Re-description of Cryptosporidium cuniculus Inman and Takeuchi, 1979 (Apicomplexa: Cryptosporidiidae): Morphology, biology and phylogeny
Re-description of Cryptosporidium cuniculus Inman and Takeuchi, 1979 (Apicomplexa: Cryptosporidiidae): Morphology, biology and phylogeny
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DOI：
10.1016/j.ijpara.2010.05.010
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发表时间：
2010-11-01
影响因子：
4
通讯作者：
Chalmers, Rachel M.
中科院分区：
文献类型：
--
作者：
Robinson, Guy;Wright, Steve;Chalmers, Rachel M.
为了重新描述与人隐孢子虫密切相关的隐孢子虫隐孢子虫Inman and Takeuchi， 1979（与兔基因型同义）的形态、自然宿主特异性和实验宿主特异性以及遗传特征。形态和诊断特征与其他肠道隐孢子虫相似，但卵囊稍大（5.55-6.40 × 5.02-5.92 μ m；平均5.98 × 538 μ m；长：宽= 1.1;n = 50）。自然宿主似乎是欧洲兔（Oryctolagus cuniculus）和人类（智人）。实验感染已在断奶兔（O. cuuniculus）、免疫抑制的蒙古沙鼠（Meriones unguiculatus）和免疫抑制的成年波顿鼠（Mus musus）中建立，但未在新生小鼠中建立。通过卵囊脱落测量的感染模式与人原梭菌明显不同，特别是在家兔中。组织学检查显示小肠绒毛上皮刷状边缘有内源性分期，但无临床症状。人HCT-8细胞的接种导致内源性阶段的离散集群。从ssrRNA、70 kDa热休克蛋白（HSP70）、肌动蛋白、隐孢子虫卵囊壁蛋白（COWP）、60 kDa糖蛋白（GP60）基因和编码未知功能产物（LIB13）的区域的分子分析推断，与人源弓形虫有密切的关系。序列在ssrRNA、HSP70和actin基因上包含有限的、一致的多态性，在COWP和LIB13基因上是相同的，在GP60基因上显示出两个独特的家族。尽管在遗传上密切相关，但在线虫和人猿之间存在显著的生物学差异，支持这些原生动物是不同的物种。这是基于目前对这些生物的理解，并依赖于这些物种之间通常不会发生交配的假设。如果随后证明了这一点，它们的分类可能需要重新调整。(c) 2010年澳大利亚寄生虫学学会Elsevier Ltd.出版。版权所有。
To provide re-description of Cryptosporidium cuniculus Inman and Takeuchi, 1979 (synonymous with rabbit genotype), a species closely related to Cryptosporidium hominis, the morphology, natural and experimental host specificity, and genetic characterisation were investigated. The morphology and diagnostic characteristics are typical of other intestinal species of Cryptosporidium, albeit with slightly larger oocysts (5.55-6.40 x 5.02-5.92 mu m; mean 5.98 x 538 urn; length:width = 1.1; n = 50). Natural hosts appear to be European rabbits (Oryctolagus cuniculus) and humans (Homo sapiens). Experimental infections have been established in weanling rabbits (O. cuniculus), immunosuppressed Mongolian gerbils (Meriones unguiculatus) and immunosuppressed adult Porton strain mice (Mus musculus), but not in neonatal mice. Patterns of infection measured by oocyst shedding are significantly different compared with C. hominis, particularly in rabbits. Histological examination reveals endogenous stages in the brush border of the epithelium of the small intestinal villi, but clinical signs are absent. Inoculation of human HCT-8 cells results in discrete clusters of endogenous stages. A close relationship with C. hominis is inferred from molecular analyses at the ssrRNA, 70 kDa heat shock protein (HSP70), actin, Cryptosporidium oocyst wall protein (COWP), 60 kDa glycoprotein (GP60) genes and a region encoding a product of unknown function (LIB13). Sequences contained limited, consistent polymorphisms at the ssrRNA, HSP70 and actin genes, were identical at the COWP and LIB13 genes and demonstrated two unique families at the GP60 gene. Although genetically closely related, there are significant biological differences between C. cuniculus and C hominis that support these protozoa being separate species. This is based on the current understanding of these organisms and relies on the assumption that mating between these species would not normally occur. If this is subsequently demonstrated their categorisation may need to be readdressed. (c) 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.