Cryptosporidium canis is an important cause of cryptosporidiosis in canines and humans. Studies of the transmission characteristics of C. canis are currently hampered by the lack of suitable subtyping tools. In this study, we conducted a genomic survey of the pathogen and developed a subtyping tool targeting the partial 60-kDa glycoprotein gene (gp60). Seventy-six isolates previously identified as C. canis were analyzed using the new subtyping tool. Amplicons of the expected size were obtained from 49 isolates, and phylogenetic analysis identified 10 subtypes clustered into five distinct groups (XXa to XXe). The largest group, XXa, contained 43 isolates from four subtypes that differed slightly from each other at the nucleotide level, while groups XXb to XXe contain one to three isolates each. The similar distributions of subtypes in humans and canines suggest that zoonotic transmission might play an important role in the epidemiology of C. canis. In addition, suspected zoonotic transmission of C. canis between dogs and humans in a household was confirmed using the subtyping tool. The subtyping tool and data generated in this study might improve our understanding of the transmission of this zoonotic pathogen.

中文翻译：

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人畜共患病病原体犬隐孢子虫亚型工具的开发

犬隐孢子虫是犬和人类隐孢子虫病的重要原因。由于缺乏合适的子分型工具，目前对犬念珠菌传播特性的研究受到阻碍。在这项研究中，我们对病原体进行了基因组调查，并开发了一种针对部分 60-kDa 糖蛋白基因 ( gp60 )的亚型工具。先前鉴定为犬念珠菌的 76个分离株使用新的子类型工具进行分析。从 49 个分离株中获得了预期大小的扩增子，系统发育分析确定了 10 个亚型，这些亚型聚集成五个不同的组（XXa 到 XXe）。最大的组 XXa 包含来自四个亚型的 43 个分离株，这些亚型在核苷酸水平上彼此略有不同，而 XXb 到 XXe 组各包含 1 到 3 个分离株。人类和犬科动物亚型的相似分布表明，人畜共患病传播可能在犬念珠菌的流行病学中发挥重要作用。此外，疑似犬念珠菌人畜共患病传播使用子分型工具确认了一个家庭中狗和人之间的关系。本研究中生成的亚型工具和数据可能会提高我们对这种人畜共患病病原体传播的理解。