Al Quraishy Saleh, Abdel-Gaber Rewaida, Dkhil Mohamed A, Alzuabi Khulud
Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt.
Acta Parasitol. 2020 Mar;65(1):208-224. doi: 10.2478/s11686-019-00151-8. Epub 2019 Dec 12.
Parasitism is a complex problem that is often ignored in companion animals, including birds, unless it develops into a severe clinical disorder. The present study was, therefore, aimed to investigate the presence of the gastrointestinal nematode infecting the domestic pigeon and provide a complete morphological description and clarify its taxonomic position through phylogenetic analysis of the ITS1-5.8s-ITS2 rDNA gene region.
During the current study, a total of twenty-six domestic pigeons, Columba livia domestica, were collected and internal organs examined for helminth detection. Using light and scanning electron microscopy, the recovered parasite species are studied. In addition, the selected gene region was obtained and sequenced using appropriate primers that aid in the formation of the phylogenetic dendrogram for the recovered parasite species with others retrieved from GenBank.
Morphological examination showed that this nematode parasite belongs to the Ascaridiidae family within the genus Ascaridia. The material was assigned to the previously described Ascaridia columbae by providing all the characteristic features as the presence of a mouth opening surrounded by three tri-lobed lips; each lip has two triangular teeth with a spoon-like structure, cephalic papillae and amphidal pores on lips surface, presence of lateral cuticular alae and pre-cloacal sucker, 10 pairs of caudal papillae, and two equal spicules in male worms. The morphological investigations of this species were supplemented by molecular analysis of ITS1-5.8s-ITS2 rDNA gene region. The data showed that the present A. coulmbae is deeply embedded in the Ascaridia genus with a 74-99% sequence similarity to other species in the Chromadorea class. Ascaridiidae appears as monophyly and represented as a sister group to Heterakidae. The ascaridiid species examined belong to the Ascaridia genus and displaced a close relationship with the previously described A. coulmbae (gb| KF147909.1, gb| AJ001509.1, gb| KC905082.1, gb| JQ995321.1, gb| JX624729.1) as putative sister taxa.
The present study revealed that the species Ascaridia is the first account of this genus as an endoparasite from the domestic pigeon inhabiting Saudi Arabia. Therefore, the combination of morphological and molecular studies helps to identify this species correctly and identified as Ascaridia columbae.
寄生虫病是一个复杂的问题，在包括鸟类在内的伴侣动物中常常被忽视，除非它发展成严重的临床疾病。因此，本研究旨在调查感染家鸽的胃肠道线虫的存在情况，提供完整的形态学描述，并通过对ITS1-5.8s-ITS2 rDNA基因区域的系统发育分析来阐明其分类地位。
在本研究中，共收集了26只家鸽（Columba livia domestica），检查其内脏以检测蠕虫。使用光学显微镜和扫描电子显微镜对回收的寄生虫物种进行研究。此外，获得选定的基因区域并使用合适的引物进行测序，这些引物有助于构建回收的寄生虫物种与从GenBank检索到的其他物种的系统发育树状图。
形态学检查表明，这种线虫寄生虫属于蛔虫科蛔虫属。通过提供所有特征，如开口被三个三叶唇包围；每个唇有两个三角形齿，带有勺状结构，唇表面有头乳突和排泄孔，有侧角质膜褶和泄殖腔前吸盘，10对尾乳突，雄性蠕虫有两个相等的交合刺，该材料被鉴定为先前描述的鸽蛔虫。对该物种的形态学研究通过对ITS1-5.8s-ITS2 rDNA基因区域的分子分析得到补充。数据表明，目前的鸽蛔虫深深嵌入蛔虫属，与色矛纲中的其他物种序列相似性为74-99%。蛔虫科表现为单系群，是异刺科的姐妹群。所检查的蛔虫物种属于蛔虫属，与先前描述的鸽蛔虫（gb|KF147909.1、gb|AJ001509.1、gb|KC905082.1、gb|JQ995321.1、gb|JX624729.1）作为假定的姐妹分类单元有密切关系。
本研究表明，蛔虫属物种是首次在居住在沙特阿拉伯的家鸽体内发现的该属内寄生虫。因此，形态学和分子研究相结合有助于正确鉴定该物种，并确定为鸽蛔虫。
