[Comparison of 3 commercial metallo-beta-lactamase detection kits]

Abstract

Using 41 metallo-beta-lactamase producing isolates and 8 metallo-beta-lactamase nonproducing and ceftazidime-resistant isolates from Kyushu Island, metallo-beta-lactamase was detected by 3 commercial metallo-beta-lactamase detection kits, which were Metallo-beta-lactamase SMA Eiken (SMA, disk diffusion, Eiken Chemical Co.), dry plate Eiken DPD1 (DPD, two-fold serial broth microdilution, Eiken Chemical Co). and Cica beta test I/ MBL (CIC, coloring reaction, Kanto Chemical Co.). Detection rate by SMA, DPD, and CIC was 97.5, 100, and 100%. Neither method used in this study produced false-positive or false-negative results. The rates of metallo-beta-lactamase nonproducer identification were 37.5%, 62.5%, and 100% for the SMA, DPD, and CIC kits, respectivily. These three methods have the following features, SMA is useful for routine work because SMA utilizes disk diffusion, which is widely used by medical technologists, and it is the least expensive of the three kits. CIC can detect metallo-beta-lactamase after only 15 minutes and can determine the presence of non-metallo-beta-lactamase producers at a high rate. DPD can simultaneously identify the MIC of some agents. Consequently these three metallo-beta-lactamase detection kits were very useful for detecting metallo-beta-lactamase producing isolates.