Duplex Enzymatic Recombinase Amplification Assay Coupled with Lateral Flow Dipstick for Rapid Identification of...

Area of Science:

• Clinical microbiology
• Molecular diagnostics
• Infectious disease detection

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant public health threat.
• Accurate and rapid detection of MRSA is crucial for effective patient management and infection control.
• Existing diagnostic methods can be time-consuming or require specialized laboratory equipment.

Purpose of the Study:

• To develop and evaluate a novel duplex isothermal enzymatic recombinase amplification assay coupled with a lateral flow assay (ERA-LFA) for MRSA detection.
• To assess the performance of the ERA-LFA method in identifying the presence of specific MRSA marker genes (nuc and mecA) in clinical samples and blood cultures.

Main Methods:

• A duplex ERA-LFA method was developed to simultaneously detect the nuc and mecA genes.
• The assay was tested on 46 clinical isolates (differentiated by nuc and mecA carriage) and 57 positive blood culture samples.
• Performance metrics including sensitivity, specificity, and limit of detection were determined.

Main Results:

• For clinical isolates, the ERA-LFA achieved 100% sensitivity and 88.9% specificity for nuc detection, and 100% for mecA detection.
• In blood cultures, the assay demonstrated 100% sensitivity and 95.7% specificity for nuc, and 96.5% specificity for mecA.
• The detection limits were as low as 1 CFU/reaction for the nuc gene and 10 CFU/reaction for the mecA gene.

Conclusions:

• The developed ERA-LFA is a highly sensitive and specific method for the rapid detection of MRSA.
• This assay shows promise for timely diagnosis of MRSA infections directly from clinical specimens, including blood cultures.
• The ERA-LFA offers a valuable tool for clinical laboratories seeking efficient MRSA screening and identification.