of articulating cement spacers impregnated with either vancomycin or fosfomycin.
  
  
  METHODS
  Vancomycin-impregnated articulating cement spacers and fosfomycin-impregnated articulating cement spacers were immersed in sterile phosphate-buffered saline (PBS) solutions and then incubated. Samples were collected for bioactivity evaluation. The aliquots were tested for MRSA inhibition with the disc diffusion method, and the inhibition zone diameters were measured. The inhibition zone differences were evaluated using the Wilcoxon Rank Sum Test.
  
  
  RESULTS
  The vancomycin group had significantly larger inhibition zones than the fosfomycin group from day three through to completion of the fourth week of incubation (p < 0.001). The vancomycin group exhibited a MRSA inhibition zone up to four weeks but the fosfomycin group showed an inhibition zone for only three days and after that did not show the the potential to inhibit MRSA.
  
  
  CONCLUSIONS
  Thisin vitrostudy found that the inhibitory effect of vancomycin-impregnated articulating cement spacers against MRSA outperformed fosfomycin-impregnated articulating cement spacers. Further comparing our results to other published reports suggests there might be a limitation of the disc diffusion bioassay to show a large inhibitory zone in a high concentration of a highly soluble antibiotic.Cite this article:V. Yuenyongviwat, N. Ingviya, P. Pathaburee, B. Tangtrakulwanich. Inhibitory effects of vancomycin and fosfomycin on methicillin-resistantStaphylococcus aureusfrom antibiotic-impregnated articulating cement spacers.Bone Joint Res2017;6:132-136. DOI: 10.1302/2046-3758.63.2000639.
authors.affiliation: Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, 90110, Thailand varahortho@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Yuenyongviwat
authors.affiliation: Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, 90110, Thailand.
authors.forename: N
authors.initials: N
authors.lastname: Ingviya
authors.affiliation: Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, 90110, Thailand.
authors.forename: P
authors.initials: P
authors.lastname: Pathaburee
authors.affiliation: Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, 90110, Thailand.
authors.forename: B
authors.initials: B
authors.lastname: Tangtrakulwanich
keywords: Cement spacer; Fosfomycin; MRSA; TKA; Vancomycin