Evaluation of Modified Rapid Carbapenem Inactivation Method (mrCIM) Combined with Rapid EDTA-Modified Carbapenem Inactivation Method (reCIM) to Detect Carbapenemase and Distinguish Metallo-Carbapenemase in Enterobacteriaceae Within Four Hours

Qiang Wei; Jide Sun; Zhu Wang; Li Yan; Chuanming Zhang; Xiuyu Xu

doi:10.2147/IDR.S249570

Evaluation of Modified Rapid Carbapenem Inactivation Method (mrCIM) Combined with Rapid EDTA-Modified Carbapenem Inactivation Method (reCIM) to Detect Carbapenemase and Distinguish Metallo-Carbapenemase in Enterobacteriaceae Within Four Hours

Infect Drug Resist. 2020 Jun 23:13:1919-1927. doi: 10.2147/IDR.S249570. eCollection 2020.

Authors

Qiang Wei¹, Jide Sun¹, Zhu Wang¹, Li Yan¹, Chuanming Zhang¹, Xiuyu Xu¹

Affiliation

¹ Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.

Abstract

Purpose: To develop a rapid EDTA-modified carbapenem inactivation method (reCIM) combined with modified rapid carbapenem inactivation method (mrCIM) to detect carbapenemase and distinguish metallo-β-lactamases from carbapenemases in Enterobacteriaceae in 4 hrs.

Materials and methods: The sensitivities and specificities of mrCIM and reCIM were retrospectively evaluated in 247 carbapenem-resistant Enterobacteriaceae of which 107 were carbapenemase producers confirmed by PCR and sequencing. In addition, mrCIM and reCIM were prospectively evaluated with 47 carbapenem-resistant enterobacterial isolates.

Results: The sensitivity and specificity of mrCIM were 96.3% and 97.1% at 2.5 hrs post incubation, and the specificity increased to 98.6% at 3 hrs. The combined mrCIM and reCIM showed a sensitivity of 95.4% and a specificity of 100% at 2.5 hrs post incubation in identifying metallo-β-lactamases, and the sensitivity increased to 97.0% at 3 hrs. These performance characteristics are comparable to mCIM and eCIM; however, compared with mCIM and reCIM tests which need at least 24 hrs to detect results, the mrCIM and reCIM required less than 4 hrs of total work time.

Conclusion: The combined mrCIM and reCIM can be used to accurately and quickly detect carbapenemase and metallo-β-lactamases in Enterobacteriaceae in 4 hrs and are suitable for routine use in most clinical microbiology laboratories.

Keywords: Enterobacteriaceae; detection; metallo-carbapenemase; modified rapid carbapenem inactivation method; rapid EDTA-modified carbapenem inactivation method.