應用毛地黃素標幟之寡核苷酸探針於食品中沙門氏菌之檢測   全文下載

The Use of Digoxigenin-labeled Oligonucleotide Probes for the Specific Detection of Salmonella in Foods

以毛地黃素標幟三段寡核?酸片段，TS11，TS21及TS31，並與臺灣出現頻率較高之沙門氏菌及非沙門氏菌進行菌落雜交，確認、這三段經毛地黃素標幟之寡核?酸片段之雜交特異性。接著，利用上述非放射性寡核?酸探針於食品中，包括豬肉、魚及草蝦樣品中沙門氏菌之檢測。結果發現使用Lactose combined tetrathionate培養基增殖目標菌，將菌液劃線培養於Salmonella Shigella agar上，並將可疑菌落點菌於平鋪於Luria agar上硝化纖維膜上，進行菌落雜交，可得清楚之檢測結果，每克食品只要含有3 cfu 或以上的沙門氏菌，即可檢測出來。

Three oligonucleotide fragment TS11, TS21, and TS31 were labeled with digoxigenin, and the hybridization specificities for three oligonucleotides confirmed with Salmonella and non-Salmonella isolates. Three non-radioactive oligonucleotide probes were used for the specific detection of Salmonella in contaminated food samples, including pork, fish and shrimp samples. It was found that enrichment of Salmonella in food samples using lactose combined tetrathionate broth followed by streaking of the culture on Salmonella-Shigella agar and spotting suspected cells on nitrocellulose paper placed on Luria agar prior to colony hybridization yield unambiguous results. Salmomella at 3 cfu per gram of food could be detected.