用荧光标记O-I噬菌体快速检测食品源沙门氏菌

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

摘要:

摘要：【目的】利用O-I噬菌体几乎可裂解沙门氏菌属细菌的特性建立快速检测食品中沙门氏菌的方法。【方法】用核酸荧光染料SYBR? gold染料标记O-I噬菌体侵染100株试验菌及120份食品样品菌，荧光显微镜鉴定沙门氏菌；并测灵敏度。【结果】100株试验菌中40株沙门氏菌可见杆状荧光，而10株变形杆菌、20株志贺氏菌、20株大肠杆菌和10株葡萄球菌均无荧光；沙门氏菌检测灵敏度达10 CFU/100 μL；120份食品样品中沙门氏菌的O-I噬菌体检测与生化鉴定结果的阳性率分别为9.17 %和10 %，符合率为91.7 %。【结论】试验表明用荧光标记的O-I噬菌体可以快速、直观、准确、大量地检测食品中沙门氏菌。

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.