Rapid Detection of Salmonella in food by Using Fluorescently Labeled Phage O-I

Abstract:

Abstract: [Objective] To develop a rapid detection method for Salmonella in food by using specific Salmonella-phage O-I. [Methods] One hundred bacteria strains and 120 food sample isolates were infected using fluorescently labeled O-I phage genome with SYBR? gold stain (a nucleic acid dye, 1×working solution), then were observed under epi-fluorescence microscopy. The sensitivity of the method was tested. [Results] Among the 100 strains infected with O-I/ SYBR? gold stain, 40 Salmonella strains exhibited rod fluorescence. Other bacteria including 10 Proteus, 20 Shigella, 20 E. coli and 10 Staphylococcus did not exhibit this feature The sensitivity of detecting Salmonella was 10 CFU/100 μL. The detection for 120 food samples by using the O-I/ SYBR? gold stain had similar results to those by using the biochemical method. [Conclusion] Fluorescent-labeled O-I phage could rapidly, sensitively and specifically detect Salmonella species in food samples.