title: Linezolid versus vancomycin for the treatment of methicillin-resistant Staphylococcus aureus keratitis in rabbits.
abstract: OBJECTIVE
  To compare the efficacy of topical linezolid (LZD) 1 mg/mL or 2 mg/mL to vancomycin (VA) 50 mg/mL for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) keratitis in rabbits.
  
  
  METHODS
  One hundred colony-forming unit (CFU) MRSA bacteria were injected intrastromally into rabbit corneas. Sixteen hours after the injection, 24 rabbits were randomly divided into 4 groups. Rabbit eyes were treated with 1 drop of topical LZD 1 mg/mL, LZD 2 mg/mL, VA 50 mg/mL, or isotonic saline every 15 minutes for 5 doses and then every 30 minutes for 14 doses. Eyes were examined before and after the treatment using slit-lamp biomicroscopy by 2 observers blinded to the study for the determination of clinical severity. Then, corneas were harvested for the quantification of bacteria and histopathology.
  
  
  RESULTS
  There were no differences in clinical severity among the groups before and after the treatment in each eye. The mean CFU × 10(6) of MRSA recovered from the LZD 1 mg/mL, LZD 2 mg/mL, and VA 50 mg/mL groups were significantly lower than that recovered from corneas treated with isotonic saline. There was no statistically significant difference among the treatment groups in terms of CFU × 10(6). Epithelial erosion in the VA 50 mg/mL group was significantly worse than that in the other groups. LZD 2 mg/mL group had the lowest mean epithelial erosion values.
  
  
  CONCLUSIONS
  Topical LZD showed activity against MRSA that was comparable to fortified VA in this experimental keratitis model.
authors.affiliation: Department of Microbiology, Abant Izzet Baysal University Medical Faculty, Bolu, Turkey.
authors.forename: Tekin
authors.initials: T
authors.lastname: Tas
authors.forename: Abdulkadir
authors.initials: A
authors.lastname: Kucukbayrak
authors.forename: Ismail N
authors.initials: IN
authors.lastname: Hakyemez
authors.forename: Firat Z
authors.initials: FZ
authors.lastname: Mengeloglu
authors.forename: Huseyin
authors.initials: H
authors.lastname: Simavli
authors.forename: Gulzade
authors.initials: G
authors.lastname: Ozyalvacli
authors.forename: Mesut
authors.initials: M
authors.lastname: Erdurmus
mesh_terms: D000081:Acetamides / Q000627:therapeutic use*; D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D058491:Bacterial Load; D015169:Colony Count, Microbial; D003114:Colony-Forming Units Assay; D003320:Corneal Ulcer / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D000069349:Linezolid; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D009883:Ophthalmic Solutions; D023303:Oxazolidinones / Q000627:therapeutic use*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D014640:Vancomycin / Q000627:therapeutic use*
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D009883:Ophthalmic Solutions; D023303:Oxazolidinones; D014640:Vancomycin; D000069349:Linezolid