Evaluation of inhibitor-combination mCIM for detecting MBL-producing Enterobacterales using three MBL inhibitors. Issue 11 (12th September 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)
• Page Start: 1604
• Page End: 1606
• Publication Date: 2019-09-12
• 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 : 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.