title: Efficacy of tigecycline alone and with rifampin in foreign-body infection by methicillin-resistant Staphylococcus aureus.
abstract: OBJECTIVE
  Tigecycline appears as an alternative therapy against methicillin-resistant Staphylococcus aureus (MRSA) with limited clinical experience. We evaluate the efficacy of tigecycline and its combination with rifampin in comparison to that for vancomycin in a rat model of foreign-body infection by MRSA.
  
  
  METHODS
  A tissue-cage infection model were used; therapy with tigecycline, vancomycin, rifampin, tigecycline plus rifampin and vancomycin plus rifampin was administered intraperitoneally for 7 days. The antibiotic efficacy was evaluated in the tissue-cage fluid and in the coverslips (attached bacteria); the emergence of resistance was screened.
  
  
  RESULTS
  Among monotherapies rifampin was the best treatment (decrease in log CFU/ml of tissue-cage fluid, 2.75) (P < 0.05). The addition of rifampin improved the efficacy of vancomycin (decrease, 2.28) and tigecycline (decrease, 1.56) in solitary; there were not significantly differences between tigecycline-rifampin (decrease, 3.39) and vancomycin-rifampin (decrease, 3.70), but only the latter was better than rifampin alone (P < 0.05). Resistant strains were only detected using rifampin alone.
  
  
  CONCLUSIONS
  tigecycline alone was the least effective treatment. Tigecycline-rifampin prevented the emergence of rifampin resistance, thus allowing the benefits of rifampin over time against staphylococcal foreign-body infections, but its efficacy needs to be evaluated in comparison with other anti-MRSA combined therapies.
authors.affiliation: Laboratory of Experimental Infection, Infectious Diseases Service, IDIBELL, Hosp. Univ. de Bellvitge Feixa Llarga s/n, 08907 Barcelona, Spain. cgarrigos@idibell.cat
authors.forename: C
authors.initials: C
authors.lastname: Garrigós
authors.forename: O
authors.initials: O
authors.lastname: Murillo
authors.forename: G
authors.initials: G
authors.lastname: Euba
authors.forename: R
authors.initials: R
authors.lastname: Verdaguer
authors.forename: F
authors.initials: F
authors.lastname: Tubau
authors.forename: C
authors.initials: C
authors.lastname: Cabellos
authors.forename: J
authors.initials: J
authors.lastname: Cabo
authors.forename: J
authors.initials: J
authors.lastname: Ariza
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D015194:Diffusion Chambers, Culture; D004195:Disease Models, Animal; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005547:Foreign Bodies / Q000150:complications*; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D012293:Rifampin / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D013203:Staphylococcal Infections / Q000188:drug therapy*; D000078304:Tigecycline; D013997:Time Factors; D016896:Treatment Outcome; D014640:Vancomycin / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D000078304:Tigecycline; D008911:Minocycline; D012293:Rifampin