Rapid visual detection of Staphylococcus epidermidis in bovine mastitis milk using LAMP-lateral flow dipstick

The use of Loop-mediated Isothermal Amplification (LAMP) technology in combination with Lateral Flow Dipstick (LFD) for the rapid detection of Staphylococcus epidermidis (S. epidermidis) offers a technical solution for early disease monitoring in dairy farms.

This method is intended to enable early and accurate identification of S. epidermidis infections in dairy farms, facilitating timely intervention and treatment to reduce economic losses and ensure milk quality and safety.

A pair of primers specific to the aaa gene of S. epidermidis was designed, and the aaa-FIP primer was 5'-end labeled with biotin for LAMP amplification, followed by hybridization with a 6-FAM-labeled probe, and the result was read out on an LFD. The specificity, sensitivity, and clinical applicability of the method were evaluated.

The results demonstrated that the optimal reaction conditions consisted of incubation at 64°C for 30 minutes, followed by probe hybridization for 5 minutes and subsequent chromogenic reaction on the LFD, which enabled the specific and visual detection of S. epidermidis. The established Loop-mediated Isothermal Amplification-Lateral Flow Dipstick (LAMP-LFD) method, which exhibits high specificity and sensitivity with a detection limit 100-fold higher than that of conventional polymerase chain reaction, achieved 100% consistency when applied to 20 clinical samples suspected of S. epidermidis infection.

This study pioneers the development of a LAMP-LFD method that is simple to operate and can visually detect S. epidermidis associated with bovine mastitis with high specificity and sensitivity, making it suitable for rapid on-site detection of early infections in grassroots farms and holding great promise for broad application.