title: Comparison of antimicrobial agents as therapy for experimental endocarditis: caused by methicillin-resistant Staphylococcus aureus.
abstract: We used an experimental rat model to compare the therapeutic efficacy of teicoplanin, linezolid, and quinupristin/dalfopristin with that of vancomycin as standard therapy for infective endocarditis.Aortic endocarditis was induced in rats by insertion of a polyethylene catheter into the left ventricle, followed by intravenous inoculation of 106 colony-forming units of methicillin-resistant Staphylococcus aureus 24 hours later. Forty-eight hours after bacterial challenge, intravenous antibiotic therapies were initiated. There were 6 groups of 8 rats each: uninfected control; infected, untreated control; vancomycin-treated (40 mg/kg twice daily); teicoplanin-treated (20 mg/kg twice daily after a loading dose of 40 mg/kg); linezolid-treated (75 mg/kg 3 times daily for 1 day, then 75 mg/kg twice daily); and quinupristin/dalfopristin-treated (30 mg/kg twice daily and an additional 10 mg/kg dalfopristin infusion over 6 to 12 hr daily). At the end of therapy, the aortic valve vegetations in the drug-treated rats were evaluated microbiologically.Compared with the infected, untreated group, all drug-treated groups had significantly reduced bacterial titers in the vegetations. Vancomycin, teicoplanin, and quinupristin/dalfopristin all effectively reduced the quantitative bacterial cultures of aortic valve vegetations. In addition, there was no significant difference in the comparative efficacy of teicoplanin, linezolid, and quinupristin/dalfopristin. Vancomycin significantly reduced bacterial counts in comparison with linezolid, which was nonetheless also effective.Our experimental model showed that each of the investigated antimicrobial agents was effective in the treatment of infective endocarditis.
authors.affiliation: Departments of Cardiovascular Surgery, Faculty of Medicine, Pamukkale University, Kinikli, 20070 Denizli, Turkey. mustafasacar@hotmail.com
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sacar
authors.forename: Suzan
authors.initials: S
authors.lastname: Sacar
authors.forename: Nural
authors.initials: N
authors.lastname: Cevahir
authors.forename: Gokhan
authors.initials: G
authors.lastname: Onem
authors.forename: Zafer
authors.initials: Z
authors.lastname: Teke
authors.forename: Ali
authors.initials: A
authors.lastname: Asan
authors.forename: Huseyin
authors.initials: H
authors.lastname: Turgut
authors.forename: Fahri
authors.initials: F
authors.lastname: Adali
authors.forename: Ilknur
authors.initials: I
authors.lastname: Kaleli
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Susam
authors.forename: Yalin Tolga
authors.initials: YT
authors.lastname: Yaylali
authors.forename: Ahmet
authors.initials: A
authors.lastname: Baltalarli
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001021:Aortic Valve / Q000187:drug effects* / Q000382:microbiology; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D004697:Endocarditis, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D000069349:Linezolid; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity; D023303:Oxazolidinones / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017334:Teicoplanin / Q000494:pharmacology; D013997:Time Factors; D014640:Vancomycin / Q000494:pharmacology; D014769:Virginiamycin / Q000494:pharmacology
chemical_list: D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D017334:Teicoplanin; D014640:Vancomycin; D000069349:Linezolid