Update of dalbavancin spectrum and potency in the USA: report from the SENTRY Antimicrobial Surveillance Program (2011).
Dalbavancin (DAL) is an investigational lipoglycopeptide with a prolonged serum half-life allowing once weekly dosing. DAL potency was assessed in the 2011 SENTRY Antimicrobial Surveillance Program among 1555 isolates sampled from all 9 US Census regions. Monitored Gram-positive cocci included Staphylococcus aureus (SA; 1,036/50.4% MRSA), coagulase-negative staphylococci (CoNS; 115), Enterococcus faecalis (25), E. faecium (31), Streptococcus pyogenes (155), Streptococcus agalactiae (153), and viridans group streptococci (VGS; 40). All susceptibility (S) testing used Clinical and Laboratory Standards Institute reference broth microdilution methods and interpretations. DAL (MIC(50/90), 0.06/0.06 μg/mL) was 8- and 16-fold more active than daptomycin (DAP) and vancomycin (VAN), respectively against SA, with MSSA and MRSA having the same MIC(90) results. CoNS was slightly more DAL-S (MIC(50), ≤0.03μg/mL). The highest staphylococcal DAL MIC was only 0.25 μg/mL. β-Haemolytic streptococci (βHS) and VGS had DAL MIC results ranging from ≤0.03 to 0.25 μg/mL (MIC(90), 0.06-0.12 μg/mL), and only enterococci showed elevated DAL MIC results. VanA phenotype-resistant E. faecalis or E. faecium had DAL MIC values at ≥1 μg/mL; VanB strains were DAL-S (MIC, ≤0.25 μg/mL). All cited DAL quantitative values were consistent with earlier surveillance data (2006-2009), without evidence of MIC creep. In conclusion, year 2011 SENTRY Program data for DAL documents sustained potent activity against SA, CoNS, βHS, VGS, and VAN-S enterococci, which averaged 4- to 32-fold greater than VAN, DAP, or linezolid.
JMI Laboratories, North Liberty, IA, USA. ronald-jones@jmilabs.com
Ronald N
RN
Jones
Helio S
HS
Sader
Robert K
RK
Flamm
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002981:Clindamycin / Q000494:pharmacology; D017576:Daptomycin / Q000494:pharmacology; D004341:Drug Evaluation; D024881:Drug Resistance, Bacterial; D016983:Enterococcus / Q000187:drug effects; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D013291:Streptococcus / Q000187:drug effects; D017334:Teicoplanin / Q000031:analogs & derivatives* / Q000494:pharmacology; D014481:United States; D014640:Vancomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D002981:Clindamycin; D017334:Teicoplanin; D014640:Vancomycin; C469289:dalbavancin; D017576:Daptomycin