title: Efficacy of quinupristin-dalfopristin against methicillin-resistant Staphylococcus aureus and vancomycin-insensitive S. aureus in a model of hematogenous pulmonary infection.
abstract: BACKGROUND
  Quinupristin-dalfopristin (Q-D) is a mixture of quinupristin and dalfopristin, which are semisynthetic antibiotics of streptogramin groups B and A, respectively.
  
  
  METHODS
  We compared the effect of Q-D to that of vancomycin (VCM) in murine models of hematogenous pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and VCM-insensitive S. aureus (VISA).
  
  
  RESULTS
  Treatment with Q-D resulted in a significant decrease in the number of viable bacteria in the lungs of mice in an MRSA infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean +/- SEM): 2.99 +/- 0.44, 6.38 +/- 0.32, 5.75 +/- 0.43 and 8.40 +/- 0.14 log10 CFU/lung, respectively]. Compared with VCM, high-dose Q-D significantly reduced the number of bacteria detected in the VISA hematogenous infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean +/- SEM): 5.17 +/- 0.52, 7.03 +/- 0.11, 7.10 +/- 0.49 and 7.18 +/- 0.36 log10 CFU/lung, respectively]. Histopathological examination confirmed the effect of Q-D.
  
  
  CONCLUSIONS
  Our results suggest that Q-D is potent and effective in the treatment of MRSA and VISA hematogenous pulmonary infections.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Pharmaceutical Sciences, Nagasaki, Japan. kyana-ngs@umin.ac.jp
authors.forename: Katsunori
authors.initials: K
authors.lastname: Yanagihara
authors.forename: Makiko
authors.initials: M
authors.lastname: Okada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Imamura
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ohno
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Higashiyama
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tsukamoto
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hirakata
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tomono
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kadota
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tashiro
authors.forename: Ikuo
authors.initials: I
authors.lastname: Murata
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000818:Animals; D016470:Bacteremia / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004352:Drug Resistance, Microbial; D007564:Japan; D008168:Lung / Q000382:microbiology / Q000503:physiopathology / Q000648:ultrastructure; D008297:Male; D016106:Methicillin Resistance / Q000187:drug effects* / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D011023:Pneumonia, Staphylococcal / Q000150:complications* / Q000188:drug therapy*; D013047:Specific Pathogen-Free Organisms; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D020713:Vancomycin Resistance / Q000187:drug effects* / Q000235:genetics; D014769:Virginiamycin / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D014769:Virginiamycin; C062940:quinupristin-dalfopristin