High prevalence of Cryptosporidium bovis and the deer-like genotype in calves compared to mature cows in beef cow-calf operations
High prevalence of Cryptosporidium bovis and the deer-like genotype in calves compared to mature cows in beef cow-calf operations
复制标题
DOI：
10.1016/j.vetpar.2007.10.012
复制
发表时间：
2008-02-14
影响因子：
2.6
通讯作者：
McEvoy, John M.
中科院分区：
文献类型：
--
作者：
Feltus, Dawn C.;Giddings, Catherine W.;McEvoy, John M.
最近的研究已经在美国、中国、印度和欧洲农场的奶牛中发现了新的、宿主适应的牛隐孢子虫和鹿样基因型。这种新物种和基因型似乎在年龄较大的断奶后奶牛中比以前认为的更为普遍。然而，关于它们在肉牛养殖中的流行情况的信息很少。在本研究中，我们测定了北达科他西部7个肉牛群中98头犊牛（6-8月龄）和114头奶牛（1 - 2岁）隐孢子虫的流行情况。从粪便样品中提取DNA，通过扩增18S rRNA基因，测序或RFLP分析鉴定隐孢子虫属。所有7个畜群的隐孢子虫检测均呈阳性。总体而言，43/212只（20.3%）动物呈阳性。这些阳性病例中只有5例来自奶牛。牛C、鹿样基因型和安德氏C分别在9.4、6.6和1.4%的样本动物中被鉴定出。在任何阳性样本中均未发现细小C。在6/7、5/7和2/7群中分别检测到牛C、鹿样基因型和安德森C。牛C和鹿样基因型主要在犊牛中检测到，安德森C仅在奶牛中检测到。6个分离株无法分型。这些结果表明，在研究的7个牛群中，与2岁以上的奶牛相比，6-8个月大的牛肉小牛中C型牛和鹿样基因型的患病率相对较高。(C) 2007 Elsevier B.V.版权所有
Recent studies have identified the novel, host adapted Cryptosporidium bovis and the deer-like genotype in dairy cattle from farms in the United States, China, India and Europe. This novel species and genotype appear to be more prevalent in older, post-weaned dairy cattle than previously thought. However, little information is available on their prevalence in beef cow-calf operations. In the present study, we determined the prevalence of Cryptosporidium species in 98 calves (6-8 months old) and 114 cows (> 2 years old) in seven beef cow-calf herds in western North Dakota. DNA was extracted from fecal samples and Cryptosporidium spp. were identified by amplification of the 18S rRNA gene followed by sequencing or RFLP analysis. All seven herds tested positive for Cryptosporidium. Overall, 43/212 (20.3%) animals were positive. Only five of these positives were from cows. C bovis, the deer-like genotype and C. andersoni were identified in 9.4, 6.6 and 1.4% of animals sampled, respectively. C parvum was not identified in any of the positive samples. C bovis, the deer-like genotype and C andersoni were detected in 6/7, 5/7 and 2/7 herds, respectively. C bovis and the deer-like genotype were primarily detected in calves, while C andersoni was only detected in cows. Six isolates could not be typed. These results show a relatively high prevalence of C bovis and the deer-like genotype in 6-8- month-old beef calves compared to cows older than 2 years in the seven herds studied. (C) 2007 Elsevier B.V. All rights reserved.