Initial Quality Control Evaluations for Susceptibility Testing of Dalbavancin (BI397), an Investigational Glycopeptide with Potent Gram-Positive Activity

Factors Influencing Broth Microdilution Antimicrobial Susceptibility Test Results for Dalbavancin, a New Glycopeptide Agent

“…As recommended by the CLSI (4) and Jones and coworkers (1,6), addition of P-80 can most easily be incorporated during the preparation of the broth dilution series for dalbavancin without introducing P-80 to the testing wells of other agents via the inoculum water. Performance characteristics were shown to be more stable when dilutions were prepared by adding P-80 at the outset.…”

“…The results of these studies indicate that 0.002% P-80 should be added to reference broth microdilution antimicrobial susceptibility tests for dalbavancin (1,3,4). As recommended by the CLSI (4) and Jones and coworkers (1,6), addition of P-80 can most easily be incorporated during the preparation of the broth dilution series for dalbavancin without introducing P-80 to the testing wells of other agents via the inoculum water.…”

“…In two additional studies performed in four laboratories, 60 clinical challenge strains of gram-positive bacteria were tested to investigate possible differences between the incorporation of P-80 directly into panel wells or into the inoculum waters (according to the method used by Anderegg et al (1). In the first study, 10 MSSA, 10 MRSA, and 20 betahemolytic streptococcus (8 S. pyogenes and 12 group B, C and G streptococcus) strains were tested in duplicate in two laboratories.…”

“…Initial broth microdilution quality control ranges for S. aureus ATCC 29213, Enterococcus faecalis ATCC 29212 and S. pneumoniae ATCC 49619 were developed as part of an eightlaboratory evaluation published in 2003 (1). In January 2004, these proposed quality control MIC ranges for dalbavancin were approved by the Antimicrobial Susceptibility Testing Subcommittee of the Clinical and Laboratory Standards Institute (CLSI; formerly National Committee for Clinical Laboratory Standards) (3,4).…”

Comparison of Dalbavancin MIC Values Determined by Etest (AB BIODISK) and Reference Dilution Methods Using Gram-Positive Organisms

“…The Clinical and Laboratory Standards Institute (CLSI; formerly the National Committee for Clinical Laboratory Standards [NCCLS]) reference broth microdilution MIC testing methodology and quality control (QC) guidelines for dalbavancin have been reported on previously, and the use of dryform broth microdilution panels for routine laboratory testing has also been validated (1,2,5,6,10). Importantly, the incorporation of the surfactant polysorbate-80 into dalbavancincontaining wells in reference frozen-form panels has been found to be critical for accuracy and reproducibility of MIC results (2,5,7).…”