Feng Xue, Norose Kazumi, Li Kexin, Hikosaka Kenji
Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
J Microbiol Methods. 2017 Oct;141:82-86. doi: 10.1016/j.mimet.2017.08.001. Epub 2017 Aug 10.
Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii, which belongs to the phylum Apicomplexa. Since this parasite causes severe clinical symptoms in immunocompromised patients, early diagnosis of toxoplasmosis is essential. PCR is currently used for early diagnosis, but there is no consensus regarding the most effective method for amplifying Toxoplasma DNA. In this study, we considered the utility of the cytochrome c subunit I (cox1) gene, which is encoded in the mitochondrial DNA of this parasite, as a novel target of PCR for the diagnosis of toxoplasmosis. To do this, we compared its copy number per haploid nuclear genome and the detection sensitivity of cox1-PCR with the previously reported target genes B1 and 18S rRNA and the AF146527 repeat element. We found that the copy number of cox1 was high and that the PCR using cox1 primers was more efficient at amplifying Toxoplasma DNA than the other PCR targets examined. In addition, PCR using clinical samples indicated that the cox1 gene would be useful for the diagnosis of toxoplasmosis. These findings suggest that use of cox1-PCR would facilitate the diagnosis of toxoplasmosis in clinical laboratories.
弓形虫病由原生动物寄生虫刚地弓形虫引起，该寄生虫属于顶复门。由于这种寄生虫会在免疫功能低下的患者中引发严重的临床症状，因此弓形虫病的早期诊断至关重要。目前，聚合酶链反应（PCR）用于早期诊断，但对于扩增弓形虫DNA的最有效方法尚无共识。在本研究中，我们考虑将该寄生虫线粒体DNA中编码的细胞色素c亚基I（cox1）基因作为用于诊断弓形虫病的PCR新靶点。为此，我们比较了其单倍体核基因组中的拷贝数以及cox1-PCR与先前报道的靶基因B1和18S rRNA以及AF146527重复元件的检测灵敏度。我们发现cox1的拷贝数很高，并且使用cox1引物的PCR在扩增弓形虫DNA方面比所检测的其他PCR靶点更有效。此外，使用临床样本进行的PCR表明，cox1基因可用于弓形虫病的诊断。这些发现表明，使用cox1-PCR将有助于临床实验室对弓形虫病的诊断。
