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Penaeus monodon. GAV virions (arrowheads) loosely and randomly enclosed in a large vacuole (V) in the cytoplasm of an infected lymphoid organ cell. Bar = 200 nm
Source publication
A rod-shaped, gill-associated virus (GAV) was found to be associated with mortalities of cultured adult Penaeus monodon from 4 farms in Queensland, Australia, from January to June 1996. infected prawns were observed swimming at the surface and edges of ponds and displayed varying degrees of red body colouration. The lymphoid organs of infected praw...
Context in source publication
Context 1
... endoplas- rmc reticulum (Fig. 5), and less commonly with frag- ments of host membranes. Enveloped vii-ions were observed in fewer :han 20% of the lymphoid organ cells within areas of tubule dis- rupbon in all prawns sampled. Enveloped virions were 183 to 200 nm long. 34 to 42 nm wide and were usually enclosed either tightly (Fig. 6) or loosely (Fig. 7) within vesicles apparently formed by budding of nucleocap- sids through the endoplasmic reticulum. The number The within a vesicle in a lymphoid organ cell. Bar = 80 nm interstitial spaces of highly infected lymphoid organs appeared to be abnormally distended (Fig. 8) and con- tained virions released by rupture of the plasma mem- Dark, ...
Citations
... Unlike the research on the viral diseases of farmed crustaceans, the reports on the spread of wild crustacean viruses and coinfection with multi-pathogen are still very limited [7]. Spann et al. [57] reported that coinfection with MoV and GAV is very common in diseased P. monodon. Notably, YHV-8 and GAV belong to Okavirus, and MoV and OWV1 belong to Wenrivirus. ...
At present, there are few studies on the epidemiology of diseases in wild Chinese white shrimp Penaeus chinensis. In order to enrich the epidemiological information of the World Organisation for Animal Health (WOAH)-listed and emerging diseases in wild P. chinensis, we collected a total of 37 wild P. chinensis from the Yellow Sea in the past three years and carried out molecular detection tests for eleven shrimp pathogens. The results showed that infectious hypodermal and hematopoietic necrosis virus (IHHNV), Decapod iridescent virus 1 (DIV1), yellow head virus genotype 8 (YHV-8), and oriental wenrivirus 1 (OWV1) could be detected in collected wild P. chinensis. Among them, the coexistence of IHHNV and DIV1 was confirmed using qPCR, PCR, and sequence analysis with pooled samples. The infection with YHV-8 and OWV1 in shrimp was studied using molecular diagnosis, phylogenetic analysis, and transmission electron microscopy. It is worth highlighting that this study revealed the high prevalence of coinfection with YHV-8 and OWV1 in wild P. chinensis populations and the transmission risk of these viruses between the wild and farmed P. chinensis populations. This study enriches the epidemiological information of WOAH-listed and emerging diseases in wild P. chinensis in the Yellow Sea and raises concerns about biosecurity issues related to wild shrimp resources.
... The virus has been divided into 8 subtypes [1][2][3][4], and it has been shown that only Type-1 (YHV-1) and Type-8 (YHV-8) [4] cause rapid and severe mortality. This contrasts with 6 less virulent variants (Types 2 to 7), one of which (YHV-2) has been given the specific name of gill associated virus (GAV) [5,6]. Penaeus (Penaeus) monodon and Penaeus (Litopenaeus) vannamei (the two main shrimp species cultivated in Thailand) are both highly susceptible to YHD caused by two known variants of YHV-1 (YHV-1a and -1b) [7,8]. ...
This short paper on yellow head virus Type-1 (YHV-1) of shrimp describes preliminary research on the potential for using YHV-1 attenuated in insect cells to protect shrimp against yellow head disease (YHD). YHV-1 can cause severe mortality in the cultivated shrimp Penaeus (Penaeus) monodon and Penaeus (Litopenaeus) vannamei. No practical vaccination has been reported. The C6/36 mosquito cell cultures inoculated with YHV-1 become positive by PCR and by immunocytochemistry (immunopositive) for up to 30 split-cell passages. Shrimp injected with homogenates from low-passage cultures die from typical YHV-1 disease while shrimp injected with homogenates from high passage cultures do not, even though they become PCR positive and immunopositive for YHV-1. This suggested that viral attenuation had occurred during insect-cell passaging, and it opened the possibility of using homogenates from high-passage insect cultures as a vaccine against YHV-1. To test this hypothesis, homogenates from 30th-passage, YHV-positive cultures were injected into shrimp followed by challenge with virulent YHV-1. Controls were injected with homogenate from 30th-passage, naive (normal stock) insect-cell cultures. No shrimp mortality occurred following injection of either homogenate, but shrimp injected with the YHV-1 homogenate became both RT-PCR positive and immunopositive. Upon challenge 10 days later with YHV-1, mortality in shrimp injected with naive insect-cell homogenate was 100% within 7 days post-challenge while 100 % mortality in the YHV-1 homogenate group did not occur until day 9 post-challenge. Kaplan-Meier log-rank survival analysis revealed that survival curves for the two groups were significantly different (p<0.001). The cause of delay in mortality may be worthy of further investigation.
... merguiensis) [3], and can stunt growth at juvenile stages in growout ponds for both Japanese tiger prawn (P. japonicas) [4] and farmed black tiger shrimp (P. monodon) [5,6]. ...
Background
Viral diseases are a major problem in shrimp aquaculture facilities as these diseases reduce growth rates, which inevitably lead to production and profit losses. Hepatopancreatic parvoviruses (HPV) are common diseases in shrimp that appear to be associated with high or low levels of replication in specific genetic lineages. Selective breeding may result in resistance to HPV and improved body traits such as body weight, meat yield and shrimp colour, facilitating shrimp farming. HPV virus titre is commonly determined by quantitative PCR (qPCR), which is a time-consuming method requiring laboratory equipment unsuitable for field implementation. The aim of this study was to develop a simple, robust, rapid and reliable method to detect HPV in low-resource environments.
Methods
We developed a rapid shrimp HPV test that uses (1) a simple three-step sample preparation protocol, followed by (2) isothermal recombinase polymerase amplification (RPA) and lateral flow strip detection (LFD). Analytical sensitivity testing was performed in a background banana shrimp sample matrix, and retrospective testing of Fenneropenaeus merguiensis hepatopancreas tissues (n = 33) with known qPCR viral titres was used to determine diagnostic sensitivity and specificity.
Results
The rapid shrimp HPV test could detect as little as 35 genome-equivalent copies per reaction in homogenized F . merguiensis banana shrimp. Retrospective testing of stored tissues (n = 33) indicated 100% diagnostic sensitivity (95% confidence interval, CI: 86–100%) and 100% specificity (95% CI: 66–100%) for detection of HPV.
Conclusion
The rapid shrimp HPV test could be completed in only 40 minutes, and required only homogenization pestles, some pipettors, and a small heating block for single temperature incubation at 39°C. Critically, our procedure eliminated the time-consuming purification of nucleic acids from samples and when combined with RPA-LFD offers a user-friendly HPV detection format that can potentially be performed on-site. Our approach represents a major step forward in the development of a simple and sensitive end-point method for quick determination of unfavourable HPV virus numbers in shrimp, and has great potential to advance on-site management of shrimps in aquaculture.
... 1,9 Apart from interactions, cannibalism can be documented as another dominant disease transmission route among the species. For example, Spawner-isolated fatality viruses 10 in Pandalusplatyceros and Gill-associated virus 11 in Penaeusmondon are transmitted through cannibalism among the population. Cannibalism is prominent and wide-spreading biological phenomenon eliminating and predating con-specifics in a prey-predator inter plays. ...
In this paper, we investigate a cannibalistic predator‐prey system with Beddington‐DeAngelis type response function when the infection only exists in the predator species. The predator species are subject to cannibalistic interaction and the infection spreads among the predators via cannibalism. The model is studied in presence of multiple delays for the maturation of prey and predator. Local stability analysis of the predator‐prey model around the biologically realistic two essential steady states is investigated. We also investigate the bifurcation analysis of the proposed model around the co‐existing steady states. Using the normal form method and center manifold theory, the direction of Hopf bifurcation and the Hopf bifurcating periodic solutions are explored. In presence of time delays, we derive the criteria for the permanence of the model. Our findings demonstrate that maturation delays destabilize the system and can produce high periodic oscillations. Cannibalism can act as a self‐regulatory scenario controlling the transmission of disease among the predator species and stabilizing the oscillations in the predator‐prey system. Our theoretical analysis is well supported with numerical simulation.
... Infection corresponds to a multifocal to generalised necrosis of connective tissues of the gill, heart, hepatopancreas and gut, with nuclei showing pyknosis and karyorrhexis. Enveloped rod-shaped virions measuring 60-110 x 24-42 nm were identified within the cytoplasm of affected cells, nonmature particles were occasionally associated with the endoplasmic reticulum, similar to that described by Spann et al. (1997) in GAV infections. Tissue tropism, histopathology and ultrastructural characteristics suggest this virus is similar to viruses within the family Roniviridae and genus Okavirus, such as YHV, GAV, however genome sequencing is needed to clarify this relationship. ...
Farming of crustaceans especially shrimp, crabs and crayfish have expanded significantly over the past four decades. The aquaculture production of crustaceans is now a multimillion-dollar industry providing jobs to millions of people around the world especially in countries with large coastal boundaries in Asia and Latin America. Crustacean farming is largely dominated by penaeid shrimp aquaculture. The emergence of infectious diseases especially diseases of viral origin has been a threat to this nascent industry. Many viruses that affect penaeid shrimp have been relatively well characterised due to their economic importance. These include viruses with single-stranded DNA containing genomes such as Infectious Hypodermal, and Hematopoietic Necrosis Virus, and Hepatopancreatic Parvovirus (family: Parvoviridae), double stranded DNA viruses such as white spot syndrome virus (family: Nimaviridae), Penaeus monodon nudivirus (Family: Nudiviridae), Decapod iridescent virus 1 (family: Iridoviridae), and Baculovirus penaei (tentatively classified in the family: Baculoviridae), single-stranded RNA viruses such as Taura syndrome virus (family: Dicistroviridae), yellow head, and Gill-associated viruses (family: Roniviridae), and Macrobrachium rosenbergii Nodavirus (family: Nodaviridae), and double-stranded RNA virus such as infectious myonecrosis virus (Totiviridae-like). White spot syndrome virus is of major concern as the virus has a wide host range and poses a threat to wild and farmed populations of decapod crustacean species, with multiple species showing differing levels of susceptibility. Viral infections have been reported in wild crustacean species including those which are commercially exploited. However, in comparison to cultured species relatively little is known about the effects of viruses in wild crustaceans.
... The NCBI database contains sequences listed as GAV collected from Australia, Indonesia, Malaysia, Thailand and Taiwan (https://www.ncbi.nlm.nih.gov/, accessed 9/08/21), however, disease events in P. monodon production have only been reported from Australian sourced samples (Spann et al., 1997). GAV was associated with mortality events termed Mid-Crop Mortality syndrome (MCMS) that occurred in Australian P. monodon pond systems during 1996/97 (Anderson and Owens, 2001). ...
... GAV was associated with mortality events termed Mid-Crop Mortality syndrome (MCMS) that occurred in Australian P. monodon pond systems during 1996/97 (Anderson and Owens, 2001). GAV particles in viral extracts from these disease events were observed under TEM (Spann et al., 1997). Although experimental challenges have been conducted for GAV in P. monodon (Spann et al., 1997;Noble et al., 2017;Noble et al., 2020), as with many historical reports, the challenge inoculum was not a purified viral extract and comprehensive screening for other pathogens in the viral inoculum is not widely reported. ...
... GAV particles in viral extracts from these disease events were observed under TEM (Spann et al., 1997). Although experimental challenges have been conducted for GAV in P. monodon (Spann et al., 1997;Noble et al., 2017;Noble et al., 2020), as with many historical reports, the challenge inoculum was not a purified viral extract and comprehensive screening for other pathogens in the viral inoculum is not widely reported. The findings of the present study suggest that the majority of wild-sourced shrimp positive for the detection of GAV have co-detections of one or more other pathogen targets (50.2%) including IHHNV, YHV-7 and When-2. ...
Disease presents a considerable challenge to the sustainability and development of global shrimp aquaculture. The Australian black tiger shrimp (Penaeus monodon) aquaculture industry is heavily reliant on wild-sourced broodstock for seedstock production, representing a large and under evaluated biosecurity risk. Currently, there is a paucity of quantitative, large-scale data detailing the extent of pathogenic agents in wild-sourced P. monodon broodstock. This study presents a comprehensive investigation of the presence and level of detection of endemic pathogen targets in wild-sourced P. monodon broodstock collected from the two primary sources of supply for the Australian shrimp aquaculture industry using quantitative polymerase chain reaction (qPCR). Broodstock pleopod samples (N = 7472) were analysed by TaqMan qPCR for the detection of six viral pathogens. In total, 44.9% of wild-sourced broodstock were positive for the detection of at least one pathogen target. Whitespot virus and Yellowhead virus-1 were not detected in any sample. Infectious hypodermal haematopoietic necrosis virus (30%) and Gill-associated virus (28.1%) were the most prevalent pathogen targets detected. Whenzhou (syn. Wenzhou) shrimp virus-2 and Yellowhead virus-7 were each cumulatively detected in less than 3% of broodstock samples. Geographic source, sex and year of collection of broodstock significantly influenced prevalence of detection. The current study will be valuable to the Australian shrimp aquaculture industry to improve understanding of the presence of pathogens in wild-sourced broodstock, along with informing management decisions related to wild broodstock collection and associated biosecurity practices.
... So this study can help in the identification of root of the coronavirus outbreak as still there are no reports for the source of this coronavirus which has recently emerged in 2019 and still is the major cause of death to humans as well as to some animals. It is hoped that this review will enable the discovery and identification of source of coronaviruses and facilitate further research into their molecular biology, phylogeny and evolution [25][26][27][28][29][30][31][32][33][34]. ...
... However, the production of intensified aquaculture is often hampered by the outbreak of infectious diseases, which is commonly caused by viruses, bacteria, or parasites. Viruses that were frequently reported to cause infections in shrimp aquaculture include white spot syndrome virus (WSSV) [2]; yellow head virus (YHV) [3,4]; Taura syndrome virus (TSV) [5]; infectious myonecrosis virus (IMNV) [6,7]; infectious hypodermal and haematopoietic necrosis virus (IHNNV) [8,9]; and M. rosenbergii nodavirus (MrNV) [10,11]. It is noteworthy that a novel hepe-like virus, tentatively named as Crustacea hepe-like virus 1 (CHEV1) has been identified in growth-retarded giant freshwater prawn [12]. ...
The giant freshwater prawn/giant river prawn, Macrobrachium rosenbergii is one of the high market value crustaceans cultured worldwide. The intensified aquaculture of the species has led to the outbreak of infectious diseases, prominently, the white tail disease (WTD). It is caused by the infection of Macrobrachium rosenbergii nodavirus (MrNV), which was classified in the family of Nodaviridae. To-date, there are no effective prophylactic and therapeutic agents available against MrNV infection. Vaccination is known to be the most effective prophylactic agent in disease prevention. However, vaccine development against virus infection in crustaceans is equivocal. The feasibility of vaccination in conferring immune protection in crustaceans against infectious diseases is disputable. The argument lies in the fact that crustaceans do not possess adaptive immunity, which is the main immune component that functions to establish immunological memory upon vaccination. Nevertheless, an increasing number of literatures has been documented, which concerns the development of vaccines against infectious diseases in crustaceans. The current review deliberates different approaches in vaccine development against MrNV, which were documented in the past years. It is noteworthy that the live-attenuated MrNV vaccine has not been experimented by far. Thus, the potential of live-attenuated MrNV vaccine in conferring long-term immune protection through the establishment of innate immune memory is currently being discussed.
... In the early to mid-1990s, yellow head virus (YHV1) and gill-associated virus (GAV; YHV2) emerged as serious pathogens of farmed Giant Tiger shrimp (Penaeus monodon) in Thailand and Australia, respectively (Limsuwan, 1991;Boonyaratpalin et al., 1993;Chantanachookin et al., 1993;Spann et al., 1998;Walker et al., 2001;Callinan and Jiang, 2003). Both viruses form rod-shaped enveloped virions (Chantanachookin et al., 1993;Lu et al., 1994;Spann et al., 1995Spann et al., , 1998 decorated with spikes formed by 2 glycoproteins Jitrapakdee et al., 2003). ...
... In the early to mid-1990s, yellow head virus (YHV1) and gill-associated virus (GAV; YHV2) emerged as serious pathogens of farmed Giant Tiger shrimp (Penaeus monodon) in Thailand and Australia, respectively (Limsuwan, 1991;Boonyaratpalin et al., 1993;Chantanachookin et al., 1993;Spann et al., 1998;Walker et al., 2001;Callinan and Jiang, 2003). Both viruses form rod-shaped enveloped virions (Chantanachookin et al., 1993;Lu et al., 1994;Spann et al., 1995Spann et al., , 1998 decorated with spikes formed by 2 glycoproteins Jitrapakdee et al., 2003). As they are also closely related genetically (Cowley et al., 1999;Sittidilokratna et al., 2002) and possess a long (∼26.2-26.6 kb) positive-sense ssRNA genome with structural, transcriptional and translational features conserved among viruses classified within the Order Nidovirales, GAV was designated type species of the genus Okavirus, family Roniviridae (Cowley et al., 2000a(Cowley et al., , 2002a(Cowley et al., ,b, 2012Cowley and Walker, 2002;Sittidilokratna et al., 2002Sittidilokratna et al., , 2008de Groot et al., 2012;Wongteerasupaya et al., 1995). ...
... Tissues were also sampled from juvenile to sub-adult P. monodon being reared in ponds either at BIRC (Batches 14, 16) or at a commercial shrimp farm (NQ-SF1; Batch 12) experiencing mortalities. As the diseased shrimp at NQ-SF1 displayed characteristics typical of mid-crop mortality syndrome (Spann et al., 1998), and as preliminary qPCR testing identified YHV7, pleopod tissue was sampled from 48 shrimp assessed visually as appearing normal and 48 assessed as displaying signs of morbidity. ...
In 2013, a unique seventh yellow head virus genotype (YHV7) was detected in Black Tiger shrimp (Penaeus monodon) broodstock that suffered high mortality following their capture from Joseph Bonaparte Gulf (JBG) in northern Australia. To assist with its diagnosis and assessment of its distribution, prevalence and pathogenicity, YHV7-specific TaqMan real-time qPCR and conventional nested PCR primer sets were designed to ORF1b gene sequences divergent from the other YHV genotypes. Using high (≥108) copies of plasmid (p)DNA controls containing ORF1b gene inserts of representative strains of YHV genotypes 1-7, both PCR tests displayed specificity for YHV7. Amplifications of serial 10-fold dilutions of quantified YHV7 pDNA and synthetic ssRNA showed that both tests could reliably detect 10 genome copies. Pleopods/gills from wild P. monodon sourced from locations in geographically disparate regions across northern Australia as well as 96 juveniles (48 either appearing normal or displaying signs of morbidity) from a commercial pond experiencing mortalities were screened to partially validate the diagnostic capacity of the qPCR test. Based on these data and PCR primer/probe sequence mismatches with other newly identified YHV genotypes, both YHV7-specific PCR tests should prove useful in the sensitive detection and discrimination of this genotype from YHV 2 (gill-associated virus) and YHV6 that can occur in Australian P. monodon, as well as from YHV genotypes currently listed as exotic to Australia.
... Reported here are data associating the sustained presence of highlevel IHHNV infection with reduced growth performance and survival of Penaeus monodon reared under simulated commercial conditions in 0.16 ha research ponds. The role of IHHNV in reduced growth performance was investigated due to the absence of both GAV, which has been associated most commonly over that past 2 decades with reduced survival and harvest yields of P. monodon farmed in eastern Australia (Spann et al., 1997;Munro et al., 2011), and YHV7, a genotypic variant of GAV which has also been associated with the similar stock losses since being introduced into Queensland more recently through the use of wild broodstock sourced from remote locations in northern Australia Moody et al., 2017;J.A. Cowley et al. unpublished). Pivotal to examining IHHNV infection severity as the cause of reduced pond productivity was its detection by TaqMan real-time qPCR at higher loads in 3 females that contributed postlarvae (PL) stocked into 2 research ponds in which growth performance and survival was markedly compromised compared to that detected in 4 females contributing PL stocked into 2 neighbouring research ponds. ...
In Australia, Infectious hypodermal and hematopoietic necrosis virus (IHHNV) occurs endemically in Black tiger shrimp (Penaeus monodon) and has been detected at high prevalence in farmed shrimp. Here we examined the role of high IHHNV infection prevalence and loads in reduced growth and survival in P. monodon reared under commercial conditions in 0.16 ha research ponds. TaqMan real-time quantitative (q)PCR testing of wild broodstock from the East Coast of Queensland identified lower and higher IHHNV infection loads among females used to generate 2 cohorts of progeny. Tracking of IHHNV loads in eggs and juveniles sampled progressively over grow-out identified these to be substantially higher and to increase more rapidly in 2 ponds stocked with a batch of postlarvae (PL) pooled from 3 females with high-level IHHNV infection at the time they spawned compared to 2 neighbouring ponds stocked with PL pooled from 4 females, of which only 1 possessed IHHNV at a relatively high load. From 120 days of culture (DOC) onwards, the growth performance in the IHHNV-high ponds began to progressively reduce compared to that in the IHHNV-low ponds. When harvested over 2 weeks starting at 155 DOC, the averaged harvest yield of the 2 IHHNV-high ponds was the equivalent of 3.72 t/ha lower than the 2 IHHNV-low ponds, and estimated survival was also markedly lower (79.5–84.5% compared to 95.9–99.8%). As real-time qPCR testing identified no involvement of either Gill-associated virus (GAV) or Yellow head virus genotype 7 (YHV7), other viruses known to cause such production losses in Australia, the data support a sustained high IHHNV infection burden as the primary contributor to the reduced growth and survival. Using a basic extrapolation of yield, stocking low-level IHHNV PL has resulted in an increase of farm gate value of $67,000 per hectare compared to stocking high-level IHHNV PL. Among other problems such as severe shell deformities that acute IHHNV infection has recently been identified to cause in locally-farmed P. monodon, the potential impacts on growth and survival identified here reinforce the value in screening-based selection of IHHNV-free/low broodstock for use in hatcheries and in breeding programs employing specific pathogen-free stocks, and strategies to select for IHHNV resistance/tolerance.
