PLoS ONE (Jan 2022)

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

  • Arpasiri Srisrattakarn,
  • Pimchanok Panpru,
  • Patcharaporn Tippayawat,
  • Aroonwadee Chanawong,
  • Ratree Tavichakorntrakool,
  • Jureerut Daduang,
  • Lumyai Wonglakorn,
  • Aroonlug Lulitanond

DOI
https://doi.org/10.1371/journal.pone.0270686
Journal volume & issue
Vol. 17, no. 6
p. e0270686

Abstract

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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.