Mallaiyaraj Mahalingam Jeevitheswara Thammannaya, Calvani Nichola Eliza Davies, Lee Rogan, Malik Richard, Šlapeta Jan
Sydney School of Veterinary Science, Faculty of Science, University of Sydney, 2006, New South Wales, Australia.
Molecular Parasitology Laboratory, Centre for One Health Ryan Institute, National University of Ireland, Galway, H91 DK59, Galway, Ireland.
Curr Res Parasitol Vector Borne Dis. 2021 Jun 1;1:100033. doi: 10.1016/j.crpvbd.2021.100033. eCollection 2021.
Both and have been identified along the east coast of Australia. A lack of genomic data until 2019, however, has precluded the unequivocal identification of the species responsible for neuroangiostrongyliasis in accidental hosts such as dog and man. The availability of a whole-genome data for , including mtDNA and ITS2 rDNA, enables discrimination of from . The aim of this study was to develop diagnostic PCR assays to determine the species of based on the detection of DNA sequences in the cerebrospinal fluid (CSF) of canine patients with eosinophilic meningitis. An workflow utilising available cytochrome oxidase 1 (1) primers streamlined the laboratory work into empirical steps, allowing optimisation and selection of a PCR assay that met the required criteria for discrimination of and DNA in low-template CSF samples. The adopted 1 qPCR assay specifically amplified and enabled the differentiation of from DNA and confirmed the presence of DNA in 11/50 archived CSF samples. The DNA sequences demonstrated the presence of two distinct 1 haplotypes in dogs from eastern Australia. Species identification was further confirmed the adoption of an ITS2 rDNA assay, providing confirmation of only ITS2 rDNA in the CSF samples. To our knowledge, this is the first study to unequivocally demonstrate the antemortem presence of DNA in CSF from clinically affected dogs. The study confirmed the long-held assumption that is the causal agent of neuroangiostrongyliasis but refutes the dogma that there was a single introduction of into Australia by the demonstration of two distinct 1 haplotypes.
两者均已在澳大利亚东海岸被发现。然而，直到2019年一直缺乏基因组数据，这使得在狗和人等意外宿主中明确鉴定出导致嗜酸性粒细胞性脑膜炎的广州管圆线虫物种成为不可能。广州管圆线虫全基因组数据的可得性，包括线粒体DNA（mtDNA）和内转录间隔区2核糖体DNA（ITS2 rDNA），使得能够将广州管圆线虫与其他物种区分开来。本研究的目的是开发诊断性PCR检测方法，以基于检测嗜酸性粒细胞性脑膜炎犬患者脑脊液（CSF）中的广州管圆线虫DNA序列来确定广州管圆线虫的物种。利用可用的细胞色素c氧化酶1（COX1）引物的工作流程将实验室工作简化为经验步骤，从而能够优化和选择一种符合在低模板CSF样本中区分广州管圆线虫和其他物种DNA所需标准的PCR检测方法。所采用的COX1定量PCR检测方法特异性地扩增并能够区分广州管圆线虫和其他物种的DNA，并在50份存档的CSF样本中的11份中确认了广州管圆线虫DNA的存在。DNA序列表明在来自澳大利亚东部的狗中存在两种不同的COX1单倍型。通过采用ITS2 rDNA检测方法进一步证实了物种鉴定，该方法仅在CSF样本中确认了广州管圆线虫的ITS2 rDNA。据我们所知，这是第一项明确证明临床受影响犬的脑脊液中存在广州管圆线虫DNA的生前研究。该研究证实了长期以来的假设，即广州管圆线虫是嗜酸性粒细胞性脑膜炎的病原体，但通过证明两种不同的COX1单倍型反驳了关于广州管圆线虫仅一次引入澳大利亚的教条。
