Ding Z, Meng Q, Liu H, Yuan S, Zhang F, Sun M, Zhao Y, Shen M, Zhou G, Pan J, Xue H, Wang W
Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China.
Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, Nanjing, China.
J Fish Dis. 2016 Sep;39(9):1043-51. doi: 10.1111/jfd.12437. Epub 2016 Feb 5.
An epidemic of hepatopancreatic necrosis disease (HPND) with a high mortality rate (40%-50%) recently occurred in the cultured Chinese mitten crab, Eriocheir sinensis, which is a very important economic crustacean species in China. Histology revealed infection by a microsporidian parasite within the cytoplasm of the epithelial cells of the hepatopancreas. Numerous discrete inclusions in the infected cells and presumably free parasite spores were also observed. By negative staining using electron microscopy, a typical morphology of spores was observed with a protuberant front of the anchoring disc. Infection was confined to the epithelial cells of the hepatopancreas, with no other organ implicated. By sequencing the PCR products using specific primers based on conserved regions of microsporidian small subunit (18S) ribosomal DNA, it was revealed that the parasite from HPND ponds had 99% sequence identity to that of Hepatospora eriocheir. Phylogentic analysis also placed the microsporidian in the same lineage as H. eriocheir. This study reported the first case of widespread infections of H. eriocheir associated with HPND found in the pond-reared Chinese mitten crab, E. sinensis. The description of microsporidian in this important commercial host is fundamental for future consideration of factors affecting stock health and sustainability.
最近，中国重要的经济甲壳类动物中华绒螯蟹养殖中爆发了肝胰腺坏死病（HPND），死亡率很高（40%-50%）。组织学检查显示，肝胰腺上皮细胞的细胞质内有微孢子虫寄生虫感染。在受感染细胞中还观察到许多离散的包涵体以及可能游离的寄生虫孢子。通过电子显微镜负染色，观察到孢子的典型形态，其锚定盘前端突出。感染仅限于肝胰腺的上皮细胞，未涉及其他器官。使用基于微孢子虫小亚基（18S）核糖体DNA保守区域的特异性引物对PCR产物进行测序，结果显示，来自HPND池塘的寄生虫与中华绒螯蟹肝孢子虫的序列同一性为99%。系统发育分析也将该微孢子虫置于与中华绒螯蟹肝孢子虫相同的谱系中。本研究报告了首例在池塘养殖的中华绒螯蟹中发现的与HPND相关的中华绒螯蟹肝孢子虫广泛感染病例。对这种重要商业宿主中微孢子虫的描述，对于未来考虑影响种群健康和可持续性的因素至关重要。
