# Comparison of Commercial Lateral Flow Immunochromatography with Phenotypic and Genotypic Assays for the Detection of Carbapenemase-Producing Gram-Negative Bacteria at Tanta University Hospitals

## TL;DR

This study compares a fast lateral flow test with traditional methods for detecting antibiotic-resistant bacteria in hospital settings.

## Contribution

The study evaluates the accuracy of lateral flow immunoassays as a rapid alternative to phenotypic and genotypic methods for detecting carbapenemase-producing bacteria.

## Key findings

- Lateral flow immunoassays showed high sensitivity and specificity for detecting specific carbapenemase genes.
- The LFIA had an overall accuracy of 92-94% when compared to molecular assays.
- blaNDM was the most frequently detected gene, while blaIMP was the least.

## Abstract

It is crucial to identify Enterobacterales that produce carbapenemase to treat and manage hospital infections. The suggested techniques for their identification need a lengthy wait, technical knowledge, and training. Lateral flow immunoassays (LFIAs) provide a solution to these requirements. Thus, this study compared LFIA with phenotypic and genotypic tests for carbapenemase-producing bacteria. Fifty clinical isolates of carbapenem-resistant superbugs were examined. KPC, VIM, NDM, IMP, and OXA-48-like enzymes were evaluated and compared with phenotypic tests and LFIA. Regarding the phenotypic characteristics, the mCIM was positive in 37/50 (74%), and the eCIM was positive in 21/50 (42%). Regarding using LFIA, 41 out of the total isolates (82%) gave a positive red line with one or more of the tested genes. The most frequently detected gene was blaNDM (27/50 (54%)), and the least detected one was blaIMP (14/50 (28%)), which was in accordance with the PCR results. While investigating the accuracy of LFIA vs. PCR, it was found that LFIA had 100% sensitivity in the detection of the blaNDM and blaOXA genes, with 85.2% and 91.4% specificity, respectively, while for the blaIMP, blaKPC, and blaVIM genes, the values were 91.7% and 92.1%, 94.1% and 90.9%, and 95.5% and 89.3%, respectively. The overall accuracy of LFIA ranged from 92 to 94%. Our comparison with molecular assays revealed remarkable agreement, so we propose that this test might be utilized as a supplementary tool.