Comparative In vitro activities of daptomycin and vancomycin against resistant gram-positive pathogens.
The in vitro activity of daptomycin against 224 current gram-positive clinical isolates including vancomycin-resistant Enterococcus faecium (VREF), methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus spp. (MRSS), and penicillin-resistant Streptococcus pneumoniae (PRSP) was evaluated. The MICs at which 90% of isolates are inhibited for daptomycin and vancomycin, respectively, were as follows: MRSA, 1 and 2 microg/ml; MRSS, 1 and 4 microg/ml; PRSP, 1 and 0.5 microg/ml; and VREF, 2 and >64 microg/ml. Daptomycin was bactericidal against 82% of 17 VREF isolates. The antibacterial activity of daptomycin was strongly dependent on the calcium concentration of the medium. Daptomycin was active against all gram-positive cocci tested.
Snydman
D R
DR
New England Medical Center, Boston, Massachusetts 02111, USA. dsnydman@lifespan.org
Jacobus
N V
NV
McDermott
L A
LA
Lonks
J R
JR
Boyce
J M
JM
D015169:Colony Count, Microbial; D017576:Daptomycin / Q000494:pharmacology*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013997:Time Factors; D014640:Vancomycin / Q000494:pharmacology*
D014640:Vancomycin; D017576:Daptomycin