Foodborne parasites (FBP) are of major public health importance and warrant appropriate detection and control strategies. Most of the FBP considered for risk-ranking by a panel of experts are potentially transmitted via consumption of contaminated fresh produce, including berries. In this study we focused on the potential of three FBP, namely Echinococcus multilocularis, Toxoplamsa gondii, and Cyclospora cayetanensis, as contaminants of berries. Surveys to assess these parasites as contaminants of fresh produce in general, and berries in particular, are scanty or non-existent mainly due to the lack of optimized laboratory methods for detection. The aim of the present study was to develop and evaluate a novel multiplex qPCR for the simultaneous detection of E. multilocularis, T. gondii, and C. cayetanensis from berry fruits. The efficiency and linearity of each channel in the multiplex qPCR were within the acceptable limits for the range of concentrations tested. Furthermore, the method was shown to have good repeatability (standard deviation ≤0.2 Cq) and intermediate precision (pooled standard deviation of 0.3-0.6 Cq). The limit of detection was estimated to 10 oocysts for Toxoplasma and Cyclospora, and 5 eggs for Echinococcus per 30 g of raspberries or blueberries. In conclusion, evaluation of the present method showed that the newly developed multiplex qPCR is highly specific, precise, and robust method that has potential for application in food-testing laboratories.
Keywords: Contamination; Food testing; Foodborne parasites (FBP); Fresh produce; Intra-laboratory validation; Limit of detection (LoD); Method development; Molecular detection.
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