title: Detection of Salmonella enterica in Meat in Less than 5 Hours by a Low-Cost and Noncomplex Sample Preparation Method.
abstract: Salmonellais recognized as one of the most important foodborne bacteria and has wide health and socioeconomic impacts worldwide. Fresh pork meat is one of the main sources ofSalmonella, and efficient and fast methods for detection are therefore necessary. Current methods forSalmonelladetection in fresh meat usually include >16 h of culture enrichment, in a few cases <12 h, thus requiring at least two working shifts. Here, we report a rapid (<5 h) and high-throughput method for screening ofSalmonellain samples from fresh pork meat, consisting of a 3-h enrichment in standard buffered peptone water and a real-time PCR-compatible sample preparation method based on filtration, centrifugation, and enzymatic digestion, followed by fast-cycling real-time PCR detection. The method was validated in an unpaired comparative study against the Nordic Committee on Food Analysis (NMKL) reference culture method 187. Pork meat samples (n= 140) were either artificially contaminated withSalmonellaat 0, 1 to 10, or 10 to 100 CFU/25 g of meat or naturally contaminated. Cohen's kappa for the degree of agreement between the rapid method and the reference was 0.64, and the relative accuracy, sensitivity, and specificity for the rapid method were 81.4, 95.1, and 97.9%, respectively. The 50% limit of detections (LOD50s) were 8.8 CFU/25 g for the rapid method and 7.7 CFU/25 g for the reference method. Implementation of this method will enable faster release ofSalmonellalow-risk meat, providing savings for meat producers, and it will help contribute to improved food safety.IMPORTANCEWhile the cost of analysis and hands-on time of the presented rapid method were comparable to those of reference culture methods, the fast product release by this method can provide the meat industry with a competitive advantage. Not only will the abattoirs save costs for work hours and cold storage, but consumers and retailers will also benefit from fresher meat with a longer shelf life. Furthermore, the presented sample preparation might be adjusted for application in the detection of other pathogenic bacteria in different sample types.
authors.affiliation: National Food Institute, Technical University of Denmark, Søborg, Denmark msrso@food.dtu.dk.
authors.forename: M S R
authors.identifier: http://orcid.org/0000-0003-4744-6969
authors.initials: MSR
authors.lastname: Fachmann
authors.affiliation: National Food Institute, Technical University of Denmark, Søborg, Denmark.
authors.forename: C
authors.identifier: http://orcid.org/0000-0001-6492-1245
authors.initials: C
authors.lastname: Löfström
authors.affiliation: National Food Institute, Technical University of Denmark, Søborg, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hoorfar
authors.affiliation: Danish Technological Institute, DMRI, Taastrup, Denmark.
authors.forename: F
authors.initials: F
authors.lastname: Hansen
authors.affiliation: National Food Institute, Technical University of Denmark, Søborg, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Christensen
authors.affiliation: Danish Technological Institute, DMRI, Taastrup, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Mansdal
authors.affiliation: National Food Institute, Technical University of Denmark, Søborg, Denmark.
authors.forename: M H
authors.initials: MH
authors.lastname: Josefsen
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000191:economics* / Q000379:methods*; D003362:Cost-Benefit Analysis; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D059022:Food Safety; D005517:Foodborne Diseases / Q000382:microbiology; D007202:Indicators and Reagents; D057230:Limit of Detection; D008460:Meat / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction / Q000191:economics / Q000379:methods; D000069466:Red Meat / Q000382:microbiology; D019779:Salmonella enterica / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine; D013997:Time Factors
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D007202:Indicators and Reagents
keywords: Salmonella; food safety; foodborne pathogens; fresh meat; rapid tests; real-time PCR; sample preparation; validation