Summary Toxocara canis of dogs and Toxocara vitulorum of cattle and buffalo are nematode parasites that cause serious economic and public health problems all over the world. This study aims to provide molecular data to identify and distinguish between Toxocara spp. from dogs, cattle and buffalo in Egypt. Moreover, constructing a phylogeny and phylogenetic relationships among these Toxocara spp. were performed through an analytic study of ATPase-6, a mitochondrial gene; 12S, small subunit ribosomal RNA gene and ITS-2, the second internal transcribed spacer nuclear ribosomal gene. T. vitulorum from cattle and buffalo were found to be almost identical. The ATPase- 6 and 12S regions showed 87.78 % and 90.38 % nucleotide similarity between T. canis and T. vitulorum, while for the ITS-2 region, only 78.38 % was found. Analysis of the three studied genes revealed that each Toxocara spp. has distinct molecular characteristics. Moreover, it was revealed that these genes, especially the ITS-2 gene, are useful and sensitive molecular markers for classifying and studying the phylogenetic analysis and relationships among closely related Toxocara spp. All sequences obtained in this study were registered in the GenBank under the accession numbers: MG214149 -MG214157.

中文翻译：

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埃及犬、牛和水牛弓蛔虫的分子特征及系统发育分析

总结犬弓蛔虫和牛和水牛弓蛔虫是线虫寄生虫，在全世界造成严重的经济和公共健康问题。本研究旨在提供分子数据来识别和区分弓首蛔虫。来自埃及的狗、牛和水牛。此外，构建这些弓首类动物之间的系统发育和系统发育关系。是通过对线粒体基因 ATPase-6 的分析研究进行的；12S，小亚基核糖体 RNA 基因和 ITS-2，第二个内部转录间隔核核糖体基因。发现来自牛和水牛的 T. vitulorum 几乎相同。ATPase-6 和 12S 区域在 T. canis 和 T. vitulorum 之间显示出 87.78% 和 90.38% 的核苷酸相似性，而对于 ITS-2 区域，仅发现 78.38%。对三个研究基因的分析表明，每个弓蛔虫属。具有明显的分子特征。此外，发现这些基因，尤其是 ITS-2 基因，是分类和研究密切相关的弓首类动物之间的系统发育分析和关系的有用和敏感的分子标记。本研究中获得的所有序列均以登录号MG214149-MG214157在GenBank中注册。