title: Evaluation of a Multiplex PCR Assay for the Identification of Salmonella Serovars Enteritidis and Typhimurium Using Retail and Abattoir Samples.
abstract: A multiplex PCR was developed to identify the two most common serovars of Salmonella causing foodborne illness in Canada, namely, serovars Enteritidis and Typhimurium. The PCR was designed to amplify DNA fragments from four Salmonella genes, namely, invA gene (211-bp fragment), iroB gene (309-bp fragment), Typhimurium STM 4497 (523-bp fragment), and Enteritidis SE147228 (612-bp fragment). In addition, a 1,026-bp ribosomal DNA (rDNA) fragment universally present in bacterial species was included in the assay as an internal control fragment. The detection rate of the PCR was 100% among Salmonella Enteritidis (n = 92) and Salmonella Typhimurium (n = 33) isolates. All tested Salmonella isolates (n = 194) were successfully identified based on the amplification of at least one Salmonella -specific DNA fragment. None of the four Salmonella DNA amplicons were detected in any of the non- Salmonella isolates (n = 126), indicating an exclusivity rate of 100%. When applied to crude extracts of 2,001 field isolates of Salmonella obtained during the course of a national microbiological baseline study in broiler chickens and chicken products sampled from abattoir and retail outlets, 163 isolates, or 8.1%, tested positive for Salmonella Enteritidis and another 80 isolates, or 4.0%, tested as Salmonella Typhimurium. All isolates identified by serological testing as Salmonella Enteritidis in the microbiological study were also identified by using the multiplex PCR. The new test can be used to identify or confirm pure isolates of the two serovars and is also amenable for integration into existing culture procedures for accurate detection of Salmonella colonies.
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Dele
authors.initials: D
authors.lastname: Ogunremi
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Susan
authors.initials: S
authors.lastname: Nadin-Davis
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Andrée Ann
authors.initials: AA
authors.lastname: Dupras
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Imelda Gálvan
authors.initials: IG
authors.lastname: Márquez
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Katayoun
authors.initials: K
authors.lastname: Omidi
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Louise
authors.initials: L
authors.lastname: Pope
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: John
authors.initials: J
authors.lastname: Devenish
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Teresa
authors.initials: T
authors.lastname: Burke
authors.affiliation: Ottawa Laboratory Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9.
authors.forename: Ray
authors.initials: R
authors.lastname: Allain
authors.affiliation: Food Safety Science Division, Floor 5, 1400 Merivale Road, Tower 2, Ottawa, Ontario, Canada K1A 0Y9.
authors.forename: Daniel
authors.initials: D
authors.lastname: Leclair
mesh_terms: D000003:Abattoirs; D000818:Animals; D002170:Canada; D002645:Chickens / Q000382:microbiology; D060885:Multiplex Polymerase Chain Reaction; D016133:Polymerase Chain Reaction; D012475:Salmonella / Q000302:isolation & purification; D012477:Salmonella enteritidis / Q000302:isolation & purification*; D012486:Salmonella typhimurium / Q000302:isolation & purification; D065288:Serogroup
keywords: Enteritidis; Identification; PCR; Salmonella; Serovars; Typhimurium