人类和非人灵长类人隐孢子虫（Cryptosporidium hominis）的人兽共患传播机制研究

Cryptosporidium hominis mainly infects humans, more than 70% of human infections caused by C. hominis. The previous study of research group found that non-human primates infected with C. hominis and two different sources of C. hominis there are genotypes differences, then these differences affect the propagation mechanism of C. hominis is unclear. By studying the molecular genetic basis of host adaptation is a importang tool of studying its zoonotic transmission mechanisms. Thus, in the present study, based on the multilocus sequence typing C. hominis isolates collected in this research group, analized multilocus genotype, illuminated the characterization of population genetic structure, and considered to the MLST subtypes and different geographical areas, three to five represent C. hominis isolates will be selected and be sequenced the genome by 454 sequencing technique. Then, the obtained genome in this study and the available genome data deposited in CryptoDB will be aligned, by which, we can find the genetic genes associated with the host-adaptation for C. hominis. The data should describe the mechanism of zoonotic transmission of C. hominis.

人隐孢子虫（Cryptosporidium hominis）主要感染人类，大部分地区70%以上的人类感染是由C. hominis造成的。课题组前期研究发现非人类灵长目感染C. hominis，而两种不同来源的C. hominis存在基因亚型差异，这种差异是否影响到C. hominis的传播机制尚不清楚，通过研究宿主适应性分子遗传基础是揭示其人兽共患传播机制的重要手段。鉴于此，本项目拟使用多位点序列分型（Multilocus sequence typing, MLST）技术，分析多位点基因亚型并解析群体遗传结构特征，基于MLST亚型和地理区域选择3-5个代表性虫株使用454 技术进行全基因组重测序，将获得人隐孢子虫代表虫株基因组测序结果与CryptoDB 中已有的隐孢子虫基因组进行比对分析，寻找与宿主适应性相关的遗传基因位点，阐明人兽共患传播机制。

隐孢子虫病是一种重要的食源性和水源性疾病，人兽共患传播来源主要来自动物。在我国非人灵长类因观赏、表演和试验研究等与人密切接触机会较多，因此研究非人灵长类感染隐孢子虫的种类和人兽共患传播风险具有重要意义。项目主要对非人灵长类和人隐孢子虫感染种类、基因型和亚型进行鉴定，并对部分虫株进行多位点鉴定，分析人兽共患共患风险性。同时对人和非人灵长类感染的卡耶坦环孢子虫、贾第虫、微孢子虫和阿米巴进行遗传多态性研究。该项目河南省5个医院的门诊病人进行隐孢子虫检测先后收集到17份阳性样品，其中C. hominis 11份，C. parvum 3份，C. felis 1份，非人灵长类源的隐孢子虫样品先后获得猴场12个阳性样品, 自由饲养7个阳性样品；其中C. hominis 14个，C. muris 5个。对全国6个动物园160份金丝猴样品进行检测发现6个隐孢子虫阳性样品，其中C. andersoni 1个, C. parvum 1个 和 C. ubiquitum 3个。基于多态性位点对基因亚型鉴定结果，人源C. hominis的亚型包括：IaA9R3, IbA16G2, IbA19G2, IbA20G2, IdA21五个亚型。对非人灵长类源的C. hominis的亚型进行鉴定仅发现IbA12G3和IiA17两个亚型，其中IbA12G3为优势亚型。从亚型分析我国人和非人灵长类亚型有显著不同，非人灵长类亚型较为单一。人和非人灵长类之间传播C. hominis缺乏广泛性。在我国5个省的马属动物中分离鉴定出87个隐孢子虫阳性样品，其中5个来自马，82个来自驴，经种类和基因型鉴定发现22个C. parvum, 4个隐孢子虫马基因型，61个C. hominis，基于HSP70，actin和SSU rRNA三个基因位点对C. hominis进行了确定性鉴定。基于gp60多态性基因位点鉴定出21个C. parvum IIdA19G1，4个马基因型VIaA15G4和VIaA11G3，61个C. hominis亚型鉴定为IkA16G1 (n=59)和IkA16 (n=2)，证明C. hominis在马属动物之间可以传播，也可能传播给人类。