title: Antimicrobial activity of daptomycin against multidrug-resistant Gram-positive strains collected worldwide.
abstract: Daptomycin is a cyclic lipopeptide recently released for clinical use in the treatment of serious Gram-positive infections in hospitalized patients. We evaluated the in vitro activity of daptomycin tested against recently isolated multidrug-resistant Gram-positive clinical strains. A total of 386 isolates were selected from a large collection of strains from more than 70 centers located in Europe, North America, and South America. The strains were tested by reference broth microdilution methods in Mueller-Hinton broth with 50 mg/L Ca++ against daptomycin. Daptomycin was the most potent compound tested against penicillin-resistant Streptococcus pneumoniae with MIC50/90 values at < or =0.12 and 0.25 microg/mL, respectively. Daptomycin was also highly active against vancomycin-resistant enterococci and staphylococcal strains with various resistance patterns. Enterococcus faecium showed higher daptomycin MIC values (MIC90, 4 microg/mL) when compared to E. faecalis (MIC90, 1 microg/mL). In summary, resistance to vancomycin, teicoplanin, quinupristin/dalfopristin, or penicillin among the Gram-positive isolates did not adversely influence daptomycin activity. Daptomycin showed a significant potency and spectrum against Gram-positive species, including multidrug-resistant strains, and may represent a reasonable therapeutic option for infections caused by these important pathogens.
authors.affiliation: The JONES Group/JMI Laboratories, North Liberty, IA, USA. helio-sader@jmilabs.com
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Streit
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Fritsche
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017576:Daptomycin / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D014943:Global Health; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D017576:Daptomycin