Sensitive and rapid detection of staphylococcus aureus in milk via cell binding domain of lysin

Staphylococcus aureus (S. aureus) is an important food-borne pathogen in dairy products contaminated through raw ingredients or improper food handling. Rapid detection of S. aureus with high sensitivity is of significance for food quality and safety. In this study, a new method was developed for detecting S. aureus in milk by coupling immunomagnetic separation with enzyme linked cell wall binding domain (CBD) of lysin plyV12, which can bind to S. aureus with high affinity. There are millions of binding sites present on the cell surface of S. aureus for the CBD attachment, which greatly improves the detection sensitivity. The method has the overall testing time of only 1.5 h with the detection limit of 4×103 CFU/mL in spiked milk. Because it is simple, rapid and sensitive, this method could be used for the detection of S. aureus in various food samples.