First Report of Enterocytozoon hepatopenaei Infection in Giant Freshwater Prawn (Macrobrachium rosenbergii de Man) Cultured in the Republic of Korea

Abstract

In the Republic of Korea, Enterocytozoon hepatopenaei (EHP) was first isolated from Pacific whiteleg shrimp in April 2020; however, there are no existing reports of EHP infection in other shrimp or prawns. Here, we aimed to investigate EHP infection and its prevalence in giant freshwater prawn farms in the Republic of Korea. We tested prawns from 22 farms for EHP infection, and samples from eight farms showed positive EHP infection results in 2021. In EHP-infected prawn farms, the prevalence ranged from 4.9% to 18.2%. The prevalence of EHP infection in the Republic of Korea, derived from the prevalence in prawn farms, was estimated to be 0.8% in 2021. The proliferation of EHP was observed within the hepatopancreatic epithelial cells of prawns using H&E and Giemsa staining. Mature EHP was observed in the sinus between epithelial cells of the digestive tubules. Phylogenetic analysis revealed a clade distinct from the previously reported EHP in Pacific whiteleg shrimps. This is the first report of EHP infection in a giant freshwater prawn in the Republic of Korea, where the prevalence of EHP infection is not high, but it is recognized as an emerging disease that requires periodic monitoring and quarantine management in giant freshwater prawns.

Enterocytozoon hepatopenaeiProliferate inProcambarus clarkii: A Warning for Crayfish and Shrimp Aquaculture

“…Spore wall of the sporoblasts gradually thicken and spores develop into mature ones (Ning, 2020). EHP can be transmitted horizontally though water (Salachan et al, 2017), feces (Singh and Singh, 2018) and carcasses (Tangprasittipap et al, 2013; Jang et al, 2022). Besides L. vannamei and P. monodon , EHP was found proliferate in blue shrimp ( Penaeus stylirostris ) (Tang et al, 2015), giant river prawn ( Macrobrachium rosenbergi ) (Wang et al, 2022) and dragonfly ( Anax parthenope , Pantala flavescens , and Ischnura senegalensis ) (Kumar Dewangan et al, 2023).…”

“…EHP can also be transmitted between live foods and other animals living in the same waters, such as polychaetes (Desrina et al, 2020), brine shrimp ( Artemia salina ) (Karthikeyan and Sudhakaran, 2020), false mussels ( Mytilopsis leucophaeata ) (Munkongwongsiri et al, 2022), marine crabs (Mani et al, 2022) and some macrofauna (Wan Sajiri et al, 2023). Although a variety of methods including specific pathogen free (SPF) shrimp larvae breeding has been taken, the outbreak of EHP remained frequently happening, suggesting a complex biological transmission pathway of EHP (Chayaburakul et al, 2004; Jang et al, 2022).…”