Comparison of antimicrobial agents as therapy for experimental endocarditis: caused by methicillin-resistant Staphylococcus aureus.
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.
Sacar
Mustafa
M
Departments of Cardiovascular Surgery, Faculty of Medicine, Pamukkale University, Kinikli, 20070 Denizli, Turkey. mustafasacar@hotmail.com
Sacar
Suzan
S
Cevahir
Nural
N
Onem
Gokhan
G
Teke
Zafer
Z
Asan
Ali
A
Turgut
Huseyin
H
Adali
Fahri
F
Kaleli
Ilknur
I
Susam
Ibrahim
I
Yaylali
Yalin Tolga
YT
Baltalarli
Ahmet
A
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
D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D017334:Teicoplanin; D014640:Vancomycin; D000069349:Linezolid