Microcystis is a widespread freshwater cyanobacterium that can produce microcystin, a potent hepatotoxin harmful to animals and humans. Therefore, it is crucial to monitor for the presence of toxigenic Microcystis spp. to provide early warning of potential microcystin contamination. Microscopy, which has been used traditionally to identify Microcystis spp., cannot differentiate toxigenic from non-toxigenic Microcystis. We developed a PCR-based method to detect toxigenic Microcystis spp. based on detection of the microcystin synthetase C (mcyC) gene and 16S rRNA gene. Specificity was validated against toxic and nontoxic M. aeruginosa strains, as well as 4 intergeneric freshwater cyanobacterial strains. Analytical sensitivity was as low as 747 fg/µL genomic DNA (or 3 cells/µL) for toxic M. aeruginosa. Furthermore, we tested 60 water samples from 4 farm ponds providing drinking water to swine facilities in the midwestern United States using this method. Although all water samples were positive for Microcystis spp. (i.e., 16S rRNA gene), toxigenic Microcystis spp. were detected in only 34 samples (57%). Seventeen water samples contained microcystin (0.1-9.1 μg/L) determined with liquid chromatography-mass spectrometry, of which 14 samples (82%) were positive for mcyC. A significant correlation was found between the presence of toxigenic Microcystis spp. and microcystin in water samples (p = 0.0004). Our PCR method can be a low-cost molecular tool for rapid and specific identification of toxigenic Microcystis spp. in farm ponds, improving detection of microcystin contamination, and ensuring water safety for farm animals.

中文翻译：

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基于 PCR 的方法用于快速、特异性检测产毒微囊藻属的实用性。在农场的池塘里。


微囊藻是一种广泛分布的淡水蓝藻，可以产生微囊藻毒素，这是一种对动物和人类有害的强效肝毒素。因此，监测产毒微囊藻属的存在至关重要。提供潜在微囊藻毒素污染的早期预警。传统上用于识别微囊藻属的显微镜无法区分产毒微囊藻和非产毒微囊藻。我们开发了一种基于 PCR 的方法来检测产毒微囊藻属。基于微囊藻毒素合成酶 C (mcyC) 基因和 16S rRNA 基因的检测。针对有毒和无毒铜绿假单胞菌菌株以及 4 种属间淡水蓝细菌菌株的特异性进行了验证。对于有毒铜绿假单胞菌，分析灵敏度低至 747 fg/μL 基因组 DNA（或 3 个细胞/μL）。此外，我们还使用这种方法测试了来自 4 个农场池塘的 60 个水样，这些池塘为美国中西部的养猪场提供饮用水。尽管所有水样均呈微囊藻属阳性。 （即 16S rRNA 基因），产毒微囊藻属。仅在 34 个样本 (57%) 中检测到。液相色谱-质谱法测定17个水样中含有微囊藻毒素（0.1-9.1μg/L），其中14个样品（82%）mcyC呈阳性。发现产毒微囊藻属的存在之间存在显着相关性。和水样中的微囊藻毒素 (p = 0.0004)。我们的 PCR 方法可以成为一种低成本的分子工具，用于快速、特异性地鉴定产毒微囊藻属。在农场池塘中，改进微囊藻毒素污染的检测，并确保农场动物的饮水安全。