title: Analysis of 5-year trends in daptomycin activity tested against Staphylococcus aureus and enterococci from European and US hospitals (2009-2013).
abstract: This study evaluated daptomycin activity trends among meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) over a 5-year period (2009-2013). Consecutive, unique patient isolates of clinical significance were collected in 67 European (EU) (17 nations) and 145 US medical centres and were susceptibility tested in a central reference laboratory against daptomycin and various comparators by CLSI broth microdilution methods. MIC results were interpreted according to EUCAST and CLSI breakpoint criteria (2014). A total of (EU/USA) 14245/22967 S. aureus (26.3/49.8% MRSA), 3043/2848 Enterococcus faecalis (1.6/3.5% vancomycin-resistant) and 1827/1537 Enterococcus faecium (29.5/77.7% vancomycin-resistant) were evaluated. Isolates were mainly from complicated skin and skin-structure infections (40%) and bacteraemia (32%). The highest MRSA rates were found in Portugal (66.3%), Russia (52.2%) and the USA (49.8%), whereas the highest rates of vancomycin-resistant E. faecium (VREFM) were observed in the USA (77.7%), Poland (63.1%) and Ireland (54.5%). VREFM and vancomycin-resistant E. faecalis (VREF) were observed in 15 and 8 EU nations, respectively. Daptomycin susceptibility rates were (EU/USA) 99.94/99.97%, 100.0/99.7% and 100.0/99.96% for S. aureus, E. faecium and E. faecalis, respectively. Daptomycin was very active against MRSA (MIC50/90, 0.25/0.5mg/L in Europe and USA), VREF (MIC50/90of 0.5/1mg/L and 1/2mg/L in Europe and USA, respectively) and VREFM (MIC50/90, 2/2mg/L in Europe and USA). Among MRSA, only 6/6 (0.19/0.05%) daptomycin-non-susceptible isolates were observed in Europe (six cities in four countries)/USA (six states), with no increasing trend over the study period. Only two daptomycin-non-susceptible VRE were identified, both E. faecium from the USA.
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA. Electronic address: helio-sader@jmilabs.com.
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farrell
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
keywords: Cyclic lipopeptide; Daptomycin; MRSA; VRE