title: The evaluation of a PCR-based method for identification of Salmonella enterica serotypes from environmental samples and various food matrices.
abstract: The most commonly used method for serotyping Salmonella spp. is based on the Kaufmann-White scheme, and is composed of serological reactions using antibodies to LPS agglutinins. The multiplex PCR used in this investigation was established by Kim et al. to serotype the 30 most common clinical Salmonella serotypes, as determined by CDC. The PCR assay consists of two five-plex reactions and a single two-plex PCR reaction, based on six genetic loci from Salmonella enterica serotype Typhimurium and four loci from S. enterica serotype Typhi. In this investigation, we further evaluated the method for serotyping Salmonella spp. using a reference collection, environmental samples collected from a Mid-Atlantic region tomato farm study, four food matrices spiked with different Salmonella serotypes and a proficiency test. The PCR assay was first evaluated using DNA isolated from pure cultures of isolates obtained from various clinical and environmental samples, and then DNA isolated from broth cultures of food matrices of "Red round" and Roma tomatoes, Romaine lettuce, green onions and Serrano peppers spiked with serotypes Newport, Typhimurium, Javiana and Saintpaul, respectively. The results showed that the PCR assay correctly serotyped Salmonella spp. from the clinical, environmental, spiked food matrices, and proficiency test samples. These findings are significant because the PCR assay was successful in the identification of Salmonella in the spiked samples in a broth culture containing other non-salmonella organism. This method may be a useful resource for the food safety community.
authors.affiliation: U.S. Food and Drug Administration, Laurel, MD 20708, USA. junia.jean-gillesbeaubrun@fda.hhs.gov
authors.forename: Junia
authors.initials: J
authors.lastname: Jean-Gilles Beaubrun
authors.forename: Chorng-Ming
authors.initials: CM
authors.lastname: Cheng
authors.forename: Kai-Shun
authors.initials: KS
authors.lastname: Chen
authors.forename: Laura
authors.initials: L
authors.lastname: Ewing
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Maria C
authors.initials: MC
authors.lastname: Agpaoa
authors.forename: Mei-Chiung J
authors.initials: MC
authors.lastname: Huang
authors.forename: Erin
authors.initials: E
authors.lastname: Dickey
authors.forename: Jamie M
authors.initials: JM
authors.lastname: Du
authors.forename: Donna M
authors.initials: DM
authors.lastname: Williams-Hill
authors.forename: Brittany
authors.initials: B
authors.lastname: Hamilton
authors.forename: Shirley A
authors.initials: SA
authors.lastname: Micallef
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Rosenberg Goldstein
authors.forename: Ashish
authors.initials: A
authors.lastname: George
authors.forename: Sam W
authors.initials: SW
authors.lastname: Joseph
authors.forename: Amy R
authors.initials: AR
authors.lastname: Sapkota
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Jacobson
authors.forename: Ben D
authors.initials: BD
authors.lastname: Tall
authors.forename: Mahendra H
authors.initials: MH
authors.lastname: Kothary
authors.forename: Kim
authors.initials: K
authors.lastname: Dudley
authors.forename: Darcy E
authors.initials: DE
authors.lastname: Hanes
mesh_terms: D004783:Environmental Microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods*; D019779:Salmonella enterica / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012703:Serotyping / Q000379:methods*; D014675:Vegetables / Q000382:microbiology*