Zahedi Alireza, Durmic Zoey, Gofton Alexander W, Kueh Susan, Austen Jill, Lawson Malcolm, Callahan Lauren, Jardine John, Ryan Una
School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.
School of Agriculture and Environment, The University of Western Australia, Perth, Australia.
Vet Parasitol. 2017 Oct 15;245:92-101. doi: 10.1016/j.vetpar.2017.08.014. Epub 2017 Aug 24.
The morphological, biological, and molecular characterisation of a new Cryptosporidium species from the guinea pig (Cavia porcellus) are described, and the species name Cryptosporidium homai n. sp. is proposed. Histological analysis conducted on a post-mortem sample from a guinea pig euthanised due to respiratory distress, identified developmental stages of C. homai n. sp. (trophozoites and meronts) along the intestinal epithelium. Molecular analysis at 18S rRNA (18S), actin and hsp70 loci was then conducted on faeces from an additional 7 guinea pigs positive for C. homai n. sp. At the 18S, actin and hsp70 loci, C. homai n. sp. exhibited genetic distances ranging from 3.1% to 14.3%, 14.4% to 24.5%, and 6.6% to 20.9% from other Cryptosporidium spp., respectively. At the 18S locus, C. homai n. sp. shared 99.1% similarity with a previously described Cryptosporidium genotype in guinea pigs from Brazil and it is likely that they are the same species, however this cannot be confirmed as actin and hsp70 sequences from the Brazilian guinea pig genotype are not available. Phylogenetic analysis of concatenated 18S, actin and hsp70 sequences showed that C. homai n. sp. exhibited 9.1% to 17.3% genetic distance from all other Cryptosporidium spp. This clearly supports the validity of C. homai n. sp. as a separate species.
描述了从豚鼠（豚鼠属）中分离出的一种新隐孢子虫物种的形态学、生物学和分子特征，并提出了该物种的名称隐孢子虫霍迈新种（Cryptosporidium homai n. sp.）。对因呼吸窘迫而安乐死的豚鼠的尸检样本进行组织学分析，在肠道上皮中鉴定出霍迈新种（滋养体和裂殖体）的发育阶段。然后对另外7只霍迈新种呈阳性的豚鼠粪便进行了18S rRNA（18S）、肌动蛋白和热休克蛋白70基因座的分子分析。在18S、肌动蛋白和热休克蛋白70基因座上，霍迈新种与其他隐孢子虫物种的遗传距离分别为3.1%至14.3%、14.4%至24.5%和6.6%至20.9%。在18S基因座上，霍迈新种与先前在巴西豚鼠中描述的隐孢子虫基因型有99.1%的相似性，它们可能是同一物种，但由于无法获得巴西豚鼠基因型的肌动蛋白和热休克蛋白70序列，这一点无法得到证实。对串联的18S、肌动蛋白和热休克蛋白70序列进行系统发育分析表明，霍迈新种与所有其他隐孢子虫物种的遗传距离为9.1%至17.3%。这清楚地支持了霍迈新种作为一个独立物种的有效性。
