Duplex PCR-lateral flow immunoassay for rapid and visual screening of Salmonella and Vibrio cholerae for food safety assurance and hygiene surveillance

Salmonella and Vibrio cholerae are the deadliest foodborne pathogens, requiring effective routine screening for food safety assurance. Hence, a duplex polymerase chain reaction integrated with a lateral flow immunoassay (PCR-LFIA) was developed for rapid detections of Salmonella and V. cholerae to overcome the laborious, time-consuming, complicated, and costly limitations of standard bacterial culture. The duplex PCR-LFIA could simultaneously detect Salmonella invA and V. cholerae lolB targets at lower limits of 0.1 and 1 ng, respectively. Without requiring culture enrichment, the duplex PCR-LFIA method enabled rapid and simple naked-eye identification of Salmonella and V. cholerae in spiked raw oysters and chicken meat at a limit of detection (LOD) of 10⁶ CFU/mL. A LOD of 10⁴ CFU/mL was achieved by visualizing the PCR amplicons by agarose gel electrophoresis (AGE). This novel duplex PCR-LFIA offers rapid and simple visual detections of pathogenic Salmonella and V. cholerae contaminations, potentially enhancing the capability to monitor and control foodborne illnesses, thereby ensuring food safety.