# Evaluation of the NG-Test CARBA 5 for Rapid Detection of Carbapenemases in Clinical Isolates of Klebsiella pneumoniae

## TL;DR

This study evaluates a rapid test for detecting carbapenemase enzymes in a drug-resistant bacteria, finding it highly effective except for one type of enzyme.

## Contribution

The study introduces and validates NG-Test CARBA 5 as a rapid diagnostic tool for carbapenemase detection in Klebsiella pneumoniae.

## Key findings

- NG-Test CARBA 5 showed high sensitivity and specificity for most carbapenemases.
- The test failed to detect VIM in five PCR-positive isolates.
- OXA-48-like was the most prevalent carbapenemase among the isolates.

## Abstract

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a critical global health threat due to its multidrug resistance, primarily driven by carbapenemase production. Rapid and accurate detection of carbapenemases is essential for effective treatment and infection control. This study evaluates the validity of the NG-Test CARBA 5, a rapid immunochromatographic assay, for detecting five major carbapenemases (KPC, NDM, VIM, IMP, OXA-48-like) in clinical CRKp isolates. Methods: Clinical isolates of CRKp were collected from various clinical specimens at the Military Medical Academy in Belgrade, Serbia, between January 2023 and October 2024. Detection of carbapenemases was performed using NG-Test CARBA 5, while PCR served as the reference method. Diagnostic performance was assessed by calculating sensitivity, specificity, and Cohen’s kappa coefficient. Results: Among 312 isolates, OXA-48-like was the most prevalent carbapenemase. NG-Test CARBA 5 showed high sensitivity (98.7%) and specificity (100%) overall, with excellent agreement for NDM (κ = 0.947), OXA-48-like (κ = 0.957), and KPC (κ = 0.978). However, it failed to detect VIM in five PCR-positive isolates, suggesting potential limitations. Conclusions: NG-Test CARBA 5 is a rapid and reliable tool for detecting major carbapenemases in CRKp, though its performance for VIM detection requires further investigation. This assay has the potential to improve clinical diagnostics and strengthen infection control in settings with high antimicrobial resistance.