Factors Influencing Broth Microdilution Antimicrobial Susceptibility Test Results for Dalbavancin, a New Glycopeptide Agent
- 1 October 2007
- journal article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 45 (10), 3151-3154
- https://doi.org/10.1128/jcm.02411-06
Abstract
Performance of antimicrobial susceptibility tests with new agents requires careful consideration of the properties of the antimicrobial to ensure that the tests are standardized, reproducible, and reflect the true potency of the drug. Dalbavancin is a new glycopeptide with potent activity against gram-positive bacterial species. The investigations described here demonstrated that methodologic modifications of procedures are necessary to ensure consistent test results, both for quality control and for routine testing of clinical isolates. Dimethyl sulfoxide is the preferred primary solvent. The addition of 0.002% polysorbate-80 (a surfactant) to dalbavancin-containing wells in the reference broth microdilution assay resulted in consistent and reproducible MIC results for three quality control strains: Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, and Streptococcus pneumoniae ATCC 49619. The same degree of consistency was observed among clinical isolates of gram-positive bacterial species tested in several clinical laboratories. These results indicate that the addition of 0.002% (final concentration) of the surfactant in broth microdilution tests produces optimal dalbavancin MICs required for accurate and reproducible clinical laboratory tests, without untoward influences of substrate binding or media constituents.Keywords
This publication has 8 references indexed in Scilit:
- Comparison of Dalbavancin MIC Values Determined by Etest (AB BIODISK) and Reference Dilution Methods Using Gram-Positive OrganismsJournal of Clinical Microbiology, 2006
- Spectrum and potency of dalbavancin tested against 3322 Gram-positive cocci isolated in the United States Surveillance Program (2004)Diagnostic Microbiology and Infectious Disease, 2006
- Microbiologic characterization of isolates from a dalbavancin clinical trial for catheter-related bloodstream infectionsDiagnostic Microbiology and Infectious Disease, 2006
- Dalbavancin activity against selected populations of antimicrobial-resistant Gram-positive pathogensDiagnostic Microbiology and Infectious Disease, 2005
- Antimicrobial Spectrum and Potency of Dalbavancin Tested Against Clinical Isolates from Europe and North America (2003): Initial Results from an International Surveillance ProtocolJournal of Chemotherapy, 2005
- Antistaphylococcal Activity of Dalbavancin, an Experimental GlycopeptideAntimicrobial Agents and Chemotherapy, 2005
- Worldwide assessment of dalbavancin activity and spectrum against over 6,000 clinical isolatesDiagnostic Microbiology and Infectious Disease, 2004
- Initial Quality Control Evaluations for Susceptibility Testing of Dalbavancin (BI397), an Investigational Glycopeptide with Potent Gram-Positive ActivityJournal of Clinical Microbiology, 2003