title: Linezolid compared with vancomycin for the prevention of methicillin-resistant Staphylococcus aureus or Staphylococcus epidermidis vascular graft infection in rats: A randomized, controlled, experimental study.
abstract: BACKGROUND
  Graft infections are severe complications of vascular surgery that may result in amputation or mortality. Staphylococci are the most frequent cause of vascular graft infections.
  
  
  OBJECTIVE
  In this study we assessed the prophylactic efficacy of linezolid in comparison with vancomycin in preventing prosthetic vascular graft infection due to methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE).
  
  
  METHODS
  This randomized, controlled, experimental study using healthy adult (aged >5 months) male Wistar rats was conducted in the research laboratory of the Pamukkale University, Denizli, Turkey. The study consisted of an uncontaminated control group and 3 groups for both staphylococcal strains: a contaminated group that did not receive any antibiotic prophylaxis; a contaminated group that received preoperative intraperitoneal (IP) prophylaxis with vancomycin; and a contaminated group that received preoperative IP prophylaxis with linezolid. All rats received a vascular Dacron graft placed inside a subcutaneous pocket created on the right side of the median line. Sterile saline solution (1 mL), to which MRSA or MRSE at a concentration of 2 × 10(7) colony-forming units per milliliter had been added, was inoculated onto the graft surface using a tuberculin syringe to fill the pocket. The grafts were explanted 7 days after implantation and assessed by quantitative culture.
  
  
  RESULTS
  Seventy rats (mean [SD]weight, 323.7 [17.9]g; mean [SD]age, 5.98 [0.64] months) were evenly divided between the 7 groups. Statistical analysis of the quantitative graft culture suggested that both vancomycin and linezolid were effective in significantly inhibiting bacterial growth when compared with the untreated contaminated groups (all, P < 0.001). However, a statistically significant difference was not observed between the bacteria count in the vancomycin and linezolid prophylaxis groups. When a comparison was made between the bacterial growth in the contaminated control groups, MRSA had significantly greater affinity to the Dacron prostheses than MRSE (all, P < 0.001).
  
  
  CONCLUSIONS
  Our study found that linezolid was as effective as vancomycin in suppressing colony counts in MRSA- or MRSE-infected vascular Dacron grafts in rats.
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Suzan
authors.initials: S
authors.lastname: Sacar
authors.affiliation: Department of Cardiovascular Surgery, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sacar
authors.affiliation: Department of Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Ilknur
authors.initials: I
authors.lastname: Kaleli
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Semra
authors.initials: S
authors.lastname: Toprak
authors.affiliation: Department of Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Nural
authors.initials: N
authors.lastname: Cevahir
authors.affiliation: Department of General Surgery, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Teke
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Asan
authors.affiliation: Experimental Animal Research Laboratory, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Barbaros
authors.initials: B
authors.lastname: Sahin
authors.affiliation: Department of Cardiovascular Surgery, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Baltalarli
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Turgut
keywords: linezolid; vancomycin; vascular graft infection