Cyclic strand displacement polymerase reaction to turn-on molecular beacons for rapid detection of Staphylococcus aureus

Abstract

Staphylococcus aureus (S. aureus) is one of the most common food-borne pathogens, and its rapid detection is important for food safety. In this paper, a method for rapid detection of S. aureus by using cyclic strand displacement polymerase reaction (CSDPR) for turn-on molecular beacons (MBs) was proposed. The highly conserved 16S rDNA fragment sequence of S. aureus was screened as the target nucleic acid, and was detected by CSDPR amplification. Under the optimized condition, the linear range of the method was 2.0 × 105–2.5 × 106 CFU/mL, and the detection limit was 9.5 × 104 CFU/mL. The reaction time of CSDPR was 15 min. This method has been applied to the rapid detection of S. aureus in spiked milk and steak samples and the detection results are consistent with those of plate counting method.