Abstract:

In order to establish a rapid and accurate detection method of Salmonella typhimurium contamination in duck-slaughtering chain, PCR was used to monitor duck-slaughtering chain in real time. A pair of primers 5＇-GCA TTCCGCTCATTAGAT-3＇and 5＇-TGGAGGCTGATAACAAGG-3＇ were designed to amplify fimY gene by PCR according to the published fimY gene sequence of Salmonella typhimurium. PCR reaction conditions were optimized. Results indicated that a fragment with 275 bp in length was amplified in both standard strain and isolated strain of Salmonella typhimurium. The detection limit of PCR assay was 1.2 pg. This established PCR method was used for the detection of Salmonella typhimurium in a typical duck-slaughtering chain. Totally 25 samples from plucking pool, cooling wax pool, cleaning pool, feathers, esophagus, intestine, colorectal feces, and dripping peritoneal were amplified to produce the 275 bp fragment. In contrast, no amplified fragment was achieved in the negative control. In the present study, a PCR assay was first developed for the detection of Salmonella typhimurium in duckslaughtering chain and typical duck-slaughtering chain with serious contamination of Salmonella typhimurium was observed. These results provided a practical application and useful guidance to the management of duck meat production and food safety.

Key words: duck, PCR, Salmonella typhimurium, detection, duck-slaughtering chain