DETECTION OF LISTERIA MONOCYTOGENES IN POWDERED MILK BY VIDAS LMO 2 – COLLABORATIVE STUDY

A multilaboratory study was conducted in March 2005 to evaluate VIDAS Listeria monocytogenes II (LMO 2) immunoassay method for the detection of L. monocytogenes in milk products and to assess the ability of the laboratories to detect L. monocytogenes according to this method. Fourteen laboratories, representing government and industry, participated in this trial including the organizer – National Veterinary Research Institute – State Research Institute, Department of Hygiene of Food of Animal Origin. Each laboratory tested eight samples – three samples in blind duplicates containing L. monocytogenes on three levels of contamination and two uninoculated control samples. The participants have analyzed the samples with a mini-VIDAS device that uses enzyme-linked fluorescent assay technique. Twelve laboratories have obtained correct results in each analyzed sample. One laboratory obtained 50% accordance in medium level contaminated samples and one laboratory obtained 50% accordance in uninoculated control sample. All participants obtained 100% accuracy in samples contaminated with low and high levels of L. monocytogenes.