文献类型：期刊文献

英文题名：Longitudinal monitoring of Cryptosporidium species in pre-weaned dairy calves on five farms in Shanghai, China

作者：Cai, Min[1,2];Guo, Yaqiong[1,2];Pan, Baoliang[3];Li, Na[2];Wang, Xiaolan[1];Tang, Chuanxiang[1];Feng, Yaoyu[1,2];Xiao, Lihua[4]

机构：[1]East China Univ Sci & Technol, Sch Resource & Environm, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]South China Agr Univ, Coll Vet Med, Guangzhou 510642, Guangdong, Peoples R China;[3]China Agr Univ, Coll Vet Med, Beijing 100094, Peoples R China;[4]Ctr Dis Control & Prevent, Div Foodborne Waterborne & Environm Dis, Natl Ctr Emerging & Zoonot Infect Dis, Atlanta, GA 30333 USA

年份：2017

卷号：241

起止页码：14

外文期刊名：VETERINARY PARASITOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000403990200003)】；

基金：This work was supported by the National Natural Science Foundation of China (31425025, 31630078, and 31602042), the China Postdoctoral Science Foundation (2016M601531), and the Fundamental Research Funds for the Central Universities, China.

语种：英文

外文关键词：Cryptosporidium; Cryptosporidium parvum; Subtypes; Dairy calves; Molecular epidemiology

摘要：In pre-weaned dairy calves, the zoonotic and pathogenic species Cryptosporidiwn parvum is the dominant Cryptosporidiwn species in most industrialized nations. In several studies in China, however, C. bovis has been the dominant one. To further examine the distribution of Cryptosporidium species in pre-weaned dairy calves in China, 818 fecal specimens were collected from five farms in Shanghai, with repeated samplings (up to five times) on each farm. PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit rRNA gene was used to detect and genotype Cryptosporidium spp. Cryptosporidium parvum was subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium occurrence on farms varied between 25.0% (Farm 2) and 55.0% (Farm 4), with a mean infection rate of 37.0%. Three Cryptosporidium species were detected, including C. bovis (193/303 or 63.7%), C. parvum (72/303 or 23.8%) and C. ryanae (32/303 or 10.6%). Concurrent infection of C. bovis and C. ryanae was detected in six (1.9%) animals. During the first two samplings, C. bovis was the dominant species on four farms and C. parvum was detected on only one farm (Farm 1). One of the study farms (Farm 3) started to have C. parvum at the third sampling. C. parvum was associated with the occurrence of moderate or watery diarrhea, while C. bovis was not. All C. parvum were subtype IIdA19G1, which is dominant in China but rare elsewhere. Genotyping and subtyping results indicated that the introduction of C. parvum to Farm 3 was caused by brief housing of several bull calves from another farm. Data from the study suggest that C. parvum is still uncommon in pre-weaned dairy calves in China and measures should be developed to prevent its spread in the country.