title: Telavancin activity tested against Gram-positive clinical isolates from European, Russian and Israeli hospitals (2011-2013) using a revised broth microdilution testing method: redefining the baseline activity of telavancin.
abstract: OBJECTIVE
  To reassess the activity of telavancin when tested against Gram-positive clinical pathogens recovered from hospitalized patients in European and adjacent regions using a revised broth microdilution method.
  
  
  METHODS
  11 601 consecutive, non-duplicate isolates originating from 36 institutions among 18 countries recovered between 2011 and 2013 were tested for susceptibility using a revised broth microdilution method for telavancin. Interpretive telavancin breakpoints appropriate for the method were those recently approved by the FDA and EUCAST, as available.
  
  
  RESULTS
  Telavancin (MIC50/90, 0.03/0.06 mg/l; 100.0% susceptible) was equally potent against methicillin-susceptible ((MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus. All Enterococcus faecalis was susceptible to telavancin (MIC50/90, 0.12/0.12 mg/l) and inhibited at the susceptibility breakpoint (i.e. ≤ 0.25 mg/l), except for VanA-phenotype vancomycin-resistant isolates (telavancin MIC, >1 mg/l). Telavancin ( ≤ 0.015/0.03 mg/l) was active against vancomycin-susceptible Enterococcus faecium, while higher MIC values were obtained for VanA strains. Telavancin (both MIC50 and MIC90, ≤ 0.015 mg/l) was potent against Streptococcus pneumoniae, beta-haemolytic streptococci (MIC50/90, ≤ 0.015/0.06 mg/l) and viridans group streptococci (MIC50/90, ≤ 0.015/0.03 mg/l).
  
  
  CONCLUSIONS
  Telavancin exhibited potent activity against this contemporary (2011-2013) collection of organisms, inhibiting indicated pathogens at or below the FDA/EUCAST-approved breakpoints for susceptibility. VanA-phenotype enterococci were less susceptible to telavancin, a feature observed using the previous testing method. These results redefine telavancin's activity against isolates from Europe.
authors.affiliation: a JMI Laboratories , North Liberty , IA , USA.
authors.forename: Rodrigo E
authors.initials: RE
authors.lastname: Mendes
authors.affiliation: a JMI Laboratories , North Liberty , IA , USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.affiliation: a JMI Laboratories , North Liberty , IA , USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farrell
authors.affiliation: a JMI Laboratories , North Liberty , IA , USA.
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.affiliation: a JMI Laboratories , North Liberty , IA , USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005060:Europe; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D007557:Israel; D000077427:Lipoglycopeptides; D008826:Microbial Sensitivity Tests / Q000379:methods; D012426:Russia
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000077427:Lipoglycopeptides; C487637:telavancin
keywords: Bactericidal; Europe; Gram-positive; Lipoglycopeptide; Telavancin