Update on the In Vitro Activity of Daptomycin Tested against 17,193 Gram-positive Bacteria Isolated From European Medical Centers (2005-2007)

Abstract

The antimicrobial susceptibility patterns of 17,193 Gram-positive isolates consecutively collected from 28 medical centers in 12 countries in Europe and Israel in 2005-2007 were evaluated by Clinical and laboratory Standards institute (CLSI) broth microdilution methods supplemented with calcium to 50 mg/L for testing daptomycin. Overall, the rate of methicillin-re-sistant Staphylococcus aureus(MRSA) was 28.3%, varying from 32.3% in 2005 to 27.1% in 2006 and 28.5% in 2007. Vancomycin resistance rates were 0.8% and 21.5% among Enterococcus faecalis and E. faecium, respectively. Among E. faecium, vancomycin resistance increased from 17.9% in 2005 to 26.3% in 2007, and varied from 0.0% in Spain, Sweden and Switzerland to as high as 54.6% in ireland for 2007. All isolates tested, except for seven CoNS(0.2%; 3,234 tested) were considered susceptible to daptomycin using breakpoints establishedby the United States food and Drug Administration, the CLSI and the EUCAST. Daptomycin wasvery active against all Gram-positive species with the highest minimum inhibitory concentration(MIC) results being 1, 4, 2 and 4 mg/L for S. aureus, coagulase-negative staphylococci, E. faecalis and E. faecium, respectively. Daptomycin activity was not adversely influenced by resistanceto oxacillin among staphylococci or to vancomycin among enterococci.

Keywords:

• Daptomycin
• Staphylococcus aureus
• MRSA
• VRE
• europe
• surveillance