Hepatopancreatic Parvo-like Virus Research Articles

Surveillance of diseases in farmed Penaeus vannamei in the indian sunderbans

Penaeus vannamei farming has been the major aquaculture practice in the Indian Sundarbans. This study investigated the physicochemical characteristics, management practices, distribution of vibrios, and the prevalence of bacterial, parasitic and viral diseases in 14 P. vannamei intensive culture farms in the Indian Sunderbans during 2016. The total heterotrophic counts of the pond water ranged from 3.53 to 6.21 log10 cfu/ml. The presumptive vibrios were in the range of 2.40-4.99log10 cfu/ml. Mild vibriosis was noted in 3 farms. Twenty out of 21 isolates from the haemolymph samples were confirmed to be Vibrio parahaemolyticus by the PCR amplification of toxR gene. No acute hepatopancreatic necrosis disease (AHPND) causing V. parahaemolyticus (Vp AHPND) strain was, however, detected. Of the 14 shrimp farms surveyed, only one farm sample was white spot virus (WSV) positive and all others were negative. All the P. vannamei farms were negative for infectious hypodermal and haematopoietic necrosis virus, hepatopancreatic parvo-like virus, and infectious myonecrosis virus. No incidence of Enterocytozoon hepatopenaei, white faecal syndrome, running mortality syndrome, protozoan infestation, and luminous vibriosis was observed during the survey period. The survival rate was 90-95% in the normal ponds, while the lowest survival was 60% in an asymptomatic WSV infected farm. The physicochemical characteristics of the farms were well within the optimum, except the WSV infected farm, which had high ammonia levels. Due to the lack of awareness on the P. vannamei farming practices and high operational costs, the biosecurity measures were not strictly followed in the surveyed farms.

Transcriptional Profiling of Banana ShrimpFenneropenaeus merguiensiswith Differing Levels of Viral Load

Viral pathogens are of serious concern to the culture of penaeid shrimps worldwide. However, little is known about the molecular response of shrimp to viral infection. Selective breeding has been suggested as an effective long-term strategy to manage viral disease, though more information on gene function is needed to help inform breeding programs. The study of cultured banana shrimp (Fenneropenaeus merguiensis) infected with hepatopancreatic parvo-like virus (HPV) provides a unique opportunity to explore the host response to viral infection independent of challenge testing. To gain insight into the genetic mechanisms underlying resistance to high levels of HPV, we examined hepatopancreas tissue from six full-sib groups of banana shrimp with differing levels of HPV infection for differences in gene expression. A total of 404 differentially expressed genes were identified with 180 being over-expressed and 224 under-expressed among high-HPV full-sib groups. Based on homology analysis, a large proportion of these genes were associated with processes reported to be involved in the immune response of crustaceans, including pattern recognition proteins, antimicrobial peptides, components of the prophenoloxidase system, and antiviral activity. The results indicate shrimp from high-HPV full-sib groups appear to have a lower presence of important immune response elements, yet possess upregulated putative antiviral pathways. Within the differentially expressed genes, over 4000 sequence variants were identified to be exclusive to either the high- or low-HPV full-sib groups. To our knowledge, this is the first report of differential expression analysis using RNA-Seq to explore differences in viral load among high- and low-HPV full-sib groups of cultured shrimp. This research has provided additional insight into our understanding of the mechanisms involved in the response of this shrimp species to a naturally occurring viral pathogen. Sequence variants identified in this study offer an exceptional resource for mining gene-associated markers of HPV resistance.

Yearly, pond, lineage and family variation of hepatopancreatic parvo-like virus (HPV) copy number in banana shrimp Fenneropenaeus merguiensis

Hepatopancreatic parvo-like virus (HPV) has been reported from a variety of shrimp species around the world, including Australia, and thought to impact negatively on production, but until now there was scant information available on variation of HPV over time, ponds and shrimp lineages or families, information that could be used to manage or reduce virus levels.Here we report HPV copy number estimated using qPCR from 1500 individual shrimp sampled over three years and encompassing 91 ponds, 21 breeding groups or lineages and 40 families.HPV copy number variation between ponds was used by farm management as a criterion to choose prospective broodstock (candidates were taken from low HPV ponds). Despite such choice, HPV levels in farmed animals were not reduced from 2011 to 2013. Accordingly, the hypothesis that HPV levels can be reduced over time simply by considering average HPV levels in ponds alone is rejected.Different lines of shrimp within the same farm had different HPV levels, but as lines were raised separately, the line differences could be due to either genetic or environmental differences, the latter including possible different rearing effects and differences in vertical transmission.There were large (up to 2–3 LOG fold) differences of HPV levels between families bred and grown together contemporaneously, and the heritability for HPV copy number was estimated to be moderate to large (0.40±0.13). Apart from genetic differences, differences of vertical transmission from dams may contribute to the between family differences, in any case we postulate that selection between families could be an effective method to reduce HPV levels.HPV levels were not genetically correlated with performance traits such as body weight or length, so selection for HPV level should not adversely affect production characteristics.This is the first evidence for an aquacultured species that viral levels, as opposed to survival/resistance to viruses, may have a substantial host genetic component. The heritability reported here for virus copy number was higher that most heritabilities reported for survival to specific pathogens such as white spot, raising the general postulate that selection for virus copy number may be more effective and repeatable than selection for survival to pathogen challenge.

Development of SYBR Green based real time PCR assay for detection of monodon baculovirus in Penaeus monodon

Shrimp farming is one of the most important aquaculture activities. Expansion and intensification of shrimp farming has been accompanied with the outbreak of diseases, which threaten the development and sustainability of the industry. Viral diseases are the major challenges faced by shrimp farming industries. The prevention/control of such diseases have become critical in determining the viability of the shrimp farming. The disease caused by monodon baculovirus (MBV) is the major limiting factor especially in shrimp hatchery. There are no therapeutic measures to control the viral diseases. So the detection of the disease is crucial in the prevention and spread of the disease. Hence, in this study, SYBR Green based real time polymerase chain reaction (PCR) assay was developed for the detection of MBV. The sensitivity of the real time PCR was determined using 10-fold dilutions of purified plasmid DNA with the concentration in the range of 101–105 copies per reaction. The assay could detect as low as 12 copies indicating that the assay was sensitive and could be effectively used for the quantification of MBV. The real time PCR assay was found to be specific and did not show any amplification with P. monodon infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV), white spot syndrome virus (WSSV) and hepatopancreatic parvo-like virus (HPV). The novelty of this assay is that it could be employed for diagnosis of low level MBV infection in broodstock using fecal matter of shrimp, a non-invasive diagnostic tool.

Tissue distribution of hepatopancreatic parvo-like virus of shrimp in freshwater rice-field crab,Paratelphusa hydrodomous(Herbst)

An attempt was made to determine the replication efficiency of hepatopancreatic parvo-like virus (HPV) of shrimp in different organs of freshwater rice-field crab Paratelphusa hydrodomous (Herbst) using bioassay, PCR, RT-PCR, ELISA, Western blot and q-PCR analyses. Another attempt was made to use this crab as an alternative to penaeid shrimp for the large-scale production of HPV. This crab was found to be highly susceptible to HPV by intramuscular injection. The systemic HPV infection was confirmed by PCR and Western blot analyses in freshwater crab. The expression of capsid protein gene in different organs of infected crab was revealed by RT-PCR analysis. Indirect ELISA was used to quantify the capsid protein in different organs of the crab. The copy number of HPV in different organs of the infected crab was quantified by q-PCR. The results revealed a steady decrease in CT values in different organs of the infected crab during the course of infection. The viral inoculum that was prepared from different organs of the infected crab caused significant mortality in post-larvae of tiger prawn, Penaeus monodon (Fabricius). The results revealed that this rice-field crab could be used as an alternative host for HPV replication and also for large-scale production of HPV.

In vitro propagation of hepatopancreatic parvo-like virus (HPV) of shrimp in C6/36 (Aedes albopictus) cell line

Hepatopancreatic parvovirus (HPV) which causes infection in many species of penaeid shrimp is a serious viral pathogen in the young life stages of shrimp. An attempt was made to develop an in vitro system using C6/36 subclone of Aedes albopictus cell line for propagation of HPV. The results revealed that C6/36 cells were susceptible to this virus and the infected cells showed CPE in the form of vacuole formation. The results of PCR, immunocytochemistry and Western blot revealed the HPV-infection in C6/36 cell line. The RT-PCR analysis confirmed the replication of HPV in C6/36 cell line. The HPV load was quantified at different time intervals by ELISA and real time PCR, and the results showed the increase of viral load in C6/36 cell line in time course of infection. HPV propagated in C6/36 cell line was used to infect post-larvae of shrimp and the results showed that the twentieth passage of HPV propagated in C6/36 cell line caused 100% mortality in post-larvae after 6weeks post infection (d.p.i.). The infected post-larvae showed clinical signs of reduced growth, reduced preening, muscle opacity and atrophy of hepatopancreas. The HPV-infection was confirmed by PCR. The results of the present study showed that C6/36 cell line can be used as an in vitro model for HPV replication instead of whole animal.

Studies on Immuno-Gold and Silver Staining Method for Rapid Diagnosis of Hepatopancreatic Parvo-like Virus Disease of Chinese Prawn, Penaeus chinensis

Studies on Immuno-Gold and Silver Staining Method for Rapid Diagnosis of Hepatopancreatic Parvo-like Virus Disease of Chinese Prawn, Penaeus chinensis

Experimental exposure of Artemia to Hepatopancreatic parvo-like Virus and Subsequent transmission to post-larvae of Penaeus monodon

The different life stages of Artemia franciscana were experimentally exposed to Hepatopancreatic parvo-like virus (HPV), in order to evaluate the possibility of Artemia acting as reservoir or carrier for HPV. All the five developmental stages of Artemia were challenged with HPV both by immersion and oral infection routes. The viral infectivity to Artemia was studied by PCR but not much difference in mortality between control and challenge groups were observed. To confirm the vector status of Artemia for HPV, the HPV exposed Artemia were fed to postlarval forms of Penaeus monodon. Post-larvae of P. monodon were fed with HPV exposed Artemia and could get infected upon feeding on them. Mortality was observed in the post-larvae, which were fed with HPV exposed Artemia, and whereas no mortality was observed in post-larvae fed with Artemia not exposed to HPV and these post-larvae were PCR negative for HPV, as well. Results of this experiment suggest that Artemia might be a possible horizontal transmission pathway for HPV. Further research however is required with histology, immunohistochemistry and transmission electron microcopy to determine whether the Artemia are actually infected with this virus or whether they are simply mechanical carriers. This will enable us to understand better whether Artemia is a carrier of this virus and if so the mechanism involved.

Viral Infections of Macrobrachium spp.: Global Status of Outbreaks, Diagnosis, Surveillance, and Research

Macrobrachium rosenbergii, a global and economically important cultured freshwater prawn, is farmed on a large scale in many countries. Compared to penaeid shrimps, M. rosenbergii is a moderately disease-resistant species. However, viruses such as Macrobrachium hepatopancreatic parvo-like virus (MHPV), Macrobrachium muscle virus (MMV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), white spot syn- drome virus (WSSV), Macrobrachium rosenbergii nodavirus (MrNV), and extra small virus-like particle (XSV) have been reported and are responsi- ble for economic losses to freshwater prawn culture. MrNV and XSV, the causes of white tail disease (WTD), have been reported as dangerous viruses to M. rosenbergii, resulting in 100% mortality in postlarvae and juve- niles within five days of infection. Clinical signs of WTD include lethargy and opaqueness of the abdominal muscle. Various aspects of WTD are dis- cussed in this paper, including tissue tropism of the causative viruses, host range, virus structure, vertical transmission, pathogenicity, and the possibil- ity of multiplying MrNV and XSV in a mosquito cell line.

A Study on the Pathogenicity of Hepatopancreatic Parvo-like Virus in Chinese Prawn, Penaeus chinensis

A Study on the Pathogenicity of Hepatopancreatic Parvo-like Virus in Chinese Prawn, Penaeus chinensis

Hepatopancreatic parvo-like virus (HPV) of Penaeus japonicus cultured in Australia

A hepatopancreatic parvo-like virus (HPV) infection was identified in the hepatopancreata of moribund Penaeus japonicus postlarvae from a hatchery in Queensland.virus formed basophilic, fine granular intranuclear inclusion bodies within the hepatopancreocytes. These caused nuclear hypertrophy and displacement of the nucleolus. Subsphencal viral particles, 17-20 nm in diameter, were observed embedded within the inclusions. We wlll refer to this virus as HPV to avoid confusion within the literature. However, molecular data is required to definitively identify

Major viral diseases of the black tiger prawn (Penaeus monodon) in Thailand

There are five different viruses which are currently being studied for their impact on commercial farming of the black tiger prawn (Penaeus monodon) in Thailand. Some of these viruses cause disease in other penaeid shrimp species and even other crustacean species. Some occur not only in cultivated shrimp in other Asian countries, but also in those from Australia and the western hemisphere. In descending order from greatest to least economic impact on the Thai shrimp industry, the five viruses are: white-spot baculovirus, yellow-head virus, hepatopancreatic parvo-like virus, infectious hypodermal and hematopoeitic necrosis virus and monodon baculovirus. The purpose of this review is to summarize recent work on these viruses and to suggest future directions of research that may be useful in the effort to develop a sustainable shrimp industry.

A study on pathogens of Chinese prawn (Penaeus Chinensis) virus diseases

This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis, O'sbeck) is due to three kinds of viruses: epithelium envelope baculovirus ofPenaeus chinensis (EEBV-PC, detected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, and hepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of the epidemic in the northern regions in 1993.

Characterization of hepatopancreatic parvo-like virus, a second unusual parvovirus pathogenic for penaeid shrimps.

The hepatopancreatic parvo-like virus (HPV) of penaeid shrimp was extracted from infected shrimp tissues, purified and subsequently characterized. The viral particles, icosahedral in shape, are 22 nm in diameter and possess a buoyant density of 1.41 g/ml. They contain ssDNA, of approximately 5 kb in size which encodes a single polypeptide of 54 kDa. On the basis of its general characteristics this pathogenic agent belongs to the Parvoviridae family, but because of two unusual characteristics (capsid protein formed with a single polypeptide and genome structure more closely related to the autonomous parvoviruses rather than the densoviruses), it seems to constitute a novel group in the Parvoviridae family.

Studies on immunodiagnosis of hepatopancreatic parvo-like virus diseases ofPenaeus orientalis

This paper describes a rapid procedure for diagnosis of penaeid viral disease using the immune serological method. The SPA (Staphylococcal Protein A) coagglutination test in early diagnosis of penaeid viral disease has yielded satisfactory results.

Studies on immunodiagnosis of hepatopancreatic parvo-like virus disease of the Chinese penaeid,Penaeus Chinensis I. Purification of the virus

The viral discase of penaeids is indistinet but highly dangerous because their symptoms are often masked by some secondary ones.

Unique Physicochemical Properties of the Occluded Penaeid Shrimp Baculoviruses and Their Use in Diagnosis of Infections

Abstract Occlusion bodies in wet mounts of phloxine-stained tissue squashes and paraffin sections of penaeid shrimp infected with Baculovirus penaei and Penaeus monodon-type baculovirus fluoresced when viewed with an epifluorescent microscope. Inclusions of hepatopancreatic parvo-like virus, infectious hypodermal and hematopoietic necrosis virus, and Autographa californica nuclear polyhedrosis virus did not fluoresce. The use of phloxine stain (alone or as a component of an eosin preparation) and fluorescent microscopy may enhance detection of lowgrade infections by these disease-causing agents.

Electron microscopic observation of hepatopancreatic parvo‐like virus (HPV) in the penaeid prawn, Penaeus merguiensis de Man, from Australia

Journal of Fish DiseasesVolume 12, Issue 2 p. 199-201 Electron microscopic observation of hepatopancreatic parvo-like virus (HPV) in the penaeid prawn, Penaeus merguiensis de Man, from Australia F. R. ROUBAL, F. R. ROUBAL Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this authorJ. L. PAYNTER, J. L. PAYNTER Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this authorR. J. G. LESTER, R. J. G. LESTER Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this author F. R. ROUBAL, F. R. ROUBAL Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this authorJ. L. PAYNTER, J. L. PAYNTER Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this authorR. J. G. LESTER, R. J. G. LESTER Department of Parasitology, University of Queensland, Brisbane, Queensland, AustraliaSearch for more papers by this author First published: March 1989 https://doi.org/10.1111/j.1365-2761.1989.tb00293.xCitations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume12, Issue2March 1989Pages 199-201 RelatedInformation

RECENT ADVANCES IN PENAEID VIRUS DISEASE INVESTIGATIONS

ABSTRACTOf the approximately 30 known viruses affecting crustaceans, at least six viruses are known in cultured penaeid shrimp. New information is presented here on five of the six penaeid viruses. Baculovirus penaei (BP) in penaeids from widely separated geographic locations was compared by transmission electron microscopy (TEM) of BP‐infected hepatopancreatocytes. Regardless of source or host species, the cytopathology and virion morphology was similar, but differences were found in the dimensions of BP nucleocapsids as a function of geographic source. P. monodon‐type baculovirus (MBV) was discovered in P. monodon from Asia, but it has recently been found to also infect cultured p. merguiensis and p. semisulcatus from other sites in Asia and the Middle East, and possibly P. kerathurus in Italy. Cytopathology and histopathology resulting from MEV infection in each of the species appears identical. Infectious hypodermal and hematopoietic necrosis virus (IHHNV), a picorna‐like virus known previously to infect P. stylirostris, P. vannamei, and P. monodon, has been found to experimentally infect P. japonicus, P. duorarum, P. aztecus and P. setiferus. IHHN appears to be widely distributed in culture facilities in the Americas, Asia, and the Pacific Basin. HPV (hepatopancreatic parvo‐like virus) was discovered in 1983, in four species of cultured or captive wild penaeids in Asia and Australia. TEM studies of HPV‐infected hepatopancreatocytes show HPV virions and cytopathology to be identical in the affected species. REO, a reo‐like virus of cultured P. japonicus in France and Hawaii, infects hepatopancreatic epithelial cells and causes chronic disease and high accumulative mortalities in tanks and possibly grow‐out ponds.

A parvo-like virus disease of penaeid shrimp

Cultured populations of four penaeid shrimp species (Crustacea, Decapoda) from four separate culture facilities in Asia were found to be adversely affected by a disease of presumed viral etiology. Individual shrimp with the disease displayed nonspecific signs, including poor growth rate, anorexia, reduced preening activity, increased surface fouling, and occasional opacity of tail musculature. These signs were accompanied by mortalities during the juvenile stages, after apparently normal development through the larval and postlarval stages. Accumulative mortality rates in epizootics in Penaeus merguiensis and P. semisulcatus reached as high as 50 to 100%, respectively, of the affected populations within 4 to 8 weeks of disease onset. The principal lesion, common to all four species, was necrosis and atrophy of the hepatopancreas, accompanied by the presence of large prominent basophilic, PAS-negative, Fuelgen-positive intranuclear inclusion bodies in affected hepatopancreatic tubule epithelial cells (hepatopancreatocytes). These inclusion bodies presumably developed from small, eosinophilic, intranuclear bodies that were also present in the affected tissues. Electron microscopy of affected hepatopancreatocytes revealed aggregations of 22- to 24-nm-diameter virus particles within the electron-dense granular inclusion body ground substance. The virus particle size and morphology, the close association of the nucleolus with the developing inclusion body, and the presence of intranuclear bodies within developing inclusion bodies are similar to cytopathological features reported for parvovirus infections in insects and vertebrates. It is suggested that this presumed virus disease of cultured penaeid shrimp be called HPV for Hepatopancreatic Parvo-like Virus disease.