Dpto. Microbiología III, Universidad Complutense de Madrid, Madrid, Spain.
Int J Food Microbiol. 2011 Jan 31;145(1):121-5. doi: 10.1016/j.ijfoodmicro.2010.11.041. Epub 2010 Dec 4.
Aflatoxins are important mycotoxins that represent a serious risk for human and animal health. These mycotoxins are mainly produced by Aspergillus flavus and Aspergillus parasiticus, two closely related species with different array of aflatoxins. In this work, two specific quantitative PCR (qPCR) assays were developed to detect and quantify both species in wheat flour using primers based on the multicopy ITS2 rDNA target sequence. The species specificity of the assays was tested in a wide range of strains of these species and others colonizing the same commodities. The sensitivity of the assay was estimated in 2.5 pg/reaction in both species. Discrimination capacity for detection and relative quantification of A. flavus and A. parasiticus DNA were analyzed using samples with DNA mixtures containing also other fungal species at different ratios. Both qPCR assays could detect spore concentrations equal or higher than 10(6)spores/g in flour samples without prior incubation. These assays are valuable tools to improve diagnosis at an early stage and in all critical control points of food chain integrated in HACCP strategies.
黄曲霉毒素是重要的真菌毒素，对人类和动物健康构成严重威胁。这些真菌毒素主要由黄曲霉和寄生曲霉产生，这两种密切相关的物种产生不同种类的黄曲霉毒素。在这项工作中，使用基于多拷贝 ITS2 rDNA 靶序列的引物，开发了两种特定的实时定量 PCR（qPCR）检测方法，用于检测和定量面粉中的这两种真菌。在广泛的这些物种和其他在同一商品上定殖的菌株中测试了检测方法的物种特异性。在两种物种中，该方法的灵敏度估计为 2.5 pg/反应。使用含有不同比例其他真菌物种的 DNA 混合物的样品分析了检测和相对定量 A. flavus 和 A. parasiticus DNA 的区分能力。这两种 qPCR 检测方法都可以检测到面粉样品中孢子浓度等于或高于 10(6)孢子/g，而无需预先培养。这些检测方法是在 HACCP 策略中改进食物链各个关键控制点早期诊断的有价值的工具。
