Microsporidium Ecytonucleospora hepatopenaei (EHP) spores were purified from the hepatopancreas of Penaeus vannamei infected with EHP by percoll density gradient centrifugation and differential centrifugation. The EHP spores contain a thick chitin wall and might not rupture using the routine DNA extraction protocol. In this study, three enzymes were used, including chitinase, proteinase K, and DNase I.
View Article and Find Full Text PDFA recurring trend in evidence scrutinized over the past few decades is that disease outbreaks will become more frequent, intense, and widespread on land and in water, due to climate change. Pathogens and the diseases they inflict represent a major constraint on seafood production and yield, and by extension, food security. The risk(s) for fish and shellfish from disease is a function of pathogen characteristics, biological species identity, and the ambient environmental conditions.
View Article and Find Full Text PDFCureus
July 2024
Introduction The development of diseases associated with () infection is closely linked to its virulence genes, which vary by geographic region. This study aimed to determine the prevalence of cytotoxin-associated gene A () and vacuolating cytotoxin gene A () genes and their genotypes in patients with gastrointestinal diseases. Methods Patients diagnosed with gastrointestinal disease based on endoscopic findings were recruited for the study.
View Article and Find Full Text PDFThe microsporidian Enterocytozoon hepatopenaei (EHP) is a major threat to shrimp health worldwide. Severe EHP infections in shrimp cause growth retardation and increase susceptibility to opportunistic infections. EHP produces spores with a chitin wall that enables them to survive prolonged environmental exposure.
View Article and Find Full Text PDFThe presence of endogenous viral elements (EVE) in the penaeid shrimp genome has been recently reported and suggested to be involved in the host recognition of viral invaders. Our previous report of a search for EVE of infectious hypodermal and haematopoietic necrosis virus (IHHNV-EVE) in the Thai Penaeus monodon whole genome sequence project (GenBank accession no. JABERT000000000) confirmed the presence of three clusters of EVE derived from IHHNV in the shrimp genome.
View Article and Find Full Text PDFBackground: Shrimp have the ability to accommodate viruses in long term, persistent infections without signs of disease. Endogenous viral elements (EVE) play a role in this process probably via production of negative-sense Piwi-interacting RNA (piRNA)-like fragments. These bind with Piwi proteins to dampen viral replication via the RNA interference (RNAi) pathway.
View Article and Find Full Text PDFSome insects use endogenous reverse transcriptase (RT) to make variable viral copy DNA (vcDNA) fragments from viral RNA in linear (lvcDNA) and circular (cvcDNA) forms. The latter form is easy to extract selectively. The vcDNA produces small interfering RNA (siRNA) variants that inhibit viral replication the RNA interference (RNAi) pathway.
View Article and Find Full Text PDFRecombinant Pichia pastoris biomass surface-expressing the viral binding protein PmRab7 (YSD-PmRab7) was prepared by fed-batch, aerobic fermentation with methanol induction for 48 h. By cell based ELISA assay, immunofluorescence and flow cytometry, 45% of the YSD-PmRab7 cells were positive for PmRab7. Freeze dried YSD-PmRab7 cells were added to formulated shrimp feed pellets at 0.
View Article and Find Full Text PDFBy using immunohistochemistry detection, yellow head virus (YHV) was found to replicate in granule-containing hemocytes including semi-granular hemocytes (SGC) and granular hemocytes (GC) during the early phase (24 h post injection) of YHV-infected shrimp. Higher signal of YHV infection was found in GC more than in SGC. Comparative phosphoproteomic profiles between YHV-infected and non-infected GC reveal a number of phosphoproteins with different expression levels.
View Article and Find Full Text PDFDouble-stranded RNA (dsRNA) is employed to down-regulate the expression of specific genes of shrimp viral pathogens through the RNA interference (RNAi) pathway. The administration of dsRNA into shrimp has been shown to be an effective strategy to block yellow head virus (YHV) progression. In this study, a vector (pLVX-AcGFP1-N1) was developed to introduce a long-hairpin RNA (lhRNA) silencing cassette under a CMV promoter, so-called "pLVX-lhRdRp", against the RNA-dependent RNA polymerase (RdRp) gene of YHV.
View Article and Find Full Text PDFHere, two monoclonal antibodies (MAbs) specific to different epitopes on ToxB, a toxin produced by Vibrio parahaemolyticus that causes acute hepatopancreatic necrosis disease (VP ), were employed to develop a rapid strip test. One MAb was conjugated to colloidal gold to bind to ToxB at the application pad, and another MAb was used to capture colloidal gold MAb-protein complexes at the test line (T) on the nitrocellulose strip. To validate test performance, a downstream control line (C) of goat anti-mouse immunoglobulin G antibody was used to capture the free colloidal gold conjugate MAb.
View Article and Find Full Text PDFPrevious work has shown that non-retroviral endogenous viral elements (EVE) are common in crustaceans, including penaeid shrimp. So far, they have been reported for infectious hypodermal and hematopoietic necrosis virus (IHHNV) and white spot syndrome virus (WSSV). For the latter, it was shown that shrimp sperm were positive for an EVE of WSSV called EVE, suggesting that it was heritable, since shrimp sperm (non-motile) do not contain mitochondria.
View Article and Find Full Text PDFTo achieve in creating permanent shrimp cell lines, cellular arrest of primary cells in the culture is needed to be firstly solved. Considering the insertion of some markers affecting cellular proliferation into primary haemocytes in order to produce the black tiger shrimp cell line and the very low percent of transduced cells previously reported in penaeid shrimps, these paved us the way to set up suitable gene delivery protocols to increase percent of transduced cells in the shrimp as our primary aim. In this study, electroporation and lipofection were used to transfer construct plasmids (pLL3.
View Article and Find Full Text PDFAcute hepatopancreatic necrosis disease (AHPND) of shrimp is caused by isolates (VP isolates) that harbor a pVA plasmid encoding toxins PirA and PirB These are released from VP isolates that colonize the shrimp stomach and produce pathognomonic AHPND lesions (massive sloughing of hepatopancreatic tubule epithelial cells). PCR results indicated that isolate XN87 lacked but carried Unexpectedly, Western blot analysis of proteins from the culture broth of XN87 revealed the absence of both toxins, and the lack of PirB was further confirmed by enzyme-linked immunosorbent assay. However, shrimp immersion challenge with XN87 resulted in 47% mortality without AHPND lesions.
View Article and Find Full Text PDFTo improve the efficacy of WSSV protection, multimeric (tetrameric) recombinant VP28 (4XrVP28) was produced and tested in comparison with those of monomeric VP28 (1XrVP28). In vitro binding of either 1XrVP28 or 4XrVP28 to shrimp hemocyte surface was evident as early as 10 min after protein inoculation. Similar results were obtained in vivo when shrimp were injected with recombinant proteins that the proteins bound to the hemocyte surface could be detected since 5 min after injection.
View Article and Find Full Text PDFYellow head virus (YHV) causes acute infections and mass mortality in black tiger shrimp culture. Our study aims to investigate molecular interaction between YHV and circulating hemocytes of Penaeus monodon at early infection. Total shrimp hemocytes were isolated by Percoll gradient centrifugation and identified by flow cytometric analysis.
View Article and Find Full Text PDFUnique isolates of Vibrio parahaemolyticus (VPAHPND) have previously been identified as the causative agent of acute hepatopancreatic necrosis disease (AHPND) in shrimp. AHPND is characterized by massive sloughing of tubule epithelial cells of the hepatopancreas (HP), proposed to be induced by soluble toxins released from VPAHPND that colonize the shrimp stomach. Since these toxins (produced in broth culture) have been reported to cause AHPND pathology in reverse gavage bioassays with shrimp, we used ammonium sulfate precipitation to prepare protein fractions from broth cultures of VPAHPND isolates for screening by reverse gavage assays.
View Article and Find Full Text PDFOur previous data revealed that viral particles of yellow head virus (YHV) specifically interacted with granule-containing hemocytes. After isolation of targeted hemocytes, biotinylation was performed using Biotin-NSH-LC. Biotinylated protein was extracted and separated by 2-D PAGE.
View Article and Find Full Text PDFIn our research efforts to reduce the impact of white spot syndrome virus (WSSV) disease outbreaks in shrimp aquaculture, we studied the effect of β-glucan administration to activate the prophenoloxidase (proPO) enzymatic cascade prior to WSSV challenge. Injection of a single dose of β-glucan (5 μg/g) prior to WSSV challenge resulted in activation of the proPO system and reduced shrimp mortality (25-50%) when compared to controls (100%). By contrast, no significant reduction was observed using yellow head virus (YHV) in a similar protocol.
View Article and Find Full Text PDFThe cellular signal-transduction process is largely controlled by protein phosphorylation. Shrimp infected with yellow head virus show dramatic changes in their hemocyte phosphoproteomic patterns, and aberrant activation of phosphorylation-based signaling networks has been implicated in a number of diseases. In this study, we focused on phosphorylation of Penaeus monodon myosin regulatory light chain (PmMRLC) that is induced at an early hour post YHV infection and is concomitant with cellular actin remodeling.
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