Rapid detection of methicillin-resistant Staphylococcus aureus in positive blood-cultures by recombinase polymerase amplification combined with lateral flow strip

PLoS One. 2022 Jun 30;17(6):e0270686. doi: 10.1371/journal.pone.0270686. eCollection 2022.

Abstract

Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), is an important bacterium that causes community and healthcare-related infections throughout the world. However, the current conventional detection methods are time-consuming. We therefore developed and evaluated a recombinase polymerase amplification-lateral flow strip (RPA-LF) approach for detection of MRSA in positive blood-culture samples. Sixty positive blood-cultures from a hospital were tested directly without DNA extraction and purification before the amplification reaction. RPA primers and probes were designed for nuc (encoding thermonuclease) and mecA (encoding penicillin-binding protein 2a) genes to diagnose S. aureus and its methicillin-resistance status. The RPA reaction occurred under isothermal conditions (45°C) within 20 min and a result was provided by the LF strip in a further 5 min at room temperature. The evaluation of RPA-LF using blood-culture samples showed 93.3% (14/15) sensitivity for identifying S. aureus, and no cross-amplification was seen [100% (45/45) specificity]. For detection of methicillin resistance, the RPA-LF test provided 100% (16/16) sensitivity and 97.7% (43/44) specificity. The RPA-LF is rapid, highly sensitive, robust and easy to use. It can be used for direct detection of MRSA with no requirement for special equipment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Methicillin-Resistant Staphylococcus aureus* / genetics
  • Nucleic Acid Amplification Techniques / methods
  • Nucleotidyltransferases
  • Recombinases / genetics
  • Sensitivity and Specificity
  • Staphylococcus aureus / genetics

Substances

  • Recombinases
  • Nucleotidyltransferases

Grants and funding

This research was supported by the Fundamental Fund of Khon Kaen University and KKU Research Grant (Project No. I62-00-19-03). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.