Karthikeyan Kesavan, Sudhakaran Raja
Aquaculture Biotechnology Laboratory, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, India.
J Fish Dis. 2019 Mar;42(3):397-404. doi: 10.1111/jfd.12945. Epub 2019 Jan 15.
Enterocytozoon hepatopenaei (EHP) is a microsporidian parasite that causes hepatopancreatic microsporidiosis (HPM) in penaeid shrimp. HPM was observed in several countries, including Thailand and India; it has become a prominent pathogen in shrimp culture. Based on observations on EHP infection in the wild, the route of transmission has been hypothesized. Identification of artificial EHP infection procedures can facilitate our understanding of EHP transmission. Experimental transmission of EHP was attempted using the immersion and oral infections of infection. In the immersion mode, post-larvae (PL) were exposed to an EHP tissue homogenate (0.2%) by immersion for 48 hr. Experimental samples were collected at various time points, and infection was confirmed using polymerase chain reaction, haematoxylin and eosin staining, transmission electron microscopy and modified trichrome staining. All test results revealed successful EHP transmission. Similar results were obtained through oral infection (oral infection). Innate immune gene expression patterns during infection were analysed; prophenoloxidase, crustin and superoxide dismutase were upregulated at 6, 6 and 48 hr post-challenge, respectively. Experimental infection procedures facilitate the development of diagnostic and prevention strategies. This is the first study demonstrating the experimental transmission of EHP in shrimp PL.
肝胰腺微孢子虫（EHP）是一种微孢子虫寄生虫，可导致对虾肝胰腺微孢子虫病（HPM）。在包括泰国和印度在内的几个国家都观察到了HPM；它已成为对虾养殖中的一种重要病原体。基于对野生环境中EHP感染的观察，人们对其传播途径进行了推测。确定人工EHP感染程序有助于我们了解EHP的传播。尝试通过浸泡感染和口服感染两种方式进行EHP的实验性传播。在浸泡感染模式下，将后期幼体（PL）浸泡在EHP组织匀浆（0.2%）中48小时。在不同时间点采集实验样本，并使用聚合酶链反应、苏木精和伊红染色、透射电子显微镜和改良三色染色法确认感染情况。所有测试结果均显示EHP传播成功。通过口服感染（经口感染）也获得了类似的结果。分析了感染期间先天免疫基因的表达模式；酚氧化酶原、甲壳素和超氧化物歧化酶分别在攻毒后6小时、6小时和48小时上调。实验性感染程序有助于制定诊断和预防策略。这是第一项证明EHP在对虾PL中进行实验性传播的研究。
