Parallel Validation of the Ng-Test Carba 5 and the Xpert Carba-R for Detection and Characterization of Carbapenem-Resistant Enterobacterales Causing Bloodstream Infections

Document Type

Article

Publication Date

5-6-2021

Publication Source

The Journal of Molecular Diagnostics

Abstract

The rapid detection and characterization of carbapenemases in isolates of Enterobacterales are crucial for precise antibiotic administration and infection control. This article reports the findings from a parallel evaluation of the NG-Test Carba 5 (NG Biotech, Guipry, France) and Xpert Carba-R (Cepheid, Sunnyvale, CA) assays in the detection and differentiation of five carbapenemases [imipenem-resistant phenotype (IMP), Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase (NDM), oxacillin-hydrolyzing β-lactamase (OXA)-48–like, and Verona integron-encoded metallo-β-lactamase] or the genes that encode them. A total of 122 isolates recovered from blood cultures and 106 positive blood culture broth (BCB) specimens, including 134 Klebsiella pneumoniae, 54 Escherichia coli, 27 Enterobacter cloacae, 8 Klebsiella oxytoca, 2 Klebsiella aerogenes, and 3 Citrobacter freundii, were collected from two tertiary hospitals (Xi'an, China). Using PCR sequencing techniques, 89 isolates and 29 BCB specimens were determined to be Enterobacterales harboring carbapenem-resistance genes. In comparison to the PCR sequencing results, the specificities with both the NG-Test Carba 5 and Xpert Carba-R assays were 100%; the sensitivities were 92.1% and 100%, respectively, for recovered isolates and 79.3% and 100% for BCB specimens. The NG-Test Carba 5 missed eight NDM, four OXA-48–like, and one IMP β-lactamases in specimens containing two or three carbapenemase types. In summary, the NG-Test Carba 5 assay may yield false-negative results if isolates or BCB specimens contain two or three carbapenemases.

Inclusive pages

1007-1014

ISBN/ISSN

Print ISSN: 1525-1578; Online ISSN: 1943-7811

Document Version

Postprint

Comments

The accepted manuscript of this publication will made available in compliance with the publisher’s policy on self-archiving. Permission documentation is on file. Until then, use the link to the DOI.

Publisher

Elsevier

Volume

23

Peer Reviewed

yes

Issue

8


Share

COinS