Sokolova Yuliya, Pelin Adrian, Hawke John, Corradi Nicolas
Department of Comparative Biomedical Studies, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA; Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
Canadian Institute for Advanced Research, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Int J Parasitol. 2015 Jan;45(1):1-16. doi: 10.1016/j.ijpara.2014.07.013. Epub 2014 Oct 18.
Since June 2012, samples of wild caught white shrimp, Litopenaeus setiferus, from the Gulf of Mexico, Plaquemines and Jefferson Parishes (Louisiana, USA) with clinical signs of microsporidiosis have been delivered to the Louisiana Aquatic Diagnostic Laboratory for identification. Infection was limited predominantly to female gonads and was caused by a microsporidium producing roundish pansporoblasts with eight spores (3.6×2.1 μm) and an anisofilar (2-3+4-6) polar filament. These features allowed identification of the microsporidium as Agmasoma penaei Sprague, 1950. Agmasoma penaei is known as a microsporidium with world-wide distribution, causing devastating epizootic disease among wild and cultured shrimps. This paper provides molecular and morphological characterisation of A. penaei from the type host and type locality. Comparison of the novel ssrDNA sequence of A. penaei from Louisiana, USA with that of A. penaei from Thailand revealed 95% similarity, which suggests these geographical isolates are two different species. The A. penaei sequences did not show significant homology to any other examined taxon. Phylogenetic reconstructions using the ssrDNA and alpha- and beta-tubulin sequences supported its affiliation with the Clade IV Terresporidia sensu Vossbrink 2005, and its association with parasites of fresh and salt water crustaceans of the genera Artemia, Daphnia and Cyclops.
自2012年6月以来，从美国路易斯安那州普拉奎明斯和杰斐逊教区墨西哥湾捕获的患有微孢子虫病临床症状的野生白虾（Litopenaeus setiferus）样本已被送至路易斯安那水生诊断实验室进行鉴定。感染主要局限于雌性性腺，由一种微孢子虫引起，该微孢子虫产生带有八个孢子（3.6×2.1μm）的圆形孢子母细胞和一条异丝（2-3+4-6）极丝。这些特征使得该微孢子虫被鉴定为1950年的对虾阿格马孢子虫（Agmasoma penaei Sprague）。对虾阿格马孢子虫是一种已知分布于全球的微孢子虫，可在野生和养殖虾中引发毁灭性的流行病。本文提供了来自模式宿主和模式产地的对虾阿格马孢子虫的分子和形态特征。将来自美国路易斯安那州的对虾阿格马孢子虫的新型小亚基核糖体DNA（ssrDNA）序列与来自泰国的对虾阿格马孢子虫的序列进行比较，发现相似度为95%，这表明这些地理分离株是两个不同的物种。对虾阿格马孢子虫的序列与任何其他检测的分类单元均未显示出显著的同源性。使用ssrDNA以及α-和β-微管蛋白序列进行的系统发育重建支持其与2005年沃斯布林克定义的IV类陆地孢子虫（Terresporidia sensu Vossbrink）的亲缘关系，以及它与卤虫属（Artemia）、水蚤属（Daphnia）和剑水蚤属（Cyclops）的淡水和咸水甲壳类寄生虫的关联。
