| evidence for interspecies transmission of oyster herpesvirus in marine bivalves. | since 1991, numerous herpesvirus infections associated with high mortality have been reported around the world in various marine bivalve species. in order to determine whether these infections are due to ostreid herpesvirus-1 (oshv1), a previously characterized pathogen of the japanese oyster (crassostrea gigas), pcr analysis was carried out on 30 samples of larvae collected from four bivalve species (c. gigas, ostrea edulis, ruditapes decussatus and ruditapes philippinarum), most exhibiting mor ... | 2001 | 11257192 |
| french scallops: a new host for ostreid herpesvirus-1. | sporadic high mortalities were reported among larval french scallops (pecten maximus). electron microscopy of moribund larvae revealed particles with the characteristics of a herpesvirus in association with cellular lesions. pcr and dna sequencing showed that the virus is a variant of ostreid herpesvirus-1 that has already been described in clams and oysters. this is the first description of a herpesvirus infection of a scallop species. the virus was transmitted successfully from an extract of i ... | 2001 | 11883198 |
| diagnosis of ostreid herpesvirus 1 in fixed paraffin-embedded archival samples using pcr and in situ hybridisation. | in 1994, some of the high mortality episodes that affected oysters cultured in france were associated with herpesviral infections. through histology analysis, however, viral presence could only be suspected and confirmation of histological diagnosis by transmission electron microscopy was performed in only a few cases. subsequently, the characterisation and genome sequencing of ostreid herpesvirus 1 (oshv-1) made possible the development of specific molecular detection (pcr and in situ hybridisa ... | 2004 | 15158586 |
| ostreid herpesvirus 1 (oshv-1) detection among three successive generations of pacific oysters (crassostrea gigas). | ostreid herpesvirus 1 (oshv-1) was likely detected in pacific oysters, crassostrea gigas, at different stages of development. viral infections were associated with high mortality rates in the spat and larvae. furthermore, the persistance of oshv-1 in asymptomatic adults was demonstrated by detection of viral dna and proteins. in the present study, three successive generations of c. gigas (g0 and g1 parental oysters, g1 and g2 larvae) were screened for oshv-1 by pcr. viral dna was detected in 2-d ... | 2005 | 15567033 |
| a novel class of herpesvirus with bivalve hosts. | ostreid herpesvirus 1 (oshv-1) is the only member of the herpesviridae that has an invertebrate host and is associated with sporadic mortality in the pacific oyster (crassostrea gigas) and other bivalve species. cryo-electron microscopy of purified capsids revealed the distinctive t=16 icosahedral structure characteristic of herpesviruses, although the preparations examined lacked pentons. the gross genome organization of oshv-1 was similar to that of certain mammalian herpesviruses (including h ... | 2005 | 15604430 |
| detection of ostreid herpesvirus 1 (oshv-1) dna in seawater by pcr: influence of water parameters in bioassays. | since 1991, herpesvirus infections have been reported among larvae and juveniles of various bivalves. most of the studies focused on detection of viral infections of economically important species. however, the persistence of bivalve herpesviruses in the marine environment is poorly documented. the present study concerns the role of seawater parameters in ostreid herpesvirus 1 (oshv-1) detection by polymerase chain reaction (pcr). viral dna extracted from purified particles or virions present in ... | 2004 | 15648829 |
| detection of ostreid herpesvirus-1 (oshv-1) by pcr using a rapid and simple method of dna extraction from oyster larvae. | a dna extraction procedure was developed for the detection of ostreid herpesvirus-1 (oshv-1) using the polymerase chain reaction (pcr) in oyster larvae. the dna extraction procedure developed was tested on 8 larval samples. abnormal nuclei with characteristic features associated with oshv-1 infections were only observed in samples in which the viral dna was detected by pcr. a previously described competitive pcr method was applied to detect inhibition during pcr reactions. the results show that ... | 2005 | 15900681 |
| in vitro research of anti-hsv-1 activity in different extracts from pacific oysters crassostrea gigas. | mortalities related to the detection of ostreid herpesvirus 1 (oshv-1) have been previously reported in france among larvae and spat of the pacific oyster crassostrea gigas. adult oysters appear less sensitive to herpesvirus infections, although oshv-1 has been detected in adults without signs of disease or mortality. this suggests that the virus is able to persist in its host and that adult oysters may be able to control oshv-1 infection. little is known about antiviral substances in invertebra ... | 2005 | 16385820 |
| mortality and herpesvirus infections of the pacific oyster crassostrea gigas in tomales bay, california, usa. | seed losses of pacific oysters crassostrea gigas have been associated with an ostreid herpesvirus-1 (oshv-1) in europe, and in 2002, a similar oshv was detected in tomales bay, california, usa. in may of 2003, 5 stocks of seed pacific oysters were planted at 2 sites (inner bay and outer bay) in tomales bay and monitored for mortality, presence/prevalence of oshv (using polymerase chain reaction [pcr] and histology), and growth. temperature (degrees c) and salinity data were collected every half ... | 2006 | 17067071 |
| detection of ostreid herpesvirus 1 dna by pcr in bivalve molluscs: a critical review. | herpes-like viral infections have been reported in different bivalve mollusc species throughout the world. high mortalities among hatchery-reared larvae and juveniles of different bivalve species have been associated often with such infections. the diagnosis of herpes-like viruses in bivalve molluscs has been performed traditionally by light and transmission electron microscopy. the genome sequencing of one of these viruses, oyster herpesvirus 1 (oshv-1), allowed the development of dna-based dia ... | 2007 | 17079025 |
| detection of panulirus argus virus 1 in caribbean spiny lobsters. | panulirus argus virus 1 (pav1) is a pathogenic virus that infects caribbean spiny lobsters p. argus in the florida keys. we have developed a pcr detection assay for pav1 for the purpose of studying the natural history of the virus and for monitoring the prevalence of infection. the detection of the virus in hemolymph and other tissues is based on the pcr amplification of a 499 bp product using specific primers designed from a cloned fragment of the pav1 genome. the sensitivity limit for the assa ... | 2007 | 17718159 |
| rapid and sensitive detection of ostreid herpesvirus 1 in oyster samples by real-time pcr. | herpes and herpes-like virus infections have been reported in various marine mollusc species associated with high mortality rates. following the characterisation and genome sequencing of ostreid herpesvirus 1 (oshv-1), specific diagnostic tools have been developed based on conventional pcr techniques or in situ hybridisation. we have now developed a real-time pcr assay for rapid, sensitive and quantitative detection of oshv-1, and compared it with a conventional pcr technique described previousl ... | 2008 | 18342377 |
| herpesvirus infection in european flat oysters ostrea edulis obtained from brood stocks of various geographic origins and grown in galicia (nw spain). | we evaluated differences in productive traits and disease susceptibility among ostrea edulis stocks. we produced 4 to 5 families from each of 4 oyster populations (irish, greek and 2 galician) in a hatchery. spat corresponding to 19 different families were transferred to a raft in the ría de arousa (galicia, spain) for grow-out. samples of each family were histologically processed every month for 2 yr. one of the pathological conditions disclosed by histological examination was characterised by ... | 2008 | 18380216 |
| the order herpesvirales. | the taxonomy of herpesviruses has been updated by the international committee on taxonomy of viruses (ictv). the former family herpesviridae has been split into three families, which have been incorporated into the new order herpesvirales. the revised family herpesviridae retains the mammal, bird and reptile viruses, the new family alloherpesviridae incorporates the fish and frog viruses, and the new family malacoherpesviridae contains a bivalve virus. three new genera have been created in the f ... | 2009 | 19066710 |
| gill erosion and herpesvirus in crassostrea gigas cultured in baja california, mexico. | recurrent episodes of mortality of crassostrea gigas cultured in northwestern mexico have been occurring since 1997. previous studies on bacteria, protozoans, and metazoans as presumptive causal agents have been inconclusive. however, erosions in the marginal indentation of gills have been frequently observed in oysters from areas affected by mortality events, and in 2000 those lesions were associated with the detection of a herpes-like virus. the present study aimed to describe the histological ... | 2010 | 20402231 |
| detection and description of a particular ostreid herpesvirus 1 genotype associated with massive mortality outbreaks of pacific oysters, crassostrea gigas, in france in 2008. | ostreid herpesvirus 1 (oshv-1) infections have been reported around the world and are associated with high mortalities of the pacific oyster (crassostrea gigas). in the summer 2008, abnormal mortality rates ranging from 80% to 100% were reported in france and affected only pacific oysters. analyses of oyster samples collected during mortality outbreaks demonstrated a significant detection of oshv-1 (75% of analysed batches), which appeared stronger than previous years. dna sequencing based on c ... | 2010 | 20638433 |
| experimental ostreid herpesvirus 1 infection of the pacific oyster crassostrea gigas: kinetics of virus dna detection by q-pcr in seawater and in oyster samples. | herpes- and herpes-like viruses are known to infect a wide range of bivalve mollusc species throughout the world. abnormal summer mortalities associated to the detection of ostreid herpesvirus 1 (oshv-1) have been currently reported in france among larvae and spat of the pacific cupped oyster crassostrea gigas. in the present work, we have developed an experimental protocol of horizontal transmission based on the cohabitation between healthy and experimentally infected oysters. through a cohabit ... | 2011 | 20709119 |
| development of a loop-mediated isothermal amplification assay for rapid and sensitive detection of ostreid herpesvirus 1 dna. | a loop-mediated isothermal amplification (lamp) assay was developed for rapid, specific and sensitive detection of ostreid herpesvirus 1 (oshv-1) dna. a set of four primers was designed, based on the sequence of the atpase subunit of the oshv-1 dna-packaging terminase gene. the reaction temperature and time were optimized to 64°c and 60min, respectively. lamp products were detected by agarose gel electrophoresis or by visual inspection of a color change due to addition of fluorescent dye. the de ... | 2010 | 20813133 |
| comparison of two real-time pcr methods for detection of ostreid herpesvirus 1 in the pacific oyster crassostrea gigas. | the real-time polymerase chain reaction (pcr) is considered to be a suitable tool for nucleic acid quantitation because it is accurate, rapid and reliable. the reference protocol for quantitation of ostreid herpesvirus 1 in pacific oysters crassostrea gigas is based on a sybr(®) green real-time pcr developed by the ifremer laboratory. the frank duncombe departmental laboratory has developed an alternative protocol based on taqman(®) chemistry (alternative technique). the quantitation limits were ... | 2010 | 20837066 |
| a neurotropic herpesvirus infecting the gastropod, abalone, shares ancestry with oyster herpesvirus and a herpesvirus associated with the amphioxus genome. | with the exception of the oyster herpesvirus oshv-1, all herpesviruses characterized thus far infect only vertebrates. some cause neurological disease in their hosts, while others replicate or become latent in neurological tissues. recently a new herpesvirus causing ganglioneuritis in abalone, a gastropod, was discovered. molecular analysis of new herpesviruses, such as this one and others, still to be discovered in invertebrates, will provide insight into the evolution of herpesviruses. | 2010 | 21062506 |
| experimental infection of pacific oyster crassostrea gigas spat by ostreid herpesvirus 1: demonstration of oyster spat susceptibility. | abstract: in 2008 and 2009, acute mortalities occurred in france among pacific cupped oyster, crassostrea gigas, spat. different hypothesis including the implication of environmental factors, toxic algae and/or pathogens have been explored. diagnostic tests indicated that oshv-1 including a particular genotype, termed oshv-1 µvar, was detected in most of samples and especially in moribund oysters with the highlighting of virus particles looking like herpes viruses by tem examination. in this stu ... | 2011 | 21314910 |
| suppression substractive hybridisation (ssh) and real time pcr reveal differential gene expression in the pacific cupped oyster, crassostrea gigas, challenged with ostreid herpesvirus 1. | virus-induced genes were identified using suppression subtractive hybridisation (ssh) from pacific cupped oyster, crassostrea gigas, haemocytes challenged by oshv-1. a total of 304 clones from ssh forward library were sequenced. among these sequences, some homologues corresponded to (i) immune related genes (macrophage express protein, ik cytokine, interferon-induced protein 44 or multicopper oxidase), (ii) apoptosis related genes (bcl-2) and (iii) cell signalling and virus receptor genes (glypi ... | 2011 | 21371503 |
| detection of different variants of ostreid herpesvirus 1 in the pacific oyster, crassostrea gigas between 2008 and 2010. | since summer 2008, high mortality rates of young pacific oysters crassostrea gigas have been recorded in association with the detection of the ostreid herpesvirus 1 (oshv-1). a new variant called μvar has been recently described, characterized mainly by 12 consecutive deletions followed by one deletion of an adenine in the c region. the purpose of this study is to characterize the genotype (variants or oshv-1 reference) of 300 positive samples of c. gigas analyzed between july 2008 and july 2010 ... | 2011 | 21600247 |
| ostreid herpesvirus 1 detection and relationship with crassostrea gigas spat mortality in france between 1998 and 2006. | abstract: since its molecular characterisation, ostreid herpesvirus 1 (oshv-1) has been regularly detected in crassostrea gigas in france. although its pathogenicity was demonstrated on larval stages, its involvement during mortality outbreaks at the juvenile stage was highly suspected but not evidenced. to investigate mortality outbreaks, the french national network for surveillance and monitoring of mollusc health (repamo) carried out two surveys in juvenile c. gigas. the first survey lasted f ... | 2011 | 21635731 |
| quantifying ostreid herpesvirus (oshv-1) genome copies and expression during transmission. | understanding the pathogenic potential of a new pathogen strain or a known pathogen in a new locale is crucial for management of disease in both wild and farmed animals. the ostreid herpesvirus-1 (oshv-1), a known pathogen of early-life-stage pacific oysters, crassostrea gigas, has been associated with mortalities of juvenile oysters in many locations around the world including tomales bay, california. in two trials, the california oshv-1 strain was transmitted from infected juvenile c. gigas to ... | 2011 | 21935610 |
| autophagy plays an important role in protecting pacific oysters from oshv-1 and vibrio aestuarianus infections. | recent mass mortality outbreaks around the world in pacific oysters, crassostrea gigas, have seriously affected the aquaculture economy. although the causes for these mortality outbreaks appear complex, infectious agents are involved. two pathogens are associated with mass mortality outbreaks, the virus ostreid herpesvirus 1 (oshv-1) and the bacterium vibrio aestuarianus. here we describe the interactions between these 2 pathogens and autophagy, a conserved intracellular pathway playing a key ro ... | 0 | 25714877 |
| the development of a loop-mediated isothermal amplification assay for rapid and sensitive detection of abalone herpesvirus dna. | a loop-mediated isothermal amplification (lamp) assay was developed for the detection of abalone herpesvirus dna. two pairs of primers were designed, based on the sequence of the dna polymerase gene of abalone herpesvirus. the reaction temperature and time were optimized to 63°c and 60min, respectively. lamp amplicons were analyzed by 2% agarose gel electrophoresis or by visual inspection of a colour change emitted by fluorescent dye. the method developed was specific for the detection of abalon ... | 2014 | 24291740 |
| antiviral activity of myticin c peptide from mussel: an ancient defense against herpesviruses. | little is known about the antiviral response in mollusks. as in other invertebrates, the interferon signaling pathways have not been identified, and in fact, there is a debate about whether invertebrates possess antiviral immunity similar to that of vertebrates. in marine bivalves, due to their filtering activity, interaction with putative pathogens, including viruses, is very high, suggesting that they should have mechanisms to address these infections. in this study, we confirmed that constitu ... | 2016 | 27307570 |
| ostreid herpesvirus type 1 replication and host response in adult pacific oysters, crassostrea gigas. | since 2008, massive mortality outbreaks associated with oshv-1 detection have been reported in crassostrea gigas spat and juveniles in several countries. nevertheless, adult oysters do not demonstrate mortality in the field related to oshv-1 detection and were thus assumed to be more resistant to viral infection. determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult pacific oysters. dual transcriptomics of virus-host in ... | 2014 | 25294338 |
| ontogeny and water temperature influences the antiviral response of the pacific oyster, crassostrea gigas. | disease is caused by a complex interaction between the pathogen, environment, and the physiological status of the host. determining how host ontogeny interacts with water temperature to influence the antiviral response of the pacific oysters, crassostrea gigas, is a major goal in understanding why juvenile pacific oysters are dying during summer as a result of the global emergence of a new genotype of the ostreid herpesvirus, termed oshv-1 μvar. we measured the effect of temperature (12 vs 22 °c ... | 2014 | 24200990 |
| differential expression of novel metabolic and immunological biomarkers in oysters challenged with a virulent strain of oshv-1. | early lifestages of the pacific oyster (crassostrea gigas) are highly susceptible to infection by oshv-1 μvar, but little information exists regarding metabolic or pathophysiological responses of larval hosts. using a metabolomics approach, we identified a range of metabolic and immunological responses in oyster larvae exposed to oshv-1 μvar; some of which have not previously been reported in molluscs. multivariate analyses of entire metabolite profiles were able to separate infected from non-in ... | 2017 | 28373065 |
| detection of ostreid herpesvirus 1 microvariant dna in aquatic invertebrate species, sediment and other samples collected from the georges river estuary, new south wales, australia. | ostreid herpesvirus 1 microvariants (oshv-1) present a serious threat to the australian crassostrea gigas industry. of great concern is the propensity for mortality due to the virus recurring each season in farmed oysters. however, the source of the virus in recurrent outbreaks remains unclear. reference strain ostreid herpesvirus 1 (oshv-1 ref) and other related variants have been detected in several aquatic invertebrate species other than c. gigas in europe, asia and the usa. the aim of this s ... | 2017 | 28117303 |
| adsorption of norovirus and ostreid herpesvirus type 1 to polymer membranes for the development of passive samplers. | this study was performed to develop a passive sampling methodology for the detection of two viruses in seawater in the area of shellfish production, the norovirus (nov), a human pathogen implicated in gastroenteritis outbreaks linked to oyster consumption and the ostreid herpesvirus type 1 (oshv-1), a virus associated with mass mortalities of pacific oysters. | 2017 | 28052549 |
| in situ hybridization and histopathological observations during ostreid herpesvirus-1-associated mortalities in pacific oysters crassostrea gigas. | in a previous longitudinal study conducted during a mortality investigation associated with ostreid herpesvirus-1 (oshv-1) microvariant in new zealand pacific oysters in 2010-2011, temporality of oshv-1 nucleic acid detection by real-time pcr assay and onset of pacific oyster mortality was observed. the present study further elucidated the role of oshv-1 using an in situ hybridization (ish) assay on sections of pacific oysters collected from the same longitudinal study. hybridization of the labe ... | 2016 | 27901503 |
| occurrence of oshv-1 in crassostrea gigas cultured in ireland during an exceptionally warm summer. selection of less susceptible oysters. | the occurrence of oshv-1, a herpes virus causing mass mortality in the pacific oyster crassostrea gigas was investigated with the aim to select individuals with different susceptibility to the infection. naïve spat transferred to infected areas and juveniles currently being grown at those sites were analyzed using molecular and histology approaches. the survey period distinguishes itself by very warm temperatures reaching up to 3.5°c above the average. the virus was not detected in the virus fre ... | 2016 | 27877131 |
| evidence of vertical transmission of ostreid herpesvirus 1 in the portuguese oyster crassostrea angulata. | in order to determine if ostreid herpesvirus 1 (oshv-1) can be vertically transmitted, 9 full-sib families of the portuguese oyster crassostrea angulata were produced using a factorial mating design with 3 males and 3 females. the parents were survivors from an oshv-1 mortality outbreak. oshv-1 dna was not detected by conventional pcr in the mantle of parents, gametes or 3day-old larvae. however, viral dna was detected by real-time pcr in all gametes and larvae samples. these results show that c ... | 2016 | 27592536 |
| ostreid herpesvirus in wild oysters from the huelva coast (sw spain). | this is the first report of ostreid herpesvirus 1 microvariant (oshv-1 µvar) infecting natural oyster beds located in huelva (sw spain). the virus was detected in 3 oyster species present in the intertidal zone: crassostrea gigas (thunberg, 1793), c. angulata (lamarck, 1819) and, for the first time, in ostrea stentina payraudeau, 1826. oysters were identified by a specific polymerase chain reaction (pcr) and posterior restriction fragment length polymorphism (rflp) analysis based on cytochrome o ... | 2016 | 27503919 |
| single or dual experimental infections with vibrio aestuarianus and oshv-1 in diploid and triploid crassostrea gigas at the spat, juvenile and adult stages. | french production of the pacific cupped oyster, crassostrea gigas, is currently threatened by two pathogens, oshv-1 and v. aestuarianus. while oysters selected for their higher resistance to oshv-1 are now available for the industry, the impact of v. aestuarianus on such oysters is unknown, especially for triploids. in addition, experimental infection has used the virus or the bacteria alone, but there have been no investigations of dual exposure to these pathogens. this study is the first repor ... | 2016 | 27503207 |
| tank-binding kinase-1 broadly affects oyster immune response to bacteria and viruses. | as a benthic filter feeder of estuaries, the immune system of oysters provides one of the best models for studying the genetic and molecular basis of the innate immune pathway in marine invertebrates and examining the influence of environmental factors on the immune system. here, the molecular function of molluscan tank-binding kinase-1 (tbk1) (which we named cgtbk1) was studied in the pacific oyster, crassostrea gigas. compared with known tbk1 proteins in other model organisms, cgtbk1 contains ... | 2016 | 27422757 |
| ostreid herpesvirus type 1 genomic diversity in wild populations of pacific oyster crassostrea gigas from italian coasts. | ostreid herpesvirus 1 (oshv-1) is a significant pathogen affecting the young pacific oyster crassostrea gigas, worldwide. a new variant, oshv-1 μvar, has been associated with recurrent mortality events in europe since 2008. epidemiological data collection is key for global risk assessment; however little is known about health status and genotypes present in european wild oyster beds. most studies to date have involved only cultivated individuals during mortality events, and reported low genotype ... | 2016 | 27234424 |
| use of polymerase chain reaction for bivalve pathogen surveillance in the yellow clam mesodesma mactroides. | the yellow clam mesodesma mactroides is a valuable shellfish occurring from the southeastern coast of brazil to the northern coast of argentina. populations of yellow clams are disappearing from their entire range, and the cause is still unknown. the objective of this paper was to search for world organisation for animal health (oie)-listed pathogens and their relatives in the genera marteilia, bonamia, and perkinsus as well as mikrocytos mackini and the virus oshv-1 μ var the yellow clam popula ... | 2016 | 27221761 |
| two oyster species that show differential susceptibility to virus infection also show differential proteomic responses to generic dsrna. | viral diseases are a significant cause of mortality and morbidity in oysters, resulting in significant economic losses. we investigated the proteomic responses of these two species of oysters to generic double-stranded rnas (poly i:c and poly a:u). analysis of proteomic data using isobaric tags for relative and absolute quantitaion (itraq) indicated that there were significant differences in the proteomic responses of the two oyster species resulting from this treatment. gene ontology analysis s ... | 2016 | 27072892 |
| in situ localization and tissue distribution of ostreid herpesvirus 1 proteins in infected pacific oyster, crassostrea gigas. | immunohistochemistry (ihc) assays were conducted on paraffin sections from experimentally infected spat and unchallenged spat produced in hatchery to determine the tissue distribution of three viral proteins within the pacific oyster, crassostrea gigas. polyclonal antibodies were produced from recombinant proteins corresponding to two putative membrane proteins and one putative apoptosis inhibitor encoded by orf 25, 72, and 87, respectively. results were then compared to those obtained by in sit ... | 2016 | 27066775 |
| experimental infection of european flat oyster ostrea edulis with ostreid herpesvirus 1 microvar (oshv-1μvar): mortality, viral load and detection of viral transcripts by in situ hybridization. | ostreid herpesvirus 1 (oshv-1) infections have been reported in several bivalve species. mortality of pacific oyster crassostrea gigas spat has increased considerably in europe since 2008 linked to the spread of a variant of oshv-1 called μvar. in the present study we demonstrated that o. edulis juveniles can be infected by oshv-1μvar when administered as an intramuscular injection. mortality in the oysters injected with oshv-1μvar was first detected 4 days after injection and reached 25% mortal ... | 2016 | 26945849 |
| infectious diseases in oyster aquaculture require a new integrated approach. | emerging diseases pose a recurrent threat to bivalve aquaculture. recently, massive mortality events in the pacific oyster crassostrea gigas associated with the detection of a microvariant of the ostreid herpesvirus 1 (oshv-1µvar) have been reported in europe, australia and new zealand. although the spread of disease is often viewed as a governance failure, we suggest that the development of protective measures for bivalve farming is presently held back by the lack of key scientific knowledge. i ... | 2016 | 26880845 |
| infectious diseases of marine molluscs and host responses as revealed by genomic tools. | more and more infectious diseases affect marine molluscs. some diseases have impacted commercial species including msx and dermo of the eastern oyster, qpx of hard clams, withering syndrome of abalone and ostreid herpesvirus 1 (oshv-1) infections of many molluscs. although the exact transmission mechanisms are not well understood, human activities and associated environmental changes often correlate with increased disease prevalence. for instance, hatcheries and large-scale aquaculture create hi ... | 2016 | 26880838 |
| identification and characterization of ostreid herpesvirus 1 associated with massive mortalities of scapharca broughtonii broodstocks in china. | in the early summer of 2012 and 2013, mass mortalities of blood ark shell (scapharca [anadara] broughtonii), broodstocks were reported in several hatcheries on the coast of northern china. clinical signs including slow response, gaping valves and pale visceral mass were observed in diseased individuals. in response to these reported mortalities, 238 samples were collected from hatcheries at 6 sites. microscopic changes including lysed connective tissue, dilation of the digestive tubules, eosinop ... | 2016 | 26865236 |
| summer mortalities and detection of ostreid herpesvirus microvariant in pacific oyster crassostrea gigas in sweden and norway. | the pacific oyster crassostrea gigas has recently expanded its range in scandinavia. the expansion is presumably a result of northwards larval drift. massive settlements were recorded in many areas along the swedish west coast and southern norway in 2013 and 2014. after the spawning season in 2014, the temperature of the surface water peaked at 24-26°c. after this period, high and sudden mortalities occurred in a swedish hatchery and in wild populations along the swedish west coast and south coa ... | 2016 | 26758650 |
| characterization of oyster voltage-dependent anion channel 2 (vdac2) suggests its involvement in apoptosis and host defense. | genomic and transcriptomic studies have revealed a sophisticated and powerful apoptosis regulation network in oyster, highlighting its adaptation to sessile life in a highly stressful intertidal environment. however, the functional molecular basis of apoptosis remains largely unexplored in oysters. in this study, we focused on a representative apoptotic gene encoding voltage-dependent anion channel 2 (vdac2), a porin that abounds at the mitochondrial outer membrane. this is the first report on t ... | 2016 | 26727366 |
| detection and distribution of ostreid herpesvirus 1 in experimentally infected pacific oyster spat. | high mortality rates are reported in spat and larvae of pacific oyster crassostrea gigas and associated with ostreid herpesvirus 1 (oshv-1) detection in france. although the viral infection has been experimentally reproduced in oyster larvae and spat, little knowledge is currently available concerning the viral entry and its distribution in organs and tissues. this study compares oshv-1 dna and rna detection and localization in experimentally infected oysters using two virus doses: a low dose th ... | 2016 | 26674009 |
| can selection for resistance to oshv-1 infection modify susceptibility to vibrio aestuarianus infection in crassostrea gigas? first insights from experimental challenges using primary and successive exposures. | since 2008, the emergent virus oshv-1µvar has provoked massive mortality events in crassostrea gigas spat and juveniles in france. since 2012, mortality driven by the pathogenic bacteria vibrio aestuarianus has stricken market-sized adults. a hypothesis to explain the sudden increase in mortality observed in france since 2012 is that selective pressure due to recurrent viral infections could have led to a higher susceptibility of adults to vibrio infection. in our study, two oshv-1-resistant lin ... | 2015 | 26646058 |
| molecular characterization and functional analysis of tumor necrosis factor receptor-associated factor 2 in the pacific oyster. | tumor necrosis factor receptor (tnfr)-associated factors (trafs) are a family of crucial adaptors, playing vital roles in mediating signal transduction in immune signaling pathways, including rig-i-like receptor (rlr) signaling pathway. in the present study, a new traf family member (cgtraf2) was identified in the pacific oyster, crassostrea gigas. comparison and phylogenetic analysis revealed that cgtraf2 could be a new member of the invertebrate traf2 family. quantitative real-time pcr reveale ... | 2016 | 26621757 |
| detection of undescribed ostreid herpesvirus 1 (oshv-1) specimens from pacific oyster, crassostrea gigas. | the ostreid herpesvirus 1 (oshv-1) and variants were implicated in mass mortality affecting the young pacific cupped oysters, crassostrea gigas, in european countries and those around the world. from 2008 onwards, oyster mortality had greatly increased on the french coast and was associated with the detection of a new oshv-1 variant, entitled oshv-1 μvar. the oshv-1 μvar is predominant in oysters; however, other oshv-1 variants have been detected in samples collected during mortality periods or ... | 2015 | 26527255 |
| crassostrea gigas mortality in france: the usual suspect, a herpes virus, may not be the killer in this polymicrobial opportunistic disease. | successive disease outbreaks in oyster (crassostrea gigas) beds in france have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. deaths of juvenile oysters have been associated with the presence of a herpes virus (oshv-1 μvar) and bacterial populations of the genus vibrio. although the pathogenicity of oshv-1 μvar, as well as several strains of vibrio has been demonstrated by experimental infections, our understanding of the complexity of infection ... | 2015 | 26217318 |
| complete genome sequence of ostreid herpesvirus-1 associated with mortalities of scapharca broughtonii broodstocks. | ostreid herpesvirus-1 (oshv-1) is the major bivalve pathogen associated with severe mortality events in a wide host range. in the early summer of 2012 and 2013, mass mortalities of blood clam (scapharca broughtonii) broodstocks associated with a newly described variant of oshv-1 (oshv-1-sb) were reported. | 2015 | 26209441 |
| pesticides and ostreid herpesvirus 1 infection in the pacific oyster, crassostrea gigas. | since 2008, mass mortality outbreaks have been reported in all french regions producing pacific oysters, and in several member states of the european union. these mass mortality events of pacific oysters are related to oshv-1 infection. they occur during spring and summer periods leaving suspect the quality of the marine environment and the role of seasonal use of pesticides associated with the arrival of freshwater in oyster rearing areas. pesticides have been also detected in french coastal wa ... | 2015 | 26107171 |
| new insight for the genetic evaluation of resistance to ostreid herpesvirus infection, a worldwide disease, in crassostrea gigas. | the pacific oyster, crassostrea gigas, is the most important commercial oyster species cultivated in the world. meanwhile, the ostreid herpesvirus 1 (oshv-1) is one of the major pathogens affecting the pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. to assess the genetic basis of resistance to oshv-1 infection in spat c. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib f ... | 2015 | 26039375 |
| transcriptome analysis reveals strong and complex antiviral response in a mollusc. | viruses are highly abundant in the oceans, and how filter-feeding molluscs without adaptive immunity defend themselves against viruses is not well understood. we studied the response of a mollusc crassostrea gigas to ostreid herpesvirus 1 µvar (oshv-1μvar) infections using transcriptome sequencing. oshv-1μvar can replicate extremely rapidly after challenge of c. gigas as evidenced by explosive viral transcription and dna synthesis, which peaked at 24 and 48 h post-inoculation, respectively, acco ... | 2015 | 26004318 |
| experimental infections of pacific oyster crassostrea gigas using the australian ostreid herpesvirus-1 (oshv-1) µvar strain. | in australia, the spread of the ostreid herpesvirus-1 microvariant (oshv-1 µvar) threatens the pacific oyster industry. there is an urgent need to develop an experimental infection model in order to study the pathogenesis of the virus under controlled laboratory conditions. the present study constitutes the first attempt to use archived frozen oysters as a source of inoculum, based on the australian oshv-1 µvar strain. experiments were conducted to test (1) virus infectivity, (2) the dose-respon ... | 2015 | 25751856 |
| design of a detection survey for ostreid herpesvirus-1 using hydrodynamic dispersion models to determine epidemiological units. | using ostreid herpesvirus-1 (oshv-1) as a case study, this paper considers a survey design methodology for an aquatic animal pathogen that incorporates the concept of biologically independent epidemiological units. hydrodynamically-modelled epidemiological units are used to divide marine areas into sensible sampling units for detection surveys of waterborne diseases. in the aquatic environment it is difficult to manage disease at the animal level, hence management practices are often aimed at a ... | 2015 | 25746929 |
| resistance of black-lip learl oyster, pinctada margaritifera, to infection by ostreid herpes virus 1μvar under experimental challenge may be mediated by humoral antiviral activity. | ostreid herpesvirus 1 (oshv-1) has induced mass mortalities of the larvae and spat of pacific oysters, crassostrea gigas, in europe and, more recently, in oceania. the production of pearls from the black-lip pearl oyster, pinctada margaritifera, represents the second largest source of income to the economies of french polynesia and many pacific island nations that could be severely compromised in the event of a disease outbreak. coincidentally with the occurrence of oshv-1 in the southern hemisp ... | 2015 | 25712854 |
| ostreid herpesvirus oshv-1 μvar in pacific oysters crassostrea gigas (thunberg 1793) of the wadden sea, a unesco world heritage site. | the wadden sea is an extensive wetland area, recognized as unesco world heritage site of international importance. since the mid-1990s, the invasive pacific oyster crassostrea gigas (thunberg 1793) population in the area has grown exponentially, having a distinct impact on the ecosystem. the recent spread of the emerging oyster pathogen ostreid herpesvirus oshv-1 μvar worldwide and specifically in the oyster culture areas in the south of the netherlands raised the question whether the virus may ... | 2016 | 25643634 |
| emerging and endemic types of ostreid herpesvirus 1 were detected in bivalves in china. | viral infection caused by ostreid herpesvirus 1 (oshv-1) is one of the proximate causes of mass mortalities of cultivated bivalves around the world. the emergence and spread of different variants of oshv-1 accompanied by different epidemiological characteristics have been reported frequently in different countries around the world. in this paper, we present a study of the detection of oshv-1 dna and their variations from 1599 samples over 18 species collected in 27 aquaculture sites and two food ... | 2015 | 25483846 |
| development of an in situ hybridization assay for the detection of ostreid herpesvirus type 1 mrnas in the pacific oyster, crassostrea gigas. | an in situ hybridization protocol for detecting mrnas of ostreid herpesvirus type 1 (oshv-1) which infects pacific oysters, crassostrea gigas, was developed. three rna probes were synthesized by cloning three partial oshv-1 genes into plasmids using three specific primer pairs, and performing a transcription in the presence of digoxigenin dutp. the rna probes were able to detect the virus mrnas in paraffin sections of experimentally infected oysters 26 h post-injection. the in situ hybridization ... | 2015 | 25455903 |
| dual analysis of host and pathogen transcriptomes in ostreid herpesvirus 1-positive crassostrea gigas. | ostreid herpesvirus type 1 (oshv-1) has become a problematic infective agent for the pacific oyster crassostrea gigas. in particular, the oshv-1 μvar subtype has been associated with severe mortality episodes in oyster spat and juvenile oysters in france and other regions of the world. factors enhancing the infectivity of the virus and its interactions with susceptible and resistant bivalve hosts are still to be understood, and only few studies have explored the expression of oyster or viral gen ... | 2015 | 25384719 |
| a simple centrifugation method for improving the detection of ostreid herpesvirus-1 (oshv-1) in natural seawater samples with an assessment of the potential for particulate attachment. | ostreid herpesvirus-1 (oshv-1) is responsible for massive mortality events in commercially farmed pacific oysters (crassostrea gigas) in australia, new zealand, europe and the usa. economic losses have been severe in many countries since 2008, associated with a strain known as oshv-1μ-var. despite intensive studies of the virus itself, there is almost no information on its detection in natural seawater, how it is spread over wide geographic distance in water or on how it is transmitted from oyst ... | 2014 | 25286178 |
| rearing practices identified as risk factors for ostreid herpesvirus 1 (oshv-1) infection in pacific oyster crassostrea gigas spat. | early detection of pacific oyster spat infected with ostreid herpesvirus 1 (oshv-1) could prevent introduction of oshv-1-infected individuals into farming areas or onshore rearing facilities, thus reducing the risk of infection of naïve oysters in such production systems. experiments were conducted on several hundred oyster spat provided by producers in order to examine whether early rearing practices could be considered as potential risk factors for (1) oshv-1 infection as detected by molecular ... | 2014 | 25114044 |
| alternative splicing and immune response of crassostrea gigas tumor necrosis factor receptor-associated factor 3. | diverse alternative splicing isoforms play an important role in immune diversity and specificity. their role in molluscan host-defense is however poorly understood. we characterized two alternative isoforms of tumor necrosis factor receptor-associated factor 3 (traf3) in the pacific oyster, crassostrea gigas, which were named cgtraf3-s and cgtraf3-l. an intron was retained in cgtraf3-l, introducing a premature termination codon. comparison and phylogenetic analysis revealed that cgtraf3 shared a ... | 2014 | 25012913 |
| dual transcriptomics of virus-host interactions: comparing two pacific oyster families presenting contrasted susceptibility to ostreid herpesvirus 1. | massive mortality outbreaks affecting pacific oyster (crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (oshv-1). however, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. in this work, experimental infection trials of c. gigas spat with oshv-1 were conducted in order to test the susceptibility of several bi-parental oyster families ... | 2014 | 25012085 |
| proteomic signatures of the oyster metabolic response to herpesvirus oshv-1 μvar infection. | pacific oyster crassostrea gigas were inoculated with oshv-1 at low load (control) or high load (challenged) to better understand the pathogenesis of ostreid herpesvirus 1 (oshv-1 μvar) and to determine which metabolic pathways might be affected during infection. animals were sampled for proteomic analysis two days post-injection, at the same time as oshv-1 initiated an intense replication phase in challenged oysters. twenty-five abundant protein spots that showed a marked change in accumulated ... | 2014 | 25009143 |
| new zealand juvenile oyster mortality associated with ostreid herpesvirus 1-an opportunistic longitudinal study. | during the 2010-11 summer outbreak of ostreid herpesvirus 1 (oshv-1) in new zealand, an opportunistic longitudinal field study was conducted. oshv-1 pcr-negative oyster spat (crassostrea gigas) were relocated to an oshv-1 pcr-positive area of the north island of new zealand that was experiencing juvenile oyster mortalities. over a period of 13 d, spat were monitored for mortality, sampled for histopathology, and tested for the presence of oshv-1 using real time pcr and vibrio culture. histopatho ... | 2014 | 24991849 |
| ostreid herpesvirus 1 infection among pacific oyster (crassostrea gigas) spat: relevance of water temperature to virus replication and circulation prior to the onset of mortality. | a number of bivalve species worldwide, including the pacific oyster, crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. a particular herpesvirus was purified from naturally infected larval pacific oysters, and its genome was completely sequenced. this virus has been classified as ostreid herpesvirus 1 (oshv-1) within the family malacoherpesviridae. since 2008, mass mortality outbreaks among c. gigas in europe have been r ... | 2014 | 24973071 |
| transcriptomic study of 39 ostreid herpesvirus 1 genes during an experimental infection. | massive mortality outbreaks have been reported in france since 2008 among pacific oysters, crassostrea gigas, with the detection of a particular oshv-1 variant called μvar. virus infection can be induced in healthy spat in experimental conditions allowing to better understand the disease process, including viral gene expression. although gene expression of other herpesviruses has been widely studied, we provide the first study following viral gene expression of oshv-1 over time. in this context, ... | 2014 | 24681357 |
| genotyping of a microsatellite locus to differentiate clinical ostreid herpesvirus 1 specimens. | ostreid herpesvirus 1 (oshv-1) is a dna virus belonging to the malacoherpesviridae family from the herpesvirales order. oshv-1 has been associated with mortality outbreaks in different bivalve species including the pacific cupped oyster, crassostrea gigas. since 2008, massive mortality events have been reported among c. gigas in europe in relation to the detection of a variant of oshv-1, called μvar. since 2009, this variant has been mainly detected in france. these results raise questions about ... | 2014 | 24410800 |
| risk factors associated with increased mortality of farmed pacific oysters in ireland during 2011. | the pacific oyster, crassostrea gigas, plays a significant role in the aquaculture industry in ireland. episodes of increased mortality in c. gigas have been described in many countries, and in ireland since 2008. the cause of mortality events in c. gigas spat and larvae is suspected to be multifactorial, with ostreid herpesvirus 1 (oshv-1, in particular oshv-1μvar) considered a necessary, but not sufficient, cause. the objectives of the current study were to describe mortality events that occur ... | 2014 | 24290496 |
| genome exploration of six variants of the ostreid herpesvirus 1 and characterization of large deletion in oshv-1μvar specimens. | the genetic polymorphism of the ostreid herpesvirus 1 (oshv-1) has generally been investigated in three areas: orfs 4/5, orfs 42/43, and orfs 35 to 38. the present study, however, focuses on 40 orfs, representing 30% of the oshv-1 genome, encoding four categories of putative proteins: 4 orfs encoding putative inhibitor of apoptosis proteins; 17 orfs encoding membrane proteins; 10 orfs encoding secreted proteins; and 9 orfs encoding ring finger proteins. the potential role of these proteins in ma ... | 2013 | 24050996 |
| physiological change under oshv-1 contamination in pacific oyster crassostrea gigas through massive mortality events on fields. | massive mortalities have been observed in france since 2008 on spat and juvenile pacific oysters, crassostrea gigas. a herpes virus called oshv-1, easily detectable by pcr, has been implicated in the mortalities as demonstrated by the results of numerous field studies linking mortality with oshv-1 prevalence. moreover, experimental infections using viral particles have documented the pathogenicity of oshv-1 but the physiological responses of host to pathogen are not well known. | 2013 | 23987141 |
| ostreid herpesvirus 1 infection in farmed pacific oyster larvae crassostrea gigas (thunberg) in korea. | | 2013 | 23957681 |
| identification and characterisation of an ostreid herpesvirus-1 microvariant (oshv-1 µ-var) in crassostrea gigas (pacific oysters) in australia. | between november 2010 and january 2011, triploid crassostrea gigas (pacific oysters) cultivated in the georges river, new south wales, experienced >95% mortality. mortalities also occurred in wild diploid c. gigas in the georges river and shortly thereafter in the adjacent parramatta river estuary upstream from sydney harbour. neighbouring saccostrea glomerata (sydney rock oysters) did not experience mortalities in either estuary. surviving oysters were collected to investigate the cause of mort ... | 2013 | 23872855 |
| poly i:c induces a protective antiviral immune response in the pacific oyster (crassostrea gigas) against subsequent challenge with ostreid herpesvirus (oshv-1 μvar). | in-vivo studies were carried out to investigate the protective effect of a synthetic viral analogue (poly i:c) against ostreid herpes virus (oshv-1 μvar). pacific oysters (crassostrea gigas) were immune-primed by intramuscular injection of 240 μg of poly i:c or sterile seawater at 1 day prior to infection with oshv-1 μvar. poly i:c injection induced an antiviral state in c. gigas as the percentage of viral-infected oysters at 48 h post infection was significantly lower in the poly i:c treatment ... | 2013 | 23685009 |
| complete genome sequence of acute viral necrosis virus associated with massive mortality outbreaks in the chinese scallop, chlamys farreri. | acute viral necrosis virus (avnv) is the causative agent of a serious disease resulting in high mortality in cultured chinese scallops, chlamys farreri. we have sequenced and analyzed the complete genome of avnv. | 2013 | 23566284 |
| validation of housekeeping genes as internal controls for studying gene expression during pacific oyster (crassostrea gigas) development by quantitative real-time pcr. | hatchery-reared larvae of the pacific oyster (crassostrea gigas) often suffer from massive mortality induced by ostreid herpesvirus 1 (oshv-1) infection, indicating the importance of better understanding of oyster immune defense systems. the accuracy of measurements of gene expression levels based on quantitative real-time pcr assays relies on the use of housekeeping genes as internal controls; however, few studies have focused on the selection of such internal controls. in this study, we conduc ... | 2013 | 23357023 |
| a previously undescribed ostreid herpes virus 1 (oshv-1) genotype detected in the pacific oyster, crassostrea gigas, in ireland. | significant mortalities of the pacific oyster, crassostrea gigas, have been reported worldwide since the 1950s. the impact these re-occurring mortality events have had on the c. gigas industry has highlighted the necessity to determine the factors that may be causing these mortalities. this study investigated the possible role of ostreid herpes virus (oshv-1) in c. gigas mortalities over 2 successive summers at 2 study areas in ireland. a single sample of adult c. gigas, which had been experienc ... | 2012 | 23036593 |
| development of a polymerase chain reaction for the detection of abalone herpesvirus infection based on the dna polymerase gene. | a 5781-base pair (bp) fragment of genomic dna from the taiwanese abalone herpesvirus was obtained and showed 99% (5767/5779) homology in the nucleotide sequence and 99% (1923/1926) in the amino acid sequence with the dna polymerase gene of the abalone herpesvirus strain victoria/aus/2007. homology of the amino acid sequence with the dna polymerase of ostreid herpesvirus 1 was 30% (563/1856). in this study, a pcr-based procedure for detecting herpesvirus infection of abalone, haliotis diversicolo ... | 2012 | 22579937 |
| analysis of clinical ostreid herpesvirus 1 (malacoherpesviridae) specimens by sequencing amplified fragments from three virus genome areas. | although there are a number of ostreid herpesvirus 1 (oshv-1) variants, it is expected that the true diversity of this virus will be known only after the analysis of significantly more data. to this end, we analyzed 72 oshv-1 "specimens" collected mainly in france over an 18-year period, from 1993 to 2010. additional samples were also collected in ireland, the united states, china, japan, and new zealand. three virus genome regions (open reading frame 4 [orf4], orf35, -36, -37, and -38, and orf4 ... | 2012 | 22419803 |
| investigation of mortality in pacific oysters associated with ostreid herpesvirus-1 μvar in the republic of ireland in 2009. | high levels of mortality in pacific oysters crassostrea gigas in the republic of ireland were recorded during the summer of 2009. the new variant of ostreid herpes 1 (oshv-1 μvar) which first emerged in france in 2008 was identified from affected stocks. retrospective data was collected from 70 oyster farmers through an interviewer-administered questionnaire to investigate the distribution and determinants of the mortality. based on farmer recall, data were recorded at the batch level for cumula ... | 2012 | 22398251 |
| qtl for resistance to summer mortality and oshv-1 load in the pacific oyster (crassostrea gigas). | summer mortality is a phenomenon severely affecting the aquaculture production of the pacific oyster (crassostrea gigas). although its causal factors are complex, resistance to mortality has been described as a highly heritable trait, and several pathogens including the virus ostreid herpes virus type 1 (oshv-1) have been associated with this phenomenon. a qtl analysis for survival of summer mortality and oshv-1 load, estimated using real-time pcr, was performed using five f(2) full-sib families ... | 2010 | 20096029 |
| ostreid herpes virus 1 infection in families of the pacific oyster, crassostrea gigas, during a summer mortality outbreak: differences in viral dna detection and quantification using real-time pcr. | ostreid herpes virus 1 (oshv-1) infections, notably reported in europe and the usa, are closely associated with significant mortalities of the pacific oyster, crassostrea gigas, especially during its early stages of life. in summer 2006, we monitored mortality by strict daily verification of three full-sib families of oysters reared under common conditions. we quantified oshv-1 using real-time pcr in dead and living individuals during and after a mortality event. mortality events were severe and ... | 2009 | 19428752 |
| herpes virus in juvenile pacific oysters crassostrea gigas from tomales bay, california, coincides with summer mortality episodes. | pacific crassostrea gigas and eastern c. virginica oysters were examined between june 2002 and april 2003 from 8 locations along the east, west and south usa coasts for oyster herpes virus (oshv) infections using the a primer set in a previously developed pcr test. only surviving pacific oysters from a mortality event in tomales bay, california, usa, where annual losses of oysters have occurred each summer since 1993, were infected with a herpes-like virus in 2002. pcr examination using template ... | 2005 | 15759798 |