Carbapenemase detection by NG-Test CARBA 5-a rapid immunochromatographic assay in carbapenem-resistant Enterobacterales diagnosis

Ying Zhu; Peiyao Jia; Xue Li; Tong Wang; Jingjia Zhang; Ge Zhang; Simeng Duan; Wei Kang; Yingchun Xu; Qiwen Yang

doi:10.21037/atm-20-8216

Carbapenemase detection by NG-Test CARBA 5-a rapid immunochromatographic assay in carbapenem-resistant Enterobacterales diagnosis

Ann Transl Med. 2021 May;9(9):769. doi: 10.21037/atm-20-8216.

Authors

Ying Zhu^{1

2}, Peiyao Jia^{1

2}, Xue Li^{1

3}, Tong Wang¹, Jingjia Zhang¹, Ge Zhang¹, Simeng Duan¹, Wei Kang¹, Yingchun Xu¹, Qiwen Yang¹

Affiliations

¹ Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
² Graduate school, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
³ Department of Clinical Laboratory, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.

Abstract

Background: The global spread of carbapenem-resistant Enterobacterales (CRE) represents a serious public health concern as these organisms are associated with limited treatment options, high mortality rate and rapid transmissibility. The identification of carbapenemase remains a challenge in microbiological laboratories as no single method is perfect when considering cost, carbapenemase coverage, accuracy, handling complexity and TATs together.

Methods: NG-Test CARBA 5 assay and modified carbapenem inactivation method in conjunction with EDTA carbapenem inactivation method (mCIM/eCIM) were challenged with a collection of 299 molecularly characterized CRE isolates in China in order to evaluate the performance in detecting five major carbapenemases (bla _KPC, bla _NDM, bla _VIM, bla _IMP, and bla _OXA-48) among Enterobacterales.

Results: NG-Test CARBA 5 detected all KPC-, NDM-, VIM- and OXA-48-producing isolates perfectly with a weak false-positive signal for NDM in an IMP-4 producer, which makes the specificity for NDM decreases to 99.6%. The overall specificity/sensitivity were 99.9%/100% for NG-Test CARBA 5. mCIM/eCIM achieved high specificity of 100%/100% and sensitivity of 99.6%/97.4%, with one S. marcescens isolate harboring VIM-2 undetected.

Conclusions: Both NG-Test CARBA 5 and mCIM/eCIM showed excellent results in the tested carbapenemase (bla _KPC, bla _NDM, bla _VIM, bla _IMP, and bla _OXA-48) detection compared with molecular genotypic test. As every assay has its own limitations, suitable methods should be combined for the establishment of the CRE diagnostic pathways.

Keywords: Carbapenemase-resistant Enterobacterales (CRE); EDTA carbapenem inactivation method (eCIM); NG-Test CARBA 5; modified carbapenem inactivation method (mCIM).