Comparison between detection power of MBT STAR-Carba test and KBM CIM Tris II for carbapenemase-producing bacteria

Abstract Objectives The rapid detection of carbapenemase-producing bacteria is clinically important for selecting appropriate antimicrobial therapy. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry was used to detect carbapenemase activity. Methods In this study, we evaluated the detection power of MBT STAR-Carba test on identifying carbapenemase-producing bacteria isolated in Kobe city, Japan, compared with that of the KBM CIM Tris II kit using the modified procedure parameters. The obtained results were expressed as normalized logRQ values indicating a measure of hydrolysis efficiency. Results The MBT STAR-Carba test rapidly detected not only major carbapenemases, such as IMP-1 and IMP-6 that are most prevalent in Japan, but also GES-type and OXA-51-like carbapenemases, which are difficult to detect by reaction with inhibitors or KBM CIM Tris II by extending the incubation time. Conclusions The MBT STAR-Carba test will be beneficial in rapid identification of carbapenemases in clinical settings and environmental investigations.