Laboratory of Parasitology, Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Adamstuen Campus, P.O. Box 369 Center, 0102, Oslo, Norway.
Department of Agriculture Science, Food and Environment, University of Foggia, 71122, Foggia, FG, Italy.
Food Microbiol. 2020 Aug;89:103447. doi: 10.1016/j.fm.2020.103447. Epub 2020 Jan 26.
The potential public health impact of foodborne parasites (FBP) transmitted via contaminated fresh produces indicates the necessity for robust and reliable laboratory methods for their detection and identification on this infection vehicle. Standardization of methods for detection of common FBP in fresh produce is to be expected and ensuring that the DNA extraction approach is most appropriate for the FBP of interest and for the matrix being analyzed is also important. Therefore, the aim of the present study was to compare the efficacy of two commercially available DNA extraction procedures, the UNEX-based method and DNeasy PowerSoil kit in the detection of three protozoan parasites, C. cayetanensis, C. parvum, and T. gondii, on contaminated berries. Oocysts of each parasite were spiked into the pellets of raspberry and blueberry washes. The spiked pellets were then randomly assigned to DNA extraction using either the PowerSoil or UNEX method, with DNA extraction with both methods performed by two independent analysts. The detection rate when berry washes were spiked with 20 oocysts of C. cayetanensis, T. gondii, and C. parvum was 95%, 85%, and 40%, respectively, when using the PowerSoil kit; whereas the equivalent results using the UNEX method were 55%, 60%, and 5%, respectively. In addition, significantly lower C values were achieved for each parasite in the samples spiked with 500 oocysts when the PowerSoil kit was used. Possible reasons for these results are discussed, and include the composition of both the beads and the buffers in each method.
食源性寄生虫（FBP）通过受污染的新鲜农产品传播，其潜在的公共卫生影响表明，有必要针对这种感染媒介物建立强大可靠的实验室检测和鉴定方法。预计将对常见的新鲜农产品中 FBP 的检测方法进行标准化，并确保 DNA 提取方法最适合感兴趣的 FBP 和正在分析的基质也很重要。因此，本研究的目的是比较两种市售 DNA 提取方法（UNEX 法和 DNeasy PowerSoil 试剂盒）在检测三种原生动物寄生虫（C. cayetanensis、C. parvum 和 T. gondii）方面的效果，这些寄生虫存在于受污染的浆果中。将每种寄生虫的卵囊混入树莓和蓝莓洗涤物的颗粒中。然后，将受污染的颗粒随机分配给使用 PowerSoil 或 UNEX 方法进行 DNA 提取，两种方法的 DNA 提取均由两名独立的分析人员进行。当使用 PowerSoil 试剂盒对浆果洗涤物进行 20 个卵囊的 C. cayetanensis、T. gondii 和 C. parvum 进行接种时，检测率分别为 95%、85%和 40%；而使用 UNEX 方法的等效结果分别为 55%、60%和 5%。此外，当使用 PowerSoil 试剂盒对含有 500 个卵囊的样本进行接种时，每个寄生虫的 C 值都显著降低。讨论了这些结果的可能原因，包括两种方法中珠子和缓冲液的组成。
