The emerging pathogen Enterocytozoon hepatopenaei drives a degenerative cyclic pattern in the hepatopancreas microbiome of the shrimp (Penaeus vannamei)

Abstract

The microsporidian Enterocytozoon hepatopenaei (EHP) is an emerging pathogen that causes substantial economic losses in shrimp (Penaeus spp.) aquaculture worldwide. To prevent diseases in shrimp, the manipulation of the gut microbiota has been suggested. However, prior knowledge of the host-microbiome is necessary. We assessed the modulation of the microbiome (bacteria/fungi) and its predicted functions over the course of disease progression in shrimp experimentally challenged with EHP for 30 days using high throughput 16S rRNA and ITS amplicon sequencing. Infection grade was assessed for the first time by quantitative digital histopathology. According to the infection intensity, three disease-stages (early/developmental/late) were registered. During the early-stage, EHP was not consistently detected, and a high diversity of potentially beneficial microorganisms related to nutrient assimilation were found. In the development-stage, most of the shrimp start to register a high infection intensity related to a decrease in beneficial microorganisms and an increase in opportunistic/pathogenic fungi. During late-stage, animals displayed different infection intensities, showed a displacement of beneficial microorganisms by opportunistic/pathogenic bacteria and fungi related to pathogen infection processes and depletion of energetic reserves. The degenerative cyclic pattern of EHP infection and its effects on beneficial microorganisms and beneficial functions of the shrimp hepatopancreas microbiome are discussed.

PREVALENSI INFEKSI EHP (Enterocytozoon Hepatopenaei) PADA UDANG VANAME (Litopenaeus vannamei) BERDASARKAN DATA SURVEILLANCE DI BALI, INDONESIA

“…Udang vaname (Litopenaeus vannamei) merupakan komoditas ekonomi penting yang berdasarkan data Food and Agriculture Organization (FAO) pada tahun 2020 menyumbang 52,9% dari total produksi udang dunia yang mencapai 9,4 juta ton (FAO, 2020). Seiring dengan terus meningkatnya jumlah produksi udang di berbagai negara, industri budidaya udang menghadapi beberapa tantangan termasuk munculnya beberapa penyakit baru seperti infeksi hepatopancreatic microsporidiosis (HPM) yang disebabkan mikrosporidia Enterocytozoon hepatopenaei (EHP) (López-Carvallo et al, 2022).…”

“…Parasit EHP menginfeksi sel hepatopankreas yang mengakibatkan kerusakan sel dan mengganggu kemampuan udang untuk mencerna makanan (Kooloth Valappil et al, 2021). Kerusakan jaringan akibat infeksi EHP menyebabkan penurunan nafsu makan dan keterlambatan pertumbuhan serta penurunan performa produksi pada udang (López-Carvallo et al, 2022). Gejala infeksi EHP dilaporkan seringkali muncul bersama dengan koinfeksi Vibrio parahaemolyticus yang menyebabkan penyakit berak putih (white feces syndrome) (Aranguren Caro et al, 2021).…”

“…Selain itu, gejala klinis seringkali tidak ditemukan pada beberapa kasus infeksi EHP. Adanya koinfeksi EHP dengan patogen lain seperti Vibrio juga seringkali menyebabkan infeksi EHP sulit dibedakan dengan penyakit lain seperti acute hepatopancreatic necrosis disease (AHPND) maupun white feces disease (WFD) (López-Carvallo et al, 2022).…”

“…Tindakan preventif yang diharapkan mampu menekan infeksi dan meningkatkan ketahanan udang terhadap infeksi EHP antara lain melalui peningkatan kelimpahan mikrobiota di saluran pencernaan udang. Modulasi mikro biota saat ini banyak diuji melalui aplikasi pemberian probiotik, prebiotik, sinbiotik maupun bioflok untuk meningkatkan kelimpahan mikrobiota (López-Carvallo et al, 2022).…”

Natural Antimicrobials Block the Host NF-κB Pathway and Reduce Enterocytozoon hepatopenaei Infection Both In Vitro and In Vivo

“…Enterocytozoon hepatopenaei (EHP), an intracellular shrimp pathogen, is required to transfer germinated spores into the cytoplasm of the host cell in order to complete its life cycle and initiate infection [ 1 ]. EHP is responsible for causing hepatopancreatic microsporidiosis (HPM) in shrimp and, once the infection occurs, has a high capacity to spread across other farms and sometimes between countries [ 2 ]; as a consequence, shrimp farmers are on constant alert to prevent the emergence of diseases, such as HPM [ 3 ]. Hence the identification of interventions, designed to reduce spore germination and subsequent infection, is vital for the industry [ 4 ].…”