Bacteriophage amplification-assisted lateral flow biosensor for rapid viability-targeted screening of Salmonella in chicken meat.

Salmonella contamination in poultry meat remains a major global food safety concern, necessitating rapid and reliable viability-targeted detection methods. Here, we developed a platform of phage amplification (PA)-assisted lateral flow biosensor for rapid screening of viable Salmonella in chicken meat. The platform combines a short selective enrichment step in Rappaport-Vassiliadis soya broth with infection by the Salmonella-specific phage SE-W109 (multiplicity of infection of 0.1). In the presence of viable Salmonella cells, progeny phages were produced and subsequently detected via lateral flow immunoassay (LFI). The entire procedure was completed within approximately 7 h, providing an instrument-free visual readout suitable for point-of-need testing. PA-LFI detected major Salmonella serovars, including S. Enteritidis and S. Typhimurium, without cross-reactivity toward non-Salmonella bacteria. The detection limit was approximately 100 colony-forming units per 25 g of chicken meat. Field evaluation of PA-LFI using 30 retail chicken samples, compared with ISO 6579-1:2017 as the reference method, showed that Salmonella was present in 36.7% (11/30) of the samples. PA-LFI correctly identified 8 of the 11 culture-positive samples and 17 of the 19 culture-negative samples, thus achieving a sensitivity of 72.7%, a specificity of 89.5%, and overall agreement of 83.3%. This work demonstrates a phage-amplified lateral flow biosensing platform that enables rapid, viability-targeted detection, complements culture-based methods as a practical screening tool for routine food safety monitoring, and can be readily adapted to other bacterial pathogens through appropriate phage selection.