Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Acta Trop. 2010 Nov;116(2):152-6. doi: 10.1016/j.actatropica.2010.07.005. Epub 2010 Jul 21.
Nematodes of the genus Angiostrongylus are parasites of rodents and carnivores. They reside in the pulmonary or mesenteric arteries of their hosts. Two species are pathogenic in humans -Angiostrongylus cantonensis causes eosinophilic meningitis or meningoencephalitis, and Angiostrongylus costaricensis produces abdominal angiostrongyliasis. In addition Angiostrongylus malaysiensis may have the potential of being pathogenic in humans. The mitochondrial gene cytochrome c oxidase subunit I (COI) of these Angiostrongylus species and three geographical isolates (China, Hawaii and Thailand) of A. cantonensis were studied by polymerase chain reaction amplification and DNA sequencing. COI sequences of A. cantonensis, A. costaricensis and Angiostrongylus vasorum in the GenBank were included for comparison. Phylogenetic analysis by maximum-likelihood (ML), maximum-parsimony (MP), neighbour-joining (NJ) and Bayesian inference (BI) produced similar tree topology except variation in the bootstrap support values. There were two major clades - (1) A. cantonensis and A. malaysiensis, and (2) A. costaricensis and A. vasorum. The three geographical isolates of A. cantonensis formed a clade with low to high bootstrap values, and consisted of two subclades: (a) China and Hawaii isolates, and (b) monophyletic Thailand isolate. The individuals of each isolate formed a distinct cluster. In the second major clade, the Europe isolates of A. vasorum were distinctly different from the Brazil isolates. For A. costaricensis, the Costa Rica isolate was distinct from the Brazil isolate with an uncorrected (p) distance of 11.39%, indicating the possible occurrence of cryptic species. The present results indicate that COI sequences might be a useful marker for differentiating geographical isolates of A. cantonensis and in uncovering cryptic species. Efforts are being made to carry out an extensive collaborative study to cover a wide range of Angiostrongylus species and geographical isolates.
旋毛线虫属的线虫是啮齿动物和食肉动物的寄生虫。它们存在于宿主的肺动脉或肠系膜动脉中。有两种旋毛线虫属物种对人类具有致病性 - 广州管圆线虫引起嗜酸性脑膜炎或脑膜脑炎，而食蟹旋毛线虫引起腹部旋毛虫病。此外，马来西亚旋毛线虫可能对人类具有致病性。通过聚合酶链反应扩增和 DNA 测序研究了这些旋毛线虫属物种和广州管圆线虫的三个地理分离株（中国、夏威夷和泰国）的线粒体基因细胞色素 c 氧化酶亚基 I（COI）。比较了 GenBank 中广州管圆线虫、食蟹旋毛线虫和血管圆线虫的 COI 序列。最大似然法（ML）、最大简约法（MP）、邻接法（NJ）和贝叶斯推断（BI）的系统发育分析产生了相似的树拓扑结构，但支持值的变化不同。有两个主要分支 - （1）广州管圆线虫和马来西亚旋毛线虫，以及（2）食蟹旋毛线虫和血管圆线虫。广州管圆线虫的三个地理分离株形成一个具有低到高支持值的分支，包含两个亚分支：（a）中国和夏威夷分离株，以及（b）单系泰国分离株。每个分离株的个体形成一个独特的聚类。在第二个主要分支中，欧洲的血管圆线虫分离株与巴西分离株明显不同。对于食蟹旋毛线虫，哥斯达黎加分离株与巴西分离株明显不同，未校正的（p）距离为 11.39%，表明可能存在隐种。目前的结果表明，COI 序列可能是区分广州管圆线虫地理分离株和揭示隐种的有用标记。正在努力进行广泛的合作研究，以涵盖广泛的旋毛线虫属物种和地理分离株。
