Dataset Information

First Report of Enterocytozoon hepatopenaei Infection in Pacific Whiteleg Shrimp (Litopenaeus vannamei) Cultured in Korea.

ABSTRACT: The consumption of cultured crustaceans has been steadily increasing, and Pacific whiteleg shrimp (Litopenaeus vannamei) are major cultivated invertebrates worldwide. However, shrimp productivity faces a variety of challenges, mainly related to outbreaks of lethal or growth retardation-related diseases. In particular, hepatopancreatic microsporidiosis caused by the microsporidian parasite Enterocytozoon hepatopenaei (EHP) is an important disease associated with growth retardation in shrimp. Here, we report the detection of EHP through histopathological, molecular and electron microscopy methods in the hepatopancreas of Pacific whiteleg shrimp with growth disorder in a South Korean farm. Phylogenetic analysis showed a clade distinct from the previously reported EHP strains isolated in Thailand, India, China and Vietnam. An EHP infection was not associated with inflammatory responses such as hemocyte infiltration. Although EHP infection has been reported worldwide, this is the first report in the shrimp aquaculture in Korea. Therefore, an EHP infection should be managed and monitored regularly for effective disease control and prevention.

SUBMITTER: Kim BS

PROVIDER: S-EPMC8614486 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BACKGROUND: The microsporidian Enterocytozoon hepatopenaei was first described from Thailand in 2009 in farmed, indigenous giant tiger shrimp Penaeus (Penaeus) monodon. The natural reservoir for the parasite is still unknown. More recently, a microsporidian closely resembling it in morphology and tissue preference was found in Thai-farmed, exotic, whiteleg shrimp Penaeus (Litopenaeus) vannamei exhibiting white feces syndrome (WFS). Our objective was to compare the newly found pathogen with E. hepatopenaei and to determine its causal relationship with WFS. RESULTS: Generic primers used to amplify a fragment of the small subunit ribosomal RNA (ssu rRNA) gene for cloning and sequencing revealed that the new parasite from WFS ponds had 99% sequence identity to that of E. hepatopenaei, suggesting it was conspecific. Normal histological analysis using tissue sections stained with hematoxylin and eosin (H&E) revealed that relatively few tubule epithelial cells exhibited spores, suggesting that the infections were light. However, the H&E results were deceptive since nested PCR and in situ hybridization analysis based on the cloned ssu rRNA gene fragment revealed very heavy infections in tubule epithelial cells in the central region of the hepatopancreas in the absence of spores. Despite these results, high prevalence of E. hepatopenaei in shrimp from ponds not exhibiting WFS and a pond that had recovered from WFS indicated no direct causal association between these infections and WFS. This was supported by laboratory oral challenge trials that revealed direct horizontal transmission to uninfected shrimp but no signs of WFS. CONCLUSIONS: The microsporidian newly found in P. vannamei is conspecific with previously described E. hepatopenaei and it is not causally associated with WFS. However, the deceptive severity of infections (much greater than previously reported in P. monodon) would undoubtedly have a negative effect on whiteleg shrimp growth and production efficiency and this could be exacerbated by the possibility of horizontal transmission revealed by laboratory challenge tests. Thus, it is recommended that the PCR and in situ hybridization methods developed herein be used to identify the natural reservoir species so they can be eliminated from the shrimp rearing system.

Project description:The functional diversity of crustacean hemocyanins is broad, encompassing O2 delivery, innate immune response, metabolite storage, and osmolyte balance, all in a heterogeneous protein structure. As such, the sequence diversity of this class of proteins and its subunit composition are the focus of many studies on crustacean adaptation to environmental challenges. Recent transcriptomic and genomic sequencing on the Pacific whiteleg shrimp Litopenaeus vannamei has identified unique isoforms of hemocyanin including an ancestral β-type subunit thought to be lost in penaeid shrimp. However, it is unknown the degree to which these isoforms are translated as proteins, and whether they differ in function. The present study uses proteomic approaches to characterize the protein-level abundance and organization of these hemocyanin isoforms within their native oligomeric structures. Fractions of each hemocyanin oligomeric form were purified by size-exclusion high performance liquid chromatography for identification of subunit isoforms using tandem mass spectrometry at <1% protein false discovery rate. Relative abundances of hemocyanin oligomers and monomeric subunits from hemolymph and fractions were also quantified by polyacrylamide gel electrophoresis with and without denaturation for comparison of relative abundance. Ten hemocyanin isoforms were identified by tandem mass spectrometry in both hemocyanin oligomer fractions including a single small subunit, eight large subunits, and the first protein-level evidence of a β-type subunit in penaeid shrimp. Hemocyanin subunits were organized primarily as hexamers (95-99% relative abundance) as opposed to dodecamers. Hexamers utilized a significantly higher ratio (2.05:1) of small subunit to large subunit compared to dodecamers (1.04:1), and the relative abundances of the large subunit isoforms was dominated by HcL1 in both fractions. The ability to distinguish and quantify hemocyanin isoforms within oligomeric structures will aid future studies linking hemocyanin genes to function and physiology as well as offer insight into the evolutionary history of crustaceans.

Dataset Information

First Report of Enterocytozoon hepatopenaei Infection in Pacific Whiteleg Shrimp (Litopenaeus vannamei) Cultured in Korea.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets