Seroprevalence and first multilocus microsatellite genotyping of Neospora caninum in dairy cattle in Henan, central China
Seroprevalence and first multilocus microsatellite genotyping of Neospora caninum in dairy cattle in Henan, central China
复制标题
河南省奶牛犬新孢子虫血清阳性率及首次多位点微卫星基因分型
DOI：
10.1016/j.vetpar.2017.07.022
复制
发表时间：
2017-09-15
影响因子：
2.6
通讯作者：
Lv, Chaochao
中科院分区：
文献类型：
--
作者：
Qian, Weifeng;Wang, Tianqi;Lv, Chaochao
犬新孢子虫是世界范围内导致牛流产的重要原因之一，新孢子虫病给养牛业造成的损失是相当大的。然而，这种寄生虫的遗传特征的知识是有限的。本研究的目的是确定中国中部河南省奶牛犬乳杆菌的流行情况和遗传特征。在河南省8个奶牛场共采集了510份血液样本和7例流产胎儿。以重组tNcSRS2蛋白为包被抗原，采用ELISA法检测血清对犬链球菌的抗体。奶牛血清总阳性率为41.2%（210/510）。流产奶牛犬新冠病毒血清阳性率（49.3%）高于未流产奶牛血清阳性率（29.3%），差异有统计学意义（p < 0.05），优势比为2.44 （95% CI, 1.61 ~ 3.41）。猪场类型与奶牛犬链球菌感染血清阳性率之间也存在统计学相关性（p < 0.01）。采用NC5基因巢式PCR方法对396份血样中的6份（1.5%）和7份流产胎儿中的4份进行犬新冠病毒DNA检测，并对10份阳性样本进行MS4、MS5、MS6A、MS7、MS8、MS10和MS12的多位点微卫星分型分析。只有2个样本在所有基因位点上成功分型，并鉴定出两个独特的等位基因图谱，包括两个新的等位基因模式。据我们所知，本研究是中国首次基于多位点微卫星（超过2个位点）对自然感染奶牛分离的犬乳杆菌进行遗传表征的报道。
Neospora caninum is one of the important causes of abortion in cattle worldwide, and losses due to neosporosis to the cattle industry are considerable. However, the knowledge of genetic characterization of this parasite is limited. The aim of the present study is to determine the prevalence and genetic characterization of N. caninum from dairy cows in Henan Province, central China. A total of 510 blood samples and 7 aborted fetuses were collected from 8 dairy farms in Henan Province. Serum antibodies to N. caninum were examined by ELISA using a recombinant tNcSRS2 protein as the coating antigen. The overall seroprevalence of N. caninum in dairy cows was 41.2% (210/510). The seropositivity rate of N. caninum in aborting cows (49.3%) was statistically significant higher than that (29.3%) in non-aborting cows (p < 0.05) with an odds ratio of 2.44 (95% CI, 1.61-3.41). Statistical association was also found between farm type and the seropositivity rate of N. caninum infection in cows (p < 0.01). N. caninum DNA was detected from 6 of 396 blood samples (1.5%) and 4 of 7 aborted fetuses by nested PCR based on NC5 gene, and the 10 N. caninum positive DNA samples were further analyzed by multilocus microsatellite (MS) genotyping for MS4, MS5, MS6A, MS7, MS8, MS10, and MS12. Only 2 samples were successfully genotyped at all genetic loci, and two unique profiles including two novel allelic patterns were identified. To our knowledge, this study is the first report of genetic characterization of N. caninum isolates from naturally infected dairy cows based on multilocus microsatellites (more than 2 loci) in China.