美国由细粒棘球绦虫严格种基因型 G1 和 G3 引起的牛羊包虫病。
Cystic echinococcosis in cattle and sheep caused by Echinococcus granulosus sensu stricto genotypes G1 and G3 in the USA.
机构信息
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA.
Pathology Branch, Eastern Laboratory, Office of Public Health Science, Food Safety and Inspection Service, United State Department of Agriculture, Athens, GA, USA.
出版信息
Parasit Vectors. 2024 Mar 14;17(1):128. doi: 10.1186/s13071-024-06192-x.
BACKGROUND
Endemic domestic dog-ruminant cycles and human cystic echinococcosis caused by Echinococcus granulosus have been sporadically reported in the United States. However, there is a paucity of molecular data describing the genotypes and haplotypes of this important cestode in domestic ruminant hosts.
METHODS
Ninety-four cysts from the lungs and/or livers of slaughtered beef cattle (76 samples), dairy cows (five samples) and sheep (13 samples) were collected from abattoirs in four states of the USA. Samples were genotyped at two mitochondrial loci, cox1 and nad5. Sequences were used to determine species, genotypes and haplotypes using median joining networks and Bayesian phylogenetic analyses. Cyst fertility was assessed in hematoxylin and eosin-stained sections. Additionally, previously reported autochthonous E. granulosus infections in the USA in various hosts were mapped.
RESULTS
Based on cox1 sequences obtained from 94 cysts, 89 (94.7%) were identified as E. granulosus G1/G3, while five (5.3%) were Taenia hydatigena. Taenia hydatigena were only isolated from sheep. Based on nad5 sequences obtained from 89 hydatid cysts, 96.6% and 3.4% belonged to E. granulosus sensu stricto genotypes G1 and G3 respectively. Two haplotypes were found among E. granulosus cox1 sequences, neither of which was geographically unique. Six haplotypes were found among nad5 sequences in genotype G1, of which five were novel, while one haplotype was found in genotype G3. In the concatenated cox1-nad5 dataset, seven haplotypes were identified, of which six were geographically unique. All cysts from cattle were non-fertile. Four cysts from sheep were fertile.
CONCLUSIONS
All genotyped samples belonged to E. granulosus s.s. This is the first study to our knowledge to confirm the presence of genotypes G1 and G3 in domestic cattle and sheep intermediate hosts in the USA and provide data for future diagnostic and epidemiological studies. Sequences have been deposited in GenBank (cox1 sequences: OR398494-OR398496, nad5 sequences: OR400695-OR400702).
背景
在美国，地方性的家养狗-反刍动物循环和由细粒棘球绦虫引起的人类包虫病偶有报道。然而，关于这种重要的绦虫在家养反刍动物宿主中的基因型和单倍型，分子数据却很少。
方法
从美国四个州的屠宰场采集了 94 个来自屠宰牛（76 个样本）、奶牛（5 个样本）和绵羊（13 个样本）肺部和/或肝脏的包囊。使用聚合酶链反应（PCR）对两个线粒体基因座 cox1 和 nad5 进行了基因分型。通过中位数连接网络和贝叶斯系统发育分析，使用序列确定了种、基因型和单倍型。在苏木精和伊红染色切片中评估了包囊的育性。此外，还绘制了之前在美国不同宿主中报道的本地细粒棘球绦虫感染。
结果
基于从 94 个包囊中获得的 cox1 序列，89 个（94.7%）被鉴定为细粒棘球绦虫 G1/G3，而 5 个（5.3%）为多头绦虫。多头绦虫仅从绵羊中分离。基于从 89 个包囊的 nad5 序列获得的序列，96.6%和 3.4%分别属于细粒棘球绦虫严格意义上的基因型 G1 和 G3。在细粒棘球绦虫 cox1 序列中发现了两种单倍型，均无地理特异性。在基因型 G1 的 nad5 序列中发现了 6 种单倍型，其中 5 种是新的，而在基因型 G3 中发现了 1 种单倍型。在 cox1-nad5 串联数据集中共发现了 7 种单倍型，其中 6 种具有地理特异性。来自牛的所有包囊均不育。来自绵羊的 4 个包囊可育。
结论
所有基因分型样本均属于细粒棘球绦虫严格意义上的种。这是我们所知的第一份确认美国家养牛和绵羊中间宿主中存在基因型 G1 和 G3 的研究，并为未来的诊断和流行病学研究提供了数据。序列已存入 GenBank（cox1 序列：OR398494-OR398496，nad5 序列：OR400695-OR400702）。
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