Rapid detection of Salmonella in food and feed by coupling loop-mediated isothermal amplification with bioluminescent assay in real-time. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Yang, Qianru; Domesle, Kelly; Wang, Fei; Ge, Beilei
• Is Part Of: BMC microbiology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 10
• Publication Date: 2016-12
• Subjects: LAMP -- BART -- Salmonella -- Food -- Feed -- Detection; Microbiology -- Periodicals; 579.05
• DOI: 10.1186/s12866-016-0730-7
• Languages: English
• ISSNs: 1471-2180

Abstract

Abstract Background Salmonella is among the most significant pathogens causing food and feed safety concerns. This study examined the rapid detection ofSalmonella in various types of food and feed samples by coupling loop-mediated isothermal amplification (LAMP) with a novel reporter, bioluminescent assay in real-time (BART). Performance of the LAMP-BART assay was compared to a conventional LAMP and the commercially available 3M Molecular Detection Assay (MDA)Salmonella . Results The LAMP-BART assay was 100 % specific among 178 strains (151Salmonella and 27 non-Salmonella ) tested. The detection limits were 36 cells per reaction in pure culture and 104 to 106 CFU per 25 g in spiked food and feed samples without enrichment, which were comparable to those of the conventional LAMP and 3M MDASalmonella but 5–10 min faster. Ground turkey showed a strong inhibition on 3M MDASalmonella, requiring at least 108 CFU per 25 g for detection. The correlation betweenSalmonella cell numbers and LAMP-BART signals was high (R 2 = 0.941–0.962), suggesting good quantification capability. After 24 h enrichment, all three assays accurately detected 1 to 3 CFU per 25 g ofSalmonella among five types of food (cantaloupe, ground beef, ground turkey, shell eggs, and tomato) and three types of feed (cattle feed, chicken feed, and dry dog food) examined. However, 101 CFU per 25 g was required for cattle feed when tested by 3M MDASalmonella . Conclusions TheSalmonella LAMP-BART assay was rapid, specific, sensitive, quantitative, and robust. Upon further validation, it may become a valuable tool for routine screening ofSalmonella in various types of food and feed samples.