title: Analysis of microbial diversity on deli slicers using polymerase chain reaction and denaturing gradient gel electrophoresis technologies.
abstract: Cross-contamination of pathogenic and spoilage bacteria from food-contact surfaces to food products is a serious public health issue. Bacteria may survive and attach to food-contact surfaces by residual food components and/or background bacteria which may subsequently transfer to other food products. Deli slicers, generally used for slicing ready-to-eat products, can serve as potential sources for considerable bacterial transfer. The objective of this study was to assess the extent and distribution of microbial diversity of deli slicers by identification of pathogenic and background bacteria. Slicer-swab samples were collected from restaurants in Arkansas and Texas in the United States. Ten surface areas for each slicer were swabbed using sterile sponges. Denaturing gradient gel electrophoresis (DGGE) was applied to investigate the fingerprint of samples, and each band was further identified by sequence analysis. Pseudomonads were identified as the dominant bacteria followed by Enterobacteriaceae family, and lactic acid bacteria such as Lactococcus lactis and Streptococcus thermophilus were also found. Bacterial distribution was similar for all surface areas, while the blade guard exhibited the greatest diversity. This study provides a profile of the microbial ecology of slicers using DGGE to develop more specific sanitation practices and to reduce cross-contamination during slicing.
authors.affiliation: Center for Food Safety, Food Science Department, University of Arkansas, Fayetteville, AR, USA.
authors.forename: O K
authors.initials: OK
authors.lastname: Koo
authors.forename: A W
authors.initials: AW
authors.lastname: Mertz
authors.forename: E L
authors.initials: EL
authors.lastname: Akins
authors.forename: S A
authors.initials: SA
authors.lastname: Sirsat
authors.forename: J A
authors.initials: JA
authors.lastname: Neal
authors.forename: R
authors.initials: R
authors.lastname: Morawicki
authors.forename: P G
authors.initials: PG
authors.lastname: Crandall
authors.forename: S C
authors.initials: SC
authors.lastname: Ricke
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000302:isolation & purification; D058645:Denaturing Gradient Gel Electrophoresis; D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling / Q000295:instrumentation*; D005516:Food Microbiology; D016133:Polymerase Chain Reaction; D012147:Restaurants; D012499:Sanitation
chemical_list: D004269:DNA, Bacterial