Antimicrobial susceptibility of Gram-positive cocci isolated from skin and skin-structure infections in European medical centres

Abstract 

Skin and skin-structure infections (SSSIs) usually involve Gram-positive organisms. Prompt initiation of appropriate antimicrobial treatment is essential for achieving a favourable outcome in severe cases. Empirical antibacterial therapy should be based on several considerations, including patient risk factors, expected pathogens and local/regional susceptibility profiles, among others. In the present study, we evaluated the antimicrobial susceptibility patterns of Gram-positive bacteria isolated from patients with SSSIs hospitalised in European medical centres. A total of 3573 bacterial isolates were collected from 33 medical centres located in 13 European countries as well as Israel over a 6-year period (2003–2008) and were tested for susceptibility to daptomycin and other comparator agents by reference broth microdilution methods in a central laboratory. The most frequently isolated organisms were Staphylococcus aureus (71.1%), β-haemolytic streptococci (10.5%) and enterococci (9.3%). Overall, rates of meticillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) were 22.5% and 5.1%, respectively, but with great intercountry variation. The overall MRSA rate varied slightly during the study period, but with no overall tendency toward increase or decrease, whilst the overall VRE rate consistently increased from 1.5% in 2003 to 11.0% in 2008. Daptomycin and linezolid were the most active agents tested overall. All isolates monitored were considered susceptible to daptomycin, and only one isolate (Enterococcus faecium) was categorised as non-susceptible to linezolid. In conclusion, the results of this contemporary surveillance study indicate that daptomycin and linezolid retain sustained in vitro activity against Gram-positive cocci isolated from patients hospitalised with SSSI in numerous European medical centres.

Keywords: Daptomycin, MRSA, VRE