应用PCR方法检测患“黄水病”锯缘青蟹中的血卵涡鞭虫

"黄水病"是目前锯缘青蟹养殖过程中的主要疾病之一,病蟹主要症状表现为肌肉白浊,体液呈土黄色或浊白色牛奶状。因该病流行范围广、发病率和死亡率高,给青蟹养殖业主造成巨大经济损失,严重地影响了青蟹养殖的健康发展。本研究从病蟹体液中发现大量疑似血卵涡鞭虫的寄生原虫,应用已建立的梭子蟹血卵涡鞭虫病的PCR检测方法对患"黄水病"青蟹进行检测。结果从患病青蟹组织的DNA中扩增出产物大小为585bp的特异性目的片段,经序列分析比较,与三疣梭子蟹上发现的血卵涡鞭虫的序列同源,同源性达99.7%。综合病原流行病学调查、组织病理学、电镜观察等分析结果,初步确定血卵涡鞭虫是引起养殖青蟹"黄水病"的重要病原。

PCR-techniques applied to detection of Hematodinium sp. infections of "yellow water"disease in mud crab Scylla serrata

"Yellow water" disease is one of the major diseases in the mud crab Scylla serrata culture.The species infected with the disease can be isolated a kind of parasite from the hemolymph and tissues of crab.Methods used to detect infection include a morphological index(pleopod diagnosis) and several immunoassays.The present study describs the application of a set of Hematodinium-specfic polymerase chain reaction(PCR) primers and DNA probes based on Hematodinium 18S ribosomal DNA(18S rDNA) and the first internal transcribed spacer(ITS1).In the PCR assay,a diagnostic band 585 bp was consistently amplified from total genomic DNA isolated from diseased mud crab. From the analytical results of pathogenic eridemiology,tissue pathology and electroscope observation,we initially ascertained that Hematodinium is the important pathogen which causes mud crab infected with "yellow water" disease.