title: Rapid detection of Listeria monocytogenes in raw milk and soft cheese by a redox potential measurement based method combined with real-time PCR.
abstract: The incidence of outbreaks of foodborne listeriosis has indicated the need for a reliable and rapid detection of the microbe in different foodstuffs. A method combining redox potential measurement and real-time polymerase chain reaction (PCR) was developed to detect Listeria monocytogenes in artificially contaminated raw milk and soft cheese. Food samples of 25 g or 25 ml were homogenised in 225 ml of Listeria Enrichment Broth (LEB) with Oxford supplement, and the redox potential measurement technique was applied. For Listeria species the measuring time was maximum 34 h. The absence of L. monocytogenes could reliably be proven by the redox potential measurement method, but Listeria innocua and Bacillus subtilis could not be differentiated from L. monocytogenes on the basis of the redox curves. The presence of L. monocytogenes had to be confirmed by real-time PCR. The combination of these two methods proved to detect < 10 cfu/g of L. monocytogenes in a cost- and time-effective manner. This method can potentially be used as an alternative to the standard nutrient method for the rapid detection of L. monocytogenes in food.
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Erdősi
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Szakmár
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Olivér
authors.initials: O
authors.lastname: Reichart
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Szili
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Noémi
authors.initials: N
authors.lastname: László
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Székely Körmöczy
authors.affiliation: Szent István University Department of Food Hygiene, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Laczay
keywords: Listeria monocytogenes; food safety; rapid detection; real-time PCR; redox potential