Detection of Salmonella in foods using a reference PN-ISO method and an alternative method based on loop-mediated isothermal amplification coupled with bioluminescence

Abstract

Background: Salmonella, one of the primary indicators of food safety, is a common cause of food poisoning of an epidemic nature around the world. These microorganisms can colonize the gastrointestinal tract of both people and animals, and next contaminate not only eggs, milk, meat and dairy products, but also vegetables, fruit, grains and even spices. Objectives: The aim of this study was to analyze the frequency of detection of Salmonella spp. in food samples using a reference PN-ISO method and an alternative method based on loop-mediated isothermal amplification (LAMP) coupled with bioluminescence. Material and Methods: Food samples were obtained in cooperation with the State Sanitary-Epidemiological Station in Wrocław. Dairy products, meat, fish, pastry and confectionery, vegetables, herbs and spices were analyzed. The food samples were examined using a standard culturing method according to PN-ISO 6579:2003 for Salmonella spp. and an alternative method based on the isothermal amplification and bioluminescence phenomenon using the 3M MDS device. Results: In 399 tested food samples in 8 materials, using both the reference and the alternative LAMP-based method, the presence of salmonella was confirmed. The results obtained show the 100% sensitivity, specificity and accuracy of the presented alternative, LAMP-based technique compared to the reference PN-ISO method. Conclusions: The alternative method using isothermal amplification and bioluminescence makes it possible to detect Salmonella in foods in a much shorter time than the referential culturing method.