Antibiotics | Evaluation of NG-Test CARBA 5 for Rapid Detection of Carbapenemases in Clinical CRKp Isolates

This article evaluates the diagnostic performance of NG-Test CARBA 5 in rapidly detecting five major carbapenemases in clinical CRKp isolates, demonstrating high sensitivity and specificity, particularly for the detection of KPC, NDM, and OXA-48-like. However, further validation is required for VIM detection.

 

Literature Overview
The article titled 'Evaluation of the NG-Test CARBA 5 for Rapid Detection of Carbapenemases in Clinical Isolates of Klebsiella pneumoniae,' published in the journal Antibiotics, reviews and summarizes the performance of NG-Test CARBA 5 in rapid carbapenemase detection, validated through PCR methods. The article highlights that NG-Test CARBA 5 demonstrates excellent overall sensitivity and specificity but presents false-negative results in VIM detection, indicating the need for further investigation.

Background Knowledge
Rapid detection of carbapenemases is critical for controlling drug-resistant Klebsiella infections, especially in hospital settings. KPC, NDM, VIM, IMP, and OXA-48-like are the major carbapenemase types in CRKp, with OXA-48-like being the most prevalent in the study. Accurate differentiation of carbapenemase types is essential for guiding therapeutic strategies (e.g., the use of β-lactam/β-lactamase inhibitors). NG-Test CARBA 5 is an immunochromatographic test kit capable of detecting five major carbapenemases directly from bacterial colonies within 15 minutes, making it suitable for rapid diagnostic workflows. However, its performance on real clinical samples, especially for VIM and IMP detection, requires further validation.

 

 

Research Methods and Experiments
Between January 2023 and October 2024, the research team collected 312 clinical CRKp isolates from the Military Medical Academy in Belgrade, Serbia. All samples were tested using NG-Test CARBA 5 and validated using PCR as the gold standard. The study evaluated the sensitivity, specificity, and Cohen’s kappa coefficient of this detection method across different carbapenemase types (KPC, NDM, VIM, IMP, OXA-48-like) and analyzed its applicability in real clinical settings.

Key Conclusions and Perspectives

• Among the 312 CRKp isolates, OXA-48-like (67.3%) was the predominant carbapenemase, followed by NDM (24.7%) and KPC (18.3%), while VIM accounted for only 1.6%, and IMP was not detected.
• The overall sensitivity of NG-Test CARBA 5 was 98.7%, with 100% specificity. The sensitivity for detecting KPC, NDM, and OXA-48-like was above 96%, with 100% specificity.
• The method performed poorly for VIM detection, failing to identify all five PCR-positive samples, indicating potential limitations in VIM detection.
• NG-Test CARBA 5 performed well in detecting multiple carbapenemases (e.g., NDM + OXA-48-like), but some co-expressing strains were missed.
• The article recommends using this method in clinical settings due to its rapid and accurate detection of carbapenemases, but it should be combined with other detection methods to ensure comprehensive coverage.

Research Significance and Prospects
NG-Test CARBA 5 demonstrates high sensitivity and specificity in rapid carbapenemase detection for CRKp, particularly for major types such as KPC, NDM, and OXA-48-like. However, its performance in VIM detection requires further optimization to improve overall diagnostic coverage. Future studies could incorporate gene sequencing technologies to verify the detection capabilities of NG-Test CARBA 5 and optimize its application in multi-drug resistant strains.

 

 

Conclusion
This article evaluates the performance of NG-Test CARBA 5 in rapid carbapenemase detection in clinical CRKp isolates and finds excellent performance in detecting KPC, NDM, and OXA-48-like, with sensitivity above 96% and specificity reaching 100%. However, significant false negatives were observed in VIM detection, suggesting that other molecular methods should be used in conjunction with NG-Test CARBA 5 to ensure comprehensive diagnostics in practical applications. Overall, NG-Test CARBA 5 is a rapid diagnostic tool suitable for high antimicrobial resistance settings, effectively supporting clinical carbapenemase detection and treatment decision-making.

 

Bojan Rakonjac, Momčilo Djurić, Danijela Djurić-Petković, Marija Milić, and Aleksandra Arsović. Evaluation of the NG-Test CARBA 5 for Rapid Detection of Carbapenemases in Clinical Isolates of Klebsiella pneumoniae. Antibiotics.