Nagano Saki, Matsubayashi Makoto, Kita Toshimasa, Narushima Tsuguto, Kimata Isao, Iseki Motohiro, Hajiri Tomoya, Tani Hiroyuki, Sasai Kazumi, Baba Eiichiroh
Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 599-8531, Japan.
Vet Parasitol. 2007 Nov 10;149(3-4):213-8. doi: 10.1016/j.vetpar.2007.07.016. Epub 2007 Sep 6.
Cryptosporidium oocysts were detected in the feces of cattle in Saga, Japan. Isolates were morphologically large. We attempted to identify the species or genotypes of the isolates by analyzing the partial sequences of the 18S rRNA and Cryptosporidium oocyst wall protein (COWP) genes, and measuring the infectivity in mice. The isolates showed 100% homology with Cryptosporidium andersoni in the COWP gene sequence and it could be transmitted to mice, but in the 18S rRNA gene, there was an additional signal in the ABI sequence chromatogram. To examine the additional signal, we analyzed both the 18S rRNA and the COWP gene sequences of a single oocyst passaged from mice using a modified multiplex PCR that was able to amplify both genes. As a result, it was revealed that two distinct genotypes (Types A and B) of a novel C. andersoni type existed in the 18S rRNA gene, whereas the COWP gene sequences of both oocysts were identical to C. andersoni. Although the sequence of the 18S rRNA gene of Type A was identical to that of C. andersoni, that of Type B had a thymine insertion and was not identical to any sequence registered with GenBank. Here we report that this is a new type of C. andersoni.
在日本佐贺县的牛粪便中检测到了隐孢子虫卵囊。分离株在形态上较大。我们试图通过分析18S rRNA和隐孢子虫卵囊壁蛋白（COWP）基因的部分序列，并检测其对小鼠的感染性，来鉴定分离株的种类或基因型。这些分离株在COWP基因序列上与安氏隐孢子虫显示出100%的同源性，并且能够传播给小鼠，但在18S rRNA基因中，ABI序列色谱图上出现了一个额外的信号。为了研究这个额外的信号，我们使用一种能够同时扩增这两个基因的改良多重PCR，分析了从小鼠体内传代的单个卵囊的18S rRNA和COWP基因序列。结果发现，在18S rRNA基因中存在两种不同基因型（A 型和B型）的新型安氏隐孢子虫，而两个卵囊的COWP基因序列均与安氏隐孢子虫相同。虽然A型的18S rRNA基因序列与安氏隐孢子虫的相同，但B型有一个胸腺嘧啶插入，与GenBank中登记的任何序列都不相同。在此我们报告这是一种新型的安氏隐孢子虫。
