ECCMID 2020 Scientific Poster: Meropenem/Vaborbactam MIC Results for Enterobacterales and Pseudomonas aeruginosa


A multicenter study was performed to evaluate the accuracy of testing meropenem/vaborbactam on a MicroScan Dried Gram-negative MIC (MSDGN) Panel when compared to a frozen ISO/CLSI broth microdilution reference panel.


An evaluation was conducted at three U.S. sites by comparing MIC values obtained using the MSDGN to MICs utilizing an ISO/CLSI broth microdilution reference panel. A total of 775 Enterobacterales and P. aeruginosa clinical isolates were tested using the turbidity and Prompt® methods of inoculation during the efficacy phase. A subset of 14 organisms for reproducibility was tested on MSDGN panels at each site. MSDGN panels were incubated at 35 ± 1ºC and read on the WalkAway System, the autoSCAN-4 instrument, and read visually. Read times for the MSDGN panels were at 16-20 hours. Frozen reference panels were prepared according to ISO/CLSI methodology, incubated for 16-20 hours and read visually. EUCAST breakpoints (mg/L) used for interpretation of MIC results were: Enterobacterales ≤ 8/8 S, > 8/8 R and P. aeruginosa ≤ 8/8 S, > 8/8 R.


Essential and categorical agreement when compared to frozen reference panel results, for all isolates tested in efficacy as follows:


Read Method

Essential Agreement %

Categorical Agreement %

Very Major Error (VMJ)* %

Major Error (MAJ)* %

WalkAway 99.2 (769/775) 99.2 (769/775) 99.5 (771/775) 99.5 (771/775) 0.0 (0/6) 0.0 (0/6) 0.1 (1/769) 0.3 (2/769)
autoSCAN-4 99.2 (769/775) 99.1 (768/775) 99.7 (773/775) 99.5 (771/775) 0.0 (0/6) 0.0 (0/6) 0.1 (1/769) 0.3 (2/769)
Visually 99.5 (771/775) 99.1 (768/775) 99.9 (774/775) 99.6 (772/775) 0.0 (0/6) 0.0 (0/6) 0.1 (1/769) 0.3 (2/769)

T = Turbidity inoculation method, P = Prompt inoculation method

*Calculation of MAJ and VMJ excluding 1 well errors


This multicenter study showed that meropenem/vaborbactam MIC results for Enterobacterales and P. aeruginosa obtained with the MSDGN panel correlate well with MICs obtained using frozen reference panels using EUCAST interpretive criteria.
MIC panel scientific poster

Poster MicroScan Meropenem/vaborbactam MIC Results Correlate with ISO/CLSI Reference Panels

Download the ECCMID 2020 poster for complete information showing the accuracy of meropenem/vaborbactam MIC panel results for Enterobacterales and P. aeruginosa correlated with frozen ISO/CLSI broth microdilution reference panel. Analyze the multicenter study’s methods, quality control parameters and conclusions based on EUCAST interpretive criteria.

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