Open AccessComparative In Vitro Activity Profile of Oritavancin against Recent Gram-Positive Clinical Isolates
Author(s) -
Francis F. Arhin,
Deborah C. Draghi,
Chris M. Pillar,
Thomas Parr,
Greg Moeck,
Daniel F. Sahm
Publication year - 2009
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.00952-09
Subject(s) - microbiology and biotechnology , enterococcus faecalis , enterococcus faecium , streptococcus agalactiae , staphylococcus aureus , streptococcus pneumoniae , enterococcus , penicillin , streptococcaceae , biology , streptococcus , antibiotics , bacteria , genetics
Oritavancin activity was tested against 15,764 gram-positive isolates collected from 246 hospital centers in 25 countries between 2005 and 2008. Organisms wereStaphylococcus aureus (n = 9,075), coagulase-negative staphylococci (n = 1,664),Enterococcus faecalis (n = 1,738),Enterococcus faecium (n = 819),Streptococcus pyogenes (n = 959),Streptococcus agalactiae (n = 415), group C, G, and F streptococci (n = 84), andStreptococcus pneumoniae (n = 1,010). Among the evaluated staphylococci, 56.7% were resistant to oxacillin. The vancomycin resistance rate among enterococci was 21.2%. Penicillin-resistant and -intermediate rates were 14.7% and 21.4%, respectively, amongS. pneumoniae isolates. Among nonpneumococcal streptococci, 18.5% were nonsusceptible to erythromycin. Oritavancin showed substantial in vitro activity against all organisms tested, regardless of resistance profile. The maximum oritavancin MIC against all staphylococci tested (n = 10,739) was 4 μg/ml; the MIC90 againstS. aureus was 0.12 μg/ml. AgainstE. faecalis andE. faecium , oritavancin MIC90 s were 0.06 and 0.12, respectively. Oritavancin was active against glycopeptide-resistant enterococci, including VanA strains (n = 486), with MIC90 s of 0.25 and 1 μg/ml against VanAE. faecium andE. faecalis , respectively. Oritavancin showed potent activity against streptococci (n = 2,468); MIC90 s for the different streptococcal species were between 0.008 and 1 μg/ml. These data are consistent with previous studies with respect to resistance rates of gram-positive isolates and demonstrate the spectrum and in vitro activity of oritavancin against a wide variety of contemporary gram-positive pathogens, regardless of resistance to currently used drugs. The data provide a foundation for interpreting oritavancin activity and potential changes in susceptibility over time once oritavancin enters into clinical use.