Aquaculture Pathology Laboratory, School of Animal & Comparative Biomedical Sciences, The University of Arizona, 1117 E Lowell St, Tucson, AZ 85721, USA.
Aquaculture Pathology Laboratory, School of Animal & Comparative Biomedical Sciences, The University of Arizona, 1117 E Lowell St, Tucson, AZ 85721, USA.
J Invertebr Pathol. 2020 Mar;171:107336. doi: 10.1016/j.jip.2020.107336. Epub 2020 Feb 8.
The microsporidium Enterocytozoon hepatopenaei (EHP) is considered as an emerging pathogen threating the shrimp industry worldwide. It is an intracellular parasite that has been associated with retarded growth syndrome and white feces syndrome in shrimp. Although the impact of EHP to the shrimp industry is well known, many aspects of host-pathogen interactions are not well understood. A major limitation in the study of EHP is the lack of a reliable method to produce large quantities of inoculum rapidly and reproducibly. The present study was designed to compare different challenge methods including intramuscular injection, oral administration, co-habitation, hepatopancreas (HP) injection and reverse gavage. The results showed that the HP injection and the reverse gavage are two promising methods to infect shrimp rapidly and generate inoculum in a reproducible manner starting with a limited amount of inoculum. Therefore, the HP injection and reverse gavage were chosen for a scale-up study. Histopathology results showed that EHP proliferated in the epithelial cells of the HP in shrimp challenged via direct injection of inoculum into HP and reverse gavage treatments. In accordance with the histopathology results, the qPCR data showed that EHP loads in the challenged shrimp increased significantly with the HP injection and reverse gavage methods. Furthermore, the histopathological and quantification results indicate that HP injection and reverse gavage are two novel methods that can be used in EHP-challenge studies and for rapidly generating viable EHP inoculum.
微孢子虫 Enterocytozoon hepatopenaei（EHP）被认为是一种新兴的病原体，对全球虾业构成威胁。它是一种细胞内寄生虫，与虾的生长迟缓综合征和白色粪便综合征有关。尽管 EHP 对虾业的影响众所周知，但宿主-病原体相互作用的许多方面仍未得到很好的理解。EHP 研究的一个主要限制是缺乏快速可靠地大量生产接种物的方法。本研究旨在比较不同的挑战方法，包括肌肉注射、口服、共饲养、肝胰腺（HP）注射和反向灌胃。结果表明，HP 注射和反向灌胃是两种有前途的方法，可以快速感染虾，并以有限数量的接种物为起始，以可重复的方式产生接种物。因此，选择 HP 注射和反向灌胃进行扩大研究。组织病理学结果表明，EHP 在通过直接将接种物注入 HP 和反向灌胃处理感染的虾的 HP 上皮细胞中增殖。与组织病理学结果一致，qPCR 数据显示，EHP 负荷在接受 HP 注射和反向灌胃方法处理的受感染虾中显著增加。此外，组织病理学和定量结果表明，HP 注射和反向灌胃是两种可用于 EHP 挑战研究和快速生成有活力的 EHP 接种物的新方法。
