title: Activity of oritavancin against Gram-positive clinical isolates responsible for documented skin and soft-tissue infections in European and US hospitals (2010-13).
abstract: OBJECTIVE
  To assess oritavancin activity in vitro against clinically relevant Gram-positive pathogens causing skin and soft-tissue infections (SSTIs) in European and US hospitals.
  
  
  METHODS
  13 262 consecutive and unique isolates deemed to be responsible for SSTIs were included. Isolates originated from 36 and 27 institutions in Europe (Israel included) and the USA, respectively, between 2010 and 2013.
  
  
  RESULTS
  Oritavancin (98.8% susceptible) showed modal MIC, MIC50 and MIC90 results of 0.03, 0.03 and 0.06 mg/L, respectively, for Staphylococcus aureus. CoNS from the USA (MIC50, 0.015 mg/L) demonstrated an MIC50 value of oritavancin slightly lower than those from Europe (MIC50, 0.03 mg/L). Overall, vancomycin-resistant (VanA-phenotype) Enterococcus faecalis had oritavancin MICs (MIC50/90, 0.25/0.5 mg/L) that were 16-fold higher than those obtained for vancomycin-susceptible isolates (MIC50/90, 0.015/0.03 mg/L; 99.2%-99.8% susceptible); nevertheless, oritavancin inhibited all VanA E. faecalis at ≤0.5 mg/L. Equivalent oritavancin MICs (MIC50/90, 0.004/0.008 mg/L) were noted for all VanB and vancomycin-susceptible Enterococcus faecium, while higher MICs (MIC50/90, 0.03/0.12 mg/L) were obtained for VanA strains. Oritavancin had low MICs against the overall populations of Streptococcus pyogenes (MIC50/90, 0.03/0.12 mg/L; 98.4%-98.6% susceptible), Streptococcus agalactiae (MIC50/90, 0.03/0.06 mg/L; 97.9%-98.0% susceptible) and the Streptococcus anginosus group (MIC50/90, 0.008/0.015 mg/L; 100.0% susceptible), with slightly higher MICs for Streptococcus dysgalactiae (MIC50/90, 0.06/0.25 mg/L; ≥98.3% susceptible).
  
  
  CONCLUSIONS
  Oritavancin had potent activity in vitro against this contemporary collection of European and US isolates causing SSTIs. These results describe oritavancin activity against Gram-positive pathogens collected shortly prior to its regulatory approval in the USA.
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA rodrigo-mendes@jmilabs.com.
authors.forename: Rodrigo E
authors.initials: RE
authors.lastname: Mendes
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farrell
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005060:Europe / Q000453:epidemiology; D006020:Glycopeptides / Q000494:pharmacology*; D006094:Gram-Positive Bacteria / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D000077427:Lipoglycopeptides; D008826:Microbial Sensitivity Tests; D062486:Public Health Surveillance; D017192:Skin Diseases, Bacterial / Q000453:epidemiology / Q000382:microbiology*; D018461:Soft Tissue Infections / Q000453:epidemiology / Q000382:microbiology*; D014481:United States / Q000453:epidemiology; D014640:Vancomycin / Q000031:analogs & derivatives
chemical_list: D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D000077427:Lipoglycopeptides; C100708:oritavancin; D014640:Vancomycin
keywords: SSTIs; bactericidal; lipoglycopeptides