Lateral flow immunoassay for rapid detection of carbapenemase-producing E. coli and K. pneumoniae at Cho Ray Hospital, Vietnam

Abstract

Introduction: Carbapenem-resistant Escherichia coli and Klebsiella pneumoniae represent an escalating threat to global public health, particularly in Southeast Asia, where antimicrobial resistance (AMR) is highly prevalent. This study aimed to evaluate the diagnostic performance of the NG-Test Carba 5 lateral flow immunoassay for the rapid detection of carbapenemase-producing E. coli and K. pneumoniae.

Methodology: A cross-sectional study was conducted using 160 carbapenem-resistant E. coli and K. pneumoniae isolates collected from Cho Ray Hospital in Vietnam. The NG-Test Carba 5 was compared with a composite reference method comprising the modified carbapenem inactivation method (mCIM) and Multiplex Real-time PCR (Entero DR Assay). Diagnostic accuracy was assessed using positive percent agreement (PPA) and negative percent agreement (NPA) with 95% confidence intervals (CIs).

Results: The assay showed excellent diagnostic performance, with a PPA of 98.7% (95% CI: 96.24%–99.56%) and an NPA of 100.0% (95% CI: 99.33%–100.0%). No false positives were observed. Three false negatives were identified in isolates co-harboring blaNDM and blaOXA-48. Importantly, no isolates tested positive by mCIM but negative by either the NG-Test Carba 5 or the Entero DR Assay.

Conclusions: The lateral flow immunoassay demonstrated high diagnostic accuracy in detecting carbapenemase-producing E. coli and K. pneumoniae. Its operational simplicity and excellent performance support its use as a reliable frontline diagnostic tool, with minimal risk of missing rare or emerging carbapenemase genotypes in this setting.