Otranto Domenico, Traversa Donato
Department of Animal Health and Welfare, Faculty of Veterinary Medicine, University of Bari, P.O. Box 7, 70010 Valenzano, Bari, Italy.
J Parasitol. 2004 Feb;90(1):185-8. doi: 10.1645/GE-115R1.
Spirurid nematodes of the genus Thelazia cause ocular infection in several mammals and are transmitted by dipteran flies. Of the 10 described species, T. gulosa, T. rhodesi, T. skrjabini (affecting cattle), T. lacrymalis (affecting horses), and T. callipaeda (affecting carnivores and humans) are the most common. The aim of this study was to characterize the first internal transcribed spacer (ITS1) ribosomal DNA sequences of these 5 species. The length of the ITS1 sequences ranged from 357 bp (T. lacrymalis) to 905 bp (T. callipaeda). Interspecific differences ranged from 35 to 77%. Polymorphic sites were detected in each species. Intraspecific variation varied from 0.3 to 2.5%. The characteristics of the ITS1 of Thelazia spp. show similarities to those of other Spirurida. The findings of this present study show that the ITS1 represent a powerful genetic marker for the molecular identification of eyeworms and a useful tool for developing molecular epidemiological techniques to study Thelazia spp. transmission patterns and prevalence in definitive and intermediate hosts.
吸吮属的旋尾线虫可导致多种哺乳动物眼部感染，并由双翅目昆虫传播。在已描述的10个物种中，牛吸吮线虫、罗德西亚吸吮线虫、斯氏吸吮线虫（感染牛）、泪管吸吮线虫（感染马）和结膜吸吮线虫（感染食肉动物和人类）最为常见。本研究的目的是对这5个物种的首个核糖体DNA内转录间隔区1（ITS1）序列进行特征分析。ITS1序列长度从357 bp（泪管吸吮线虫）到905 bp（结膜吸吮线虫）不等。种间差异在35%至77%之间。在每个物种中均检测到多态性位点。种内变异在0.3%至2.5%之间。吸吮属线虫ITS1的特征与其他旋尾目线虫相似。本研究结果表明，ITS1是用于眼部线虫分子鉴定的有力遗传标记，也是开发分子流行病学技术以研究吸吮属线虫在终末宿主和中间宿主中的传播模式及流行情况的有用工具。
