Development of dual polymerase spiral reaction for detection of Listeria monocytogenes and Staphylococcus aureus simultaneously

Listeria monocytogenes and Staphylococcus aureus are prevalent foodborne pathogens responsible for poisoning humans with food. The present study was devoted to the establishment of a method based on dual polymerase spiral reaction (dual-PSR) and melting curve analysis for concurrent identification L. monocytogenes and S. aureus. Specifically, the primer pairs were aimed at the conserved hlyA gene of L. monocytogenes and that of S. aureus (nuc). These reactions were carried out isothermally at 65 degrees C for 45 min within the same reaction vessel, and the amplified products were analyzed in a melting curve. Different average temperatures of melting allow the discrimination in the dual-PSR assay between the two target bacteria. The limits of simultaneous determination of L. monocytogenes and S. aureus in artificially contaminated fresh-cut fruit samples were 1 x 10-4 ng of genomic DNA and 1 x 102 CFU/g, respectively. This method is characterized by its expeditious nature and simultaneous detection capability, and it promises to be a valuable technology for the monitoring of pathogenic microorganisms around health and quality control of foodstuffs within that industry.