title: Antimicrobial activity of daptomycin tested against Gram-positive pathogens collected in Europe, Latin America, and selected countries in the Asia-Pacific Region (2011).
abstract: We report the results of the international daptomycin surveillance programs for Europe, Latin America, and selected Asia-Pacific nations. A total of 7948 consecutive Gram-positive organisms of clinical significance were collected in 2011 and susceptibility tested against daptomycin and various comparator agents by Clinical and Laboratory Standards Institute (Clinical and Laboratory Standards Institute. M07-A9. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; approved standard: ninth edition Wayne, PA: CLSI. 2012.; Cubicin Package Insert 2012. Cubist Pharmaceuticals, Inc, Lexington, MA. Available at http://www.cubicin.com/pdf/PrescribingInformation.pdf. Accessed January 1, 2012.) broth microdilution methods. The test medium was adjusted to contain physiological levels of calcium (50 mg/L) when testing daptomycin. Daptomycin exhibited potent activity against methicillin-susceptible and -resistant Staphylococcus aureus overall and for each region (MIC(50/90), 0.25-0.5/0.5 μg/mL), with susceptibility rates at 100.0% in Latin America, Australia/New Zealand, and India, and at 99.9% in Europe. The daptomycin MIC(50/90) for coagulase-negative staphylococci was also at 0.25-0.5/0.5 μg/mL, and only 1 isolate was considered nonsusceptible with a MIC value at 2 μg/mL. Daptomycin was also highly active against Enterococcus faecalis (MIC(50/90), 1/1-2 μg/mL) and E. faecium (MIC(50/90), 2/2 μg/mL for both vancomycin-susceptible and -resistant isolates). All enterococcal isolates were susceptible to daptomycin (MIC, ≤4 μg/mL) and tigecycline. Susceptibility to linezolid for E. faecalis was at 100.0%, while for E. faecium regional susceptibility rates were at 100.0% except in Europe (99.0%). Viridans group streptococci (MIC(50/90), 0.25/1 μg/mL) and β-haemolytic streptococci (MIC(50/90), ≤0.06/0.25 μg/mL) continue to be very susceptible to daptomycin. In summary, the results of this investigation document the high potency and wide spectrum of daptomycin when tested against a large resistance-surveillance collection of Gram-positive pathogens and indicate that daptomycin nonsusceptibility remains rare among indicated species after many years of clinical use worldwide.
authors.affiliation: JMI Laboratories, North Liberty, IA, USA. helio-sader@jmilabs.com
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D044362:Australasia; D017576:Daptomycin / Q000494:pharmacology*; D005060:Europe; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000302:isolation & purification*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D007843:Latin America; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D017576:Daptomycin