Evaluation of PhageDX Assay for Detection in Hydroponic Curly Lettuce.

Lettuce is one of the most consumed leafy vegetables worldwide and has been involved in multiple foodborne outbreaks. is one of the most prevalent etiological agents of foodborne disease (FBD) in lettuces, and its detection may take several days depending on the chosen method. This study evaluates a new rapid method that uses recombinant bacteriophages to detect in hydroponic curly lettuce. First, the ability of the assay to detect six serovars at three different concentrations (1, 10, and 100 CFU/well) was tested. Second, the detection of was tested in lettuces using a cocktail of the same serovars and concentrations after a 7 h enrichment. The results of these experiments showed that the detection limit was dependent on the serovar tested. Most serovars were detected in only 2 h when the concentration was 100 CFU/well. was detected in 9 h (7 h enrichment + 2 h bioluminescence assay) in all lettuce samples with 10 CFU/25 g or more. detection was not influenced by natural microbiota of lettuces. This study demonstrated that the phage assay was sensitive and faster than other detection methods, indicating that it is a better alternative for detection on lettuces.