A broadly reactive monoclonal antibody-based immunochromatographic test kit for pan-detection of Salmonella in foods

Abstract

Foodborne illnesses caused by a variety of Salmonella enterica serotypes are public health problems globally. A reliable detection method with rapid turn-around time and easy to perform is needed to ensure food safety. This study reports the use of a broadly reactive monoclonal antibody-based lateral flow immunochromatographic test (ICT) for rapid detection of Salmonella in food matrices. The assay employs a monoclonal antibody (clone 102B2) against the conserved region of Salmonella lipopolysaccharides as the capture antibody at the test line, and a colloidal gold-conjugated polyclonal antibody as the detection probe. The ICT strips provide visually interpretable results within 10 min and demonstrate a limit of detection of 0.1 μg/mL for Salmonella whole-cell homogenate, with no cross-reactivity with Listeria monocytogenes . The assay showed a sensing range of 0.1–500 μg/mL of Salmonella whole-cell homogenate, corresponding to approximately 10⁵–10⁸ CFU/mL after ISO-based pre-enrichment. Multiple Salmonella serovars, including Enteritidis, Typhi, and Poona, were successfully detected with high specificity. Stability tests under standard (2–8 °C and 25–30 °C) and accelerated (40 °C) storage conditions revealed consistent performance for up to 14 and 60 days, respectively. These findings highlight the robustness and suitability of the ICT as a rapid screening tool for Salmonella contamination in food products, particularly in resource-limited or field settings.