High intragenotypic diversity of Giardia duodenalis in dairy cattle on three farms
High intragenotypic diversity of Giardia duodenalis in dairy cattle on three farms
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DOI：
10.1007/s00436-008-0932-5
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发表时间：
2008-06-01
影响因子：
2
通讯作者：
Xiao, Lihua
中科院分区：
文献类型：
--
作者：
Feng, Yaoyu;Ortega, Ynes;Xiao, Lihua
对来自美国格鲁吉亚州3个奶牛场的58份贾第鞭毛虫阳性粪便标本进行磷酸丙糖异构酶基因序列分析，进行基因分型和亚型分析。同时发现了家畜特有的组合E和潜在的人畜共患病的组合A，前者组合中检测到的标本的83%。一个高度的遗传多态性是显而易见的组合E内，11个不同的亚型，其中8个代表新的亚型。在组合A中鉴定出三种亚型，其中A2亚型在一个农场的小牛和奶牛中短暂发现。所有农场在每次采样时都有多个聚集的E亚型在牛中传播，24%的动物同时感染混合亚型或基因型。因此，G.尿道炎传播不仅反映在感染的高流行率上，而且还反映在高基因型内多样性和同时发生的混合感染上。牛G.在亚型水平上，需要进一步研究的组合A标本的广泛表征。
Fifty-eight Giardia duodenalis-positive fecal specimens from three dairy farms in Georgia, USA were genotyped and subtyped by sequence analysis of the triosephosphate isomerase gene. Both the livestock-specific assemblage E and the potentially zoonotic assemblage A were found, with the former assemblage detected in 83% of the specimens. A high degree of genetic polymorphism was evident within assemblage E, with 11 distinct subtypes identified, eight of which represented new subtypes. Three subtypes were identified in assemblage A, with the subtype A2 transiently found in calves and cows on one farm. All farms had multiple assemblage E subtypes circulating in cattle at each sampling, and concurrent infection with mixed subtypes or genotypes occurred in 24% of animals. Thus, the high intensity of G. duodenalis transmission is not only reflected by the high prevalence of the infection but also by the high intragenotypic diversity and concurrent occurrence of mixed infections. The zoonotic potential of bovine G. duodenalis needs to be further studied by extensive characterization of assemblage A specimens at the subtype level.