Rapid detection of trace Salmonella in milk using an effective pretreatment combined with droplet digital polymerase chain reaction

Meihong Du; Jingwen Li; Qingjun Liu; Yanfei Wang; Erning Chen; Fuying Kang; Chenxiao Tu

doi:10.1016/j.micres.2021.126838

Rapid detection of trace Salmonella in milk using an effective pretreatment combined with droplet digital polymerase chain reaction

Microbiol Res. 2021 Oct:251:126838. doi: 10.1016/j.micres.2021.126838. Epub 2021 Aug 5.

Authors

Meihong Du¹, Jingwen Li², Qingjun Liu², Yanfei Wang³, Erning Chen², Fuying Kang², Chenxiao Tu²

Affiliations

¹ Beijing Engineering Research Center of Food Safety Analysis, Beijing Engineering Technology Research Centre of Gene Sequencing and Gene Function Analysis, Beijing Center for Physical and Chemical Analysis, Beijing, 100089, China. Electronic address: dumeihong@bcpca.ac.cn.
² Beijing Engineering Research Center of Food Safety Analysis, Beijing Engineering Technology Research Centre of Gene Sequencing and Gene Function Analysis, Beijing Center for Physical and Chemical Analysis, Beijing, 100089, China.
³ Solid Waste and Chemicals Management Center, MEE, Beijing, 100029, China.

PMID: 34390956
DOI: 10.1016/j.micres.2021.126838

Abstract

Salmonella is one of the most dangerous food-borne pathogens around the world to cause a threat to humans and it is urgent to develop the rapid detection method of trace Salmonella in food. Although many advanced techniques have been widely applied to shorten the detection time, the pretreatment method usually used of traditional enrichment and plate culturing to separate Salmonella are complicated and time-consuming. Herein, we developed an effective pretreatment method based on in situ enrichment culture with an immunomagnetic separation step, combined with droplet digital polymerase chain reaction (ddPCR) technology to achieve rapid detection of trace Salmonella in milk, which allowed detecting as low as 10^-1 CFU/mL level of Salmonella. It took 8 h to perform the entire testing process from pretreatment to ddPCR detection and analysis. The pretreatment method could be a suitable platform integrating with many detection techniques for the rapid detection of trace Salmonella.

Keywords: Droplet digital polymerase chain reaction (ddPCR); Immunomagnetic separation; Pretreatment; Rapid detection; Salmonella.

MeSH terms

Animals
Food Microbiology* / methods
Limit of Detection
Milk* / microbiology
Polymerase Chain Reaction
Salmonella* / genetics
Salmonella* / isolation & purification