Wide geographic distribution of Cryptosporidium bovis and the deer-like genotype in bovines
Wide geographic distribution of Cryptosporidium bovis and the deer-like genotype in bovines
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DOI：
10.1016/j.vetpar.2006.10.001
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发表时间：
2007-03-15
影响因子：
2.6
通讯作者：
Xiao, Lihua
中科院分区：
文献类型：
--
作者：
Feng, Yaoyu;Ortega, Ynes;Xiao, Lihua
美国最近的研究报告称，近85%的断奶前奶牛感染了人畜共患隐孢子虫，而只有1-2%的断奶后牛犊和1-2岁的小母牛感染了这一物种。在断奶后的动物中，牛隐孢子虫和鹿形隐孢子虫的基因频率更高。目前尚不清楚同样的感染模式是否也发生在其他地理区域。为了确定隐孢子虫在其他地区是否存在相同的感染模式，我们对从中国和印度两个农场采集的隐孢子虫标本进行了基因分型，并与美国佐治亚州农场的标本进行了比较。在所有三个地区的断奶前和断奶后的牛犊中，牛黄杆菌是最常见的物种。在佐治亚州，在断奶前和断奶后的牛犊中经常发现类似鹿的基因，在一头断奶后的牛犊中发现了安德森隐孢子虫。在佐治亚州检查的几头挤奶奶牛中，既发现了牛链球菌，也发现了类似鹿的基因。3个地区牛黄地衣原体和鹿的小亚基rRNA基因序列没有差异。然而，中国的一头成年牦牛感染了一种类似牛隐孢子虫的物种，目标基因只有三个核苷酸突变。所有四种常见的牛隐孢子虫。用SspI和MboII酶对扩增产物进行限制性片段长度多态性分析，将它们区分开来。因此，在不同地理区域的所有年龄组的牛中都发现了牛链球菌和鹿一样的基因，牛链球菌的宿主适应可能发生在牦牛身上。爱思唯尔出版公司(Elsevier B.V.)
Recent studies in the United States reported that similar to 85% of pre-weaned dairy calves were infected with zoonotic Cryptosporidium parvum, whereas only 1-2% of post-weaned calves and 1-2-year-old heifers were infected with this species. Cryptosporidium bovis and Cryptosporidium deer-like genotype were much more prevalent in the post-weaned animals. It is not clear whether the same infection pattern also occurs in other geographic areas. In this study, to determine whether the same Cryptosporidium infection pattern was present in other geographic areas, we genotyped Cryptosporidium specimens collected from two farms in China and India, using specimens from farms in Georgia, USA for comparison. C. bovis was the most common species found in pre- and post-weaned calves in all three areas. In Georgia, the deer-like genotype was found frequently in pre- and post-weaned calves and Cryptosporidium andersoni was found in one post-weaned calf. Both C. bovis and the deer-like genotype were found in the few milking cows examined in Georgia. There were no differences in the small subunit rRNA gene sequences obtained from C. bovis or deer-like genotype among the three areas. One adult yak in China, however, was infected with a species similar to C. bovis, with only three nucleotide mutations in the target gene. All four common bovine Cryptosporidium spp. were differentiated from each other by restriction fragment length polymorphism analysis of PCR products with enzymes SspI and MboII. Thus, both C. bovis and the deer-like genotype are found in all age groups of cattle in diverse geographic areas and host adaptation of C. bovis might have occurred in yaks. Published by Elsevier B.V.