Department of Biology, MEEL, Lund University, Lund, Sweden.
Laboratory of Biomedical Science, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Japan.
Mol Ecol Resour. 2021 Feb;21(2):355-362. doi: 10.1111/1755-0998.13272. Epub 2020 Oct 31.
The polymerase chain reaction (PCR) is a very powerful method to detect and identify pathogens. The high sensitivity of the method, however, comes with a cost; any of the millions of artificial DNA copies generated by PCR can serve as a template in a following experiment. If not identified as contaminations, these may result in erroneous conclusions on the occurrence of the pathogen, thereby inflating estimates of host range and geographic distribution. In the present paper, we evaluate whether several published records of avian haemosporidian parasites, in either unusual host species or geographical regions, might stem from PCR contaminations rather than novel biological findings. The detailed descriptions of these cases are shedding light upon the steps in the work process that might lead to PCR contaminations. By increasing the awareness of this problem, it will aid in developing procedures that keep these to a minimum. The examples in the present paper are from haemosporidians of birds, however the problem of contaminations and suggested actions should apply generally to all kinds of PCR-based identifications, not just of parasites and pathogens.
聚合酶链式反应（PCR）是一种非常强大的方法，可用于检测和鉴定病原体。然而，该方法的高灵敏度是有代价的；PCR 产生的数以百万计的人工 DNA 拷贝中的任何一个都可以作为后续实验的模板。如果这些 DNA 没有被鉴定为污染，它们可能会导致对病原体发生的错误结论，从而夸大宿主范围和地理分布的估计。在本文中，我们评估了一些已发表的关于禽类血孢子虫寄生虫的记录，这些寄生虫要么出现在不寻常的宿主物种中，要么出现在地理区域中，这些记录是否可能源于 PCR 污染，而不是新的生物学发现。这些案例的详细描述揭示了可能导致 PCR 污染的工作流程步骤。通过提高对这个问题的认识，有助于制定将这些污染降到最低的程序。本文中的例子来自鸟类的血孢子虫，但污染问题和建议的措施应该普遍适用于所有基于 PCR 的鉴定，而不仅仅是寄生虫和病原体。
