frog virus 3-like infections in aquatic amphibian communities.frog virus 3 (fv3) and fv3-like viruses, are members of the genus ranavirus (family iridoviridae), and they have been associated with infectious diseases that may be contributing to amphibian population declines. we examined the mode of transmission of an fv3-like virus, and potential hosts and reservoirs of the virus in a local amphibian community. using the polymerase chain reaction to detect infected animals, we found an fv3-like virus in south-central ontario, canada, amphibian communities, ...200818263826
in vivo and in vitro techniques for comparative study of antiviral t-cell responses in the amphibian xenopus.activation of lymphocytes in mammals is often quantified by measuring the amount of proliferation during the expansion phase of an immune response. bromodeoxyuridine (brdu) incorporation and carboxyfluorescein diacetate succinimidyl ester (cfse) dilution assays are some of the techniques widely used in mammalian studies of pathogen-induced proliferation and provide a convenient way of quantifying the cellular response. we have extended the use of these proliferation assays to the amphibian xenop ...200818385804
in pursuit of the first recognized epigenetic signal--dna methylation: a 1976 to 2008 synopsis.a synopsis will be presented of work on dna methylation, the first epigenetic signal to be recognized. in the author's laboratory, the following problems dealing with dna methylation have been addressed over the past 32 years: (1) the de novo methylation of foreign dna integrated into mammalian genomes. (2) inverse correlations between promoter methylation and activity. (3) the long-term inactivating effect of site-specific promoter methylation. (4) adenovirus e1 functions in trans and a strong ...200818487948
a temperature-sensitive (ts) mutant of frog virus 3 (fv3) is defective in second-stage dna has been suggested that fv3 dna replication occurs in two stages [r. goorha (1982) j. virol. 43, 519-528]. first-stage dna synthesis is restricted to the nucleus, where the replicating dna ranges from genome to twice genome size; second-stage dna replication occurs exclusively in the cytoplasm, and the replicating dna is concatameric. a temperature-sensitive mutant (ts 12488) of fv3, at a nonpermissive temperature (30 degrees), synthesized dna in the nucleus only, and the size of the replicat ...19846740949
cell-free translation of frog virus 3 messenger rnas. initiation factors from infected cells discriminate between early and late viral mrnas.cell-free protein-synthesizing extracts prepared from rabbit reticulocytes, wheat germ, or cultured baby hamster kidney cells efficiently translated frog virus 3 early mrnas; in contrast, late mrnas were translated poorly under similar conditions. however, the translational efficiency of the late viral mrnas was markedly enhanced in cell-free extracts prepared from frog virus 3 (fv 3)-infected baby hamster kidney cells and in nuclease-treated rabbit reticulocyte extracts by the addition of a 0.5 ...19836848520
susceptibility of pike esox lucius to a panel of ranavirus order to study the pathogenicity of ranaviruses to a wild european freshwater fish species, pike esox lucius fry were challenged with the following ranavirus isolates: epizootic haematopoietic necrosis virus (ehnv), european sheatfish virus (esv), european catfish virus (ecv), pike-perch iridovirus (ppiv), new zealand eel virus (nzeelv) and frog virus 3 (fv3). the fry were infected using bath challenge at 12 and 22 degrees c. significant mortalities were observed at 12 degrees c for ehnv, esv ...200919402450
complete sequence determination of a novel reptile iridovirus isolated from soft-shelled turtle and evolutionary analysis of iridoviridae.soft-shelled turtle iridovirus (stiv) is the causative agent of severe systemic diseases in cultured soft-shelled turtles (trionyx sinensis). to our knowledge, the only molecular information available on stiv mainly concerns the highly conserved stiv major capsid protein. the complete sequence of the stiv genome is not yet available. therefore, determining the genome sequence of stiv and providing a detailed bioinformatic analysis of its genome content and evolution status will facilitate furthe ...200919439104
in vivo and electron microscopic observations of the responses of the hepatic sinusoid to interleukin-1.interleukin-1 (il-1), which is produced by kupffer cells and sinusoidal endothelial cells, may play an important role in immunological and microvascular responses to a variety of stimuli in the liver. the responses of the hepatic microvasculature including phagocytic activity of sinusoidal lining cells to il-1 alpha were examined in c57bl/6 mice in vivo and using electron microscopy. one hour after recombinant mouse il-1 alpha was injected at doses of 80 u, the low dose group, and 800 u, the hig ...199910825814
frog virus 3 dna replication occurs in two stages.viral dna synthesis in frog virus 3 (fv3)-infected cells occurs both in the nucleus and in the cytoplasm (goorha et al., virology 84:32-51, 1978). relationships between viral dna molecules synthesized in these two compartments and their role in the virus replication were examined. the data presented here suggest that (i) fv3 dna replicated in two stages and (ii) nucleus and cytoplasm were the sites of stages 1 and 2 of dna replication, respectively. stages 1 and 2 were further distinguished by t ...19827109033
mass mortality associated with a frog virus 3-like ranavirus infection in farmed tadpoles rana catesbeiana from brazil.ranaviruses (iridoviridae) are increasingly associated with mortality events in amphibians, fish, and reptiles. they have been recently associated with mass mortality events in brazilian farmed tadpoles of the american bullfrog rana catesbeiana shaw, 1802. the objectives of the present study were to further characterize the virus isolated from sick r. catesbeiana tadpoles and confirm the etiology in these outbreaks. sick tadpoles were collected in 3 farms located in goiás state, brazil, from 200 ...200920066953
antibody dependent enhancement of frog virus 3 infection.viruses included in the family iridoviridae are large, icosahedral, dsdna viruses that are subdivided into 5 genera. frog virus 3 (fv3) is the type species of the genus ranavirus and the best studied iridovirus at the molecular level. typically, antibodies directed against a virus act to neutralize the virus and limit infection. antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it.201020167100
innate immune responses and permissiveness to ranavirus infection of peritoneal leukocytes in the frog xenopus laevis.ranaviruses such as frog virus 3 ([fv3] family iridoviridae) are increasingly prevalent pathogens that infect reptiles, amphibians, and fish worldwide. whereas studies in the frog xenopus laevis have revealed the critical involvement of cd8 t-cell and antibody responses in host resistance to fv3, little is known about the role played by innate immunity to infection with this virus. we have investigated the occurrence, composition, activation status, and permissiveness to infection of peritoneal ...201020200236
induction of intranuclear microtubules in chick embryo fibroblasts by frog virus 3.intranuclear microtubules appear in chick embryo fibroblasts upon infection with frog virus 3 (fv 3). both the diameter and the annular shape of the microtubule profiles, established from electron microscopic observations using a goniometer, suggest that they are identical to naturally occurring cytoplasmic microtubules. furthermore, the use of vinblastine allowed demonstration of the tubulin composition of the intranuclear microtubules.19807397769
comparative study of ranavirus isolates from cod (gadus morhua) and turbot (psetta maxima) with reference to other ranaviruses.two iridovirus isolates recovered from cod (gadus morhua) and turbot (psetta maxima) in denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (fv3), the reference strain for the genus ranavirus. the isolates were assessed according to their reactivity in immunofluoresent antibody tests (ifat) using both homologous and heterologous antisera and their amplification in pcr using primers targeting five genomic regions. the corresponding pcr fragments were sequenc ...201020552236
frog virus 3 orf 53r, a putative myristoylated membrane protein, is essential for virus replication in vitro.although previous work identified 12 complementation groups with possible roles in virus assembly, currently only one frog virus 3 protein, the major capsid protein (mcp), has been linked with virion formation. to identify other proteins required for assembly, we used an antisense morpholino oligonucleotide to target 53r, a putative myristoylated membrane protein, and showed that treatment resulted in marked reductions in 53r levels and a 60% drop in virus titers. immunofluorescence assays confi ...201020633916
comparative studies of iridoviruses: further support for a new classification.changes in the classification of invertebrate iridoviruses (ivs) (iridoviridae) have recently been proposed (williams and cory, 1994). the previous system of naming isolates according to the host and sequence of discovery (iv type 1, iv2, iv3, etc.) is not adequate for the purposes of taxonomy, since iridovirus isolates may infect many species, including hosts from diverse invertebrate orders. the new system of invertebrate iridovirus nomenclature, as with several other virus families, is based ...19947975884
preliminary amphibian health survey in the delaware water gap national recreation detect aquatic animal diseases of national concern, 111 individual amphibians, including wood frogs rana sylvatica (28), spring peepers pseudacris crucifer (35), red-spotted newts notophthalmus viridescens (41), and gray tree frogs hyla versicolor (7), were sampled at seven different sites in the delaware water gap national recreation area (dgnra), pennsylvania, from june 14 to july 19, 2007. these samples were screened for batrachochytrium dendrobatidis and viral pathogens at the u.s. fish a ...201020848885
quantitation of ranaviruses in cell culture and tissue samples.a quantitative real-time pcr (qpcr) based on a standard curve was developed for detection and quantitation of ranaviruses. the target gene for the qpcr was viral dna polymerase (dnapol). all ten ranavirus isolates studied (epizootic haematopoietic necrosis virus, ehnv; european catfish virus, ecv; european sheatfish virus, esv; frog virus 3, fv3; bohle iridovirus, biv; doctor fish virus, dfv; guppy virus 6, gv6; pike-perch iridovirus, ppiv; rana esculenta virus italy 282/i02, rev282/i02 and shor ...201021087639
instability of frog virus 3 mrna in productively infected cells.cloned dna restriction fragments encoding representative frog virus 3 messages were used as probes to assess the stability of viral transcripts in infected fathead minnow cells. analysis of northern blot hybridization profiles confirmed earlier findings and revealed that in infected cells the steady-state level of representative frog virus 3 (fv3) messages increased throughout the replication cycle. however, when actinomycin d was added at 4 hr after infection to block the synthesis of new trans ...19948030277
proposals for a new classification of iridescent viruses.the need for comparative studies of iridoviruses to elucidate the relationships between them has been well appreciated. sixteen iridoviruses, including type species from each of the four recognized genera of the iridoviridae, were compared by restriction endonuclease characterization, hybridization to the major structural protein (msp) gene of an invertebrate iridescent virus (iv) isolate at various stringencies, pcr amplification of the msp gene region and by dot-blot hybridization studies. the ...19948207395
induction of apoptosis in frog virus 3-infected cells.the ability of frog virus 3 (fv3), the type species of the family iridoviridae, to induce apoptosis was examined by monitoring dna cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (ps) in fathead minnow (fhm) and baby hamster kidney (bhk) cells. in productively infected fhm cells, dna fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. as with some oth ...200312642103
identification and determination of antigenic proteins of korean ranavirus-1 (krv-1) using maldi-tof/tof ms analysis.ranaviruses are serious pathogens of fish, amphibians, and reptiles, and pose a major threat to global biodiversity. a ranavirus isolated from tissues of diseased tadpoles and frogs in gangwon province, korea, in 2006 and 2007, was designated korean ranavirus-1 (krv-1) and was infectious in a variety of fish cell lines with highest titers (10(10)tcid(50)/ml) in epithelioma papulosum cyprini cells (epcs) and baby hamster kidney-21 (bhk-21) cells. bullfrog (rana catesbeiana) tadpoles challenged by ...201121388683
tiger frog virus (an iridovirus) entry into hepg2 cells via a ph-dependent, atypical caveola-mediated endocytosis pathway.tiger frog virus (tfv), in the genus ranavirus of the family iridoviridae, causes high mortality of cultured tiger frog tadpoles in china. to explore the cellular entry mechanism of tfv, hepg2 cells were treated with drugs that inhibit the main endocytic pathways. we observed that tfv entry was inhibited by nh(4)cl, chloroquine, and bafilomycin, which all can elevate the ph of acidic organelles. in contrast, tfv entry was not influenced by chlorpromazine or overexpression of a dominant-negative ...201121543502
waterborne infectivity of the ranavirus frog virus 3 in xenopus laevis.ranaviruses like frog virus 3 (fv3) are responsible for emerging infectious diseases spreading worldwide to fish, amphibian and reptilian species. we have developed, in xenopus laevis, an experimental model to investigate viral transmission. we show that fv3 released in water by immunocompromised infected adults can infect adult and larval stages of xenopus within 3h of exposure. time course of virus load and viral transcription in different tissues suggests that early waterborne fv3 infection t ...201121783222
comparative genomic analyses of frog virus 3, type species of the genus ranavirus (family iridoviridae).frog virus 3 (fv3) is the type species member of the genus ranavirus (family iridoviridae). to better understand the molecular mechanisms involved in the replication of fv3, including transcription of its highly methylated dna genome, we have determined the complete nucleotide sequence of the fv3 genome. the fv3 genome is 105903 bp long excluding the terminal redundancy. the g + c content of fv3 genome is 55% and it encodes 98 nonoverlapping potential open reading frames (orfs) containing 50-129 ...200415165820
phylogeny, life history, and ecology contribute to differences in amphibian susceptibility to ranaviruses.research that identifies the potential host range of generalist pathogens as well as variation in host susceptibility is critical for understanding and predicting the dynamics of infectious diseases within ecological communities. ranaviruses have been linked to amphibian die-off events worldwide with the greatest number of reported mortality events occurring in the united states. while reports of ranavirus-associated mortality events continue to accumulate, few data exist comparing the relative ...201122071720
the genomic diversity and phylogenetic relationship in the family iridoviridae.the iridoviridae family are large viruses (~120-200 nm) that contain a linear double-stranded dna genome. the genomic size of iridoviridae family members range from 105,903 bases encoding 97 open reading frames (orfs) for frog virus 3 to 212,482 bases encoding 211 orfs for chilo iridescent virus. the family iridoviridae is currently subdivided into five genera: chloriridovirus, iridovirus, lymphocystivirus, megalocytivirus, and ranavirus. iridoviruses have been found to infect invertebrates and ...201021994690
identification of a bohle iridovirus thymidine kinase gene and demonstration of activity using vaccinia recent years interest in the family iridoviridae has been renewed by the identification of a number of viruses, particularly from the genus ranavirus, associated with disease in a range of poikilotherms. ranaviruses have been isolated from amphibian, piscine and reptilian species. here we describe an open reading frame (orf) identified in the genome of bohle iridovirus (biv) which contains a nucleotide binding motif conserved within the thymidine kinase (tk) genes of iridoviruses from other g ...200515883656
The molecular biology of frog virus 3 and other iridoviruses infecting cold-blooded vertebrates.Frog virus 3 (FV3) is the best characterized member of the family Iridoviridae. FV3 study has provided insights into the replication of other family members, and has served as a model of viral transcription, genome replication, and virus-mediated host-shutoff. Although the broad outlines of FV3 replication have been elucidated, the precise roles of most viral proteins remain unknown. Current studies using knock down (KD) mediated by antisense morpholino oligonucleotides (asMO) and small, interfe ...201122069524
improved knockout methodology reveals that frog virus 3 mutants lacking either the 18k immediate-early gene or the truncated vif-2alpha gene are defective for replication and growth in better assess the roles of frog virus 3 (fv3; genus ranavirus, family iridoviridae) genes in virulence and immune evasion, we have developed a reliable and efficient method to systematically knock out (ko) putative virulence genes by site-specific integration into the fv3 genome. our approach utilizes a dual selection marker consisting of the puromycin resistance gene fused in frame with the enhanced green fluorescent protein (egfp) reporter (puro-egfp cassette) under the control of the fv3 i ...201121865381
development and validation of taqman quantitative pcr for detection of frog virus 3-like virus in eastern box turtles (terrapene carolina carolina).ranavirus has caused disease epidemics and mass mortality events globally in free-ranging fish, amphibian, and reptile populations. viral isolation and conventional pcr are the most common methods for diagnosis. in this study, a quantitative real-time pcr (qpcr) assay was developed using a taqman probe-based assay targeting a highly conserved region of the major capsid protein of frog virus 3-like virus (fv3-like) (family iridoviridae, genera ranavirus). standard curves were generated from a vir ...201223274753
differential transcription of fathead minnow immune-related genes following infection with frog virus 3, an emerging pathogen of ectothermic vertebrates.frog virus 3 (fv3) and other ranaviruses are responsible for die-offs involving wild, farmed, and captive amphibians, fish, and reptiles. to ascertain which elements of the immune system respond to infection, we explored transcriptional responses following infection of fathead minnow cells with either wild type (wt) fv3 or a knock out (ko) mutant targeting the 18 kda immediate early gene (18k). at 8h post infection we observed marked upregulation of multiple transcripts encoding proteins affecti ...201424889227
complete genome analysis of a frog virus 3 (fv3) isolate and sequence comparison with isolates of differing levels of virulence.frog virus 3 (fv3) is the type species of the genus ranavirus, and in the past few decades, fv3 infections have resulted in considerable morbidity and mortality in a range of wild and cultivated amphibian species in the americas, europe, and asia. the reasons for the pathogenicity of fv3 are not well understood.201424620832
selected emerging diseases of amphibia.this review summarizes the most recent updates on emerging infectious diseases of amphibia. a brief summary of batrachochytrium dendrobatidis history, epidemiology, pathogenesis, life cycle, diagnosis, treatment, and biosecurity is provided. ambystoma tigrinum virus, common midwife toad virus, frog virus 3, rana grylio virus, rana catesbeiana ranavirus, mahaffey road virus, rana esculenta virus, bohle iridovirus, and tiger frog virus ranaviruses are extensively reviewed. emerging bacterial patho ...201323642863
xenopus laevis and emerging amphibian pathogens in chile.amphibians face an extinction crisis with no precedence. two emerging infectious diseases, ranaviral disease caused by viruses within the genus ranavirus and chytridiomycosis due to batrachochytrium dendrobatidis (bd), have been linked with amphibian mass mortalities and population declines in many regions of the globe. the african clawed frog (xenopus laevis) has been indicated as a vector for the spread of these pathogens. since the 1970s, this species has been invasive in central chile. we co ...201627682604
susceptibility of the european common frog rana temporaria to a panel of ranavirus isolates from fish and amphibian hosts.ranaviruses are an emerging group of viruses and have been implicated in an increase of epidemics in susceptible species. they have a wide host range, infecting fish, amphibians and reptiles, with some isolates able to infect multiple species from different animal classes. whilst some information exists on the pathogenicity of ranaviruses to novel hosts, there is none on the pathogenicity of fish ranaviruses to amphibians; this information is needed to develop measures to prevent the further spr ...201323574703
generation of a long-lasting, protective, and neutralizing antibody response to the ranavirus fv3 by the frog xenopus.xenopus serves as an experimental model to evaluate the contribution of adaptive immunity in host susceptibility to emerging ranaviral diseases that may contribute to amphibian population declines. it has been previously shown that following a secondary infection with the ranavirus frog virus 3 (fv3), adult xenopus more rapidly clear fv3 and generate specific anti-fv3 igy antibodies. we have further evaluated the potency and persistence of the xenopus antibody response against fv3. frogs inocula ...200616380162
mechanisms of amphibian macrophage development: characterization of the xenopus laevis colony-stimulating factor-1 receptor.macrophage-lineage cells are indispensable to vertebrate homeostasis and immunity. in turn, macrophage development is largely regulated through colony-stimulating factor-1 (csf1) binding to its cognate receptor (csf1r). to study amphibian monopoiesis, we identified and characterized the x. laevis csf1r cdna transcript. quantitative analysis revealed that csf1r tissue gene expression increased with x. laevis development, with greatest transcript levels detected in the adult lung, spleen and liver ...201426154317
the benefits of coinfection: trematodes alter disease outcomes associated with virus infection.1.coinfections are increasingly recognized as important drivers of disease dynamics. consequently, greater emphasis has been placed on integrating principles from community ecology with disease ecology to understand within-host interactions among parasites. using larval amphibians and two amphibian parasites (ranaviruses and the trematode echinoparyphium sp.), we examined the influence of coinfection on disease outcomes. 2.our first objective was to examine how priority effects (the timing and s ...201728317105
immune roles of amphibian (xenopus laevis) tadpole granulocytes during frog virus 3 ranavirus infections.infections by frog virus 3 (fv3) and other ranaviruses (rvs) are contributing to the amphibian declines, while the mechanisms controlling anuran tadpole susceptibility and adult frog resistance to rvs, including the roles of polymorphonuclear granulocytes (pmns) during anti-fv3 responses, remain largely unknown. since amphibian kidneys represent an important fv3 target, the inability of amphibian (xenopus laevis) tadpoles to mount effective kidney inflammatory responses to fv3 is thought to cont ...201728238879
amphibian (xenopus laevis) tadpoles and adult frogs mount distinct interferon responses to the frog virus 3 ranavirus.infections of amphibians by frog virus 3 (fv3) and other ranavirus genus members are significantly contributing to the amphibian declines, yet much remains unknown regarding amphibian antiviral immunity. notably, amphibians represent an important step in the evolution of antiviral interferon (ifn) cytokines as they are amongst the first vertebrates to possess both type i and type iii ifns. accordingly, we examined the roles of type i and iii ifns in the skin of fv3-challenged amphibian xenopus l ...201728081430
pathogenesis of frog virus 3 ( ranavirus, iridoviridae) infection in wood frogs ( rana sylvatica).wood frogs ( rana sylvatica) are highly susceptible to infection with frog virus 3 (fv3, ranavirus, iridoviridae), a cause of mass mortality in wild populations. to elucidate the pathogenesis of fv3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 10(4.43) pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during ...201728060677
long term effects of carbaryl exposure on antiviral immune responses in xenopus laevis.water pollutants associated with agriculture may contribute to the increased prevalence of infectious diseases caused by ranaviruses. we have established the amphibian xenopus laevis and the ranavirus frog virus 3 (fv3) as a reliable experimental platform for evaluating the effects of common waterborne pollutants, such as the insecticide carbaryl. following 3 weeks of exposure to 10 ppb carbaryl, x. laevis tadpoles exhibited a marked increase in mortality and accelerated development. exposure at ...201727988452
reciprocal effects of pesticides and pathogens on amphibian hosts: the importance of exposure order and timing.ecological communities are increasingly exposed to natural and anthropogenic stressors. while the effects of individual stressors have been broadly investigated, there is growing evidence that multiple stressors are frequently encountered underscoring the need to examine interactive effects. pesticides and infectious diseases are two common stressors that regularly occur together in nature. given the documented lethal and sublethal effects of each stressor on individuals, there is the potential ...201727939635
hematologic reference intervals for rana sylvatica (lithobates sylvaticus) and effect of infection with frog virus 3 (ranavirus sp., iridoviridae).although the wood frog, rana sylvatica, is used in research on infectious diseases of amphibians, hematologic ris or response to infection have not been established.201627564850
is the major capsid protein of iridoviruses a suitable target for the study of viral evolution?iridoviruses are large cytoplasmic dna viruses that are specific for different insect or vertebrate hosts. the major structural component of the non-enveloped icosahedral virus particles is the major capsid protein (mcp) which appears to be highly conserved among members of the family iridoviridae, phycodnaviridae, and african swine fever virus. the amino acid sequences of the known mcps were used in comparative analyses to elucidate the phylogenic relationships between different cytoplasmic dna ...19989562891
first case of ranavirus-associated morbidity and mortality in natural populations of the south american frog atelognathus patagonicus.atelognathus patagonicus is an endangered leptodactylid frog endemic to a small region in and around laguna blanca national park in northern patagonia, argentina. all of the lakes and small ponds of the region (except laguna blanca itself) contain a. patagonicus and in all but one of these lakes the species shows clinical signs of a previously undiagnosed disease, the characteristics of which suggested a ranavirus. we collected symptomatic and asymptomatic a. patagonicus frogs and tadpoles from ...200617067077
frog virus 3 dissemination in the brain of tadpoles, but not in adult xenopus, involves blood brain barrier dysfunction.while increasing evidence points to a key role of monocytes in amphibian host defenses, monocytes are also thought to be important in the dissemination and persistent infection caused by ranavirus. however, little is known about the fate of infected macrophages or if ranavirus exploits immune privileged organs, such as the brain, in order to establish a reservoir. the amphibian xenopus laevis and frog virus 3 (fv3) were established as an experimental platform for investigating in vivo whether ra ...201626931458
fish viruses make dsrna in fish cells: characterization of dsrna production in rainbow trout (oncorhynchus mykiss) cells infected with viral haemorrhagic septicaemia virus, chum salmon reovirus and frog virus 3. 201626775727
experimental challenge study of fv3-like ranavirus infection in previously fv3-like ranavirus infected eastern box turtles (terrapene carolina carolina) to assess infection and survival.the maryland zoo in baltimore experienced an outbreak of frog virus-3 (fv3)-like ranavirus during the summer of 2011, during which 14 of 27 (52%) of its captive eastern box turtles (terrapene carolina carolina) survived. to assess survival, immunity, and viral shedding, an experimental challenge study was performed in which the surviving, previously infected turtles were reinfected with the outbreak strain of fv3-like ranavirus. seven turtles were inoculated with virus intramuscularly and four c ...201526667529
characterization of an iridescent virus isolated from gryllus bimaculatus (orthoptera: gryllidae).we have isolated an iridescent virus from commercially produced colonies of gryllus bimaculatus in germany, which showed apparent mortality. transmission electron microscopy studies on adult cricket specimens revealed the paracrystalline assembly of icosahedral virus particles in the cytoplasm of hypertrophied abdominal fat body cells. the infecting agent could be cultivated in the lepidopteran cell line sf-9, where it caused cytopathogenic effects such as cell hypertrophy, cytoplasmic vacuoliza ...200111161994
comparative analysis of the genome and host range characteristics of two insect iridoviruses: chilo iridescent virus and a cricket iridovirus isolate.the iridovirus isolate termed cricket iridovirus (criv) was isolated in 1996 from gryllus campestris l. and acheta domesticus l. (both orthoptera, gryllidae). criv dna shows distinct dna restriction patterns different from those known for insect iridescent virus type 6 (iiv-6). this observation led to the assumption that criv might be a new species within the family iridoviridae. criv can be transmitted perorally to orthopteran species, resulting in specific, fatal diseases. these species includ ...200211807240
development of an immunochromatography assay kit for rapid detection of ranavirus.ranaviruses are large, double-stranded dna viruses of the family iridoviridae and are known to be primary pathogens in frogs, fish and other amphibians. these viruses have been shown to be highly adaptable and have the ability to cross species barriers, making them a potent threat to global biodiversity. there is therefore, a need for rapid and efficient diagnostic methods to control the spread of these viruses. to address this, monoclonal antibodies (mabs) were developed against ranavirus strai ...201526210698
nonclassical mhc-restricted invariant vα6 t cells are critical for efficient early innate antiviral immunity in the amphibian xenopus laevis.nonclassical mhc class ib-restricted invariant t (it) cell subsets are attracting interest because of their potential to regulate immune responses against various pathogens. the biological relevance and evolutionary conservation of it cells have recently been strengthened by the identification of it cells (invariant vα6 [ivα6]) restricted by the nonclassical mhc class ib molecule xnc10 in the amphibian xenopus laevis. these ivα6 t cells are functionally similar to mammalian cd1d-restricted invar ...201526062996
use of cell lines and primary cultures to explore the capacity of rainbow trout to be a host for frog virus 3 (fv3).the capacity of rainbow trout, oncorhynchus mykiss, to be a host for frog virus 3 (fv3) was evaluated at the cellular level. cell cultures from this species were tested for their ability to express fv3 major capsid protein (mcp) gene, to develop cytopathic effect (cpe), and to produce fv3. after fv3 addition, mcp transcripts were detected in six of six cell lines and in primary macrophage cultures. cpe developed in all cell culture systems, except primary lymphocytes. for the macrophage cell lin ...201525948044
prominent amphibian (xenopus laevis) tadpole type iii interferon response to the frog virus 3 ranavirus.ranaviruses (iridoviridae) are posing an increasing threat to amphibian populations, with anuran tadpoles being particularly susceptible to these viral infections. moreover, amphibians are the most basal phylogenetic class of vertebrates known to possess both type i and type iii interferon (ifn)-mediated immunity. moreover, little is known regarding the respective roles of the ifn mediators in amphibian antiviral defenses. accordingly, we transcriptionally and functionally compared the amphibian ...201525717104
clinical signs, pathology and dose-dependent survival of adult wood frogs, rana sylvatica, inoculated orally with frog virus 3 ranavirus sp., iridoviridae.amphibian populations suffer massive mortalities from infection with frog virus 3 fv3, genus ranavirus, family iridoviridae, a pathogen also involved in mortalities of fish and reptiles. experimental oral infection with fv3 in captive-raised adult wood frogs, rana sylvatica lithobates sylvaticus, was performed as the first step in establishing a native north american animal model of ranaviral disease to study pathogenesis and host response. oral dosing was successful ld50 was 10(2.93 2.423.44) p ...201525593158
environmental dependency of amphibian-ranavirus genotypic interactions: evolutionary perspectives on infectious diseases.the context-dependent investigations of host-pathogen genotypic interactions, where environmental factors are explicitly incorporated, allow the assessment of both coevolutionary history and contemporary ecological influences. such a functional explanatory framework is particularly valuable for describing mortality trends and identifying drivers of disease risk more accurately. using two common north american frog species (lithobates pipiens and lithobates sylvaticus) and three strains of frog v ...201425469155
inflammation-induced reactivation of the ranavirus frog virus 3 in asymptomatic xenopus laevis.natural infections of ectothermic vertebrates by ranaviruses (rv, family iridoviridae) are rapidly increasing, with an alarming expansion of rv tropism and resulting die-offs of numerous animal populations. notably, infection studies of the amphibian xenopus laevis with the ranavirus frog virus 3 (fv3) have revealed that although the adult frog immune system is efficient at controlling rv infections, residual quiescent virus can be detected in mononuclear phagocytes of otherwise asymptomatic ani ...201425390636
ranaviruses (family iridoviridae): emerging cold-blooded killers.although possessing novel replicative and structural features, the family iridoviridae has not been as extensively studied as other families of large, dna-containing viruses (e.g., poxviridae and herpesviridae). this oversight most likely reflects the inability of iridoviruses to infect mammals and birds, and their heretofore low pathogenicity among cold-blooded animals and invertebrates. in fact, the original frog virus isolates (e.g., frog viruses 1-3) would likely have been considered orphan ...200211958449
rapid differentiation of australian, european and american ranaviruses based on variation in major capsid protein gene sequence.epizootic haematopoietic necrosis virus (ehnv), bohle iridovirus (biv) and wamena virus (wv) cause serious diseases in fish, amphibians and snakes, respectively but are restricted to australasia. european catfish virus (ecv) and sheatfish virus (esv) have caused epizootics in fish on farms in continental europe. currently there are no simple or readily available methods to distinguish these viruses, which are in the iridoviridae. they are culturally, morphologically and antigenically very simila ...200212030764
effects of ranavirus infection of red-eared sliders (trachemys scripta elegans) on plasma proteins.ranavirus is an emerging disease that infects fish, amphibians, and reptiles. ranavirus induces an inflammatory response leading to death in many susceptible species. red-eared sliders (res; trachemys scripta elegans) are vulnerable to ranavirus infection and are economically significant chelonians kept in the pet trade and utilized in research. early identification of res with inflammatory diseases would allow for isolation of affected individuals and subsequent disease investigation, including ...201425000690
negative effects of low dose atrazine exposure on the development of effective immunity to fv3 in xenopus laevis.the recent dramatic increase of the prevalence and range of amphibian host species and populations infected by ranaviruses such as frog virus 3 (fv3) raises concerns about the efficacies of amphibian antiviral immunity. in this context, the potential negative effects of water contaminants such as the herbicide atrazine, at environmentally relevant levels, on host antiviral immunity remains unclear. here we describe the use of the amphibian xenopus laevis as an ecotoxicology platform to elucidate ...201424984115
susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes.ranaviruses have been associated with mortality of lower vertebrates around the world. frog virus 3 (fv3)-like ranaviruses have been isolated from different ectothermic vertebrate classes; however, few studies have demonstrated whether this pathogen can be transmitted among classes. using fv3-like ranaviruses isolated from the american bullfrog lithobates catesbeianus, eastern box turtle terrapene carolina carolina, and pallid sturgeon scaphirhynchus albus, we tested for the occurrence of interc ...201424895866
transmission of ranavirus between ectothermic vertebrate hosts.transmission is an essential process that contributes to the survival of pathogens. ranaviruses are known to infect different classes of lower vertebrates including amphibians, fishes and reptiles. differences in the likelihood of infection among ectothermic vertebrate hosts could explain the successful yearlong persistence of ranaviruses in aquatic environments. the goal of this study was to determine if transmission of a frog virus 3 (fv3)-like ranavirus was possible among three species from d ...201424667325
the amphibian (xenopus laevis) type i interferon response to frog virus 3: new insight into ranavirus pathogenicity.the increasing prevalence of ranavirus (rv; iridoviridae) infections of wild and commercially maintained aquatic species is raising considerable concerns. while xenopus laevis is the leading model for studies of immunity to rv, amphibian antiviral interferon (ifn) responses remain largely uncharacterized. accordingly, an x. laevis type i interferon was identified, the expression of the gene for this ifn was examined in rv (frog virus 3 [fv3])-infected tadpoles and adult frogs by quantitative pcr ...201424623410
low detection of ranavirus dna in wild postmetamorphic green frogs, rana (lithobates) clamitans, despite previous or concurrent tadpole mortality.ranavirus (iridoviridae) infection is a significant cause of mortality in amphibians. detection of infected individuals, particularly carriers, is necessary to prevent and control outbreaks. recently, the use of toe clips to detect ranavirus infection through pcr was proposed as an alternative to the more frequently used lethal liver sampling in green frogs (rana [lithobates] clamitans). we attempted reevaluate the use of toe clips, evaluate the potential use of blood onto filter paper and hepat ...201324502715
corexit 9500 inactivates two enveloped viruses of aquatic animals but enhances the infectivity of a nonenveloped fish virus.the effects of corexit 9500, a dispersant used to clean up oil spills, on invertebrates, lower vertebrates, birds, and human health have been examined, but there is a significant lack of study of the effect of this dispersant on aquatic viruses. in this study, the effects of corexit 9500 on four aquatic viruses of differing structural composition were examined. corexit 9500 reduced the titer of the enveloped viral hemorrhagic septicemia virus (vhsv) at all concentrations (10% to 0.001%) examined ...201424271186
ranavirus infections associated with skin lesions in lizards.ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. in this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. virological ...201324073785
co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in florida, usa.a multispecies amphibian larval mortality event, primarily affecting american bullfrogs lithobates catesbeianus, was investigated during april 2011 at the mike roess gold head branch state park, clay county, florida, usa. freshly dead and moribund tadpoles had hemorrhagic lesions around the vent and on the ventral body surface, with some exhibiting a swollen abdomen. bullfrogs (100%), southern leopard frogs l. sphenocephalus (33.3%), and gopher frogs l. capito (100%) were infected by alveolate p ...201323872853
frog virus 3 open reading frame 97r localizes to the endoplasmic reticulum and induces nuclear invaginations.frog virus 3 (fv3) is the type species of the genus ranavirus, family iridoviridae. the genome of fv3 is 105,903 bases in length and encodes 97 open reading frames (orfs). the fv3 orf 97r contains a b-cell lymphoma 2 (bcl-2) homology 1 (bh1) domain and has sequence similarity to the myeloid cell leukemia-1 (mcl-1) protein, suggesting a potential role in apoptosis. to begin to understand the role of 97r, we characterized 97r through immunofluorescence and mutagenesis. here we demonstrated that 97 ...201323760249
characterization of a novel ranavirus isolated from grouper epinephelus tauvina.a large icosahedral virus was isolated from diseased grouper epinephelus tauvina. the virus grew well in several cultured fish cell lines, with stable and high infectivity after serial passages in grouper cell line (gp). the virus was sensitive to both acid and heat treatments. virus replication was inhibited by 5-iodo-2-deoxyuridine (iudr), indicative of a dna-containing genome. the virus infectivity was reduced with ether treatment, suggesting that the virus was lipid-enveloped. electron micro ...200312608562
diagnostic and molecular evaluation of three iridovirus-associated salamander mortality 1998 viruses were isolated from tiger salamander larvae (ambystoma tigrinum diaboli and a. tigrinum melanostictum) involved in north dakota and utah (usa) mortality events and spotted salamander (a. maculatum) larvae in a third event in maine (usa). although sympatric caudates and anurans were present at all three sites only ambystomid larvae appeared to be affected. mortality at the north dakota site was in the thousands while at the utah and maine sites mortality was in the hundreds. sick l ...200314567216
genomic sequence of a ranavirus (family iridoviridae) associated with salamander mortalities in north america.disease is among the suspected causes of amphibian population declines, and an iridovirus and a chytrid fungus are the primary pathogens associated with amphibian mortalities. ambystoma tigrinum virus (atv) and a closely related strain, regina ranavirus (rrv), are implicated in salamander die-offs in arizona and canada, respectively. we report the complete sequence of the atv genome and partial sequence of the rrv genome. sequence analysis of the atv/rrv genomes showed marked similarity to other ...200314599794
cellular litaf interacts with frog virus 3 75l protein and alters its subcellular localization.iridoviruses are a family of large double-stranded dna (dsdna) viruses that are composed of 5 genera, including the lymphocystivirus, ranavirus, megalocytivirus, iridovirus, and chloriridovirus genera. the frog virus 3 (fv3) 75l gene is a nonessential gene that is highly conserved throughout the members of the ranavirus genus but is not found in other iridoviruses. fv3 75l shows high sequence similarity to a conserved domain found in the c terminus of litaf, a small cellular protein with unknown ...201323097445
immune evasion strategies of ranaviruses and innate immune responses to these emerging pathogens.ranaviruses (rv, iridoviridae) are large double-stranded dna viruses that infect fish, amphibians and reptiles. for ecological and commercial reasons, considerable attention has been drawn to the increasing prevalence of ranaviral infections of wild populations and in aquacultural settings. importantly, rvs appear to be capable of crossing species barriers of numerous poikilotherms, suggesting that these pathogens possess a broad host range and potent immune evasion mechanisms. indeed, while som ...201222852041
susceptibility of xenopus laevis tadpoles to infection by the ranavirus frog-virus 3 correlates with a reduced and delayed innate immune response in comparison with adult frogs.xenopus laevis adults mount effective immune responses to ranavirus frog virus 3 (fv3) infections and clear the pathogen within 2-3 weeks. in contrast, most tadpoles cannot clear fv3 and succumb to infections within a month. while larval susceptibility has been attributed to ineffective adaptive immunity, the contribution of innate immune components has not been addressed. accordingly, we performed a comprehensive gene expression analysis on fv3-infected tadpoles and adults. in comparison to adu ...201222819836
environmental persistence of amphibian and reptilian ranaviruses.ranaviruses infect fish, amphibians, and reptiles. the present study was conducted to compare the persistence of amphibian and reptilian ranaviruses in a pond habitat. the 4 viruses used in this study included 2 amphibian ranaviruses, frog virus 3 (fv3, the type species of the genus ranavirus) and an isolate from a frog, and 2 ranaviruses of reptilian origin (from a tortoise and from a gecko). a sandwich germ-carrier technique was used to study the persistence of these viruses in sterile and uns ...201222535867
water temperature affects susceptibility to ranavirus.the occurrence of emerging infectious diseases in wildlife populations is increasing, and changes in environmental conditions have been hypothesized as a potential driver. for example, warmer ambient temperatures might favor pathogens by providing more ideal conditions for propagation or by stressing hosts. our objective was to determine if water temperature played a role in the pathogenicity of an emerging pathogen (ranavirus) that infects ectothermic vertebrate species. we exposed larvae of fo ...201627283058
ranavirus phylogenomics: signatures of recombination and inversions among bullfrog ranaculture isolates.ranaviruses are emerging pathogens of fish, amphibians, and reptiles that threaten aquatic animal industries and wildlife worldwide. our objective was to genetically characterize ranaviruses isolated during separate bullfrog lithobates catesbeianus die-offs that occurred eight years apart on the same north american farm. the earlier outbreak was due to a highly pathogenic strain of common midwife toad virus (cmtv) previously known only from europe and china. the later outbreak was due to a chime ...201728803676
ranavirus epizootic in captive eastern box turtles (terrapene carolina carolina) with concurrent herpesvirus and mycoplasma infection: management and monitoring.frog virus 3 (fv3) and fv3-like viruses are members of the genus ranavirus (family iridoviridae) and are becoming recognized as significant pathogens of eastern box turtles (terrapene carolina carolina) in north america. in july 2011, 5 turtles from a group of 27 in maryland, usa, presented dead or lethargic with what was later diagnosed as fibrinonecrotic stomatitis and cloacitis. the presence of fv3-like virus and herpesvirus was detected by polymerase chain reaction (pcr) in the tested index ...201627010285
frog virus 3 replication: induction and intracellular distribution of polypeptides in infected cells.the synthesis of the polypeptides induced in frog virus 3-infected cells was analyzed by high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radiolabeled cell extracts. purified frog virus 3 contained 22 polypeptides, with molecular weights in the range 9 x 10(3) to 114 x 10(3). all of the structural and an additional seven nonstructural polypeptides were detected in infected cell lysates. the following three classes of induced polypeptides (under temporal control) were ...198016789186
phosphonoacetic acid inhibition of frog virus 3 replication.phosphonoacetic acid at concentrations above 200 mug/ml inhibited the replication of frog virus 3 in bhk cells. the inhibition of viral dna replication observed in these cells was reversible and correlated with the inhibition of the virus-induced dna polymerase activity in an in vitro assay. the synthesis of frog virus 3-induced late or gamma polypeptides was also inhibited by phosphonoacetic acid, although the early (alpha and beta) polypeptides were unaffected.198016789189
ranavirus-associated mass mortality in imported red tailed knobby newts (tylototriton kweichowensis): a case report.a mass die-off of imported red tailed knobby newts (tylototriton kweichowensis) occurred in 2004 in belgium and the netherlands. in addition to massive infection with rhabdias tokyoensis, ranavirus was isolated from three dead newts examined virologically and the gene coding for the major capsid protein of the virus was sequenced. the isolate showed 99.8% similarity to the published sequence of frog virus 3. upon experimental infection of axolotls (ambystoma mexicanum) with this isolate, no mark ...200817449300
screening of a long-term sample set reveals two ranavirus lineages in british herpetofauna.reports of severe disease outbreaks in amphibian communities in mainland europe due to strains of the common midwife toad virus (cmtv)-like clade of ranavirus are increasing and have created concern due to their considerable population impacts. in great britain, viruses in another clade of ranavirus-frog virus 3 (fv3)-like-have caused marked declines of common frog (rana temporaria) populations following likely recent virus introductions. the british public has been reporting mortality incidents ...201728931029
expression of frog virus 3 genes is impaired in mammalian cell lines.frog virus 3 (fv3) is a large dna virus that is the prototypic member of the family iridoviridae. to examine levels of fv3 gene expression we generated a polyclonal antibody against the fv3 protein 75l. following a fv3 infection in fathead minnow (fhm) cells 75l was found in vesicles throughout the cytoplasm as early as 3 hours post-infection. while 75l expressed strongly in fhm cells, our findings revealed no 75l expression in mammalian cells lines despite evidence of a fv3 infection. one expla ...200818644137
differentiation-dependent antiviral capacities of amphibian (xenopus laevis) macrophages.infections by ranaviruses such as frog virus 3 (fv3) are significantly contributing to the worldwide amphibian population declines. notably, amphibian macrophages (mφs) are important to both the fv3 infection strategies and the immune defense against this pathogen. however, the mechanisms underlying amphibian mφ fv3 susceptibility and resistance remain unknown. mφ differentiation is mediated by signaling through the colony-stimulating factor-1 receptor (csf-1r), which is now known to be bound by ...201729259133
effect of imidacloprid on the survival of xenopus tadpoles challenged with wild type frog virus 3.the sensitivity of amphibians to ranavirus may be increased by exposure to other environmental stressors, including chemical contaminants. neonicotinoid insecticides comprise 27% of the global insecticide market and have been detected in wetlands and other aquatic habitats. the present study focused on the effects of exposure of pre-metamorphic xenopus laevis to the neonicotinoid, imidacloprid (imi) on sensitivity to frog virus 3 (fv3) infection. it was hypothesized that exposure of tadpoles to ...029179150
ranavirus infection of free-ranging and captive box turtles and tortoises in the united states.iridoviruses of the genus ranavirus are well known for causing mass mortality events of fish and amphibians with sporadic reports of infection in reptiles. this article describes five instances of ranavirus infection in chelonians between 2003 and 2005 in georgia, florida, new york, and pennsylvania, usa. affected species included captive burmese star tortoises (geochelone platynota), a free-ranging gopher tortoise (gopherus polyphemus), free-ranging eastern box turtles (terrapene carolina carol ...200818957641
transcriptome analysis of frog virus 3, the type species of the genus ranavirus, family iridoviridae.frog virus 3 is the best characterized species within the genus ranavirus, family iridoviridae. fv3's large ( approximately 105 kbp) dsdna genome encodes 98 putative open reading frames (orfs) that are expressed in a coordinated fashion leading to the sequential appearance of immediate early (ie), delayed early (de) and late (l) viral transcripts. as a step toward elucidating molecular events in fv3 replication, we sought to identify the temporal class of viral messages. to accomplish this objec ...200919608212
ranavirus phylogeny and differentiation based on major capsid protein, dna polymerase and neurofilament triplet h1-like protein this study, we developed new methods for differentiation of ranaviruses based on polymerase chain reaction and restriction enzyme analysis of dna polymerase and neurofilament triplet h1-like (nf-h1) protein gene. using these methods, we were able to differentiate the 6 known ranaviruses--bohle iridovirus (biv), european catfish virus (ecv), epizootic haematopoietic necrosis virus (ehnv), european sheatfish virus (esv), frog virus 3 (fv3) and singapore grouper iridovirus (sgiv)--with 3 less ch ...200919694168
anuran susceptibilities to ranaviruses: role of species identity, exposure route, and a novel virus isolate.ranaviruses are responsible for widespread amphibian die-offs, particularly with larval anurans. to understand the factors that may be contributing to the emergence of ranaviruses, we conducted 3 experiments that exposed 3 species of larval anurans to either endemic frog virus 3 (fv3) or an fv3-like isolate from a ranaculture facility. our goals were to (1) determine the susceptibility of each species to each virus, (2) determine whether direct ingestion of virions or exposure to virions in a wa ...201020402227
susceptibility of black bullhead ameiurus melas to a panel of ranavirus isolates.ranaviruses are considered a serious threat to lower vertebrates, including fish, amphibians and reptiles. however, epidemiological data on these agents are lacking, and further investigations are needed to understand the role of carriers and to update the list of susceptible hosts. we carried out various experimental infections under controlled conditions to contribute to the current knowledge on the susceptibility of black bullhead ameiurus melas to european catfish virus (ecv) and other ranav ...201020815324
new viruses from lacerta monticola (serra da estrela, portugal): further evidence for a new group of nucleo-cytoplasmic large deoxyriboviruses.lizard erythrocytic viruses (levs) have previously been described in lacerta monticola from serra da estrela, portugal. like other known erythrocytic viruses of heterothermic vertebrates, these viruses have never been adapted to cell cultures and remain uncharacterized at the molecular level. in this study, we made attempts to adapt the virus to cell cultures that resulted instead in the isolation of a previously undetected ranavirus closely related to fv3. the ranavirus was subsequently detecte ...201021138619
antisense approaches for elucidating ranavirus gene function in an infected fish cell line.viral virulence/immune evasion strategies and host anti-viral responses represent different sides of the continuing struggle between virus and host survival. to identify virus-encoding molecules whose function is to subvert or blunt host immune responses, we have adapted anti-sense approaches to knock down the expression of specific viral gene products. our intention is to correlate knock down with loss of function and thus infer the role of a given viral gene. as a starting point in this proces ...201021147160
amphibian chytrid fungus and ranaviruses in the northwest territories, canada.pathogens can cause serious declines in host species, and knowing where pathogens associated with host declines occur facilitates understanding host-pathogen ecology. suspected drivers of global amphibian declines include infectious diseases, with 2 pathogens in particular, batrachochytrium dendrobatidis (bd) and ranaviruses, causing concern. we explored the host range and geographic distribution of bd and ranaviruses in the taiga plains ecoregion of the northwest territories, canada, in 2007 an ...201021268986
new disease records for hatchery-reared sturgeon. i. expansion of frog virus 3 host range into scaphirhynchus 2009, juvenile pallid sturgeon scaphirhynchus albus, reared at the blind pony state fish hatchery (missouri, usa) to replenish dwindling wild stocks, experienced mass mortality. histological examination revealed extensive necrosis of the haematopoietic tissues, and a virus was isolated from affected organs in cell culture and then observed by electron microscopy. experimental infection studies revealed that the virus is highly pathogenic to juvenile pallid sturgeon, one of several species of ...201425320034
persistence of an amphibian ranavirus in aquatic dynamics can be strongly influenced by interactions with other members of the biotic community, particularly when the parasite spends some fraction of its life in the environment unprotected by its host. ranaviruses-often lethal viruses of cold-blooded vertebrate hosts transmitted by direct contact, and via water and fomites-offer an interesting system for understanding these community influences. previous laboratory studies have shown that ranaviruses can persist for anywhere from ...201425266900
pathogenicity of frog virus 3-like virus in red-eared slider turtles (trachemys scripta elegans) at two environmental temperatures.ranaviral disease has affected several species of reptiles, but disease progression and mortality in relation to environmental temperature has yet to be determined. in this study, two separate trials challenged adult female red-eared slider turtles (trachemys scripta elegans) with a ranavirus (frog virus 3-like virus; fv3) isolate at environmental temperatures of 22 °c (n = 4) and 28 °c (n = 4). the mortality rates in the turtles in the 22 °c and 28 °c trials were 100% and 50%, respectively. med ...201323582975
ranavirus infection in a group of wild-caught lake urmia newts neurergus crocatus imported from iraq into germany.high mortality, in association with anorexia and skin ulcerations, occurred in a group of wild-caught lake urmia newts neurergus crocatus, imported from iraq in 2011. predominant findings in the pathological examinations consisted of systemic hemorrhages and ulcerative dermatitis. ranavirus dna was detected via pcr in 2 of 3 dead animals, and a part of the major capsid protein (mcp) gene was sequenced. the analyzed portion of the mcp gene was 99% identical to the corresponding portion of the fro ...201323574704
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