Rapid enrichment and detection of Staphylococcus aureus in milk using polyethyleneimine functionalized magnetic nanoparticles

Staphylococcus aureus (S. aureus) is a common foodborne pathogen, which could cause serious bacteremia and infective endocarditis. Establishing a rapid and low-cost method to capture and detect S. aureus in food samples is necessary. In this study, we have developed a method on the basis of polyethyleneimine-functionalized magnetic nanoparticles (MNP-PEI) and recombinase aided amplification (RAA) for rapid enrichment and analysis of S. aureus in milk. The capture efficiency of MNP-PEI on multiple strains of bacteria and influencing factors were studied. The limits of detection (LOD) of the MNP-PEI-RAA strategy were 2.9 x 10(1) CFU.mL(-1) in phosphatebuffered saline (PBS) and 2.9 x 10(2) CFU.mL(-1) in milk. The entire enrichment and detection processes could be completed within 60 min. The detection strategy based on MNP-PEI and RAA had low cost, short detection time, and high sensitivity. In addition, the broad-spectrum of bacteria captured by MNP-PEI was important for simultaneous analysis of a variety of bacteria, which provided an effective tool for evaluating the microbiological safety of food samples.

Automated summary

This study developed a method based on magnetic nanoparticles and recombinase aided amplification for rapid capture and detection of Staphylococcus aureus in food samples. The method has low cost, short detection time, and high sensitivity, and can simultaneously analyze multiple bacteria, which is important for evaluating the microbiological safety of food samples.