Laboratory of Food Microbiology and Hygiene, School of Agriculture, Department of Food Science and Technology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Food Microbiol. 2013 Sep;35(2):86-91. doi: 10.1016/j.fm.2013.03.007. Epub 2013 Apr 8.
Real-time PCR (RTiPCR) assays including enrichment stage were evaluated for the rapid detection of Listeria monocytogenes, Salmonella spp. and Escherichia coli O157:H7 in raw ingredients and ready-to-eat products using molecular beacon probes available as commercial kits (WARNEX Genevision, Canada & AES Chemunex detection system, France). The accuracy of the assays was evaluated analyzing 1032 naturally contaminated food samples in combination to the conventional cultural methods. Presence/absence testing of the above pathogens was performed in 25 g samples of each product. In case of L. monocytogenes of 39 positive RTiPCR samples, 37 were confirmed by the cultural method (based on McNemar's test the difference between the two methods is insignificant). The highest incidence of L. monocytogenes in food products was found in desserts and the second highest in frozen pastries. None of the samples were cultural positive but negative in the RTiPCR test. One among the 343 investigated samples was positive for Salmonella spp. by RTiPCR and the cultural method. Out of 333 samples analyzed for E. coli O157:H7 no positive sample was detected. RTiPCR-based methods proved to be powerful tools for fast, sensitive and accurate pathogen detection in raw food ingredients and ready-to-eat products.
实时聚合酶链反应（RTiPCR）检测方法（包括富集阶段），采用分子信标探针（WARNEX Genevision，加拿大和 AES Chemunex 检测系统，法国），用于快速检测生原料和即食产品中的单核细胞增生李斯特菌、沙门氏菌和大肠杆菌 O157：H7。通过与传统的文化方法相结合，分析了 1032 个自然污染食品样本，评估了这些检测方法的准确性。对每种产品的 25 克样品进行上述病原体的存在/不存在检测。在 39 个阳性 RTiPCR 样本中，37 个通过培养方法得到证实（基于 McNemar 检验，两种方法之间的差异不显著）。在食品产品中，单核细胞增生李斯特菌的发病率最高的是甜点，其次是冷冻糕点。在 RTiPCR 检测中，没有一个样本是文化阳性但 RTiPCR 检测为阴性的。在 343 个调查样本中，有 1 个样本通过 RTiPCR 检测为沙门氏菌阳性，通过文化方法检测为阳性。在分析的 333 个大肠杆菌 O157：H7 样本中，没有检测到阳性样本。基于 RTiPCR 的方法被证明是快速、敏感和准确检测生原料和即食产品中病原体的有力工具。
