Open AccessAn improved carbapenem inactivation method, CIMTrisII, for carbapenemase production by Gram-negative pathogens
Author(s) -
Kohei Uechi,
Tatsuya Tada,
Kyoko KuwaharaArai,
Junichiro Sekiguchi,
Izumi Yanagisawa,
Takaaki Tome,
Isamu Nakasone,
Shiro Maeda,
San Mya,
Khin Nyein Zan,
Htay Htay Tin,
Teruo Kirikae,
Jiro Fujita
Publication year - 2019
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/jmm.0.000888
Subject(s) - gram , microbiology and biotechnology , carbapenem , gram negative bacteria , gram negative bacterial infections , biology , bacteria , antibiotics , escherichia coli , gene , genetics
The modified carbapenem inactivation method (mCIM) is a simple phenotypic screening method for detecting carbapenemase production by Enterobacteriaceae and Pseudomonas aeruginosa. We recently developed another modified carbapenem inactivation method (CIMTris), in which carbapenemase is extracted from bacteria with Tris-HCl buffer, to detect carbapenemase production by Acinetobacter and Pseudomonas species. This study describes an improved carbapenem inactivation method, CIMTrisII, for detecting carbapenemase production by Gram-negative pathogens, including Enterobacteriaceae, Acinetobacter and Pseudomonas species. CIMTrisII was different from CIMTris in the concentration of Meropenem disks (5-µg MEM disks vs. 10-µg MEM disks), the inoculum volume of the bacteria (a 5-µl loopful vs. a 10 µl loopful) and the incubation time (1 vs. 2 h). CIMTrisII showed an overall sensitivity of 99.3 % and an overall specificity of 95.0 % for tested isolates. In comparison, CIMTris showed a sensitivity of 96.1 % and a specificity of 96.3 %, and mCIM showed a sensitivity of 67.1 % and a specificity of 100 %. CIMTrisII is thus deemed useful for detecting carbapenemase production by Gram-negative pathogens.