Analysis of microbial diversity on deli slicers using polymerase chain reaction and denaturing gradient gel electrophoresis technologies

• Published in: Letters in applied microbiology Vol. 56; no. 2; pp. 111 - 119
• Main Authors: Koo, O.K., Mertz, A.W., Akins, E.L., Sirsat, S.A., Neal, J.A., Morawicki, R., Crandall, P.G., Ricke, S.C.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01.02.2013; Oxford University Press
• Subjects: Bacteria; Bacteria - classification; Bacteria - isolation & purification; Biodiversity; Biological and medical sciences; deli slicer; Denaturing Gradient Gel Electrophoresis; DNA, Bacterial - isolation & purification; Enterobacteriaceae; Food; Food Contamination - prevention & control; Food Handling - instrumentation; Food industries; Food Microbiology; food‐contact surfaces; Fundamental and applied biological sciences. Psychology; General aspects; Hygiene and safety; Lactococcus lactis; microbial diversity; Microbiology; Polymerase Chain Reaction; pseudomonads; Restaurants; Sanitation; Streptococcus thermophilus; USA, Texas; Pseudomonadales; food-contact surfaces; Applied microbiology; Diversity; Denaturing gradient gel electrophoresis; Pseudomonas; pseudomonads; Contamination; Contact surface; Polymerase chain reaction; Food contact; deli slicer; Technology; Bacteria; Pseudomonadaceae; Microorganism; microbial diversity; Public health
• ISSN: 0266-8254; 1472-765X
• DOI: 10.1111/lam.12021

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 rkansas 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. Significance and Impact of the Study This study is the first to demonstrate the application of DGGE methodology to investigate the microbial diversity of food‐contact surfaces such as deli slicer. These results can further enhance current understanding of the microbial ecology of food‐contact surfaces and aid in developing effective cleaning and sanitization methods. Significance and impact of the Study: This study is the first to demonstrate the application of DGGE methodology to investigate the microbial diversity of food‐contact surfaces such as deli slicer. These results can further enhance current understanding of the microbial ecology of food‐contact surfaces and aid in developing effective cleaning and sanitization methods.