Zhai Ligong, Liu Hongxia, Chen Qiming, Lu Zhaoxin, Zhang Chong, Lv Fengxia, Bie Xiaomei
College of Food Science and Technology, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
College of Food and Drug, Anhui Science and Technology University, Fengyang, 233100, People's Republic of China.
Braz J Microbiol. 2019 Jan;50(1):255-261. doi: 10.1007/s42770-018-0002-9. Epub 2018 Dec 3.
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 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 × 10 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.
沙门氏菌属是最常见的食源性感染病原体之一。本研究旨在开发一种基于实时核酸序列扩增（NASBA）的检测食品中沙门氏菌的方法。设计了针对沙门氏菌特异性xcd基因的引物和分子信标用于mRNA转录，并检测了48株沙门氏菌和18株非沙门氏菌菌株。该方法在预富集12小时后对沙门氏菌显示出高特异性和低检测限（7×10 CFU/mL）。重要的是，它能够检测活细胞。此外，在有猪肉背景微生物群存在的情况下检测了NASBA方法的效能；它能够检测到9.5×10 CFU/mL的沙门氏菌细胞。最后，该方法成功用于检测猪肉、牛肉和牛奶中的沙门氏菌，其检测限低至10 CFU/25 g（mL）。本研究开发的实时NASBA方法可能有助于快速、特异性和灵敏地检测动物源性食品中的沙门氏菌。
