Scientific journal

49 2010

Journal of Food and Nutrition Research
Summary No. 2 / 2010

Rapid detection of Escherichia coli O157:H7 in food using enrichment and real-time polymerase chain reaction
Journal of Food and Nutrition Research, 49, 2010, No. 2, s. 78-84

Saša Piskernik, Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia. E-mail:, tel.: + 386 1 320 37 29; fax: + 386 1 256 62 96

Summary: Escherichia coli O157:H7 may contaminate various types of meat products and cause diarrhea and vomiting, and also more serious complications such as haemorrhagic colitis and haemolytic-uremic syndrome (HUS) in humans. Traditional microbiological analyses to detect this pathogen are labour-intensive and time-consuming. The objective of this study was to evaluate a real-time polymerase chain reaction (PCR) for detection of E. coli O157:H7 in raw and ready-to-eat meat products. The detection limit of real-time PCR determined on pure culture was 1.1 ? 102 CFU•ml-1 when DNA was obtained by lysing cells and 30.6 pg•µl-1 when DNA was isolated and purified. Following a 20 h enrichment of a food sample in universal enrichment broth (UPB), the real-time PCR assay could detect 1.6 CFU•per 10 g of E. coli O157:H7 in chicken juice, raw beef, minced beef, beefsteak tartare, brunch beef and beefburger with background flora in the range of < 102 CFU•g-1 to 2.1 × 106 CFU•g-1. The applied method could be a useful tool for rapid detection of E. coli O157:H7 in raw meat and ready-to-eat meat products.

Keywords: Escherichia coli O157:H7; detection; real-time PCR; meat; ready-to-eat meat products

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