Open AccessGarenoxacin Treatment of Experimental Endocarditis Caused by Viridans Group Streptococci
Author(s) -
Paloma Anguita-Alonso,
Mark S. Rouse,
Kerryl E. Piper,
James M. Steckelberg,
Robin Patel
Publication year - 2006
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.50.4.1263-1267.2006
Subject(s) - levofloxacin , streptococcus mitis , penicillin , microbiology and biotechnology , endocarditis , streptococcus sanguinis , streptococcus pneumoniae , antimicrobial , antibacterial agent , medicine , viridans streptococci , streptococcus , pharmacology , antibiotics , biology , bacteria , streptococcus mutans , genetics
The activity of garenoxacin was compared to that of levofloxacin or penicillin in a rabbit model ofStreptococcus mitis group (penicillin MIC, 0.125 μg/ml) andStreptococcus sanguinis group (penicillin MIC, 0.25 μg/ml) endocarditis. Garenoxacin and levofloxacin had MICs of 0.125 and 0.5 μg/ml, respectively, for both study isolates. Rabbits with catheter-induced aortic valve endocarditis were given no treatment, penicillin at 1.2 × 106 IU/8 h intramuscularly, garenoxacin at 20 mg/kg of body weight/12 h intravenously, or levofloxacin at 40 mg/kg/12 h intravenously. For both isolates tested, garenoxacin area under the curve (AUC)/MIC and maximum concentration of drug in serum (C max )/MIC ratios were 368 and 91, respectively. Rabbits were sacrificed after 3 days of treatment; cardiac valve vegetations were aseptically removed and quantitatively cultured. ForS. mitis group experimental endocarditis, all studied antimicrobial agents were more active than no treatment (P < 0.001), whereas forS. sanguinis group endocarditis, no studied antimicrobial agents were more active than no treatment. We conclude that AUC/MIC andC max /MIC ratios may not predict activity of some quinolones in experimental viridans group endocarditis and that garenoxacin and levofloxacin may not be ideal choices for serious infections caused by some quinolone-susceptible viridans group streptococci.