Evaluation of inhibitor‐combination mCIM for detecting MBL‐producingEnterobacteralesusing three MBL inhibitors. Issue 11 (November 2019)

• Record Type: Journal Article
• Authors: Yamada, Kageto; Sasaki, Masakazu; Imai, Waka; Murakami, Hinako; Morita, Toshisuke; Aoki, Kotaro; Ishii, Yoshikazu; Tateda, Kazuhiro
• Is Part Of: Journal of medical microbiology. Volume 68:Issue 11(2019)
• Publication Date: 2019-11
• Subjects: inhibitor combination mCIM -- dipicolinic acid -- EDTA -- metallo‐β‐lactamase -- modified carbapenem inactivation method -- sodium mercaptoacetate; Medical microbiology -- Periodicals; 616.9041
• DOI: 10.1099/jmm.0.001073
• Languages: English
• ISSNs: 0022-2615

Abstract

Abstract : N/A: The increase in carbapenemase‐producing Enterobacterales (CPE), including metallo‐β‐lactamase (MBL) producers, is a severe global health concern. Thus, highly sensitive and specific methods for detecting MBL producers are needed. In this study, we tested the detectability of MBL‐producing Enterobacterales against three types of MBL inhibitors (sodium mercaptoacetate, SMA; ethylenediaminetetraacetic acid, EDTA; and dipicolinic acid, DPA) used in combination with a modified carbapenem inactivation method (mCIM). These inhibitor‐combination mCIMs were tested against 129 CPE (IMP, 93; NDM, 11; KPC, 13; NMC, 1; OXA‐48, 11) and 75 non‐CPE. For evaluation of MBL inhibitors, we used two concentrations for each of the three inhibitors: DPA (200 and 300 mg l − 1 ), EDTA (5 and 10 mM), and SMA (1500 and 3000 mg l − 1 ). The overall sensitivities of SMA, EDTA and DPA were 97.1‐99.0%, 81.7‐99.0% and 88.5‐96.2%, respectively. Moreover, each method showed high specificity (99.0‐100%). Although inhibitor‐combination mCIMs were highly sensitive and specific for the detection of MBL producers, we found that sensitivity was dependent on the concentration of inhibitors.