Development of a real-time nucleic acid sequence–based amplification assay for the rapid detection of Salmonella spp. from food
Salmonella spp. is one of the most common foodborne infectious pathogen. This study aimed to develop a real-time nucleic acid sequence–based amplification (NASBA) assay for detecting Salmonella in foods. Primers and a molecular beacon targeting the Salmonella-specific xcd gene were designed for mRNA transcription, and 48 Salmonella and 18 non-Salmonella strains were examined. The assay showed a high specificity and low detection limit for Salmonella (7 × 10−1 CFU/mL) after 12 h of pre-enrichment. Importantly, it could detect viable cells. Additionally, the efficacy of the NASBA assay was examined in the presence of pork background microbiota; it could detect Salmonella cells at 9.5 × 103 CFU/mL. Lastly, it was successfully used to detect Salmonella in pork, beef, and milk, and its detection limit was as low as 10 CFU/25 g (mL). The real-time NASBA assay developed in this study may be useful for rapid, specific, and sensitive detection of Salmonella in food of animal origin.
KeywordsSalmonella spp. Real-time NASBA Food Detection
This work was supported by grants from the National Science and Technology Support Program, the Social Development Program of Jiangsu Province, the Independent Innovation Program of Jiangsu Province, and the University Natura Science Key Project of Anhui Province (Grant Nos. 2012BAK08807, BE2012746, CX (12)3087, and KJ2016A182).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict interest.
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