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Sample records for viral pathogen ranavirus

  1. Response of the Italian agile frog (Rana latastei) to a Ranavirus, frog virus 3: a model for viral emergence in naïve populations.

    PubMed

    Pearman, Peter B; Garner, Trenton W J; Straub, Monika; Greber, Urs F

    2004-10-01

    Ranavirus (family Iridoviridae) is a genus of pathogens of poikilotherms, and some ranaviruses may play a role in widespread mortality of amphibians. Ecology of viral transmission in amphibians is poorly known but can be addressed through experimentation in the laboratory. In this study, we use the Ranavirus frog virus 3 (FV3) as an experimental model for pathogen emergence in naive populations of tadpoles. We simulated emerging disease by exposing tadpoles of the Italian agile frog (Rana latastei), to the North American Ranavirus FV3. We demonstrated that mortality occurred due to viral exposure, exposure of tadpoles to decreasing concentrations of FV3 in the laboratory produced dose-dependent survival rates, and cannibalism of virus-carrying carcasses increased mortality due to FV3. These experiments suggest the potential for ecological mechanisms to affect the level of exposure of tadpoles to Ranavirus and to impact transmission of viral pathogens in aquatic systems.

  2. Rana catesbeiana virus Z (RCV-Z): a novel pathogenic ranavirus.

    PubMed

    Majji, Sai; LaPatra, Scott; Long, Scott M; Sample, Robert; Bryan, Locke; Sinning, Allan; Chinchar, V Gregory

    2006-11-21

    A virus, designated Rana catesbeiana virus Z (RCV-Z), was isolated from the visceral tissue of moribund tadpoles of the North American bullfrog Rana catesbeiana. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) analysis of viral proteins and sequence analysis of the amino terminal end of the major capsid protein showed that RCV-Z was similar to frog virus 3 (FV3) and other ranaviruses isolated from anurans and fish. However, analysis of restriction fragment profiles following digestion of viral genomic DNA with XbaI and BamHI indicated that RCV-Z was markedly different from FV3. Moreover, in contrast to FV3, RCV-Z contained a full-length copy of the viral homolog of eukaryotic initiation factor 2 alpha (eIF-2alpha). Experimental infection of bullfrog tadpoles with FV3 and RCV-Z demonstrated that RCV-Z was much more pathogenic than FV3, and that prior infection with FV3 protected them from subsequent RCV-Z induced mortality. Collectively, these results suggest that RCV-Z may represent a novel species of ranavirus capable of infecting frogs and that possession of a viral eIF-2alpha homolog (vIF-2alpha) correlates with enhanced virulence. PMID:17240747

  3. Rana catesbeiana virus Z (RCV-Z): a novel pathogenic ranavirus.

    PubMed

    Majji, Sai; LaPatra, Scott; Long, Scott M; Sample, Robert; Bryan, Locke; Sinning, Allan; Chinchar, V Gregory

    2006-11-21

    A virus, designated Rana catesbeiana virus Z (RCV-Z), was isolated from the visceral tissue of moribund tadpoles of the North American bullfrog Rana catesbeiana. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) analysis of viral proteins and sequence analysis of the amino terminal end of the major capsid protein showed that RCV-Z was similar to frog virus 3 (FV3) and other ranaviruses isolated from anurans and fish. However, analysis of restriction fragment profiles following digestion of viral genomic DNA with XbaI and BamHI indicated that RCV-Z was markedly different from FV3. Moreover, in contrast to FV3, RCV-Z contained a full-length copy of the viral homolog of eukaryotic initiation factor 2 alpha (eIF-2alpha). Experimental infection of bullfrog tadpoles with FV3 and RCV-Z demonstrated that RCV-Z was much more pathogenic than FV3, and that prior infection with FV3 protected them from subsequent RCV-Z induced mortality. Collectively, these results suggest that RCV-Z may represent a novel species of ranavirus capable of infecting frogs and that possession of a viral eIF-2alpha homolog (vIF-2alpha) correlates with enhanced virulence.

  4. Recent host-shifts in ranaviruses: signatures of positive selection in the viral genome.

    PubMed

    Abrams, A Jeanine; Cannatella, David C; Hillis, David M; Sawyer, Sara L

    2013-09-01

    Ranaviruses have been implicated in recent declines in global amphibian populations. Compared with the family Iridoviridae, to which the genus Ranavirus belongs, ranaviruses have a wide host range in that species/strains are known to infect fish, amphibians and reptiles, presumably due to recent host-switching events. We used eight sequenced ranavirus genomes and two selection-detection methods (site based and branch based) to identify genes that exhibited signatures of positive selection, potentially due to the selective pressures at play during host switching. We found evidence of positive selection acting on four genes via the site-based method, three of which were newly acquired genes unique to ranavirus genomes. Using the branch-based method, we identified eight additional candidate genes that exhibited signatures of dN/dS (non-synonymous/synonymous substitution rate) >1 in the clade where intense host switching had occurred. We found that these branch-specific patterns of elevated dN/dS were enriched in a small group of viral genes that have been acquired most recently in the ranavirus genome, compared with core genes that are shared among all members of the family Iridoviridae. Our results suggest that the group of newly acquired genes in the ranavirus genome may have undergone recent adaptive changes that have facilitated interspecies and interclass host switching.

  5. Immune evasion strategies of ranaviruses and innate immune responses to these emerging pathogens.

    PubMed

    Grayfer, Leon; Andino, Francisco De Jesús; Chen, Guangchun; Chinchar, Gregory V; Robert, Jacques

    2012-07-01

    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 some of the 95-100 predicted ranavirus genes encode putative evasion proteins (e.g., vIFα, vCARD), roughly two-thirds of them do not share significant sequence identity with known viral or eukaryotic genes. Accordingly, the investigation of ranaviral virulence and immune evasion strategies is promising for elucidating potential antiviral targets. In this regard, recombination-based technologies are being employed to knock out gene candidates in the best-characterized RV member, Frog Virus (FV3). Concurrently, by using animal infection models with extensively characterized immune systems, such as the African clawed frog, Xenopus laevis, it is becoming evident that components of innate immunity are at the forefront of virus-host interactions. For example, cells of the macrophage lineage represent important combatants of RV infections while themselves serving as targets for viral infection, maintenance and possibly dissemination. This review focuses on the recent advances in the understanding of the RV immune evasion strategies with emphasis on the roles of the innate immune system in ranaviral infections.

  6. Recombinant Ranaviruses for Studying Evolution of Host–Pathogen Interactions in Ectothermic Vertebrates

    PubMed Central

    Robert, Jacques; Jancovich, James K.

    2016-01-01

    Ranaviruses (Iridoviridae) are large DNA viruses that are causing emerging infectious diseases at an alarming rate in both wild and captive cold blood vertebrate species all over the world. Although the general biology of these viruses that presents some similarities with poxvirus is characterized, many aspects of their replication cycles, host cell interactions and evolution still remain largely unclear, especially in vivo. Over several years, strategies to generate site-specific ranavirus recombinant, either expressing fluorescent reporter genes or deficient for particular viral genes, have been developed. We review here these strategies, the main ranavirus recombinants characterized and their usefulness for in vitro and in vivo studies. PMID:27399758

  7. Recombinant Ranaviruses for Studying Evolution of Host-Pathogen Interactions in Ectothermic Vertebrates.

    PubMed

    Robert, Jacques; Jancovich, James K

    2016-01-01

    Ranaviruses (Iridoviridae) are large DNA viruses that are causing emerging infectious diseases at an alarming rate in both wild and captive cold blood vertebrate species all over the world. Although the general biology of these viruses that presents some similarities with poxvirus is characterized, many aspects of their replication cycles, host cell interactions and evolution still remain largely unclear, especially in vivo. Over several years, strategies to generate site-specific ranavirus recombinant, either expressing fluorescent reporter genes or deficient for particular viral genes, have been developed. We review here these strategies, the main ranavirus recombinants characterized and their usefulness for in vitro and in vivo studies.

  8. Recombinant Ranaviruses for Studying Evolution of Host-Pathogen Interactions in Ectothermic Vertebrates.

    PubMed

    Robert, Jacques; Jancovich, James K

    2016-01-01

    Ranaviruses (Iridoviridae) are large DNA viruses that are causing emerging infectious diseases at an alarming rate in both wild and captive cold blood vertebrate species all over the world. Although the general biology of these viruses that presents some similarities with poxvirus is characterized, many aspects of their replication cycles, host cell interactions and evolution still remain largely unclear, especially in vivo. Over several years, strategies to generate site-specific ranavirus recombinant, either expressing fluorescent reporter genes or deficient for particular viral genes, have been developed. We review here these strategies, the main ranavirus recombinants characterized and their usefulness for in vitro and in vivo studies. PMID:27399758

  9. The Amphibian (Xenopus laevis) Type I Interferon Response to Frog Virus 3: New Insight into Ranavirus Pathogenicity

    PubMed Central

    Grayfer, Leon; De Jesús Andino, Francisco

    2014-01-01

    ABSTRACT 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, and a recombinant form of this molecule (recombinant X. laevis interferon [rXlIFN]) was produced for the purpose of functional studies. This rXlIFN protected the kidney-derived A6 cell line and tadpoles against FV3 infection, decreasing the infectious viral burdens in both cases. Adult frogs are naturally resistant to FV3 and clear the infection within a few weeks, whereas tadpoles typically succumb to this virus. Hence, as predicted, virus-infected adult X. laevis frogs exhibited significantly more robust FV3-elicited IFN gene expression than tadpoles; nevertheless, they also tolerated substantially greater viral burdens following infection. Although tadpole stimulation with rXlIFN prior to FV3 challenge markedly impaired viral replication and viral burdens, it only transiently extended tadpole survival and did not prevent the eventual mortality of these animals. Furthermore, histological analysis revealed that despite rXlIFN treatment, infected tadpoles had considerable organ damage, including disrupted tissue architecture and extensive necrosis and apoptosis. Conjointly, these findings indicate a critical protective role for the amphibian type I IFN response during ranaviral infections and suggest that these viruses are more pathogenic to tadpole hosts than was previously believed, causing extensive and fatal damage to multiple organs, even at very low titers. IMPORTANCE Ranavirus infections are threatening wild and commercially maintained aquatic species. The

  10. Ecology and pathology of amphibian ranaviruses.

    PubMed

    Gray, Matthew J; Miller, Debra L; Hoverman, Jason T

    2009-12-01

    Mass mortality of amphibians has occurred globally since at least the early 1990s from viral pathogens that are members of the genus Ranavirus, family Iridoviridae. The pathogen infects multiple amphibian hosts, larval and adult cohorts, and may persist in herpetofaunal and osteichthyan reservoirs. Environmental persistence of ranavirus virions outside a host may be several weeks or longer in aquatic systems. Transmission occurs by indirect and direct routes, and includes exposure to contaminated water or soil, casual or direct contact with infected individuals, and ingestion of infected tissue during predation, cannibalism, or necrophagy. Some gross lesions include swelling of the limbs or body, erythema, swollen friable livers, and hemorrhage. Susceptible amphibians usually die from chronic cell death in multiple organs, which can occur within a few days following infection or may take several weeks. Amphibian species differ in their susceptibility to ranaviruses, which may be related to their co-evolutionary history with the pathogen. The occurrence of recent widespread amphibian population die-offs from ranaviruses may be an interaction of suppressed and naïve host immunity, anthropogenic stressors, and novel strain introduction. This review summarizes the ecological research on amphibian ranaviruses, discusses possible drivers of emergence and conservation strategies, and presents ideas for future research directions. We also discuss common pathological signs of ranaviral disease, methods for diagnostic evaluation, and ranavirus surveillance methods. In as much as ranaviral disease is listed as a notifiable disease by the World Organization for Animal Health and is a threat to amphibian survival, we recommend that biosecurity precautions are implemented by nations to reduce the likelihood of transporting ranavirus virions among populations. Biosecurity precautions include disinfecting footwear and equipment that comes in contact with surface water inhabited

  11. Leafhopper viral pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four newly discovered viral pathogens in leafhopper vectors of Pierce’s disease of grapes, have been shown to replicate in sharpshooter leafhoppers; the glassy-winged sharpshooter, GWSS, Homalodisca vitripennis, and Oncometopia nigricans (Hemiptera: Cicadellidae). The viruses were classified as memb...

  12. Detection of the emerging amphibian pathogens Batrachochytrium dendrobatidis and ranavirus in Russia

    USGS Publications Warehouse

    Reshetnikov, Andrey N.; Chestnut, Tara E.; Brunner, Jesse L.; Charles, Kaylene M.; Nebergall, Emily E.; Olson, Deanna H.

    2014-01-01

    In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and a nearby site for the emerging amphibian pathogens Batrachochytrium dendrobatidis (Bd) and ranavirus (Rv). Both pathogens were detected, and at the rural pond site, with the above-noted losses and decline in toad breeding success, 40% of B. bufo metamorphs were Bd positive, 46% were Rv positive and 20% were co-infected with both pathogens. Toad metamorphs from a neighbouring water body were also Bd and Rv positive (25 and 55%, respectively). This is the first confirmation of these pathogens in Russia. Questions remain as to the origins of these pathogens in Russia and their roles in documented mass mortality events.

  13. Detection of the emerging amphibian pathogens Batrachochytrium dendrobatidis and ranavirus in Russia.

    PubMed

    Reshetnikov, Andrey N; Chestnut, Tara; Brunner, Jesse L; Charles, Kaylene; Nebergall, Emily E; Olson, Deanna H

    2014-08-11

    In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and a nearby site for the emerging amphibian pathogens Batrachochytrium dendrobatidis (Bd) and ranavirus (Rv). Both pathogens were detected, and at the rural pond site, with the above-noted losses and decline in toad breeding success, 40% of B. bufo metamorphs were Bd positive, 46% were Rv positive and 20% were co-infected with both pathogens. Toad metamorphs from a neighbouring water body were also Bd and Rv positive (25 and 55%, respectively). This is the first confirmation of these pathogens in Russia. Questions remain as to the origins of these pathogens in Russia and their roles in documented mass mortality events.

  14. Amphibian pathogens at northern latitudes: presence of chytrid fungus and ranavirus in northeastern Canada.

    PubMed

    D'Aoust-Messier, Andrée-Michelle; Echaubard, Pierre; Billy, Vincent; Lesbarrères, David

    2015-03-01

    Infections by the fungal pathogen Batrachochytrium dendrobatidis (Bd) and members of the genus Ranavirus (Rv) are increasingly reported as significant determinants of amphibian population die-offs. The complexity associated with their transmission and spatial distribution leads to an increase in demand for comprehensive reporting systems and global mapping of their distribution. Here, we document the distribution of these 2 pathogens in a remote northern temperate lowland where environmental sensitivity is high, providing important insight into the pathogens' natural history and infection patterns. Wood frog Lithobates sylvaticus tissues were collected from the James Bay area in northeastern Canada and were screened for the presence of Bd and Rv using conventional and real-time PCR. Both pathogens were present in the study area, which is the northernmost record in eastern North America. Interestingly, different patterns of distribution were observed between the eastern and western coasts of James Bay, suggesting differences in the spatial and transmission dynamics for each pathogen. Anthropogenic introduction may still influence the distribution patterns observed, even at these latitudes. The presence of infections in this remote area also raises further questions on the risk these pathogens pose to northern amphibian communities. We encourage further research in remote locations for a better understanding of these pathogens, their transmission dynamics, and especially their respective impacts on amphibian populations worldwide.

  15. Amphibian pathogens at northern latitudes: presence of chytrid fungus and ranavirus in northeastern Canada.

    PubMed

    D'Aoust-Messier, Andrée-Michelle; Echaubard, Pierre; Billy, Vincent; Lesbarrères, David

    2015-03-01

    Infections by the fungal pathogen Batrachochytrium dendrobatidis (Bd) and members of the genus Ranavirus (Rv) are increasingly reported as significant determinants of amphibian population die-offs. The complexity associated with their transmission and spatial distribution leads to an increase in demand for comprehensive reporting systems and global mapping of their distribution. Here, we document the distribution of these 2 pathogens in a remote northern temperate lowland where environmental sensitivity is high, providing important insight into the pathogens' natural history and infection patterns. Wood frog Lithobates sylvaticus tissues were collected from the James Bay area in northeastern Canada and were screened for the presence of Bd and Rv using conventional and real-time PCR. Both pathogens were present in the study area, which is the northernmost record in eastern North America. Interestingly, different patterns of distribution were observed between the eastern and western coasts of James Bay, suggesting differences in the spatial and transmission dynamics for each pathogen. Anthropogenic introduction may still influence the distribution patterns observed, even at these latitudes. The presence of infections in this remote area also raises further questions on the risk these pathogens pose to northern amphibian communities. We encourage further research in remote locations for a better understanding of these pathogens, their transmission dynamics, and especially their respective impacts on amphibian populations worldwide. PMID:25751857

  16. Phylogeny and differentiation of reptilian and amphibian ranaviruses detected in Europe.

    PubMed

    Stöhr, Anke C; López-Bueno, Alberto; Blahak, Silvia; Caeiro, Maria F; Rosa, Gonçalo M; Alves de Matos, António Pedro; Martel, An; Alejo, Alí; Marschang, Rachel E

    2015-01-01

    Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6-100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of

  17. Phylogeny and Differentiation of Reptilian and Amphibian Ranaviruses Detected in Europe

    PubMed Central

    Stöhr, Anke C.; López-Bueno, Alberto; Blahak, Silvia; Caeiro, Maria F.; Rosa, Gonçalo M.; Alves de Matos, António Pedro; Martel, An; Alejo, Alí; Marschang, Rachel E.

    2015-01-01

    Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6–100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of

  18. Phylogeny and differentiation of reptilian and amphibian ranaviruses detected in Europe.

    PubMed

    Stöhr, Anke C; López-Bueno, Alberto; Blahak, Silvia; Caeiro, Maria F; Rosa, Gonçalo M; Alves de Matos, António Pedro; Martel, An; Alejo, Alí; Marschang, Rachel E

    2015-01-01

    Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6-100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of

  19. Persistence of an amphibian ranavirus in aquatic communities.

    PubMed

    Johnson, A F; Brunner, J L

    2014-09-30

    Host-parasite 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 days to years, depending on the conditions, with much longer times under sterile conditions. To address the role of the biotic community and particulate matter on ranavirus persistence, we experimentally inoculated filter-sterilized, UV-treated, and unmanipulated pond water with a Frog virus 3 (FV3)-like Ranavirus and took samples over 78 d, quantifying viral titers with real-time quantitative PCR and plaque assays. Viral counts dropped quickly in all treatments, by an order of magnitude in under a day in unmanipulated pond water and in 8 d in filter-sterilized pond water. In a second experiment, we measured viral titers over 24 h in virus-spiked spring water with Daphnia pulex. Presence of D. pulex reduced the concentration of infectious ranavirus, but not viral DNA, by an order of magnitude in 24 h. D. pulex themselves did not accumulate the virus. We conclude that both microbial and zooplanktonic communities can play an important role in ranavirus epidemiology, rapidly inactivating ranavirus in the water and thereby minimizing environmental transmission. We suspect that interactions with the biotic community will be important for most pathogens with environmental resting or transmission stages.

  20. Persistence of an amphibian ranavirus in aquatic communities.

    PubMed

    Johnson, A F; Brunner, J L

    2014-09-30

    Host-parasite 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 days to years, depending on the conditions, with much longer times under sterile conditions. To address the role of the biotic community and particulate matter on ranavirus persistence, we experimentally inoculated filter-sterilized, UV-treated, and unmanipulated pond water with a Frog virus 3 (FV3)-like Ranavirus and took samples over 78 d, quantifying viral titers with real-time quantitative PCR and plaque assays. Viral counts dropped quickly in all treatments, by an order of magnitude in under a day in unmanipulated pond water and in 8 d in filter-sterilized pond water. In a second experiment, we measured viral titers over 24 h in virus-spiked spring water with Daphnia pulex. Presence of D. pulex reduced the concentration of infectious ranavirus, but not viral DNA, by an order of magnitude in 24 h. D. pulex themselves did not accumulate the virus. We conclude that both microbial and zooplanktonic communities can play an important role in ranavirus epidemiology, rapidly inactivating ranavirus in the water and thereby minimizing environmental transmission. We suspect that interactions with the biotic community will be important for most pathogens with environmental resting or transmission stages. PMID:25266900

  1. Asian citrus psyllid viral pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A newly discovered viral pathogen of Asian citrus psyllid, AsCP, Diaphorina citri, Kuwayama (Psyllidae: Hemiptera) was classified as a Reoviridae. This virus may serve as a biological control agent for AsCP. The AsCP is an efficient vector of the plant-infecting bacterium (Candidatus Liberibacter as...

  2. Genome architecture changes and major gene variations of Andrias davidianus ranavirus (ADRV).

    PubMed

    Chen, Zhongyuan; Gui, Jianfang; Gao, Xiaochan; Pei, Chao; Hong, Yijiang; Zhang, Qiya

    2013-10-21

    Ranaviruses are emerging pathogens that have led to global impact and public concern. As a rarely endangered species and the largest amphibian in the world, the Chinese giant salamander, Andrias davidianus, has recently undergone outbreaks of epidemic diseases with high mortality. In this study, we isolated and identified a novel ranavirus from the Chinese giant salamanders that exhibited systemic hemorrhage and swelling syndrome with high death rate in China during May 2011 to August 2012. The isolate, designated Andrias davidianus ranavirus (ADRV), not only could induce cytopathic effects in different fish cell lines and yield high viral titers, but also caused severely hemorrhagic lesions and resulted in 100% mortality in experimental infections of salamanders. The complete genome of ADRV was sequenced and compared with other sequenced amphibian ranaviruses. Gene content and phylogenetic analyses revealed that ADRV should belong to an amphibian subgroup in genus Ranavirus, and is more closely related to frog ranaviruses than to other salamander ranaviruses. Homologous gene comparisons show that ADRV contains 99%, 97%, 94%, 93% and 85% homologues in RGV, FV3, CMTV, TFV and ATV genomes respectively. In addition, several variable major genes, such as duplicate US22 family-like genes, viral eukaryotic translation initiation factor 2 alpha gene and novel 75L gene with both motifs of nuclear localization signal (NLS) and nuclear export signal (NES), were predicted to contribute to pathogen virulence and host susceptibility. These findings confirm the etiologic role of ADRV in epidemic diseases of Chinese giant salamanders, and broaden our understanding of evolutionary emergence of ranaviruses.

  3. Ecopathology of ranaviruses infecting amphibians.

    PubMed

    Miller, Debra; Gray, Matthew; Storfer, Andrew

    2011-11-01

    Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well as, exogenous environmental factors. Field studies have demonstrated that the likelihood of epizootics is increased in areas of cattle grazing, where aquatic vegetation is sparse and water quality is poor. Translocation of infected amphibians through commercial trade (e.g., food, fish bait, pet industry) contributes to the spread of ranaviruses. Such introductions may be of particular concern, as several studies report that ranaviruses isolated from ranaculture, aquaculture, and bait facilities have greater virulence (i.e., ability to cause disease) than wild-type isolates. Future investigations should focus on the genetic basis for pathogen virulence and host susceptibility, ecological and anthropogenic mechanisms contributing to emergence, and vaccine development for use in captive populations and species reintroduction programs.

  4. Ecopathology of Ranaviruses Infecting Amphibians

    PubMed Central

    Miller, Debra; Gray, Matthew; Storfer, Andrew

    2011-01-01

    Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well as, exogenous environmental factors. Field studies have demonstrated that the likelihood of epizootics is increased in areas of cattle grazing, where aquatic vegetation is sparse and water quality is poor. Translocation of infected amphibians through commercial trade (e.g., food, fish bait, pet industry) contributes to the spread of ranaviruses. Such introductions may be of particular concern, as several studies report that ranaviruses isolated from ranaculture, aquaculture, and bait facilities have greater virulence (i.e., ability to cause disease) than wild-type isolates. Future investigations should focus on the genetic basis for pathogen virulence and host susceptibility, ecological and anthropogenic mechanisms contributing to emergence, and vaccine development for use in captive populations and species reintroduction programs. PMID:22163349

  5. Development of an immunochromatography assay kit for rapid detection of ranavirus.

    PubMed

    Kim, Young Rim; Park, Seong Bin; Fagutao, Fernand F; Nho, Seong Won; Jang, Ho Bin; Cha, In Seok; Thompson, Kim D; Adams, Alexandra; Bayley, Amanda; Jung, Tae Sung

    2015-10-01

    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 strain FV-3 (standard frog virus 3) to detect the major capsid protein and FV-3gorf19R related hypothetical protein in both the FV-3 and KRV-1 (Korean ranavirus) strains. The antibodies were then applied on a colloidal gold-immunochromatographic assay (GICA) as a kit for the detection of ranaviruses. The kit was able to detect low concentrations of the virus (10(1)TCID50/ml) and showed analytical specificity when tested against other viral pathogens, including those belonging to the same family. It was possible to detect ranavirus in experimentally infected frogs within 30 min using the kit. The kit described here is expected to be a valuable and informative tool for on-site detection of ranavirus in frog.

  6. Evaluating environmental DNA-based quantification of ranavirus infection in wood frog populations.

    PubMed

    Hall, Emily M; Crespi, Erica J; Goldberg, Caren S; Brunner, Jesse L

    2016-03-01

    A variety of challenges arise when monitoring wildlife populations for disease. Sampling tissues can be invasive to hosts, and obtaining sufficient sample sizes can be expensive and time-consuming, particularly for rare species and when pathogen prevalence is low. Environmental DNA (eDNA)-based detection of pathogens is an alternative approach to surveillance for aquatic communities that circumvents many of these issues. Ranaviruses are emerging pathogens of ectothermic vertebrates linked to die-offs of amphibian populations. Detecting ranavirus infections is critical, but nonlethal methods have the above issues and are prone to false negatives. We report on the feasibility and effectiveness of eDNA-based ranavirus detection in the field. We compared ranavirus titres in eDNA samples collected from pond water to titres in wood frog (Lithobates sylvaticus; n = 5) tadpoles in sites dominated by this one species (n = 20 pond visits). We examined whether ranavirus DNA can be detected in eDNA from pond water when infections are present in the pond and if viral titres detected in eDNA samples correlate with the prevalence or intensity of ranavirus infections in tadpoles. With three 250 mL water samples, we were able to detect the virus in all visits with infected larvae (0.92 diagnostic sensitivity). Also, we found a strong relationship between the viral eDNA titres and titres in larval tissues. eDNA titres increased prior to observed die-offs and declined afterwards, and were two orders of magnitude higher in ponds with a die-off. Our results suggest that eDNA is useful for detecting ranavirus infections in wildlife and aquaculture.

  7. Virion-associated viral proteins of a Chinese giant salamander (Andrias davidianus) iridovirus (genus Ranavirus) and functional study of the major capsid protein (MCP).

    PubMed

    Li, Wei; Zhang, Xin; Weng, Shaoping; Zhao, Gaoxiang; He, Jianguo; Dong, Chuanfu

    2014-08-01

    Chinese giant salamander iridovirus (CGSIV) is the emerging causative agent to farmed Chinese giant salamanders in nationwide China. CGSIV is a member of the common midwife toad ranavirus (CMTV) subset of the amphibian-like ranavirus (ALRV) in the genus Ranavirus of Iridoviridae family. However, viral protein information on ALRV is lacking. In this first proteomic analysis of ALRV, 40 CGSIV viral proteins were detected from purified virus particles by liquid chromatography-tandem mass spectrometry analysis. The transcription products of all 40 identified virion proteins were confirmed by reverse transcription polymerase chain reaction analysis. Temporal expression pattern analysis combined with drug inhibition assay indicated that 37 transcripts of the 40 virion protein genes could be classified into three temporal kinetic classes, namely, 5 immediate early, 12 delayed early, and 20 late genes. The presence of major capsid proteins (MCP, ORF019L) and a proliferating cell nuclear antigen (ORF025L) was further confirmed by Western blot analysis. The functions of MCP were also determined by small interfering RNA (siRNA)-based knockdown assay and anti-recombinant MCP serum-based neutralization testing. At low dosages of CGSIV, siRNA-based knockdown of the MCP gene effectively inhibited CGSIV replication in fathead minnow cells. The antiviral effect observed in the anti-MCP serum-based neutralization test confirms the crucial function of the MCP gene in CGSIV replication. Taken together, detailed information on the virion-associated viral proteins of ALRV is presented for the first time. Our results also provide evidence that MCP is essential for CGSIV replication in vitro.

  8. Ranavirus outbreaks in amphibian populations of northern Idaho

    USGS Publications Warehouse

    Russell, Danelle M.; Goldberg, Caren S.; Sprague, Laura; Waits, Lisette P.; Green, D. Earl; Schuler, Krysten L.; Rosenblum, Erica Bree

    2011-01-01

    Ranavirus outbreaks, caused by pathogens in the genus Ranavirus (Family Iridoviridae), were the largest single cause of reported amphibian mass mortality events in the United States from 1996–2001 (Green et al. 2002). Mortality events associated with ranaviruses have been documented on five continents and throughout the latitudes and elevations where amphibians occur (Gray et al. 2009). However, the threat of ranaviruses to amphibian and reptile populations in specific regions is still largely unknown (Chinchar 2002; Gray et al. 2009).

  9. Water Temperature Affects Susceptibility to Ranavirus.

    PubMed

    Brand, Mabre D; Hill, Rachel D; Brenes, Roberto; Chaney, Jordan C; Wilkes, Rebecca P; Grayfer, Leon; Miller, Debra L; Gray, Matthew J

    2016-06-01

    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 four amphibian species to a Frog Virus 3 (FV3)-like ranavirus at two temperatures (10 and 25°C). We found that FV3 copies in tissues and mortality due to ranaviral disease were greater at 25°C than at 10°C for all species. In a second experiment with wood frogs (Lithobates sylvaticus), we found that a 2°C change (10 vs. 12°C) affected ranaviral disease outcomes, with greater infection and mortality at 12°C. There was evidence that 10°C stressed Cope's gray tree frog (Hyla chrysoscelis) larvae, which is a species that breeds during summer-all individuals died at this temperature, but only 10% tested positive for FV3 infection. The greater pathogenicity of FV3 at 25°C might be related to faster viral replication, which in vitro studies have reported previously. Colder temperatures also may decrease systemic infection by reducing blood circulation and the proportion of phagocytes, which are known to disseminate FV3 through the body. Collectively, our results indicate that water temperature during larval development may play a role in the emergence of ranaviruses.

  10. Water Temperature Affects Susceptibility to Ranavirus.

    PubMed

    Brand, Mabre D; Hill, Rachel D; Brenes, Roberto; Chaney, Jordan C; Wilkes, Rebecca P; Grayfer, Leon; Miller, Debra L; Gray, Matthew J

    2016-06-01

    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 four amphibian species to a Frog Virus 3 (FV3)-like ranavirus at two temperatures (10 and 25°C). We found that FV3 copies in tissues and mortality due to ranaviral disease were greater at 25°C than at 10°C for all species. In a second experiment with wood frogs (Lithobates sylvaticus), we found that a 2°C change (10 vs. 12°C) affected ranaviral disease outcomes, with greater infection and mortality at 12°C. There was evidence that 10°C stressed Cope's gray tree frog (Hyla chrysoscelis) larvae, which is a species that breeds during summer-all individuals died at this temperature, but only 10% tested positive for FV3 infection. The greater pathogenicity of FV3 at 25°C might be related to faster viral replication, which in vitro studies have reported previously. Colder temperatures also may decrease systemic infection by reducing blood circulation and the proportion of phagocytes, which are known to disseminate FV3 through the body. Collectively, our results indicate that water temperature during larval development may play a role in the emergence of ranaviruses. PMID:27283058

  11. Transmission of ranavirus between ectothermic vertebrate hosts.

    PubMed

    Brenes, Roberto; Gray, Matthew J; Waltzek, Thomas B; Wilkes, Rebecca P; Miller, Debra L

    2014-01-01

    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 different ectothermic vertebrate classes: Cope's gray treefrog (Hyla chrysoscelis) larvae, mosquito fish (Gambusia affinis), and red-eared slider (Trachemys scripta elegans). We housed individuals previously exposed to the FV3-like ranavirus with naïve (unexposed) individuals in containers divided by plastic mesh screen to permit water flow between subjects. Our results showed that infected gray treefrog larvae were capable of transmitting ranavirus to naïve larval conspecifics and turtles (60% and 30% infection, respectively), but not to fish. Also, infected turtles and fish transmitted ranavirus to 50% and 10% of the naïve gray treefrog larvae, respectively. Nearly all infected amphibians experienced mortality, whereas infected turtles and fish did not die. Our results demonstrate that ranavirus can be transmitted through water among ectothermic vertebrate classes, which has not been reported previously. Moreover, fish and reptiles might serve as reservoirs for ranavirus given their ability to live with subclinical infections. Subclinical infections of ranavirus in fish and aquatic turtles could contribute to the pathogen's persistence, especially when highly susceptible hosts like amphibians are absent as a result of seasonal fluctuations in relative abundance.

  12. Widespread occurrence of ranavirus in pond-breeding amphibian populations.

    PubMed

    Hoverman, Jason T; Gray, Matthew J; Miller, Debra L; Haislip, Nathan A

    2012-03-01

    Ranaviruses are an emerging threat for many amphibian populations, yet their distribution in amphibian communities and the association of infection with possible stressors and species is not fully understood due to historically sparse surveillance. Agricultural practices that reduce the water quality of amphibian breeding habitats (e.g., cattle access to wetlands) and environmental stressors (e.g., lower temperatures) may contribute to ranavirus emergence. We tested larval amphibians for ranavirus infection across four seasons in farm ponds (n = 40) located in Tennessee, USA. Cattle at various densities were allowed access to half of the sampled ponds. Ranavirus infections were detected in nine species and in 33 of the sampled ponds (83%), illustrating widespread occurrence of the pathogen. Species within the family Ranidae were the most frequently infected. In 13 of the ponds containing infected individuals, prevalence exceeded 40% during at least one season. Infections were detected in multiple seasons in 20 of the sampled ponds containing infections, suggesting that ranaviruses are relatively persistent in these systems. Cattle had negative effects on water quality (turbidity and ammonia) and there was a positive association between cattle abundance and ranavirus prevalence in the summer. Counter to previous field studies in North America, we found a significant positive association between water temperature and ranavirus prevalence in the fall sampling events. Despite these findings, the influences of cattle and temperature on ranavirus prevalence were not consistent across seasons. As such, the mechanisms driving high ranavirus prevalence across the landscape and over time remain unclear. Given the widespread occurrence of ranaviruses in wild amphibians, we encourage the implementation of surveillance programs to help identify potential drivers of emergence. Sites with high ranavirus prevalence should be monitored annually for outbreaks, and the long

  13. Establishment of three cell lines from Chinese giant salamander and their sensitivities to the wild-type and recombinant ranavirus.

    PubMed

    Yuan, Jiang-Di; Chen, Zhong-Yuan; Huang, Xing; Gao, Xiao-Chan; Zhang, Qi-Ya

    2015-06-12

    Known as lethal pathogens, Ranaviruses have been identified in diseased fish, amphibians (including Chinese giant salamander Andrias davidianus, the world's largest amphibian) and reptiles, causing organ necrosis and systemic hemorrhage. Here, three Chinese giant salamander cell lines, thymus cell line (GSTC), spleen cell line (GSSC) and kidney cell line (GSKC) were initially established. Their sensitivities to ranaviruses, wild-type Andrias davidianus ranavirus (ADRV) and recombinant Rana grylio virus carrying EGFP gene (rRGV-EGFP) were tested. Temporal transcription pattern of ranavirus major capsid protein (MCP), fluorescence and electron microscopy observations showed that both the wild-type and recombinant ranavirus could replicate in the cell lines.

  14. Ranavirus could facilitate local extinction of rare amphibian species.

    PubMed

    Earl, Julia E; Chaney, Jordan C; Sutton, William B; Lillard, Carson E; Kouba, Andrew J; Langhorne, Cecilia; Krebs, Jessi; Wilkes, Rebecca P; Hill, Rachel D; Miller, Debra L; Gray, Matthew J

    2016-10-01

    There is growing evidence that pathogens play a role in population declines and species extinctions. For small populations, disease-induced extinction may be especially probable. We estimated the susceptibility of two amphibian species of conservation concern (the dusky gopher frog [Lithobates sevosus] and boreal toad [Anaxyrus boreas boreas]) to an emerging pathogen (ranavirus) using laboratory challenge experiments, and combined these data with published demographic parameter estimates to simulate the potential effects of ranavirus exposure on extinction risk. We included effects of life stage during pathogen exposure, pathogen exposure interval, hydroperiod of breeding habitat, population carrying capacity, and immigration in simulations. We found that both species were highly susceptible to ranavirus when exposed to the pathogen in water at environmentally relevant concentrations. Dusky gopher frogs experienced 100 % mortality in four of six life stages tested. Boreal toads experienced 100 % mortality when exposed as tadpoles or metamorphs, which were the only life stages tested. Simulations showed population declines, greater extinction probability, and faster times to extinction with ranavirus exposure. These effects were more evident with more frequent pathogen exposure intervals and lower carrying capacity. Immigration at natural rates did little to mitigate effects of ranavirus exposure unless immigration occurred every 2 years. Our results demonstrate that disease-induced extinction by emerging pathogens, such as ranavirus, is possible, and that threat may be especially high for species with small population sizes. For the species in this study, conservation organizations should incorporate ranavirus surveillance into monitoring programs and devise intervention strategies in the event that disease outbreaks occur.

  15. Ranavirus could facilitate local extinction of rare amphibian species.

    PubMed

    Earl, Julia E; Chaney, Jordan C; Sutton, William B; Lillard, Carson E; Kouba, Andrew J; Langhorne, Cecilia; Krebs, Jessi; Wilkes, Rebecca P; Hill, Rachel D; Miller, Debra L; Gray, Matthew J

    2016-10-01

    There is growing evidence that pathogens play a role in population declines and species extinctions. For small populations, disease-induced extinction may be especially probable. We estimated the susceptibility of two amphibian species of conservation concern (the dusky gopher frog [Lithobates sevosus] and boreal toad [Anaxyrus boreas boreas]) to an emerging pathogen (ranavirus) using laboratory challenge experiments, and combined these data with published demographic parameter estimates to simulate the potential effects of ranavirus exposure on extinction risk. We included effects of life stage during pathogen exposure, pathogen exposure interval, hydroperiod of breeding habitat, population carrying capacity, and immigration in simulations. We found that both species were highly susceptible to ranavirus when exposed to the pathogen in water at environmentally relevant concentrations. Dusky gopher frogs experienced 100 % mortality in four of six life stages tested. Boreal toads experienced 100 % mortality when exposed as tadpoles or metamorphs, which were the only life stages tested. Simulations showed population declines, greater extinction probability, and faster times to extinction with ranavirus exposure. These effects were more evident with more frequent pathogen exposure intervals and lower carrying capacity. Immigration at natural rates did little to mitigate effects of ranavirus exposure unless immigration occurred every 2 years. Our results demonstrate that disease-induced extinction by emerging pathogens, such as ranavirus, is possible, and that threat may be especially high for species with small population sizes. For the species in this study, conservation organizations should incorporate ranavirus surveillance into monitoring programs and devise intervention strategies in the event that disease outbreaks occur. PMID:27344151

  16. Isolation and characterization of a ranavirus from koi, Cyprinus carpio L., experiencing mass mortalities in India.

    PubMed

    George, M R; John, K R; Mansoor, M M; Saravanakumar, R; Sundar, P; Pradeep, V

    2015-04-01

    We investigated mass mortalities of koi, Cyprinus carpio Linnaeus, 1758, experienced in South Indian fish farms by virus isolation, electron microscopy, PCR detection, sequencing of capsid protein gene and transmission studies. Samples of moribund koi brought to the laboratory suffered continuous mortality exhibiting swimming abnormalities, intermittent surfacing and skin darkening. Irido-like virus was isolated from the infected fish in the indigenous snakehead kidney cell line (SNKD2a). Icosahedral virus particles of 100 to 120 nm were observed in the infected cell cultures, budding from the cell membrane. Virus transmission and pathogenicity studies revealed that horizontal transmission occurred associated with mortality. PCR analysis of infected fish and cell cultures confirmed the presence of Ranavirus capsid protein sequences. Sequence analysis of the major capsid protein gene showed an identity of 99.9% to that of largemouth bass virus isolated from North America. Detection and successful isolation of this viral agent becomes the first record of isolation of a virus resembling Santee-Cooper Ranavirus from a koi and from India. We propose the name koi ranavirus to this agent. PMID:24720625

  17. Isolation and characterization of a ranavirus from koi, Cyprinus carpio L., experiencing mass mortalities in India.

    PubMed

    George, M R; John, K R; Mansoor, M M; Saravanakumar, R; Sundar, P; Pradeep, V

    2015-04-01

    We investigated mass mortalities of koi, Cyprinus carpio Linnaeus, 1758, experienced in South Indian fish farms by virus isolation, electron microscopy, PCR detection, sequencing of capsid protein gene and transmission studies. Samples of moribund koi brought to the laboratory suffered continuous mortality exhibiting swimming abnormalities, intermittent surfacing and skin darkening. Irido-like virus was isolated from the infected fish in the indigenous snakehead kidney cell line (SNKD2a). Icosahedral virus particles of 100 to 120 nm were observed in the infected cell cultures, budding from the cell membrane. Virus transmission and pathogenicity studies revealed that horizontal transmission occurred associated with mortality. PCR analysis of infected fish and cell cultures confirmed the presence of Ranavirus capsid protein sequences. Sequence analysis of the major capsid protein gene showed an identity of 99.9% to that of largemouth bass virus isolated from North America. Detection and successful isolation of this viral agent becomes the first record of isolation of a virus resembling Santee-Cooper Ranavirus from a koi and from India. We propose the name koi ranavirus to this agent.

  18. Mosquitoes as a Potential Vector of Ranavirus Transmission in Terrestrial Turtles.

    PubMed

    Kimble, Steven J A; Karna, Ajit K; Johnson, April J; Hoverman, Jason T; Williams, Rod N

    2015-06-01

    Ranaviruses are significant pathogens of amphibians, reptiles, and fishes, contributing to mass mortality events worldwide. Despite an increasing focus on ranavirus ecology, our understanding of ranavirus transmission, especially among reptilian hosts, remains limited. For example, experimental evidence for oral transmission of the virus in chelonians is mixed. Consequently, vector-borne transmission has been hypothesized in terrestrial turtle species. To test this hypothesis, mosquitoes captured during a 2012/2013 ranavirus outbreak in box turtles from southwestern Indiana were pooled by genus and tested for ranavirus DNA using qPCR. Two of 30 pools tested positive for ranavirus. Additionally, an individual Aedes sp. mosquito observed engorging on a box turtle also tested positive for ranavirus. Although our approach does not rule out the possibility that the sequenced ranavirus was simply from virus in bloodmeal, it does suggests that mosquitoes may be involved in virus transmission as a mechanical or biological vector among ectothermic vertebrates. While additional studies are needed to elucidate the exact role of mosquitoes in ranavirus ecology, our study suggests that a greater focus on vector-borne transmission may be necessary to fully understand ranaviral disease dynamics in herpetofauna.

  19. Comparing viral metagenomics methods using a highly multiplexed human viral pathogens reagent

    PubMed Central

    Li, Linlin; Deng, Xutao; Mee, Edward T.; Collot-Teixeira, Sophie; Anderson, Rob; Schepelmann, Silke; Minor, Philip D.; Delwart, Eric

    2014-01-01

    Unbiased metagenomic sequencing holds significant potential as a diagnostic tool for the simultaneous detection of any previously genetically described viral nucleic acids in clinical samples. Viral genome sequences can also inform on likely phenotypes including drug susceptibility or neutralization serotypes. In this study, different variables of the laboratory methods often used to generate viral metagenomics libraries on the efficiency of viral detection and virus genome coverage were compared. A biological reagent consisting of 25 different human RNA and DNA viral pathogens was used to estimate the effect of filtration and nuclease digestion, DNA/RNA extraction methods, pre-amplification and the use of different library preparation kits on the detection of viral nucleic acids. Filtration and nuclease treatment led to slight decreases in the percentage of viral sequence reads and number of viruses detected. For nucleic acid extractions silica spin columns improved viral sequence recovery relative to magnetic beads and Trizol extraction. Pre-amplification using random RT-PCR while generating more viral sequence reads resulted in detection of fewer viruses, more overlapping sequences, and lower genome coverage. The ScriptSeq library preparation method retrieved more viruses and a greater fraction of their genomes than the TruSeq and Nextera methods. Viral metagenomics sequencing was able to simultaneously detect up to 22 different viruses in the biological reagent analyzed including all those detected by qPCR. Further optimization will be required for the detection of viruses in biologically more complex samples such as tissues, blood, or feces. PMID:25497414

  20. Comparing viral metagenomics methods using a highly multiplexed human viral pathogens reagent.

    PubMed

    Li, Linlin; Deng, Xutao; Mee, Edward T; Collot-Teixeira, Sophie; Anderson, Rob; Schepelmann, Silke; Minor, Philip D; Delwart, Eric

    2015-03-01

    Unbiased metagenomic sequencing holds significant potential as a diagnostic tool for the simultaneous detection of any previously genetically described viral nucleic acids in clinical samples. Viral genome sequences can also inform on likely phenotypes including drug susceptibility or neutralization serotypes. In this study, different variables of the laboratory methods often used to generate viral metagenomics libraries were compared for their abilities to detect multiple viruses and generate full genome coverage. A biological reagent consisting of 25 different human RNA and DNA viral pathogens was used to estimate the effect of filtration and nuclease digestion, DNA/RNA extraction methods, pre-amplification and the use of different library preparation kits on the detection of viral nucleic acids. Filtration and nuclease treatment led to slight decreases in the percentage of viral sequence reads and number of viruses detected. For nucleic acid extractions silica spin columns improved viral sequence recovery relative to magnetic beads and Trizol extraction. Pre-amplification using random RT-PCR while generating more viral sequence reads resulted in detection of fewer viruses, more overlapping sequences, and lower genome coverage. The ScriptSeq library preparation method retrieved more viruses and a greater fraction of their genomes than the TruSeq and Nextera methods. Viral metagenomics sequencing was able to simultaneously detect up to 22 different viruses in the biological reagent analyzed including all those detected by qPCR. Further optimization will be required for the detection of viruses in biologically more complex samples such as tissues, blood, or feces.

  1. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil.

    PubMed

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H B

    2009-11-01

    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 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As far as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens. PMID:20066953

  2. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil.

    PubMed

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H B

    2009-11-01

    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 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As far as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens.

  3. Comparative study of ranavirus isolates from cod (Gadus morhua) and turbot (Psetta maxima) with reference to other ranaviruses.

    PubMed

    Ariel, Ellen; Holopainen, Riikka; Olesen, Niels Jørgen; Tapiovaara, Hannele

    2010-08-01

    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 sequenced, and the sequences obtained were used in phylogenetic analysis. In addition, the pathogenicity to rainbow trout under experimental challenge conditions was investigated. The viruses were serologically and genetically closely related to highly pathogenic ranaviruses such as European catfish iridovirus (ECV), European sheatfish iridovirus (ESV) and epizootic haematopoietic necrosis virus (EHNV). The challenge trials indicate that rainbow trout fry cultured at 15 degrees C are not target species for the virus isolates in the present panel. We suggest that the two isolates belong in the genus Ranavirus and propose the name Ranavirus maxima (Rmax) for the turbot isolate.

  4. The genome sequence of the emerging common midwife toad virus identifies an evolutionary intermediate within ranaviruses.

    PubMed

    Mavian, Carla; López-Bueno, Alberto; Balseiro, Ana; Casais, Rosa; Alcamí, Antonio; Alejo, Alí

    2012-04-01

    Worldwide amphibian population declines have been ascribed to global warming, increasing pollution levels, and other factors directly related to human activities. These factors may additionally be favoring the emergence of novel pathogens. In this report, we have determined the complete genome sequence of the emerging common midwife toad ranavirus (CMTV), which has caused fatal disease in several amphibian species across Europe. Phylogenetic and gene content analyses of the first complete genomic sequence from a ranavirus isolated in Europe show that CMTV is an amphibian-like ranavirus (ALRV). However, the CMTV genome structure is novel and represents an intermediate evolutionary stage between the two previously described ALRV groups. We find that CMTV clusters with several other ranaviruses isolated from different hosts and locations which might also be included in this novel ranavirus group. This work sheds light on the phylogenetic relationships within this complex group of emerging, disease-causing viruses.

  5. The Genome Sequence of the Emerging Common Midwife Toad Virus Identifies an Evolutionary Intermediate within Ranaviruses

    PubMed Central

    Mavian, Carla; López-Bueno, Alberto; Balseiro, Ana; Casais, Rosa; Alcamí, Antonio

    2012-01-01

    Worldwide amphibian population declines have been ascribed to global warming, increasing pollution levels, and other factors directly related to human activities. These factors may additionally be favoring the emergence of novel pathogens. In this report, we have determined the complete genome sequence of the emerging common midwife toad ranavirus (CMTV), which has caused fatal disease in several amphibian species across Europe. Phylogenetic and gene content analyses of the first complete genomic sequence from a ranavirus isolated in Europe show that CMTV is an amphibian-like ranavirus (ALRV). However, the CMTV genome structure is novel and represents an intermediate evolutionary stage between the two previously described ALRV groups. We find that CMTV clusters with several other ranaviruses isolated from different hosts and locations which might also be included in this novel ranavirus group. This work sheds light on the phylogenetic relationships within this complex group of emerging, disease-causing viruses. PMID:22301140

  6. Collapse of amphibian communities due to an introduced Ranavirus.

    PubMed

    Price, Stephen J; Garner, Trenton W J; Nichols, Richard A; Balloux, François; Ayres, César; Mora-Cabello de Alba, Amparo; Bosch, Jaime

    2014-11-01

    The emergence of infectious diseases with a broad host range can have a dramatic impact on entire communities and has become one of the main threats to biodiversity. Here, we report the simultaneous exploitation of entire communities of potential hosts with associated severe declines following invasion by a novel viral pathogen. We found two phylogenetically related, highly virulent viruses (genus Ranavirus, family Iridoviridae) causing mass mortality in multiple, diverse amphibian hosts in northern Spain, as well as a third, relatively avirulent virus. We document host declines in multiple species at multiple sites in the region. Our work reveals a group of pathogens that seem to have preexisting capacity to infect and evade immunity in multiple diverse and novel hosts, and that are exerting massive impacts on host communities. This report provides an exceptional record of host population trends being tracked in real time following emergence of a wildlife disease and a striking example of a novel, generalist pathogen repeatedly crossing the species barrier with catastrophic consequences at the level of host communities.

  7. Collapse of amphibian communities due to an introduced Ranavirus.

    PubMed

    Price, Stephen J; Garner, Trenton W J; Nichols, Richard A; Balloux, François; Ayres, César; Mora-Cabello de Alba, Amparo; Bosch, Jaime

    2014-11-01

    The emergence of infectious diseases with a broad host range can have a dramatic impact on entire communities and has become one of the main threats to biodiversity. Here, we report the simultaneous exploitation of entire communities of potential hosts with associated severe declines following invasion by a novel viral pathogen. We found two phylogenetically related, highly virulent viruses (genus Ranavirus, family Iridoviridae) causing mass mortality in multiple, diverse amphibian hosts in northern Spain, as well as a third, relatively avirulent virus. We document host declines in multiple species at multiple sites in the region. Our work reveals a group of pathogens that seem to have preexisting capacity to infect and evade immunity in multiple diverse and novel hosts, and that are exerting massive impacts on host communities. This report provides an exceptional record of host population trends being tracked in real time following emergence of a wildlife disease and a striking example of a novel, generalist pathogen repeatedly crossing the species barrier with catastrophic consequences at the level of host communities. PMID:25438946

  8. Richness and composition of niche-assembled viral pathogen communities.

    PubMed

    Seabloom, Eric W; Borer, Elizabeth T; Lacroix, Christelle; Mitchell, Charles E; Power, Alison G

    2013-01-01

    The pathogen and parasite community that inhabits every free-living organism can control host vital rates including lifespan and reproductive output. To date, however, there have been few experiments examining pathogen community assembly replicated at large-enough spatial scales to inform our understanding of pathogen dynamics in natural systems. Pathogen community assembly may be driven by neutral stochastic colonization and extinction events or by niche differentiation that constrains pathogen distributions to particular environmental conditions, hosts, or vectors. Here, we present results from a regionally-replicated experiment investigating the community of barley and cereal yellow dwarf viruses (B/CYDV's) in over 5000 experimentally planted individuals of six grass species along a 700 km latitudinal gradient along the Pacific coast of North America (USA) in response to experimentally manipulated nitrogen and phosphorus supplies. The composition of the virus community varied predictably among hosts and across nutrient-addition treatments, indicating niche differentiation among virus species. There were some concordant responses among the viral species. For example, the prevalence of most viral species increased consistently with perennial grass cover, leading to a 60% increase in the richness of the viral community within individual hosts (i.e., coinfection) in perennial-dominated plots. Furthermore, infection rates of the six host species in the field were highly correlated with vector preferences assessed in laboratory trials. Our results reveal the importance of niche differentiation in structuring virus assemblages. Virus species distributions reflected a combination of local host community composition, host species-specific vector preferences, and virus responses to host nutrition. In addition, our results suggest that heterogeneity among host species in their capacity to attract vectors or support pathogens between growing seasons can lead to positive

  9. Introduction of ranavirus to isolated wood frog populations could cause local extinction.

    PubMed

    Earl, Julia E; Gray, Matthew J

    2014-12-01

    Amphibian declines and extinction have been attributed to many causes, including disease such as chytridiomycosis. Other pathogens may also contribute to declines, with ranavirus as the most likely candidate given reoccurring die-offs observed in the wild. We were interested in whether it is possible for ranavirus to cause extinction of a local, closed population of amphibians. We used susceptibility data from experimental challenges on different life stages combined with estimates of demographic parameters from a natural population to predict the likelihood of extinction using a stage-structured population model for wood frogs (Lithobates sylvaticus). Extinction was most likely when the larval or metamorph stage was exposed under frequent intervals in smaller populations. Extinction never occurred when only the egg stage was exposed to ranavirus. Under the worst-case scenario, extinction could occur in as quickly as 5 years with exposure every year and 25-44 years with exposure every 2 years. In natural wood frog populations, die-offs typically occur in the larval stage and can reoccur in subsequent years, indicating that our simulations represent possible scenarios. Additionally, wood frog populations are particularly sensitive to changes in survival during the pre-metamorphic stages when ranavirus tends to be most pathogenic. Our results suggest that ranavirus could contribute to amphibian species declines, especially for species that are very susceptible to ranavirus with closed populations. We recommend that ranavirus be considered in risk analyses for amphibian species.

  10. Point detection of bacterial and viral pathogens using oral samples

    NASA Astrophysics Data System (ADS)

    Malamud, Daniel

    2008-04-01

    Oral samples, including saliva, offer an attractive alternative to serum or urine for diagnostic testing. This is particularly true for point-of-use detection systems. The various types of oral samples that have been reported in the literature are presented here along with the wide variety of analytes that have been measured in saliva and other oral samples. The paper focuses on utilizing point-detection of infectious disease agents, and presents work from our group on a rapid test for multiple bacterial and viral pathogens by monitoring a series of targets. It is thus possible in a single oral sample to identify multiple pathogens based on specific antigens, nucleic acids, and host antibodies to those pathogens. The value of such a technology for detecting agents of bioterrorism at remote sites is discussed.

  11. Ranavirus: past, present and future.

    PubMed

    Lesbarrères, D; Balseiro, A; Brunner, J; Chinchar, V G; Duffus, A; Kerby, J; Miller, D L; Robert, J; Schock, D M; Waltzek, T; Gray, M J

    2012-08-23

    Emerging infectious diseases are a significant threat to global biodiversity. While historically overlooked, a group of iridoviruses in the genus Ranavirus has been responsible for die-offs in captive and wild amphibian, reptile and fish populations around the globe over the past two decades. In order to share contemporary information on ranaviruses and identify critical research directions, the First International Symposium on Ranaviruses was held in July 2011 in Minneapolis, MN, USA. Twenty-three scientists and veterinarians from nine countries examined the ecology and evolution of ranavirus-host interactions, potential reservoirs, transmission dynamics, as well as immunological and histopathological responses to infection. In addition, speakers discussed possible mechanisms for die-offs, and conservation strategies to control outbreaks.

  12. High susceptibility of the endangered dusky gopher frog to ranavirus.

    PubMed

    Sutton, William B; Gray, Matthew J; Hardman, Rebecca H; Wilkes, Rebecca P; Kouba, Andrew J; Miller, Debra L

    2014-11-13

    Amphibians are one of the most imperiled vertebrate groups, with pathogens playing a role in the decline of some species. Rare species are particularly vulnerable to extinction because populations are often isolated and exist at low abundance. The potential impact of pathogens on rare amphibian species has seldom been investigated. The dusky gopher frog Lithobates sevosus is one of the most endangered amphibian species in North America, with 100-200 individuals remaining in the wild. Our goal was to determine whether adult L. sevosus were susceptible to ranavirus, a pathogen responsible for amphibian die-offs worldwide. We tested the relative susceptibility of adult L. sevosus to ranavirus (103 plaque-forming units) isolated from a morbid bullfrog via 3 routes of exposure: intra-coelomic (IC) injection, oral (OR) inoculation, and water bath (WB) exposure. We observed 100% mortality of adult L. sevosus in the IC and WB treatments after 10 and 19 d, respectively. Ninety-five percent mortality occurred in the OR treatment over the 28 d evaluation period. No mortality was observed in the control treatment after 28 d. Our results indicate that L. sevosus is susceptible to ranavirus, and if adults in the wild are exposed to this pathogen, significant mortality could occur. Additionally, our study demonstrates that some adult amphibian species can be very susceptible to ranavirus, which has been often overlooked in North American studies. We recommend that conservation planners consider testing the susceptibility of rare amphibian species to ranavirus and that the adult age class is included in future challenge experiments. PMID:25392038

  13. High susceptibility of the endangered dusky gopher frog to ranavirus.

    PubMed

    Sutton, William B; Gray, Matthew J; Hardman, Rebecca H; Wilkes, Rebecca P; Kouba, Andrew J; Miller, Debra L

    2014-11-13

    Amphibians are one of the most imperiled vertebrate groups, with pathogens playing a role in the decline of some species. Rare species are particularly vulnerable to extinction because populations are often isolated and exist at low abundance. The potential impact of pathogens on rare amphibian species has seldom been investigated. The dusky gopher frog Lithobates sevosus is one of the most endangered amphibian species in North America, with 100-200 individuals remaining in the wild. Our goal was to determine whether adult L. sevosus were susceptible to ranavirus, a pathogen responsible for amphibian die-offs worldwide. We tested the relative susceptibility of adult L. sevosus to ranavirus (103 plaque-forming units) isolated from a morbid bullfrog via 3 routes of exposure: intra-coelomic (IC) injection, oral (OR) inoculation, and water bath (WB) exposure. We observed 100% mortality of adult L. sevosus in the IC and WB treatments after 10 and 19 d, respectively. Ninety-five percent mortality occurred in the OR treatment over the 28 d evaluation period. No mortality was observed in the control treatment after 28 d. Our results indicate that L. sevosus is susceptible to ranavirus, and if adults in the wild are exposed to this pathogen, significant mortality could occur. Additionally, our study demonstrates that some adult amphibian species can be very susceptible to ranavirus, which has been often overlooked in North American studies. We recommend that conservation planners consider testing the susceptibility of rare amphibian species to ranavirus and that the adult age class is included in future challenge experiments.

  14. Morphological changes in amphibian and fish cell lines infected with Andrias davidianus ranavirus.

    PubMed

    Gao, X C; Chen, Z Y; Yuan, J D; Zhang, Q Y

    2015-01-01

    Andrias davidianus ranavirus (ADRV) is an emerging viral pathogen that causes severe disease in Chinese giant salamanders, the largest extant amphibian in the world. A fish cell line, Epithelioma papulosum cyprinid (EPC), and a new amphibian cell line, Chinese giant salamander spleen cell (GSSC), were infected with ADRV and observed by light and electron microscopy. The morphological changes in these two cell lines infected with ADRV were compared. Cytopathic effect (CPE) began with rounding of the cells, progressing to cell detachment in the cell monolayer, followed by cell lysis. Significant CPE was visualized as early as 24 h post infection (hpi) in EPC cells and at 36 hpi in GSSC cells. Microscopical examination showed clear and significant CPE in EPC cells, while less extensive and irregular CPE with some adherent cells remaining was observed in GSSC cells. Following ADRV infection, CPE became more extensive. Transmission electron micrographs showed many virus particles around cytoplasmic vacuoles, formed as crystalline arrays or scattered in the cytoplasm of infected cells. Infected cells showed alteration in nuclear morphology, with condensed and marginalized nuclear chromatin on the inner aspect of the nuclear membrane and formation of a cytoplasmic viromatrix adjacent to the nucleus in both cell lines. Some virus particles were also detected in the nucleus of infected GSSC cells. Both cell lines are able to support replication of ADRV and can therefore be used to investigate amphibian ranaviruses.

  15. [Efficient approach for potato viral pathogen sensitive diagnostic and identification].

    PubMed

    Riazantsev, D Iu; Zavriev, S K

    2009-01-01

    Potato, one of the most widespread agricultural plants in Russia, is strongly affected by various pathogens of viral, bacterial, and fungal origin as well as by pests. Their simple and accurate diagnostics and identification sound rather important both for production of virus free planting material and to perform monitoring of the phytosanitary state of planting areas. Based on qualitative Fluorescent Amplification--based Specific Hybridization Polymerase Chain Reaction (FLASH-PCR) we have developed the diagnostic systems, which provided fast, careful, and with the minimum risk of contamination in the working zone by amplification products, detection of the major potato pathogens, i. e. A, Y, X, M, S potato viruses, potato leafroll virus, potato mop top virus, as well as potato spindle tuber viroids. PMID:19548542

  16. Infection and co-infection by the amphibian chytrid fungus and ranavirus in wild Costa Rican frogs.

    PubMed

    Whitfield, Steven M; Geerdes, Erica; Chacon, Iria; Ballestero Rodriguez, Erick; Jimenez, Randall R; Donnelly, Maureen A; Kerby, Jacob L

    2013-05-27

    Amphibian populations are globally threatened by emerging infectious diseases, and 2 pathogens in particular are recognized as major threats: the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) and ranaviruses. Here, we evaluated the prevalence of infection by Bd and ranavirus in an assemblage of frogs from a lowland wet forest in Costa Rica. We found an overall prevalence of 21.3% for Bd and 16.6% for ranavirus, and detected both pathogens widely among our 20 sampled species. We found a positive association between ranavirus and Bd infection in one of our 4 most commonly sampled species. We also found a positive but non-significant association between infection by ranavirus and infection by Bd among species overall. Our study is among the first detailed evaluations of ranavirus prevalence in the American tropics, and to our knowledge is the first to detect a positive association between Bd and ranavirus in any species. Considerable research attention has focused on the ecology of Bd in tropical regions, yet we argue that greater research focus is necessary to understand the ecology and conservation impact of ranaviruses on amphibian populations already decimated by the emergence of Bd.

  17. Investigation of ornamental fish entering the EU for the presence of ranaviruses.

    PubMed

    Vesely, T; Cinkova, K; Reschova, S; Gobbo, F; Ariel, E; Vicenova, M; Pokorova, D; Kulich, P; Bovo, G

    2011-02-01

    A survey was performed on ornamental fish imported into the EU to detect viral agents belonging to the genus Ranavirus. The objective was to gain knowledge of the potential for these systemic iridoviruses to gain entry into the EU via international trade in ornamental fish. A total of 208 pooled samples, representing 753 individual fish, were tested. The samples included 13 orders and 37 families, originating from different countries and continents. Tissues from fish that died during or just after transport were collected and examined by standard virological techniques in epithelioma papulosum cyprini cells, by transmission electron microscopy and by PCR for the detection of the major capsid protein and DNA polymerase gene sequences of ranaviruses. Virus was isolated from nine fish species but ranavirus was not identified in those samples. The results suggest that ranaviruses are not highly prevalent in ornamental fish imported into the EU.

  18. Expression analysis of immune response genes in fish epithelial cells following ranavirus infection.

    PubMed

    Holopainen, Riikka; Tapiovaara, Hannele; Honkanen, Jarno

    2012-06-01

    Ranaviruses (family Iridoviridae) are a growing threat to fish and amphibian populations worldwide. The immune response to ranavirus infection has been studied in amphibians, but little is known about the responses elicited in piscine hosts. In this study, the immune response and apoptosis induced by ranaviruses were investigated in fish epithelial cells. Epithelioma papulosum cyprini (EPC) cells were infected with four different viral isolates: epizootic haematopoietic necrosis virus (EHNV), frog virus 3 (FV3), European catfish virus (ECV) and doctor fish virus (DFV). Quantitative real-time PCR (qPCR) assays were developed to measure the mRNA expression of immune response genes during ranavirus infection. The target genes included tumour necrosis factor α (TNF-α), interleukin-1β (IL-1β), β2-microglobulin (β2M), interleukin-10 (IL-10) and transforming growth factor β (TGF-β). All ranaviruses elicited changes in immune gene expression. EHNV and FV3 caused a strong pro-inflammatory response with an increase in the expression of both IL-1β and TNF-α, whereas ECV and DFV evoked transient up-regulation of regulatory cytokine TGF-β. Additionally, all viral isolates induced increased β2M expression as well as apoptosis in the EPC cells. Our results indicate that epithelial cells can serve as an in vitro model for studying the mechanisms of immune response in the piscine host in the first stages of ranavirus infection.

  19. RANAVIRUS CAUSES MASS DIE-OFFS OF ALPINE AMPHIBIANS IN THE SOUTHWESTERN ALPS, FRANCE.

    PubMed

    Miaud, Claude; Pozet, Françoise; Gaudin, Nadine Curt Grand; Martel, An; Pasmans, Frank; Labrut, Sophie

    2016-04-28

    Pathogenic fungi and viruses cause mortality outbreaks in wild amphibians worldwide. In the summer of 2012, dead tadpoles and adults of the European common frog Rana temporaria were reported in alpine lakes in the southwestern Alps (Mercantour National Park, France). A preliminary investigation using molecular diagnostic techniques identified a Ranavirus as the potential pathogenic agent. Three mortality events were recorded in the park, and samples were collected. The amphibian chytrid fungus Batrachochytrium dendrobatidis was not detected in any of the dead adult and juvenile frogs sampled (n=16) whereas all specimens were positive for a Ranavirus. The genome sequence of this Ranavirus was identical to previously published sequences of the common midwife toad virus (CMTV), a Ranavirus that has been associated with amphibian mortalities throughout Europe. We cultured virus from the organs of the dead common frogs and infecting adult male common frogs collected in another alpine region where no frog mortality had been observed. The experimentally infected frogs suffered 100% mortality (n=10). The alpine die-off is the first CMTV outbreak associated with mass mortality in wild amphibians in France. We describe the lesions observed and summarize amphibian populations affected by Ranaviruses in Europe. In addition, we discuss the ecologic specificities of mountain amphibians that may contribute to increasing their risk of exposure to and transmission of Ranaviruses.

  20. RANAVIRUS CAUSES MASS DIE-OFFS OF ALPINE AMPHIBIANS IN THE SOUTHWESTERN ALPS, FRANCE.

    PubMed

    Miaud, Claude; Pozet, Françoise; Gaudin, Nadine Curt Grand; Martel, An; Pasmans, Frank; Labrut, Sophie

    2016-04-28

    Pathogenic fungi and viruses cause mortality outbreaks in wild amphibians worldwide. In the summer of 2012, dead tadpoles and adults of the European common frog Rana temporaria were reported in alpine lakes in the southwestern Alps (Mercantour National Park, France). A preliminary investigation using molecular diagnostic techniques identified a Ranavirus as the potential pathogenic agent. Three mortality events were recorded in the park, and samples were collected. The amphibian chytrid fungus Batrachochytrium dendrobatidis was not detected in any of the dead adult and juvenile frogs sampled (n=16) whereas all specimens were positive for a Ranavirus. The genome sequence of this Ranavirus was identical to previously published sequences of the common midwife toad virus (CMTV), a Ranavirus that has been associated with amphibian mortalities throughout Europe. We cultured virus from the organs of the dead common frogs and infecting adult male common frogs collected in another alpine region where no frog mortality had been observed. The experimentally infected frogs suffered 100% mortality (n=10). The alpine die-off is the first CMTV outbreak associated with mass mortality in wild amphibians in France. We describe the lesions observed and summarize amphibian populations affected by Ranaviruses in Europe. In addition, we discuss the ecologic specificities of mountain amphibians that may contribute to increasing their risk of exposure to and transmission of Ranaviruses. PMID:26967128

  1. Interferon Induction by RNA Viruses and Antagonism by Viral Pathogens

    PubMed Central

    Nan, Yuchen; Nan, Guoxin; Zhang, Yan-Jin

    2014-01-01

    Interferons are a group of small proteins that play key roles in host antiviral innate immunity. Their induction mainly relies on host pattern recognition receptors (PRR). Host PRR for RNA viruses include Toll-like receptors (TLR) and retinoic acid-inducible gene I (RIG-I) like receptors (RLR). Activation of both TLR and RLR pathways can eventually lead to the secretion of type I IFNs, which can modulate both innate and adaptive immune responses against viral pathogens. Because of the important roles of interferons, viruses have evolved multiple strategies to evade host TLR and RLR mediated signaling. This review focuses on the mechanisms of interferon induction and antagonism of the antiviral strategy by RNA viruses. PMID:25514371

  2. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    PubMed

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    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.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models.

  3. 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.

    PubMed

    Hausmann, Jennifer C; Wack, Allison N; Allender, Matthew C; Cranfield, Mike R; Murphy, Kevin J; Barrett, Kevin; Romero, Jennell L; Wellehan, James F X; Blum, Stella A; Zink, M Christine; Bronson, Ellen

    2015-12-01

    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 control turtles received saline intramuscularly. The turtles were monitored for 8 wk with blood and oral swabs collected for quantitative polymerase chain reaction (qPCR). During that time, one of seven (14%) inoculated turtles and none of the controls (0%) died; there was no significant difference in survival. Clinical signs of the inoculated turtles, except for the turtle that died, were mild compared to the original outbreak. Quantitative PCR for FV3-like ranavirus on blood and oral swabs was positive for all inoculated turtles and negative for all controls. The turtle that died had intracytoplasmic inclusion bodies in multiple organs. Three inoculated and two control turtles were euthanized at the end of the study. No inclusion bodies were present in any of the organs. Quantitative PCR detected FV3-like ranavirus in the spleen of a control turtle, which suggested persistence of the virus. The surviving five turtles were qPCR-negative for FV3-like ranavirus from blood and oral swabs after brumation. Quantitative PCR for Terrapene herpesvirus 1 found no association between ranavirus infection and herpesvirus loads. In conclusion, previously infected eastern box turtles can be reinfected with the same strain of FV3-like ranavirus and show mild to no clinical signs but can shed the virus from the oral cavity.

  4. Trends in Ranavirus Prevalence Among Plethodontid Salamanders in the Great Smoky Mountains National Park.

    PubMed

    Sutton, William B; Gray, Matthew J; Hoverman, Jason T; Secrist, Richard G; Super, Paul E; Hardman, Rebecca H; Tucker, Jennifer L; Miller, Debra L

    2015-06-01

    Emerging pathogens are a potential contributor to global amphibian declines. Ranaviruses, which infect ectothermic vertebrates and are common in aquatic environments, have been implicated in die-offs of at least 72 amphibian species worldwide. Most studies on the subject have focused on pool-breeding amphibians, and infection trends in other amphibian species assemblages have been understudied. Our primary study objective was to evaluate hypotheses explaining ranavirus prevalence within a lungless salamander assemblage (Family Plethodontidae) in the Great Smoky Mountains National Park, USA. We sampled 566 total plethodontid salamanders representing 14 species at five sites over a 6-year period (2007-2012). We identified ranavirus-positive individuals in 11 of the 14 (78.6%) sampled species, with salamanders in the genus Desmognathus having greatest infection prevalence. Overall, we found the greatest support for site elevation and sampling year determining infection prevalence. We detected the greatest number of infections in 2007 with 82.5% of sampled individuals testing positive for ranavirus, which we attribute to record drought during this year. Infection prevalence remained relatively high in low-elevation sites in 2008 and 2009. Neither body condition nor aquatic dependence was a significant predictor of ranavirus prevalence. Overall, our results indicate that life history differences among species play a minor role determining ranavirus prevalence compared to the larger effects of site elevation and yearly fluctuations (likely due to environmental stressors) during sampling years. PMID:25537630

  5. Phylogeny, life history, and ecology contribute to differences in amphibian susceptibility to ranaviruses.

    PubMed

    Hoverman, Jason T; Gray, Matthew J; Haislip, Nathan A; Miller, Debra L

    2011-09-01

    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 susceptibility of different species. Using a series of laboratory exposure experiments and comparative phylogenetics, we compared the susceptibilities of 19 amphibian species from two salamander families and five anurans families for two ranavirus isolates: frog virus 3 (FV3) and an FV3-like isolate from an American bullfrog culture facility. We discovered that ranaviruses were capable of infecting 17 of the 19 larval amphibian species tested with mortality ranging from 0 to 100%. Phylogenetic comparative methods demonstrated that species within the anuran family Ranidae were generally more susceptible to ranavirus infection compared to species from the other five families. We also found that susceptibility to infection was associated with species that breed in semi-permanent ponds, develop rapidly as larvae, and have limited range sizes. Collectively, these results suggest that phylogeny, life history characteristics, and habitat associations of amphibians have the potential to impact susceptibility to ranaviruses. PMID:22071720

  6. Trends in Ranavirus Prevalence Among Plethodontid Salamanders in the Great Smoky Mountains National Park.

    PubMed

    Sutton, William B; Gray, Matthew J; Hoverman, Jason T; Secrist, Richard G; Super, Paul E; Hardman, Rebecca H; Tucker, Jennifer L; Miller, Debra L

    2015-06-01

    Emerging pathogens are a potential contributor to global amphibian declines. Ranaviruses, which infect ectothermic vertebrates and are common in aquatic environments, have been implicated in die-offs of at least 72 amphibian species worldwide. Most studies on the subject have focused on pool-breeding amphibians, and infection trends in other amphibian species assemblages have been understudied. Our primary study objective was to evaluate hypotheses explaining ranavirus prevalence within a lungless salamander assemblage (Family Plethodontidae) in the Great Smoky Mountains National Park, USA. We sampled 566 total plethodontid salamanders representing 14 species at five sites over a 6-year period (2007-2012). We identified ranavirus-positive individuals in 11 of the 14 (78.6%) sampled species, with salamanders in the genus Desmognathus having greatest infection prevalence. Overall, we found the greatest support for site elevation and sampling year determining infection prevalence. We detected the greatest number of infections in 2007 with 82.5% of sampled individuals testing positive for ranavirus, which we attribute to record drought during this year. Infection prevalence remained relatively high in low-elevation sites in 2008 and 2009. Neither body condition nor aquatic dependence was a significant predictor of ranavirus prevalence. Overall, our results indicate that life history differences among species play a minor role determining ranavirus prevalence compared to the larger effects of site elevation and yearly fluctuations (likely due to environmental stressors) during sampling years.

  7. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil

    PubMed Central

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F.; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A.; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H. B.

    2010-01-01

    Ranviruses (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 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As for as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens. PMID:20066953

  8. Susceptibility of the European common frog Rana temporaria to a panel of ranavirus isolates from fish and amphibian hosts.

    PubMed

    Bayley, Amanda E; Hill, Barry J; Feist, Stephen W

    2013-04-11

    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 spread of ranaviral disease in the aquatic environment. We undertook bath infection trials to assess the susceptibility of the European common frog Rana temporaria to 9 ranavirus isolates comprising doctor fish virus (DFV), European sheatfish virus (ESV), epizootic haematopoietic necrosis virus (EHNV), guppy virus 6 (GV6), pike-perch iridovirus (PPIV) and short-finned eel ranavirus (SERV) from fish hosts, and Bohle iridovirus (BIV), frog virus 3 (FV3) and Rana esculenta virus 282/I02 (REV) from amphibians. Animals were challenged as tadpoles at 15 and 20°C and as recent metamorphs at room temperature (20 ± 1°C) to investigate the effect of temperature and amphibian developmental stage on virus pathogenicity. Tadpoles were susceptible to FV3, PPIV and REV, but refractory to the other ranaviruses. Post-metamorphs were susceptible to FV3 and REV but refractory to BIV (the other ranaviruses were not tested). Significant mortality occurred in post-metamorphs and in tadpoles challenged at 20°C but was low in tadpoles challenged at 15°C. This study presents the first evidence of mortality in an amphibian species after challenge with ranavirus originally isolated from fish.

  9. The role of respiratory syncytial virus and other viral pathogens in acute otitis media.

    PubMed

    Klein, B S; Dollete, F R; Yolken, R H

    1982-07-01

    We utilized recently developed enzyme immunoassay techniques to examine the role of selected viruses in the etiology of acute otitis media. Viral pathogens were found in middle ear fluids obtained from 13 (24%) of 53 children with acute otitis media; respiratory syncytial virus accounted for ten of the 13 viral agents identified. In addition, respiratory syncytial viral antigen was found in nasopharyngeal washings obtained from 15 of the 53 children. Seven of these children had RSV identified as the sole middle ear pathogen, whereas six children had otitis caused by Streptococcus pneumoniae as either the sole middle ear pathogen or in combination with RSV. Similarly, all three children with respiratory infections caused by influenza virus had ear infections caused by bacterial pathogens, either alone or in combination with influenza virus. These findings suggest that, in patients with viral respiratory infection, coexisting acute otitis media may be associated with the recovery of either viruses or bacteria from the middle ear exudates.

  10. Long-Term Care Facilities: A Cornucopia of Viral Pathogens

    PubMed Central

    Falsey, Ann R.; Dallal, Gerard E.; Formica, Maria A.; Andolina, Gloria G.; Hamer, Davidson H.; Leka, Lynette L.; Meydani, Simin Nikbin

    2010-01-01

    Objectives To determine the frequency and types of respiratory viruses circulating in Boston long-term care facilities (LTCFs) during a 3-year period. Design Observational. Setting Thirty-three Boston-area LTCFs over a 3-year period. Participants Residents of long-term care who had previously participated in a trial of vitamin E supplementation and had paired serum samples available for viral analysis. Measurements Viral antibody titers to eight respiratory viruses (influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus serotype three (PIV-3), PIV-2, human metapneumovirus (hMPV), and coronaviruses 229E and OC43) were measured using enzyme immunoassay at baseline and 53 weeks. Infection was defined as a more than quadrupling of viral titers. Clinical data on respiratory illnesses were collected throughout the study period. Results A total of 617 persons were enrolled in the trial. Of these, 382 (62%) had sera available for viral analysis. A total of 204 viral infections were documented in 157 subjects. Serological responses to all eight viruses were documented, with hMPV (12.8%) and coronavirus 229E (10.5%) being the most common and PIV-2 (2.4%) the least common. The occurrence of bronchitis (P = .007), pneumonia (P = .02), and any lower respiratory tract infection (P = .002) was significantly associated with having a viral diagnosis. Conclusion A wide range of respiratory viruses cocirculates in LTCFs and contributes to respiratory illness morbidity in these populations. PMID:18557966

  11. First report of a ranavirus associated with morbidity and mortality in farmed Chinese giant salamanders (Andrias davidianus).

    PubMed

    Geng, Y; Wang, K Y; Zhou, Z Y; Li, C W; Wang, J; He, M; Yin, Z Q; Lai, W M

    2011-07-01

    From February to May 2010, an outbreak of disease occurred amongst farmed Chinese giant salamanders (Andrias davidianus) in Hanzhong County, Shanxi Province, China. Clinical signs included anorexia, lethargy, ecchymoses and swollen areas on the head and limbs, and skin ulceration. The aim of this study was to determine the cause of this disease. Necropsy examination revealed subcutaneous and intramuscular oedema, swollen and pale livers with multifocal haemorrhage, swollen kidneys with multifocal haemorrhage and distended fluid-filled intestines with areas of haemorrhage. Light microscopy revealed intracytoplasmic inclusions suggestive of a viral infection in a variety of organs, as well as degeneration and necrosis of these organs. Electron microscopy of ultrathin sections of the same tissues revealed iridovirus-like particles within the inclusions. Of the six specimens tested, all were positive for ranavirus major capsid protein (MCP) gene. Sequence alignments of the ranavirus MCP gene from these specimens showed 95-98% similarity with published ranavirus data. The virus, provisionally designated as Chinese giant salamander virus (CGSV), was isolated from tissue homogenates of diseased salamanders following inoculation of epithelioma papilloma cyprini cells. Sequence analysis of the MCP genes showed that the isolated virus was a ranavirus with marked sequence identity to other members of the genus Ranavirus. Koch's postulates were fulfilled by infecting healthy Chinese giant salamanders with the CGSV. These salamanders all died within 6-8 days. This is the first report of ranavirus infection associated with mass mortality in Chinese giant salamanders.

  12. High occupancy of stream salamanders despite high ranavirus prevalence in a southern appalachians watershed.

    PubMed

    Rothermel, Betsie B; Travis, Emilie R; Miller, Debra L; Hill, Robert L; McGuire, Jessica L; Yabsley, Michael J

    2013-06-01

    The interactive effects of environmental stressors and emerging infectious disease pose potential threats to stream salamander communities and their headwater stream ecosystems. To begin assessing these threats, we conducted occupancy surveys and pathogen screening of stream salamanders (Family Plethodontidae) in a protected southern Appalachians watershed in Georgia and North Carolina, USA. Of the 101 salamanders screened for both chytrid fungus (Batrachochytrium dendrobatidis) and Ranavirus, only two exhibited low-level chytrid infections. Prevalence of Ranavirus was much higher (30.4% among five species of Desmognathus). Despite the ubiquity of ranaviral infections, we found high probabilities of site occupancy (≥0.60) for all stream salamander species.

  13. Phylogenetic analysis of a frog virus 3-like ranavirus found at a site with recurrent mortality and morbidity events in southeastern Ontario, Canada: partial major capsid protein sequence alone is not sufficient for fine-scale differentiation.

    PubMed

    Duffus, Amanda L J; Andrews, Abby M

    2013-04-01

    Ranaviruses are emerging pathogens of amphibians. We examined the phylogenetic relationship of ranaviruses from infected Lithobates sylvaticus tadpoles 2001-2004 from Oliver Pond, Ontario, Canada. The isolates sequenced are primarily frog virus 3-like, but because of sequence convergence, finer-scale analysis based on the major capsid protein was uninformative.

  14. First evidence of amphibian chytrid fungus (Batrachochytrium dendrobatidis) and ranavirus in Hong Kong amphibian trade.

    PubMed

    Kolby, Jonathan E; Smith, Kristine M; Berger, Lee; Karesh, William B; Preston, Asa; Pessier, Allan P; Skerratt, Lee F

    2014-01-01

    The emerging infectious amphibian diseases caused by amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranaviruses are responsible for global amphibian population declines and extinctions. Although likely to have been spread by a variety of activities, transcontinental dispersal appears closely associated with the international trade in live amphibians. The territory of Hong Kong reports frequent, high volume trade in amphibians, and yet the presence of Bd and ranavirus have not previously been detected in either traded or free-ranging amphibians. In 2012, a prospective surveillance project was conducted to investigate the presence of these pathogens in commercial shipments of live amphibians exported from Hong Kong International Airport. Analysis of skin (Bd) and cloacal (ranavirus) swabs by quantitative PCR detected pathogen presence in 31/265 (11.7%) and in 105/185 (56.8%) of amphibians, respectively. In addition, the water in which animals were transported tested positive for Bd, demonstrating the risk of pathogen pollution by the disposal of untreated wastewater. It is uncertain whether Bd and ranavirus remain contained within Hong Kong's trade sector, or if native amphibians have already been exposed. Rapid response efforts are now urgently needed to determine current pathogen distribution in Hong Kong, evaluate potential trade-associated exposure to free-ranging amphibians, and identify opportunities to prevent disease establishment.

  15. First Evidence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Hong Kong Amphibian Trade

    PubMed Central

    Kolby, Jonathan E.; Smith, Kristine M.; Berger, Lee; Karesh, William B; Preston, Asa; Pessier, Allan P.; Skerratt, Lee F.

    2014-01-01

    The emerging infectious amphibian diseases caused by amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranaviruses are responsible for global amphibian population declines and extinctions. Although likely to have been spread by a variety of activities, transcontinental dispersal appears closely associated with the international trade in live amphibians. The territory of Hong Kong reports frequent, high volume trade in amphibians, and yet the presence of Bd and ranavirus have not previously been detected in either traded or free-ranging amphibians. In 2012, a prospective surveillance project was conducted to investigate the presence of these pathogens in commercial shipments of live amphibians exported from Hong Kong International Airport. Analysis of skin (Bd) and cloacal (ranavirus) swabs by quantitative PCR detected pathogen presence in 31/265 (11.7%) and in 105/185 (56.8%) of amphibians, respectively. In addition, the water in which animals were transported tested positive for Bd, demonstrating the risk of pathogen pollution by the disposal of untreated wastewater. It is uncertain whether Bd and ranavirus remain contained within Hong Kong’s trade sector, or if native amphibians have already been exposed. Rapid response efforts are now urgently needed to determine current pathogen distribution in Hong Kong, evaluate potential trade-associated exposure to free-ranging amphibians, and identify opportunities to prevent disease establishment. PMID:24599268

  16. DEVELOPMENT OF BIOMARKER OF EXPOSURE TO VIRAL PATHOGENS

    EPA Science Inventory

    Interferon gamma (IFN-γ) was selected as a biomarker for a viral exposure study. Twelve-week-old BALB/c mice were intraperitoneally injected with 0.2ml of 104 PFU/ml of coxsackievirus B3 or B4 diluted in phosphate-buffered saline (PBS). Control mice were injected with PBS on...

  17. Differential host response, rather than early viral replication efficiency, correlates with pathogenicity caused by influenza viruses.

    PubMed

    Askovich, Peter S; Sanders, Catherine J; Rosenberger, Carrie M; Diercks, Alan H; Dash, Pradyot; Navarro, Garnet; Vogel, Peter; Doherty, Peter C; Thomas, Paul G; Aderem, Alan

    2013-01-01

    Influenza viruses exhibit large, strain-dependent differences in pathogenicity in mammalian hosts. Although the characteristics of severe disease, including uncontrolled viral replication, infection of the lower airway, and highly inflammatory cytokine responses have been extensively documented, the specific virulence mechanisms that distinguish highly pathogenic strains remain elusive. In this study, we focused on the early events in influenza infection, measuring the growth rate of three strains of varying pathogenicity in the mouse airway epithelium and simultaneously examining the global host transcriptional response over the first 24 hours. Although all strains replicated equally rapidly over the first viral life-cycle, their growth rates in both lung and tracheal tissue strongly diverged at later times, resulting in nearly 10-fold differences in viral load by 24 hours following infection. We identified separate networks of genes in both the lung and tracheal tissues whose rapid up-regulation at early time points by specific strains correlated with a reduced viral replication rate of those strains. The set of early-induced genes in the lung that led to viral growth restriction is enriched for both NF-κB binding site motifs and members of the TREM1 and IL-17 signaling pathways, suggesting that rapid, NF-κB -mediated activation of these pathways may contribute to control of viral replication. Because influenza infection extending into the lung generally results in severe disease, early activation of these pathways may be one factor distinguishing high- and low-pathogenicity strains.

  18. Presence of viral nucleic acids in the middle ear: acute otitis media pathogen or bystander?

    PubMed

    Chonmaitree, Tasnee; Ruohola, Aino; Hendley, J Owen

    2012-04-01

    Viruses play an important role in acute otitis media (AOM) pathogenesis, and live viruses may cause AOM in the absence of pathogenic bacteria. Detection of AOM pathogens generally relies on bacterial culture of middle ear fluid. When viral culture is used and live viruses are detected in the middle ear fluid of children with AOM, the viruses are generally accepted as AOM pathogens. Because viral culture is not sensitive and does not detect the comprehensive spectrum of respiratory viruses, polymerase chain reaction assays are commonly used to detect viral nucleic acids in the middle ear fluid. Although polymerase chain reaction assays have greatly increased the viral detection rate, new questions arise on the significance of viral nucleic acids detected in the middle ear because nucleic acids of multiple viruses are detected simultaneously, and nucleic acids of specific viruses are detected repeatedly and in a high proportion of asymptomatic children. This article first reviews the role of live viruses in AOM and presents the point-counterpoint arguments on whether viral nucleic acids in the middle ear represent an AOM pathogen or a bystander status. Although there is evidence to support both directions, helpful information for interpretation of the data and future research direction is outlined.

  19. Viral pathogen production in a wild grass host driven by host growth and soil nitrogen.

    PubMed

    Whitaker, Briana K; Rúa, Megan A; Mitchell, Charles E

    2015-08-01

    Nutrient limitation is a basic ecological constraint that has received little attention in studies on virus production and disease dynamics. Nutrient availability could directly limit the production of viral nucleic acids and proteins, or alternatively limit host growth and thus indirectly limit metabolic pathways necessary for viral replication. In order to compare direct and indirect effects of nutrient limitation on virus production within hosts, we manipulated soil nitrogen (N) and phosphorus (P) availability in a glasshouse for the wild grass host Bromus hordeaceus and the viral pathogen Barley yellow dwarf virus-PAV. We found that soil N additions increased viral concentrations within host tissues, and the effect was mediated by host growth. Specifically, in statistical models evaluating the roles of host biomass production, leaf N and leaf P, viral production depended most strongly on host biomass, rather than the concentration of either nutrient. Furthermore, at low soil N, larger plants supported greater viral concentrations than smaller ones, whereas at high N, smaller plants supported greater viral concentrations. Our results suggest that enhanced viral productivity under N enrichment is an indirect consequence of nutrient stimulation to host growth rate. Heightened pathogen production in plants has important implications for a world facing increasing rates of nutrient deposition.

  20. Prevalence of infection by Batrachochytrium dendrobatidis and Ranavirus in eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in eastern Tennessee.

    PubMed

    Souza, Marcy J; Gray, Matthew J; Colclough, Phillip; Miller, Debra L

    2012-07-01

    Hellbenders (n=97) were collected from the Little and Hiwassee Rivers in eastern Tennessee, USA, during 2009 and 2010. Location and morphometrics for each animal were recorded, and nonlethal tissue samples were collected to estimate the prevalence of infection with Batrachochytrium dendrobatidis (Bd) and Ranavirus in each watershed and year. Real-time polymerase chain reaction was performed on skin swabs for Bd and on tail clips for ranaviruses. Overall prevalences of DNA of Bd, Ranavirus, and coinfections (i.e., detectable DNA of both pathogens in the same individual) were 26%, 19%, and 5%, respectively. Differences in infection prevalence were detected between watersheds and years. Gross lesions were observed in 31 animals (32%), but the types of lesions were not consistent with chytridiomycosis or ranaviral disease. This is the first report of infection of eastern hellbenders with Bd and Ranavirus. Despite infection by both pathogens, it is unclear whether chytridiomycosis or ranaviral disease develops in wild populations of hellbenders. More research is needed to determine the susceptibility of hellbenders to Bd and ranaviruses and their role in the epidemiology of these pathogens.

  1. Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes.

    PubMed

    Brenes, Roberto; Miller, Debra L; Waltzek, Thomas B; Wilkes, Rebecca P; Tucker, Jennifer L; Chaney, Jordan C; Hardman, Rebecca H; Brand, Mabre D; Huether, Rebecca R; Gray, Matthew J

    2014-06-01

    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 interclass transmission (i.e., infection) and host susceptibility (i.e., percent mortality) for five juvenile fish and three juvenile turtle species exposed to each of these isolates. Exposure was administered via water bath (10(3) PFU/mL) for 3 d and survival was monitored for 28 d. Florida softshell turtles Apalone ferox experienced no mortality, but 10% and 20% of individuals became infected by the turtle and fish isolate, respectively. Similarly, 5% of Mississippi map turtles Graptemys pseudogeographica kohni were subclinically infected with the turtle isolate at the end of the experiment. Channel Catfish Ictalurus punctatus experienced 5% mortality when exposed to the turtle isolate, while Western Mosquitofish Gambusia affinis experienced 10% mortality when exposed to the turtle and amphibian isolates and 5% mortality when exposed to the fish isolate. Our results demonstrated that interclass transmission of FV3-like ranaviruses is possible. Although substantial mortality did not occur in our experiments, the occurrence of low mortality and subclinical infections suggest that fish and aquatic turtles may function as reservoirs for FV3-like ranaviruses. Additionally, our study is the first to report transmission of FV3-like ranaviruses between fish and chelonians. PMID:24895866

  2. Reliability of non-lethal surveillance methods for detecting ranavirus infection.

    PubMed

    Gray, Matthew J; Miller, Debra L; Hoverman, Jason T

    2012-05-15

    Ranaviruses have been identified as the etiologic agent in many amphibian die-offs across the globe. Polymerase chain reaction (PCR) is commonly used to detect ranavirus infection in amphibian hosts, but the test results may vary between tissue samples obtained by lethal and non-lethal procedures. Testing liver samples for infection is a common lethal sampling technique to estimate ranavirus prevalence because the pathogen often targets this organ and the liver is easy to identify and collect. However, tail clips or swabs may be more practicable for ranavirus surveillance programs compared with collecting and euthanizing animals, especially for uncommon species. Using PCR results from liver samples for comparison, we defined false-positive test results as occurrences when a non-lethal technique indicated positive but the liver sample was negative. Similarly, we defined false-negative test results as occurrences when a non-lethal technique was negative but the liver sample was positive. Using these decision rules, we estimated false-negative and false-positive rates for tail clips and swabs. Our study was conducted in a controlled facility using American bullfrog Lithobates catesbeianus tadpoles; false-positive and false-negative rates were estimated after different periods of time following exposure to ranavirus. False-negative and false-positive rates were 20 and 6%, respectively, for tail samples, and 22 and 12%, respectively, for swabs. False-negative rates were constant over time, but false-positive rates decreased with post-exposure duration. Our results suggest that non-lethal sampling techniques can be useful for ranavirus surveillance, although the prevalence of infection may be underestimated when compared to results obtained with liver samples. PMID:22585297

  3. Reliability of non-lethal surveillance methods for detecting ranavirus infection.

    PubMed

    Gray, Matthew J; Miller, Debra L; Hoverman, Jason T

    2012-05-15

    Ranaviruses have been identified as the etiologic agent in many amphibian die-offs across the globe. Polymerase chain reaction (PCR) is commonly used to detect ranavirus infection in amphibian hosts, but the test results may vary between tissue samples obtained by lethal and non-lethal procedures. Testing liver samples for infection is a common lethal sampling technique to estimate ranavirus prevalence because the pathogen often targets this organ and the liver is easy to identify and collect. However, tail clips or swabs may be more practicable for ranavirus surveillance programs compared with collecting and euthanizing animals, especially for uncommon species. Using PCR results from liver samples for comparison, we defined false-positive test results as occurrences when a non-lethal technique indicated positive but the liver sample was negative. Similarly, we defined false-negative test results as occurrences when a non-lethal technique was negative but the liver sample was positive. Using these decision rules, we estimated false-negative and false-positive rates for tail clips and swabs. Our study was conducted in a controlled facility using American bullfrog Lithobates catesbeianus tadpoles; false-positive and false-negative rates were estimated after different periods of time following exposure to ranavirus. False-negative and false-positive rates were 20 and 6%, respectively, for tail samples, and 22 and 12%, respectively, for swabs. False-negative rates were constant over time, but false-positive rates decreased with post-exposure duration. Our results suggest that non-lethal sampling techniques can be useful for ranavirus surveillance, although the prevalence of infection may be underestimated when compared to results obtained with liver samples.

  4. Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes.

    PubMed

    Brenes, Roberto; Miller, Debra L; Waltzek, Thomas B; Wilkes, Rebecca P; Tucker, Jennifer L; Chaney, Jordan C; Hardman, Rebecca H; Brand, Mabre D; Huether, Rebecca R; Gray, Matthew J

    2014-06-01

    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 interclass transmission (i.e., infection) and host susceptibility (i.e., percent mortality) for five juvenile fish and three juvenile turtle species exposed to each of these isolates. Exposure was administered via water bath (10(3) PFU/mL) for 3 d and survival was monitored for 28 d. Florida softshell turtles Apalone ferox experienced no mortality, but 10% and 20% of individuals became infected by the turtle and fish isolate, respectively. Similarly, 5% of Mississippi map turtles Graptemys pseudogeographica kohni were subclinically infected with the turtle isolate at the end of the experiment. Channel Catfish Ictalurus punctatus experienced 5% mortality when exposed to the turtle isolate, while Western Mosquitofish Gambusia affinis experienced 10% mortality when exposed to the turtle and amphibian isolates and 5% mortality when exposed to the fish isolate. Our results demonstrated that interclass transmission of FV3-like ranaviruses is possible. Although substantial mortality did not occur in our experiments, the occurrence of low mortality and subclinical infections suggest that fish and aquatic turtles may function as reservoirs for FV3-like ranaviruses. Additionally, our study is the first to report transmission of FV3-like ranaviruses between fish and chelonians.

  5. Rapid Accurate Identification of Bacterial and Viral Pathogens

    SciTech Connect

    Dunn, John

    2007-03-09

    The goals of this program were to develop two assays for rapid, accurate identification of pathogenic organisms at the strain level. The first assay "Quantitative Genome Profiling or QGP" is a real time PCR assay with a restriction enzyme-based component. Its underlying concept is that certain enzymes should cleave genomic DNA at many sites and that in some cases these cuts will interrupt the connection on the genomic DNA between flanking PCR primer pairs thereby eliminating selected PCR amplifications. When this occurs the appearance of the real-time PCR threshold (Ct) signal during DNA amplification is totally eliminated or, if cutting is incomplete, greatly delayed compared to an uncut control. This temporal difference in appearance of the Ct signal relative to undigested control DNA provides a rapid, high-throughput approach for DNA-based identification of different but closely related pathogens depending upon the nucleotide sequence of the target region. The second assay we developed uses the nucleotide sequence of pairs of shmi identifier tags (-21 bp) to identify DNA molecules. Subtle differences in linked tag pair combinations can also be used to distinguish between closely related isolates..

  6. VIRAL PATHOGENS AND MICROBIOLOGICAL INDICATORS IN GROUND WATER FROM SMALL PUBLIC WATER SUPPLIES IN SOUTHEASTERN MICHIGAN

    EPA Science Inventory

    Thirty-eight public ground-water-supply wells serving less than 3,300 people were sampled from July 1999 through July 2001 in southeastern Michigan to determine (1) occurrence of viral pathogens and microbiological indicators, (2) whether indicators are adequate predictors of the...

  7. Spectrum of Viral Pathogens in Blood of Malaria-Free Ill Travelers Returning to Canada

    PubMed Central

    Kariyawasam, Ruwandi; Lau, Rachel; Eshaghi, Alireza; Patel, Samir N.; Sider, Doug; Gubbay, Jonathan B.

    2016-01-01

    Malaria is the most common specific cause of fever in returning travelers, but many other vectorborne infections and viral infections are emerging and increasingly encountered by travelers. We documented common and emerging viral pathogens in malaria-negative specimens from ill travelers returning to Canada. Anonymized, malaria-negative specimens were examined for various viral pathogens by real-time PCR. Samples were positive for herpes simplex viruses 1 or 2 (n = 21, 1.6%), cytomegalovirus (n = 4, 0.3%), Epstein-Barr virus (n = 194, 14.9%), dengue virus types 1–4 (n = 27, 2.1%), chikungunya virus (n = 5, 0.4%), and hepatitis A virus (n = 12, 0.9%). Travel-acquired viral pathogens were documented in >20% of malaria-negative specimens, of which 2.5% were infected with dengue and chikungunya viruses. Our findings support the anecdotal impression that these vectorborne pathogens are emerging among persons who travel from Canada to other countries. PMID:27089008

  8. RANAVIRUS EPIZOOTIC IN CAPTIVE EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) WITH CONCURRENT HERPESVIRUS AND MYCOPLASMA INFECTION: MANAGEMENT AND MONITORING.

    PubMed

    Sim, Richard R; Allender, Matthew C; Crawford, LaTasha K; Wack, Allison N; Murphy, Kevin J; Mankowski, Joseph L; Bronson, Ellen

    2016-03-01

    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 cases. The remaining 22 animals were isolated, segregated by severity of clinical signs, and treated with nutritional support, fluid therapy, ambient temperature management, antibiotics, and antiviral therapy. Oral swabs were tested serially for FV3-like virus by quantitative real-time PCR (qPCR) and tested at day 0 for herpesvirus and Mycoplasma sp. by conventional PCR. With oral swabs, 77% of the 22 turtles were FV3-like virus positive; however, qPCR on tissues taken during necropsy revealed the true prevalence was 86%. FV3-like virus prevalence and the median number of viral copies being shed significantly declined during the outbreak. The prevalence of herpesvirus and Mycoplasma sp. by PCR of oral swabs at day 0 was 55% and 68%, respectively. The 58% survival rate was higher than previously reported in captive eastern box turtles for a ranavirus epizootic. All surviving turtles brumated normally and emerged the following year with no clinical signs during subsequent monitoring. The immediate initiation of treatment and intensive supportive care were considered the most important contributing factors to the successful outcome in this outbreak. PMID:27010285

  9. RANAVIRUS EPIZOOTIC IN CAPTIVE EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) WITH CONCURRENT HERPESVIRUS AND MYCOPLASMA INFECTION: MANAGEMENT AND MONITORING.

    PubMed

    Sim, Richard R; Allender, Matthew C; Crawford, LaTasha K; Wack, Allison N; Murphy, Kevin J; Mankowski, Joseph L; Bronson, Ellen

    2016-03-01

    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 cases. The remaining 22 animals were isolated, segregated by severity of clinical signs, and treated with nutritional support, fluid therapy, ambient temperature management, antibiotics, and antiviral therapy. Oral swabs were tested serially for FV3-like virus by quantitative real-time PCR (qPCR) and tested at day 0 for herpesvirus and Mycoplasma sp. by conventional PCR. With oral swabs, 77% of the 22 turtles were FV3-like virus positive; however, qPCR on tissues taken during necropsy revealed the true prevalence was 86%. FV3-like virus prevalence and the median number of viral copies being shed significantly declined during the outbreak. The prevalence of herpesvirus and Mycoplasma sp. by PCR of oral swabs at day 0 was 55% and 68%, respectively. The 58% survival rate was higher than previously reported in captive eastern box turtles for a ranavirus epizootic. All surviving turtles brumated normally and emerged the following year with no clinical signs during subsequent monitoring. The immediate initiation of treatment and intensive supportive care were considered the most important contributing factors to the successful outcome in this outbreak.

  10. Structural basis of glycan interaction in gastroenteric viral pathogens

    PubMed Central

    Prasad, B.V. Venkataram; Shanker, Sreejesh; Hu, Liya; Choi, Jae-Mun; Crawford, Sue E; Ramani, Sasirekha; Czako, Rita; Atmar, Robert L; Estes, Mary K

    2014-01-01

    A critical event in the life cycle of a virus is its initial attachment to host cells. This involves recognition by the viruses of specific receptors on the cell surface, including glycans. Viruses typically exhibit strain-dependent variations in recognizing specific glycan receptors, a feature that contributes significantly to cell tropism, host specificity, host adaptation and interspecies transmission. Examples include influenza viruses, noroviruses, rotaviruses, and parvoviruses. Both rotaviruses and noroviruses are well known gastroenteric pathogens that are of significant global health concern. While rotaviruses, in the family Reoviridae, are the major causative agents of life-threatening diarrhea in children, noroviruses, which belong to Caliciviridae family, cause epidemic and sporadic cases of acute gastroenteritis across all age groups. Both exhibit enormous genotypic and serotypic diversity. Consistent with this diversity each exhibits strain-dependent variations in the types of glycans they recognize for cell attachment. This chapter reviews current status of the structural biology of such strain-dependent glycan specificities in these two families of viruses. PMID:25073118

  11. Prominent Amphibian (Xenopus laevis) Tadpole Type III Interferon Response to the Frog Virus 3 Ranavirus

    PubMed Central

    Grayfer, Leon; De Jesús Andino, Francisco

    2015-01-01

    ABSTRACT 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 Xenopus laevis type I (IFN) and III (IFN-λ) IFNs in the context of infections by the ranavirus frog virus 3 (FV3). X. laevis IFN and IFN-λ displayed distinct tissue expression profiles. In contrast to our previous findings that X. laevis tadpoles exhibit delayed and modest type I IFN responses to FV3 infections compared to the responses of adults, here we report that tadpoles mount timely and robust type III IFN gene responses. Recombinant forms of these cytokines (recombinant X. laevis IFN [rXlIFN] and rXlIFN-λ) elicited antiviral gene expression in the kidney-derived A6 cell line as well as in tadpole leukocytes and tissues. However, rXlIFN-λ was less effective than rXlIFN in preventing FV3 replication in A6 cells and tadpoles and inferior at promoting tadpole survival. Intriguingly, FV3 impaired A6 cell and tadpole kidney type III IFN receptor gene expression. Furthermore, in A6 cultures rXlIFN-λ conferred equal or greater protection than rXlIFN against recombinant viruses deficient for the putative immune evasion genes, the viral caspase activation and recruitment domain (vCARD) or a truncated vIF-2α gene. Thus, in contrast to previous assumptions, tadpoles possess intact antiviral defenses reliant on type III IFNs, which are overcome by FV3 pathogens. IMPORTANCE Anuran tadpoles, including those of Xenopus laevis, are particularly susceptible to infection by ranavirus such as FV3. We investigated the respective roles of X. laevis type I and type III

  12. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    PubMed

    Price, Stephen J; Garner, Trenton W J; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H; Moore, Karen; Griffiths, Amber G F

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses), but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research.

  13. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis

    PubMed Central

    Price, Stephen J.; Garner, Trenton W. J.; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H.; Moore, Karen; Griffiths, Amber G. F.

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses), but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research. PMID:26111016

  14. Human ecology in pathogenic landscapes: two hypotheses on how land use change drives viral emergence

    PubMed Central

    Murray, Kris. A.; Daszak, Peter

    2013-01-01

    The emergence of novel viral diseases is driven by socioeconomic, demographic and environmental changes. These include land use changes such as deforestation, agricultural expansion and habitat degradation. However, the links between land use change and disease emergence are poorly understood and likely complex. In this review, we propose two hypotheses for the mechanisms by which land use change can lead to viral emergence: 1) by perturbing disease dynamics in multi-host disease systems via impacts on cross-species transmission rates (the ‘perturbation’ hypothesis); and 2) by allowing exposure of novel hosts to a rich pool of pathogen diversity (the ‘pathogen pool’ hypothesis). We discuss ways that these two hypotheses might be tested using a combination of ecological and virological approaches, and how this may provide novel control and prevention strategies. PMID:23415415

  15. Screening of Viral Pathogens from Pediatric Ileal Tissue Samples after Vaccination

    DOE PAGESBeta

    Hewitson, Laura; Thissen, James B.; Gardner, Shea N.; McLoughlin, Kevin S.; Glausser, Margaret K.; Jaing, Crystal J.

    2014-01-01

    In 2010, researchers reported that the two US-licensed rotavirus vaccines contained DNA or DNA fragments from porcine circovirus (PCV). Although PCV, a common virus among pigs, is not thought to cause illness in humans, these findings raised several safety concerns. In this study, we sought to determine whether viruses, including PCV, could be detected in ileal tissue samples of children vaccinated with one of the two rotavirus vaccines. A broad spectrum, novel DNA detection technology, the Lawrence Livermore Microbial Detection Array (LLMDA), was utilized, and confirmation of viral pathogens using the polymerase chain reaction (PCR) was conducted. The LLMDAmore » technology was recently used to identify PCV from one rotavirus vaccine. Ileal tissue samples were analyzed from 21 subjects, aged 15–62 months. PCV was not detected in any ileal tissue samples by the LLMDA or PCR. LLMDA identified a human rotavirus A from one of the vaccinated subjects, which is likely due to a recent infection from a wild type rotavirus. LLMDA also identified human parechovirus, a common gastroenteritis viral infection, from two subjects. Additionally, LLMDA detected common gastrointestinal bacterial organisms from the Enterobacteriaceae , Bacteroidaceae , and Streptococcaceae families from several subjects. This study provides a survey of viral and bacterial pathogens from pediatric ileal samples, and may shed light on future studies to identify pathogen associations with pediatric vaccinations.« less

  16. A unified method to process biosolids samples for the recovery of bacterial, viral, and helminths pathogens.

    PubMed

    Alum, Absar; Rock, Channah; Abbaszadegan, Morteza

    2014-01-01

    For land application, biosolids are classified as Class A or Class B based on the levels of bacterial, viral, and helminths pathogens in residual biosolids. The current EPA methods for the detection of these groups of pathogens in biosolids include discrete steps. Therefore, a separate sample is processed independently to quantify the number of each group of the pathogens in biosolids. The aim of the study was to develop a unified method for simultaneous processing of a single biosolids sample to recover bacterial, viral, and helminths pathogens. At the first stage for developing a simultaneous method, nine eluents were compared for their efficiency to recover viruses from a 100 gm spiked biosolids sample. In the second stage, the three top performing eluents were thoroughly evaluated for the recovery of bacteria, viruses, and helminthes. For all three groups of pathogens, the glycine-based eluent provided higher recovery than the beef extract-based eluent. Additional experiments were performed to optimize performance of glycine-based eluent under various procedural factors such as, solids to eluent ratio, stir time, and centrifugation conditions. Last, the new method was directly compared with the EPA methods for the recovery of the three groups of pathogens spiked in duplicate samples of biosolids collected from different sources. For viruses, the new method yielded up to 10% higher recoveries than the EPA method. For bacteria and helminths, recoveries were 74% and 83% by the new method compared to 34% and 68% by the EPA method, respectively. The unified sample processing method significantly reduces the time required for processing biosolids samples for different groups of pathogens; it is less impacted by the intrinsic variability of samples, while providing higher yields (P = 0.05) and greater consistency than the current EPA methods.

  17. Identification of viral pathogen diversity in sewage sludge by metagenome analysis.

    PubMed

    Bibby, Kyle; Peccia, Jordan

    2013-02-19

    The large diversity of viruses that exist in human populations are potentially excreted into sewage collection systems and concentrated in sewage sludge. In the U.S., the primary fate of processed sewage sludge (class B biosolids) is application to agricultural land as a soil amendment. To characterize and understand infectious risks associated with land application, and to describe the diversity of viruses in human populations, shotgun viral metagenomics was applied to 10 sewage sludge samples from 5 wastewater treatment plants throughout the continental U.S, each serving between 100,000 and 1,000,000 people. Nearly 330 million DNA sequences were produced and assembled, and annotation resulted in identifying 43 (26 DNA, 17 RNA) different types of human viruses in sewage sludge. Novel insights include the high abundance of newly emerging viruses (e.g., Coronavirus HKU1, Klassevirus, and Cosavirus) the strong representation of respiratory viruses, and the relatively minor abundance and occurrence of Enteroviruses. Viral metagenome sequence annotations were reproducible and independent PCR-based identification of selected viruses suggests that viral metagenomes were a conservative estimate of the true viral occurrence and diversity. These results represent the most complete description of human virus diversity in any wastewater sample to date, provide engineers and environmental scientists with critical information on important viral agents and routes of infection from exposure to wastewater and sewage sludge, and represent a significant leap forward in understanding the pathogen content of class B biosolids. PMID:23346855

  18. Parasitic, bacterial, and viral enteric pathogens associated with diarrhea in the Central African Republic.

    PubMed Central

    Georges, M C; Wachsmuth, I K; Meunier, D M; Nebout, N; Didier, F; Siopathis, M R; Georges, A J

    1984-01-01

    A total of 1,197 diarrheic children less than 15 years old were investigated for parasitic, bacterial, and viral enteropathogens from March 1981 through February 1982 in the Central African Republic. One or more pathogens were identified from 49.4% of the patients. Rotavirus was the most frequently identified pathogen among children less than 18 months old. Enteropathogenic Escherichia coli was the second most frequently isolated pathogen (12.1%) in children less than 2 years of age. Campylobacter jejuni was also isolated frequently from diarrheic children less than 5 years of age (10.9%). Entamoeba histolytica was identified in very young children and was found to be the most frequent enteropathogen associated with diarrhea in children over the age of 2 years. Enterotoxigenic Escherichia coli was rarely isolated (ca. 2%). There was a peak in the incidence of rotavirus during the dry season and in the incidence of Campylobacter jejuni during the rainy season. PMID:6330161

  19. Bacterial and viral pathogens detected in sea turtles stranded along the coast of Tuscany, Italy.

    PubMed

    Fichi, G; Cardeti, G; Cersini, A; Mancusi, C; Guarducci, M; Di Guardo, G; Terracciano, G

    2016-03-15

    During 2014, six loggerhead turtles, Caretta caretta and one green turtle, Chelonia mydas, found stranded on the Tuscany coast of Italy, were examined for the presence of specific bacterial and viral agents, along with their role as carriers of fish and human pathogens. Thirteen different species of bacteria, 10 Gram negative and 3 Gram positive, were identified. Among them, two strains of Vibrio parahaemolyticus and one strain of Lactococcus garviae were recovered and confirmed by specific PCR protocols. No trh and tdh genes were detected in V. parahaemolyticus. The first isolation of L. garviae and the first detection of Betanodavirus in sea turtles indicate the possibility for sea turtles to act as carriers of fish pathogens. Furthermore, the isolation of two strains of V. parahaemolyticus highlights the possible role of these animals in human pathogens' diffusion.

  20. Bacterial and viral pathogens detected in sea turtles stranded along the coast of Tuscany, Italy.

    PubMed

    Fichi, G; Cardeti, G; Cersini, A; Mancusi, C; Guarducci, M; Di Guardo, G; Terracciano, G

    2016-03-15

    During 2014, six loggerhead turtles, Caretta caretta and one green turtle, Chelonia mydas, found stranded on the Tuscany coast of Italy, were examined for the presence of specific bacterial and viral agents, along with their role as carriers of fish and human pathogens. Thirteen different species of bacteria, 10 Gram negative and 3 Gram positive, were identified. Among them, two strains of Vibrio parahaemolyticus and one strain of Lactococcus garviae were recovered and confirmed by specific PCR protocols. No trh and tdh genes were detected in V. parahaemolyticus. The first isolation of L. garviae and the first detection of Betanodavirus in sea turtles indicate the possibility for sea turtles to act as carriers of fish pathogens. Furthermore, the isolation of two strains of V. parahaemolyticus highlights the possible role of these animals in human pathogens' diffusion. PMID:26931392

  1. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar.

    PubMed

    Kolby, Jonathan E; Smith, Kristine M; Ramirez, Sara D; Rabemananjara, Falitiana; Pessier, Allan P; Brunner, Jesse L; Goldberg, Caren S; Berger, Lee; Skerratt, Lee F

    2015-01-01

    We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease

  2. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar

    PubMed Central

    Kolby, Jonathan E.; Smith, Kristine M.; Ramirez, Sara D.; Rabemananjara, Falitiana; Pessier, Allan P.; Brunner, Jesse L.; Goldberg, Caren S.; Berger, Lee; Skerratt, Lee F.

    2015-01-01

    We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease

  3. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar.

    PubMed

    Kolby, Jonathan E; Smith, Kristine M; Ramirez, Sara D; Rabemananjara, Falitiana; Pessier, Allan P; Brunner, Jesse L; Goldberg, Caren S; Berger, Lee; Skerratt, Lee F

    2015-01-01

    We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease

  4. Occurrence of viral pathogens in Penaeus monodon post-larvae from aquaculture hatcheries

    PubMed Central

    Joseph, Toms C.; James, Roswin; Anbu Rajan, L.; Surendran, P.K.; Lalitha, K.V.

    2015-01-01

    Viral pathogens appear to exert the most significant constraints on the growth and survival of crustaceans under culture conditions. The prevalence of viral pathogens White Spot Syndrome Virus (WSSV), Hepatopancreatic Parvo Virus (HPV), Monodon Baculo Virus (MBV) and Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Penaeus monodon post-larvae was studied. Samples collected from different hatcheries and also samples submitted by farmers from Kerala were analyzed. Out of 104 samples collected, WSSV was detected in 12.5% of the post-larvae samples. Prevalence of concurrent infections by HPV, MBV and WSSV (either dual or triple infection) was present in 60.6% of the total post-larvae tested. Out of the 51 double positives, 98% showed either HPV or IHHNV infection. HPV or IHHNV was detected in 11 post-larval samples showing triple viral infection. This is the first report of IHHNV from India. Result of this study reveals the lack of efficient screening strategies to eradicate viruses in hatchery reared post-larvae. PMID:26217783

  5. Identification and determination of antigenic proteins of Korean ranavirus-1 (KRV-1) using MALDI-TOF/TOF MS analysis.

    PubMed

    Kim, Young Rim; Hikima, Jun-Ichi; Jang, Ho Bin; Nho, Seong Won; Park, Seong Bin; Cha, In Seok; Ohtani, Maki; Eom, Ahn Heume; Aoki, Takashi; Jung, Tae Sung

    2011-05-01

    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 immersion in 10(5)TCID(50)/ml of KRV-1 showed 60% mortality within 10 days. SDS-PAGE of frog virus 3 (FV3) and KRV-1 proteins yielded several bands 35-49kDa in size, which were identified as major capsid proteins (MCPs) by MALDI-TOF MS. Immunoblotting of FV3 proteins showed antigenic bands 34kDa and 93kDa in size which were identified by MALDI-TOF/TOF MS as MCP and neurofilament triplet H1-like protein (NF-H1), respectively. In KRV-1, antigenic bands at 32kDa, 69kDa, and 72kDa were identified as MCP, Hypothetical protein, and NF-H1, respectively. The genes encoding these KRV-1 proteins were sequenced. KRV-1 appeared to be closely related to the soft-shelled turtle iridovirus (STIV), based on alignments of amino acid sequences from various ranaviruses. Variability in ranavirus antigenic proteins was apparent in an earlier study. It is expected that use of the methods employed here, together with the results of the present work, will contribute to an understanding of the pathogenesis of ranaviruses, and will further the development of DNA- or protein-based bait vaccines for conservation of natural habitats.

  6. Evaluation of PCR Based Assays for the Improvement of Proportion Estimation of Bacterial and Viral Pathogens in Diarrheal Surveillance.

    PubMed

    Guan, Hongxia; Zhang, Jingyun; Xiao, Yong; Sha, Dan; Ling, Xia; Kan, Biao

    2016-01-01

    Diarrhea can be caused by a variety of bacterial, viral and parasitic organisms. Laboratory diagnosis is essential in the pathogen-specific burden assessment. In the pathogen spectrum monitoring in the diarrheal surveillance, culture methods are commonly used for the bacterial pathogens' detection whereas nucleic acid based amplification, the non-cultural methods are used for the viral pathogens. Different methodology may cause the inaccurate pathogen spectrum for the bacterial pathogens because of their different culture abilities with the different media, and for the comparison of bacterial vs. viral pathogens. The application of nucleic acid-based methods in the detection of viral and bacterial pathogens will likely increase the number of confirmed positive diagnoses, and will be comparable since all pathogens will be detected based on the same nucleic acid extracts from the same sample. In this study, bacterial pathogens, including diarrheagenic Escherichia coli (DEC), Salmonella spp., Shigella spp., Vibrio parahaemolyticus and V. cholerae, were detected in 334 diarrheal samples by PCR-based methods using nucleic acid extracted from stool samples and associated enrichment cultures. A protocol was established to facilitate the consistent identification of bacterial pathogens in diarrheal patients. Five common enteric viruses were also detected by RT-PCR, including rotavirus, sapovirus, norovirus (I and II), human astrovirus, and enteric adenovirus. Higher positive rates were found for the bacterial pathogens, showing the lower proportion estimation if only using culture methods. This application will improve the quality of bacterial diarrheagenic pathogen survey, providing more accurate information pertaining to the pathogen spectrum associated with finding of food safety problems and disease burden evaluation. PMID:27065958

  7. Evaluation of PCR Based Assays for the Improvement of Proportion Estimation of Bacterial and Viral Pathogens in Diarrheal Surveillance

    PubMed Central

    Guan, Hongxia; Zhang, Jingyun; Xiao, Yong; Sha, Dan; Ling, Xia; Kan, Biao

    2016-01-01

    Diarrhea can be caused by a variety of bacterial, viral and parasitic organisms. Laboratory diagnosis is essential in the pathogen-specific burden assessment. In the pathogen spectrum monitoring in the diarrheal surveillance, culture methods are commonly used for the bacterial pathogens' detection whereas nucleic acid based amplification, the non-cultural methods are used for the viral pathogens. Different methodology may cause the inaccurate pathogen spectrum for the bacterial pathogens because of their different culture abilities with the different media, and for the comparison of bacterial vs. viral pathogens. The application of nucleic acid-based methods in the detection of viral and bacterial pathogens will likely increase the number of confirmed positive diagnoses, and will be comparable since all pathogens will be detected based on the same nucleic acid extracts from the same sample. In this study, bacterial pathogens, including diarrheagenic Escherichia coli (DEC), Salmonella spp., Shigella spp., Vibrio parahaemolyticus and V. cholerae, were detected in 334 diarrheal samples by PCR-based methods using nucleic acid extracted from stool samples and associated enrichment cultures. A protocol was established to facilitate the consistent identification of bacterial pathogens in diarrheal patients. Five common enteric viruses were also detected by RT-PCR, including rotavirus, sapovirus, norovirus (I and II), human astrovirus, and enteric adenovirus. Higher positive rates were found for the bacterial pathogens, showing the lower proportion estimation if only using culture methods. This application will improve the quality of bacterial diarrheagenic pathogen survey, providing more accurate information pertaining to the pathogen spectrum associated with finding of food safety problems and disease burden evaluation. PMID:27065958

  8. Evaluation of PCR Based Assays for the Improvement of Proportion Estimation of Bacterial and Viral Pathogens in Diarrheal Surveillance.

    PubMed

    Guan, Hongxia; Zhang, Jingyun; Xiao, Yong; Sha, Dan; Ling, Xia; Kan, Biao

    2016-01-01

    Diarrhea can be caused by a variety of bacterial, viral and parasitic organisms. Laboratory diagnosis is essential in the pathogen-specific burden assessment. In the pathogen spectrum monitoring in the diarrheal surveillance, culture methods are commonly used for the bacterial pathogens' detection whereas nucleic acid based amplification, the non-cultural methods are used for the viral pathogens. Different methodology may cause the inaccurate pathogen spectrum for the bacterial pathogens because of their different culture abilities with the different media, and for the comparison of bacterial vs. viral pathogens. The application of nucleic acid-based methods in the detection of viral and bacterial pathogens will likely increase the number of confirmed positive diagnoses, and will be comparable since all pathogens will be detected based on the same nucleic acid extracts from the same sample. In this study, bacterial pathogens, including diarrheagenic Escherichia coli (DEC), Salmonella spp., Shigella spp., Vibrio parahaemolyticus and V. cholerae, were detected in 334 diarrheal samples by PCR-based methods using nucleic acid extracted from stool samples and associated enrichment cultures. A protocol was established to facilitate the consistent identification of bacterial pathogens in diarrheal patients. Five common enteric viruses were also detected by RT-PCR, including rotavirus, sapovirus, norovirus (I and II), human astrovirus, and enteric adenovirus. Higher positive rates were found for the bacterial pathogens, showing the lower proportion estimation if only using culture methods. This application will improve the quality of bacterial diarrheagenic pathogen survey, providing more accurate information pertaining to the pathogen spectrum associated with finding of food safety problems and disease burden evaluation.

  9. Investigation of parasitic and viral pathogens in mussels (Mytilus galloprovincialis) in the Gulf of Izmir, Turkey

    PubMed Central

    Erol, Nural; Delibaş, Songül B.; Özkoç, Soykan; Ergüden, Ceren; Aksoy, Ümit

    2016-01-01

    Objectives: To investigate Microsporidia spp. parasite, hepatitis A virus (HAV), and norovirus (NoV) contamination in mussels collected from 8 stations in the inner, middle, and outer regions of the Gulf of Izmir. Methods: In this cross-sectional study carried out between August 2009 and September 2010 in the Gulf of Izmir, Turkey, 15 mussels collected from each of the stations each season were pooled and homogenized to create a single representative sample. Thirty representative samples were available for analysis. Direct polymerase chain reaction (PCR), RT-nested PCR, and RT-booster PCR were used to investigate the pathogens. Results: The mussels were negative for Microsporidia spp., but 8 (26.7%) samples analyzed were positive for HAV and 9 (30%) were positive for NoV. Excluding Foca and Gediz, viral contamination was detected in all of the stations sampled. Conclusion: Our results suggest that viral contamination is present in mussels in the Gulf of Izmir and may pose a potential threat to human health in the region. Necessary measures should be taken to prevent future illness due to these pathogens. PMID:27279520

  10. Thermodynamic instability of viral proteins is a pathogen-associated molecular pattern targeted by human defensins.

    PubMed

    Kudryashova, Elena; Koneru, Pratibha C; Kvaratskhelia, Mamuka; Strömstedt, Adam A; Lu, Wuyuan; Kudryashov, Dmitri S

    2016-01-01

    Human defensins are innate immune defense peptides with a remarkably broad repertoire of anti-pathogen activities. In addition to modulating immune response, inflammation, and angiogenesis, disintegrating bacterial membranes, and inactivating bacterial toxins, defensins are known to intercept various viruses at different stages of their life cycles, while remaining relatively benign towards human cells and proteins. Recently we have found that human defensins inactivate proteinaceous bacterial toxins by taking advantage of their low thermodynamic stability and acting as natural "anti-chaperones", i.e. destabilizing the native conformation of the toxins. In the present study we tested various proteins produced by several viruses (HIV-1, PFV, and TEV) and found them to be susceptible to destabilizing effects of human α-defensins HNP-1 and HD-5 and the synthetic θ-defensin RC-101, but not β-defensins hBD-1 and hBD-2 or structurally related plant-derived peptides. Defensin-induced unfolding promoted exposure of hydrophobic groups otherwise confined to the core of the viral proteins. This resulted in precipitation, an enhanced susceptibility to proteolytic cleavage, and a loss of viral protein activities. We propose, that defensins recognize and target a common and essential physico-chemical property shared by many bacterial toxins and viral proteins - the intrinsically low thermodynamic protein stability. PMID:27581352

  11. Thermodynamic instability of viral proteins is a pathogen-associated molecular pattern targeted by human defensins

    PubMed Central

    Kudryashova, Elena; Koneru, Pratibha C.; Kvaratskhelia, Mamuka; Strömstedt, Adam A.; Lu, Wuyuan; Kudryashov, Dmitri S.

    2016-01-01

    Human defensins are innate immune defense peptides with a remarkably broad repertoire of anti-pathogen activities. In addition to modulating immune response, inflammation, and angiogenesis, disintegrating bacterial membranes, and inactivating bacterial toxins, defensins are known to intercept various viruses at different stages of their life cycles, while remaining relatively benign towards human cells and proteins. Recently we have found that human defensins inactivate proteinaceous bacterial toxins by taking advantage of their low thermodynamic stability and acting as natural “anti-chaperones”, i.e. destabilizing the native conformation of the toxins. In the present study we tested various proteins produced by several viruses (HIV-1, PFV, and TEV) and found them to be susceptible to destabilizing effects of human α-defensins HNP-1 and HD-5 and the synthetic θ-defensin RC-101, but not β-defensins hBD-1 and hBD-2 or structurally related plant-derived peptides. Defensin-induced unfolding promoted exposure of hydrophobic groups otherwise confined to the core of the viral proteins. This resulted in precipitation, an enhanced susceptibility to proteolytic cleavage, and a loss of viral protein activities. We propose, that defensins recognize and target a common and essential physico-chemical property shared by many bacterial toxins and viral proteins – the intrinsically low thermodynamic protein stability. PMID:27581352

  12. Natural stressors and ranavirus susceptibility in larval wood frogs (Rana sylvatica).

    PubMed

    Reeve, Brooke C; Crespi, Erica J; Whipps, Christopher M; Brunner, Jesse L

    2013-06-01

    Chronic exposure to stressors has been shown to suppress immune function in vertebrates, making them more susceptible to pathogens. It is less clear, however, whether many natural stressors are immunosuppressive. Moreover, whether stressors make disease more likely or more severe in populations is unclear because animals respond to stressors both behaviorally and physiologically. We tested whether chronic exposure to three natural stressors of wood frog tadpoles-high-densities, predator-cues, and low-food conditions-influence their susceptibility to a lethal ranavirus both individually in laboratory experiments, and collectively in outdoor mesocosms. Prior to virus exposure, we observed elevated corticosterone only in low-food treatments, although other treatments altered rates of growth and development as well as tadpole behavior. None of the treatments, however, increased susceptibility to ranavirus as measured by the proportion of tadpoles that became infected or died, or the time to death compared to controls. In fact, mortality in the mesocosms was actually lower in the high-density treatment even though most individuals became infected, largely because of increased rates of metamorphosis. Overall we find no support for the hypothesis that chronic exposure to common, ecologically relevant challenges necessarily elevates corticosterone levels in a population or leads to more severe ranaviral disease or epidemics. Conditions may, however, conspire to make ranavirus infection more common in metamorphosing amphibians.

  13. Inflammation-Induced Reactivation of the Ranavirus Frog Virus 3 in Asymptomatic Xenopus laevis

    PubMed Central

    Robert, Jacques; Grayfer, Leon; Edholm, Eva-Stina; Ward, Brian; De Jesús Andino, Francisco

    2014-01-01

    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 animals following the resolution of RV infections. It is noteworthy that macrophage-lineage cells are now believed to be a critical element in the RV infection strategy. In the present work, we report that inflammation induced by peritoneal injection of heat-killed bacteria in asymptomatic frogs one month after infection with FV3 resulted in viral reactivation including detectable viral DNA and viral gene expression in otherwise asymptomatic frogs. FV3 reactivation was most prominently detected in kidneys and in peritoneal HAM56+ mononuclear phagocytes. Notably, unlike adult frogs that typically clear primary FV3 infections, a proportion of the animals succumbed to the reactivated FV3 infection, indicating that previous exposure does not provide protection against subsequent reactivation in these animals. PMID:25390636

  14. Inflammation-induced reactivation of the ranavirus Frog Virus 3 in asymptomatic Xenopus laevis.

    PubMed

    Robert, Jacques; Grayfer, Leon; Edholm, Eva-Stina; Ward, Brian; De Jesús Andino, Francisco

    2014-01-01

    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 animals following the resolution of RV infections. It is noteworthy that macrophage-lineage cells are now believed to be a critical element in the RV infection strategy. In the present work, we report that inflammation induced by peritoneal injection of heat-killed bacteria in asymptomatic frogs one month after infection with FV3 resulted in viral reactivation including detectable viral DNA and viral gene expression in otherwise asymptomatic frogs. FV3 reactivation was most prominently detected in kidneys and in peritoneal HAM56+ mononuclear phagocytes. Notably, unlike adult frogs that typically clear primary FV3 infections, a proportion of the animals succumbed to the reactivated FV3 infection, indicating that previous exposure does not provide protection against subsequent reactivation in these animals.

  15. Diagnostic value of the Vesikari Scoring System for predicting the viral or bacterial pathogens in pediatric gastroenteritis

    PubMed Central

    Shim, Dong Ho; Kim, Dong Yeon

    2016-01-01

    Purpose To evaluate the diagnostic value of the Vesikari Scoring System (VSS) as an early predictor of pathogens in children with acute gastroenteritis (AG). Methods In this retrospective study, the VSS score, absolute neutrophil count (ANC), and C-reactive protein (CRP) levels were analyzed in 107 hospitalized children with AG, aged 6 months to 17 years. Patients were divided into nonspecific, viral, and bacterial groups according to the pathogens detected using a multiplex polymerase chain reaction (PCR) test. Results Patients in the bacterial group had significantly higher CRP values and VSS scores compared to those in the viral group and significantly higher VSS scores compared to those in the nonspecific group (P<0.05). Patients in the viral group had significantly higher VSS scores than those in the nonspecific group (P<0.05). Logistic regression analysis revealed that VSS was the most effective diagnostic tool for predicting the type of pathogen (P<0.05). The area under the receiver operating characteristics curve of VSS was significantly greater than that for ANC and CRP (P<0.05). At a cutoff point of 10 in the VSS, an acceptable diagnostic accuracy could be achieved for distinguishing between bacterial and viral pathogens in AG. Conclusion VSS can be considered a useful and reliable infectious marker for pediatric gastroenteritis. VSS may be a good early predictor of the type of pathogen, enabling development of a treatment plan before results from a stool culture or PCR test are available. PMID:27186219

  16. Molecular characterization of a ranavirus isolated from largemouth bass Micropterus salmoides.

    PubMed

    Mao, J; Wang, J; Chinchar, G D; Chinchar, V G

    1999-07-30

    An iridovirus, isolated from largemouth bass Micropterus salmoides following a die-off among adult fish and provisionally designated largemouth bass virus (LMBV), was characterized by analysis of viral protein synthesis in infected cells, viral DNA restriction fragment length polymorphisms (RFLP), and sequence determination of the major capsid protein and viral DNA methyltransferase genes. All 3 approaches yielded results consistent with the suggestion that LMBV was a member of the genus Ranavirus. Moreover, LMBV was nearly identical to 2 isolates from Southeast Asia which had been previously detected in imported ornamental fish. It remains to be determined whether infection of largemouth bass resulted from exposure to an imported virus, or whether the presence of similar viruses in southeast Asia and the southeastern United States indicates that iridovirus species are not geographically limited as suggested earlier, but rather globally distributed.

  17. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes.

    PubMed

    Warne, Robin W; LaBumbard, Brandon; LaGrange, Seth; Vredenburg, Vance T; Catenazzi, Alessandro

    2016-01-01

    While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife

  18. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes.

    PubMed

    Warne, Robin W; LaBumbard, Brandon; LaGrange, Seth; Vredenburg, Vance T; Catenazzi, Alessandro

    2016-01-01

    While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife

  19. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes

    PubMed Central

    Warne, Robin W.; LaBumbard, Brandon; LaGrange, Seth; Vredenburg, Vance T.; Catenazzi, Alessandro

    2016-01-01

    While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife

  20. Efficient transmission of Cassava brown streak disease viral pathogens by chip bud grafting

    PubMed Central

    2013-01-01

    Background Techniques to study plant viral diseases under controlled growth conditions are required to fully understand their biology and investigate host resistance. Cassava brown streak disease (CBSD) presents a major threat to cassava production in East Africa. No infectious clones of the causal viruses, Cassava brown streak virus (CBSV) or Ugandan cassava brown streak virus (UCBSV) are available, and mechanical transmission to cassava is not effective. An improved method for transmission of the viruses, both singly and as co-infections has been developed using bud grafts. Findings Axillary buds from CBSD symptomatic plants infected with virulent isolates of CBSV and UCBSV were excised and grafted onto 6–8 week old greenhouse-grown, disease-free cassava plants of cultivars Ebwanateraka, TME204 and 60444. Plants were assessed visually for development of CBSD symptoms and by RT-PCR for presence of the viruses in leaf and storage root tissues. Across replicated experiments, 70-100% of plants inoculated with CBSV developed CBSD leaf and stem symptoms 2–6 weeks after bud grafting. Infected plants showed typical, severe necrotic lesions in storage roots at harvest 12–14 weeks after graft inoculation. Sequential grafting of buds from plants infected with UCBSV followed 10–14 days later by buds carrying CBSV, onto the same test plant, resulted in 100% of the rootstocks becoming co-infected with both pathogens. This dual transmission rate was greater than that achieved by simultaneous grafting with UCBSV and CBSV (67%), or when grafting first with CBSV followed by UCBSV (17%). Conclusions The bud grafting method described presents an improved tool for screening cassava germplasm for resistance to CBSD causal viruses, and for studying pathogenicity of this important disease. Bud grafting provides new opportunities compared to previously reported top and side grafting systems. Test plants can be inoculated as young, uniform plants of a size easily handled in a

  1. Assay platforms for the rapid detection of viral pathogens by the ultrahigh sensitivity monitoring of antigen-antibody binding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The drive for early disease detection and growing threat of bioterrorism has markedly amplified the demand for ultrasensitive, high-speed diagnostic tests for viral pathogens. This presentation describes innovations in the development of platforms and readout methodologies that potentially address d...

  2. Phylogenetic concordance analysis shows an emerging pathogen is novel and endemic.

    PubMed

    Storfer, Andrew; Alfaro, Michael E; Ridenhour, Benjamin J; Jancovich, James K; Mech, Stephen G; Parris, Matthew J; Collins, James P

    2007-11-01

    Distinguishing whether pathogens are novel or endemic is critical for controlling emerging infectious diseases, an increasing threat to wildlife and human health. To test the endemic vs. novel pathogen hypothesis, we present a unique analysis of intraspecific host-pathogen phylogenetic concordance of tiger salamanders and an emerging Ranavirus throughout Western North America. There is significant non-concordance of host and virus gene trees, suggesting pathogen novelty. However, non-concordance has likely resulted from virus introductions by human movement of infected salamanders. When human-associated viral introductions are excluded, host and virus gene trees are identical, strongly supporting coevolution and endemism. A laboratory experiment showed an introduced virus strain is significantly more virulent than endemic strains, likely due to artificial selection for high virulence. Thus, our analysis of intraspecific phylogenetic concordance revealed that human introduction of viruses is the mechanism underlying tree non-concordance and possibly disease emergence via artificial selection.

  3. Structured literature review of responses of cattle to viral and bacterial pathogens causing bovine respiratory disease complex.

    PubMed

    Grissett, G P; White, B J; Larson, R L

    2015-01-01

    Bovine respiratory disease (BRD) is an economically important disease of cattle and continues to be an intensely studied topic. However, literature summarizing the time between pathogen exposure and clinical signs, shedding, and seroconversion is minimal. A structured literature review of the published literature was performed to determine cattle responses (time from pathogen exposure to clinical signs, shedding, and seroconversion) in challenge models using common BRD viral and bacterial pathogens. After review a descriptive analysis of published studies using common BRD pathogen challenge studies was performed. Inclusion criteria were single pathogen challenge studies with no treatment or vaccination evaluating outcomes of interest: clinical signs, shedding, and seroconversion. Pathogens of interest included: bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), parainfluenza-3 virus, bovine respiratory syncytial virus, Mannheimia haemolytica, Mycoplasma bovis, Pastuerella multocida, and Histophilus somni. Thirty-five studies and 64 trials were included for analysis. The median days to the resolution of clinical signs after BVDV challenge was 15 and shedding was not detected on day 12 postchallenge. Resolution of BHV-1 shedding resolved on day 12 and clinical signs on day 12 postchallenge. Bovine respiratory syncytial virus ceased shedding on day 9 and median time to resolution of clinical signs was on day 12 postchallenge. M. haemolytica resolved clinical signs 8 days postchallenge. This literature review and descriptive analysis can serve as a resource to assist in designing challenge model studies and potentially aid in estimation of duration of clinical disease and shedding after natural pathogen exposure.

  4. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees.

    PubMed

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-11-12

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture.

  5. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees.

    PubMed

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-11-12

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture. PMID:24145453

  6. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees

    PubMed Central

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-01-01

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture. PMID:24145453

  7. Metagenomics Study of Viral Pathogens in Undiagnosed Respiratory Specimens and Identification of Human Enteroviruses at a Thailand Hospital.

    PubMed

    Zhou, Yanfei; Fernandez, Stefan; Yoon, In-Kyu; Simasathien, Sriluck; Watanaveeradej, Veerachai; Yang, Yu; Marte-Salcedo, Omely A; Shuck-Lee, Deidra J; Thomas, Stephen J; Hang, Jun; Jarman, Richard G

    2016-09-01

    Numerous pathogens cause respiratory infections with similar symptoms. Routine diagnostics detect only a limited number of pathogens, leaving a gap in respiratory illness etiology surveillance. This study evaluated next-generation sequencing for unbiased pathogen identification. Respiratory samples collected in Thailand, Philippines, Bhutan, and Nepal, that were negative by several molecular and immunofluorescence assays, underwent viral cultivation. Samples which demonstrated cytopathic effect in culture (N = 121) were extracted and tested by Luminex xTAG respiratory viral panel (RVP) assay and deep sequencing by Roche 454 FLX Titanium system. Using RVP assay, 52 (43%) samples were positive for enterovirus or rhinovirus and another three were positive for respiratory syncytial virus B, parainfluenza 4, and adenovirus. Deep sequencing confirmed the Luminex assay results and identified additional viral pathogens. Human enteroviruses, including Enterovirus A type 71 and 12 types of Enterovirus B (EV-B) were identified from a hospital in Bangkok. Phylogenetic and recombination analysis showed high correlation of VP1 gene-based phylogeny with genome-wide phylogeny and the frequent genetic exchange among EV-B viruses. The high number and diversity of enteroviruses in the hospital in Bangkok suggests prevalent existence. The metagenomic approach used in our study enabled comprehensive diagnoses of respiratory viruses.

  8. Metagenomics Study of Viral Pathogens in Undiagnosed Respiratory Specimens and Identification of Human Enteroviruses at a Thailand Hospital.

    PubMed

    Zhou, Yanfei; Fernandez, Stefan; Yoon, In-Kyu; Simasathien, Sriluck; Watanaveeradej, Veerachai; Yang, Yu; Marte-Salcedo, Omely A; Shuck-Lee, Deidra J; Thomas, Stephen J; Hang, Jun; Jarman, Richard G

    2016-09-01

    Numerous pathogens cause respiratory infections with similar symptoms. Routine diagnostics detect only a limited number of pathogens, leaving a gap in respiratory illness etiology surveillance. This study evaluated next-generation sequencing for unbiased pathogen identification. Respiratory samples collected in Thailand, Philippines, Bhutan, and Nepal, that were negative by several molecular and immunofluorescence assays, underwent viral cultivation. Samples which demonstrated cytopathic effect in culture (N = 121) were extracted and tested by Luminex xTAG respiratory viral panel (RVP) assay and deep sequencing by Roche 454 FLX Titanium system. Using RVP assay, 52 (43%) samples were positive for enterovirus or rhinovirus and another three were positive for respiratory syncytial virus B, parainfluenza 4, and adenovirus. Deep sequencing confirmed the Luminex assay results and identified additional viral pathogens. Human enteroviruses, including Enterovirus A type 71 and 12 types of Enterovirus B (EV-B) were identified from a hospital in Bangkok. Phylogenetic and recombination analysis showed high correlation of VP1 gene-based phylogeny with genome-wide phylogeny and the frequent genetic exchange among EV-B viruses. The high number and diversity of enteroviruses in the hospital in Bangkok suggests prevalent existence. The metagenomic approach used in our study enabled comprehensive diagnoses of respiratory viruses. PMID:27352877

  9. Metagenomics Study of Viral Pathogens in Undiagnosed Respiratory Specimens and Identification of Human Enteroviruses at a Thailand Hospital

    PubMed Central

    Zhou, Yanfei; Fernandez, Stefan; Yoon, In-Kyu; Simasathien, Sriluck; Watanaveeradej, Veerachai; Yang, Yu; Marte-Salcedo, Omely A.; Shuck-Lee, Deidra J.; Thomas, Stephen J.; Hang, Jun; Jarman, Richard G.

    2016-01-01

    Numerous pathogens cause respiratory infections with similar symptoms. Routine diagnostics detect only a limited number of pathogens, leaving a gap in respiratory illness etiology surveillance. This study evaluated next-generation sequencing for unbiased pathogen identification. Respiratory samples collected in Thailand, Philippines, Bhutan, and Nepal, that were negative by several molecular and immunofluorescence assays, underwent viral cultivation. Samples which demonstrated cytopathic effect in culture (N = 121) were extracted and tested by Luminex xTAG respiratory viral panel (RVP) assay and deep sequencing by Roche 454 FLX Titanium system. Using RVP assay, 52 (43%) samples were positive for enterovirus or rhinovirus and another three were positive for respiratory syncytial virus B, parainfluenza 4, and adenovirus. Deep sequencing confirmed the Luminex assay results and identified additional viral pathogens. Human enteroviruses, including Enterovirus A type 71 and 12 types of Enterovirus B (EV-B) were identified from a hospital in Bangkok. Phylogenetic and recombination analysis showed high correlation of VP1 gene-based phylogeny with genome-wide phylogeny and the frequent genetic exchange among EV-B viruses. The high number and diversity of enteroviruses in the hospital in Bangkok suggests prevalent existence. The metagenomic approach used in our study enabled comprehensive diagnoses of respiratory viruses. PMID:27352877

  10. On the role of RNA silencing in the pathogenicity and evolution of viroids and viral satellites

    PubMed Central

    Wang, Ming-Bo; Bian, Xue-Yu; Wu, Li-Min; Liu, Li-Xia; Smith, Neil A.; Isenegger, Daniel; Wu, Rong-Mei; Masuta, Chikara; Vance, Vicki B.; Watson, John M.; Rezaian, Ali; Dennis, Elizabeth S.; Waterhouse, Peter M.

    2004-01-01

    Viroids and most viral satellites have small, noncoding, and highly structured RNA genomes. How they cause disease symptoms without encoding proteins and why they have characteristic secondary structures are two longstanding questions. Recent studies have shown that both viroids and satellites are capable of inducing RNA silencing, suggesting a possible role of this mechanism in the pathology and evolution of these subviral RNAs. Here we show that preventing RNA silencing in tobacco, using a silencing suppressor, greatly reduces the symptoms caused by the Y satellite of cucumber mosaic virus. Furthermore, tomato plants expressing hairpin RNA, derived from potato spindle tuber viroid, developed symptoms similar to those of potato spindle tuber viroid infection. These results provide evidence suggesting that viroids and satellites cause disease symptoms by directing RNA silencing against physiologically important host genes. We also show that viroid and satellite RNAs are significantly resistant to RNA silencing-mediated degradation, suggesting that RNA silencing is an important selection pressure shaping the evolution of the secondary structures of these pathogens. PMID:14978267

  11. Akabane virus nonstructural protein NSm regulates viral growth and pathogenicity in a mouse model

    PubMed Central

    ISHIHARA, Yukari; SHIODA, Chieko; BANGPHOOMI, Norasuthi; SUGIURA, Keita; SAEKI, Kohei; TSUDA, Shumpei; IWANAGA, Tatsuya; TAKENAKA-UEMA, Akiko; KATO, Kentaro; MURAKAMI, Shin; UCHIDA, Kazuyuki; AKASHI, Hiroomi; HORIMOTO, Taisuke

    2016-01-01

    The biological function of a nonstructural protein, NSm, of Akabane virus (AKAV) is unknown. In this study, we generated a series of NSm deletion mutant viruses by reverse genetics and compared their phenotypes. The mutant in which the NSm coding region was almost completely deleted could not be rescued, suggesting that NSm plays a role in virus replication. We next generated mutant viruses possessing various partial deletions in NSm and identified several regions critical for virus infectivity. All rescued mutant viruses produced smaller plaques and grew inefficiently in cell culture, compared to the wild-type virus. Interestingly, although the pathogenicity of NSm deletion mutant viruses varied in mice depending on their deletion regions and sizes, more than half the mice died following infection with any mutant virus and the dead mice exhibited encephalitis as in wild-type virus-inoculated mice, indicating their neuroinvasiveness. Abundant viral antigens were detected in the brain tissues of dead mice, whereas appreciable antigen was not observed in those of surviving mice, suggesting a correlation between virus growth rate in the brain and neuropathogenicity in mice. We conclude that NSm affects AKAV replication in vitro as well as in vivo and that it may function as a virulence factor. PMID:27181086

  12. Waterborne infectivity of the Ranavirus frog virus 3 in Xenopus laevis.

    PubMed

    Robert, Jacques; George, Erica; De Jesús Andino, Francisco; Chen, Guangchun

    2011-09-01

    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 through the digestive tract leads to dissemination in the kidney. Finally, a fraction of adult macrophages becomes infected following exposure to waterborne FV3 as visualized by fluorescence microscopy using macrophage- and FV3-specific antibodies. Little cytopathicity and apoptosis were detected in infected macrophages, which is consistent with our proposition that macrophages are permissive to FV3. These data highlight the efficiency of FV3 infectivity by the water route and the ability of FV3 to adapt to its hosts.

  13. Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis).

    PubMed

    Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta; Steckler, Natalie K; Olesen, Niels J; Ariel, Ellen; Waltzek, Thomas B

    2016-01-01

    The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses. PMID:27540067

  14. Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis)

    PubMed Central

    Toffan, Anna; Cappellozza, Elisabetta; Steckler, Natalie K.; Olesen, Niels J.; Ariel, Ellen

    2016-01-01

    The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses. PMID:27540067

  15. Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis).

    PubMed

    Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta; Steckler, Natalie K; Olesen, Niels J; Ariel, Ellen; Waltzek, Thomas B

    2016-08-18

    The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses.

  16. Susceptibility of farmed juvenile giant grouper Epinephelus lanceolatus to a newly isolated grouper iridovirus (genus Ranavirus).

    PubMed

    Peng, Chao; Ma, Hongling; Su, Youlu; Wen, Weigeng; Feng, Juan; Guo, Zhixun; Qiu, Lihua

    2015-06-12

    A ranavirus was isolated from the diseased farmed groupers (Grouper iridovirus in genus Ranavirus, GIV-R), Epinephelus hybrids (blotchy rock cod, Epinephelus fuscoguttatus ♀×giant grouper, Epinephelus lanceolatus ♂), in Sanya, Hainan, in July 2013. In this study, susceptibility of farmed juvenile giant grouper E. lanceolatus to GIV-R was determined by intraperitoneally injection. The cumulative mortality reached to 81% at 5 day post infection. Histologically, severe degeneration with massive pycnotic nuclei in spleen and kidney tissues was observed, and some small-size inclusion body-bearing cells (IBCs) existed in spleen. Hemorrhage and infiltration of inflammatory cells were presented in gill, liver and heart along with tissue degeneration and necrosis of varying severity. The results of immunohistochemistry analysis showed that the strongest immunolabellings were obtained from the kidney and spleen tissues, while intermediate intensity signals were observed in the heart, stomach, gill and liver tissues, and the weakest signals were obtained from the intestine and brain, but no signal was obtained in eyes. Electron microscopy revealed that spleen of moribund fish contained many viral particles in cytoplasm. Interestingly, in surviving fish, abnormal hypertrophic cells were observed in both splenic corpuscle and renal corpuscle, while no hypertrophic cell was observed in the other parts of spleen and kidney tissues. Moreover, immunolabellings only stained the hypertrophic cells in splenic corpuscle and renal corpuscle. This indicated that splenic corpuscle and renal corpuscle play an important role in GIV-R infection and replication.

  17. Susceptibility of farmed juvenile giant grouper Epinephelus lanceolatus to a newly isolated grouper iridovirus (genus Ranavirus).

    PubMed

    Peng, Chao; Ma, Hongling; Su, Youlu; Wen, Weigeng; Feng, Juan; Guo, Zhixun; Qiu, Lihua

    2015-06-12

    A ranavirus was isolated from the diseased farmed groupers (Grouper iridovirus in genus Ranavirus, GIV-R), Epinephelus hybrids (blotchy rock cod, Epinephelus fuscoguttatus ♀×giant grouper, Epinephelus lanceolatus ♂), in Sanya, Hainan, in July 2013. In this study, susceptibility of farmed juvenile giant grouper E. lanceolatus to GIV-R was determined by intraperitoneally injection. The cumulative mortality reached to 81% at 5 day post infection. Histologically, severe degeneration with massive pycnotic nuclei in spleen and kidney tissues was observed, and some small-size inclusion body-bearing cells (IBCs) existed in spleen. Hemorrhage and infiltration of inflammatory cells were presented in gill, liver and heart along with tissue degeneration and necrosis of varying severity. The results of immunohistochemistry analysis showed that the strongest immunolabellings were obtained from the kidney and spleen tissues, while intermediate intensity signals were observed in the heart, stomach, gill and liver tissues, and the weakest signals were obtained from the intestine and brain, but no signal was obtained in eyes. Electron microscopy revealed that spleen of moribund fish contained many viral particles in cytoplasm. Interestingly, in surviving fish, abnormal hypertrophic cells were observed in both splenic corpuscle and renal corpuscle, while no hypertrophic cell was observed in the other parts of spleen and kidney tissues. Moreover, immunolabellings only stained the hypertrophic cells in splenic corpuscle and renal corpuscle. This indicated that splenic corpuscle and renal corpuscle play an important role in GIV-R infection and replication. PMID:25912024

  18. Seroprevalences to Viral Pathogens in Free-Ranging and Captive Cheetahs (Acinonyx jubatus) on Namibian Farmland▿

    PubMed Central

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L.; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-01-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts

  19. Seroprevalences to viral pathogens in free-ranging and captive cheetahs (Acinonyx jubatus) on Namibian Farmland.

    PubMed

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-02-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts

  20. Seroprevalences to viral pathogens in free-ranging and captive cheetahs (Acinonyx jubatus) on Namibian Farmland.

    PubMed

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-02-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts.

  1. [Detection of viral infection pathogens in medicinal plants grown in Ukraine].

    PubMed

    Mishchenko, L T; Korenieva, A A; Molchanets', O V; Boĭko, A L

    2009-01-01

    Monitoring of viral infection on medicinal plant plantations is carried out. Panax ginseng C.A. Meyer, Valeriana officinalis L., Plantago major L. with symptoms of viral infection were revealed. Viral nature of symptoms was proved with biotesting method. Morphology and sizes of virus particles, detected in Panax ginseng method. Morphology and sizes of virus particles, detected in Panax ginseng C.A. Meyer, Valeriana officinalis L., Plantago major L., were determined with electron microscopy method. The paper is presented in Ukrainian.

  2. Ranavirus infections associated with skin lesions in lizards.

    PubMed

    Stöhr, Anke C; Blahak, Silvia; Heckers, Kim O; Wiechert, Jutta; Behncke, Helge; Mathes, Karina; Günther, Pascale; Zwart, Peer; Ball, Inna; Rüschoff, Birgit; Marschang, Rachel E

    2013-09-27

    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 screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards.

  3. Ranavirus infections associated with skin lesions in lizards

    PubMed Central

    2013-01-01

    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 screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards. PMID:24073785

  4. The pathogenic role of torque teno sus virus 1 and 2 and their correlations with various viral pathogens and host immunocytes in wasting pigs.

    PubMed

    Lee, Yao; Lin, Chun-Ming; Jeng, Chian-Ren; Chang, Hui-Wen; Chang, Chih-Cheng; Pang, Victor Fei

    2015-11-18

    The pathogenic role of torque teno sus virus (TTSuV) in swine is controversial among different studies. The present study intended to evaluate the potential pathogenicity of TTSuV based on its correlations with the histopathological changes, various common concurrently infected viral pathogens including porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), and porcine parvovirus (PPV), as well as changes in the distribution and population of host immunocytes such as B lymphocytes, T lymphocytes, and macrophages by using the superficial inguinal lymph nodes (siLNs) of wasting pigs. A tissue microarray consisting of 270 available siLNs collected from 262 clinically wasting and 8 healthy pigs, respectively, were used for the detection of TTSuV1, TTSuV2, PCV2, PRRSV, and PPV by either in situ hybridization (ISH) or immunohistochemical (IHC) staining, and for the detection of various subsets of immunocytes by IHC staining with monoclonal antibodies to CD3, CD79a, and lysozyme. The slides were then subject to digital scanning followed by a semi-quantitative positive pixel evaluation for further statistical analysis. Although a high prevalence of TTSuV1 and/or TTSuV2 infection was noted in both wasting and healthy pigs, the wasting pigs had a significantly higher intensity in both TTSuV1 and TTSuV2 ISH-positive signals than healthy ones did. In the wasting pigs, a significant positive correlation in the tissue viral load was noted between TTSuV1 and TTSuV2 and between TTSuV2 and PCV2, but not between TTSuV1 and PCV2. Conversely, a significant negative correlation in the tissue viral load was revealed between TTSuV2, but not TTSuV1, and PRRSV. The tissue viral load of TTSuV1 was significantly correlated with B cell hyperplasia, while the tissue viral load of TTSuV2 was significantly correlated with increased macrophage population. The ISH positivity of TTSuV2 was significantly correlated with lymphoid depletion and granulomatous

  5. Removal of phages and viral pathogens in a full-scale MBR: Implications for wastewater reuse and potable water.

    PubMed

    Purnell, Sarah; Ebdon, James; Buck, Austen; Tupper, Martyn; Taylor, Huw

    2016-09-01

    The aim of this study was to demonstrate how seasonal variability in the removal efficacy of enteric viral pathogens from an MBR-based water recycling system might affect risks to human health if the treated product were to be used for the augmentation of potable water supplies. Samples were taken over a twelve month period (March 2014-February 2015), from nine locations throughout a water recycling plant situated in East London and tested for faecal indicator bacteria (thermotolerant coliforms, intestinal enterococci n = 108), phages (somatic coliphage, F-specific RNA phage and Bacteroides phage (GB-124) n = 108), pathogenic viruses (adenovirus, hepatitis A, norovirus GI/GII n = 48) and a range of physico-chemical parameters (suspended solids, DO, BOD, COD). Thermotolerant coliforms and intestinal enterococci were removed effectively by the water recycling plant throughout the study period. Significant mean log reductions of 3.9-5.6 were also observed for all three phage groups monitored. Concentrations of bacteria and phages did not vary significantly according to season (P < 0.05; Kruskal-Wallis), though recorded levels of norovirus (GI) were significantly higher during autumn/winter months (P = 0.027; Kruskal-Wallis). Log reduction values for norovirus and adenovirus following MBR treatment were 2.3 and 4.4, respectively. However, both adenovirus and norovirus were detected at low levels (2000 and 3240 gene copies/L, respectively) post chlorination in single samples. Whilst phage concentrations did correlate with viral pathogens, the results of this study suggest that phages may not be suitable surrogates, as viral pathogen concentrations varied to a greater degree seasonally than did the phage indicators and were detected on a number of occasions on which phages were not detected (false negative sample results).

  6. Environmental dependency of amphibian-ranavirus genotypic interactions: evolutionary perspectives on infectious diseases.

    PubMed

    Echaubard, Pierre; Leduc, Joel; Pauli, Bruce; Chinchar, V Gregory; Robert, Jacques; Lesbarrères, David

    2014-08-01

    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 virus 3 (FV3) at different temperatures, we conducted a laboratory experiment to investigate the influence of host species/genotype, ranavirus strains, temperature, and their interactions, in determining mortality and infection patterns. Our results revealed variability in host susceptibility and strain infectivity along with significant host-strain interactions, indicating that the outcome of an infection is dependent on the specific combination of host and virus genotypes. Moreover, we observed a strong influence of temperature on infection and mortality probabilities, revealing the potential for genotype-genotype-environment interactions to be responsible for unexpected mortality in this system. Our study thus suggests that amphibian hosts and ranavirus strains genetic characteristics should be considered in order to understand infection outcomes and that the investigation of coevolutionary mechanisms within a context-dependent framework provides a tool for the comprehensive understanding of disease dynamics.

  7. Environmental dependency of amphibian–ranavirus genotypic interactions: evolutionary perspectives on infectious diseases

    PubMed Central

    Echaubard, Pierre; Leduc, Joel; Pauli, Bruce; Chinchar, V Gregory; Robert, Jacques; Lesbarrères, David

    2014-01-01

    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 virus 3 (FV3) at different temperatures, we conducted a laboratory experiment to investigate the influence of host species/genotype, ranavirus strains, temperature, and their interactions, in determining mortality and infection patterns. Our results revealed variability in host susceptibility and strain infectivity along with significant host–strain interactions, indicating that the outcome of an infection is dependent on the specific combination of host and virus genotypes. Moreover, we observed a strong influence of temperature on infection and mortality probabilities, revealing the potential for genotype–genotype–environment interactions to be responsible for unexpected mortality in this system. Our study thus suggests that amphibian hosts and ranavirus strains genetic characteristics should be considered in order to understand infection outcomes and that the investigation of coevolutionary mechanisms within a context-dependent framework provides a tool for the comprehensive understanding of disease dynamics. PMID:25469155

  8. Viral meningitis.

    PubMed

    Chadwick, David R

    2005-01-01

    Viruses probably account for most cases of acute meningitis. Viral meningitis is often assumed to be a largely benign disease. For the commonest pathogens causing meningitis, enteroviruses, this is usually the case; however, for many of the other pathogens causing viral meningitis, and for common pathogens in the immunocompromised or infants, viral meningitis is frequently associated with substantial neurological complications and a significant mortality. Diagnostic methods for rapid and accurate identification of pathogens have improved over recent years, permitting more precise and earlier diagnoses. There have been fewer developments in therapies for viral meningitis, and there remain no effective therapies for most pathogens, emphasising the importance of prevention and early diagnosis. This review focuses on the presentation, diagnosis and management of viral meningitis and also covers the prevention of meningitis for pathogens where effective vaccines are available. PMID:16474042

  9. Viral meningitis.

    PubMed

    Chadwick, David R

    2005-01-01

    Viruses probably account for most cases of acute meningitis. Viral meningitis is often assumed to be a largely benign disease. For the commonest pathogens causing meningitis, enteroviruses, this is usually the case; however, for many of the other pathogens causing viral meningitis, and for common pathogens in the immunocompromised or infants, viral meningitis is frequently associated with substantial neurological complications and a significant mortality. Diagnostic methods for rapid and accurate identification of pathogens have improved over recent years, permitting more precise and earlier diagnoses. There have been fewer developments in therapies for viral meningitis, and there remain no effective therapies for most pathogens, emphasising the importance of prevention and early diagnosis. This review focuses on the presentation, diagnosis and management of viral meningitis and also covers the prevention of meningitis for pathogens where effective vaccines are available.

  10. Pathogen host switching in commercial trade with management recommendations.

    PubMed

    Picco, Angela M; Karam, Abraham P; Collins, James P

    2010-06-01

    Global wildlife trade exacerbates the spread of nonindigenous species. Pathogens also move with hosts through trade and often are released into naïve populations with unpredictable outcomes. Amphibians are moved commercially for pets, food, bait, and biomedicine, and are an excellent model for studying how wildlife trade relates to pathogen pollution. Ranaviruses are amphibian pathogens associated with annual population die-offs; multiple strains of tiger salamander ranaviruses move through the bait trade in the western United States. Ranaviruses infect amphibians, reptiles, and fish and are of additional concern because they can switch hosts. Tiger salamanders are used as live bait for freshwater fishing and are a potential source for ranaviruses switching hosts from amphibians to fish. We experimentally injected largemouth bass with a bait trade tiger salamander ranavirus. Largemouth bass became infected but exhibited no signs of disease or mortality. Amphibian bait ranaviruses have the potential to switch hosts to infect fish, but fish may act as dead-end hosts or nonsymptomatic carriers, potentially spreading infection as a result of trade.

  11. Prevalence of swine viral and bacterial pathogens in rodents and stray cats captured around pig farms in Korea.

    PubMed

    Truong, Quang Lam; Seo, Tae Won; Yoon, Byung-Il; Kim, Hyeon-Cheol; Han, Jeong Hee; Hahn, Tae-Wook

    2013-12-30

    In 2008, 102 rodents and 24 stray cats from the areas around 9 pig farms in northeast South Korea were used to determine the prevalence of the following selected swine pathogens: ten viral pathogens [porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), rotavirus, classical swine fever virus (CSFV), porcine circovirus type 2 (PCV2), encephalomyocarditis virus (EMCV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), pseudorabies virus (PRV) and Japanese encephalitis virus (JEV)] and four bacterial pathogens (Brucella, Leptospira, Salmonella and Lawsonia intracellularis). In total, 1,260 tissue samples from 102 rodents and 24 stray cats were examined by specific PCR and RT-PCR assays, including tissue samples of the brain, tonsils, lungs, heart, liver, kidneys, spleen, small intestine, large intestine and mesenteric lymph nodes. The percentages of PCR-positive rodents for the porcine pathogens were as follows: 63.7% for Leptospira, 39.2% for Brucella, 6.8% for Salmonella, 15.7% for L. intracellularis, 14.7% for PCV2 and 3.9% for EMCV. The percentages of PCR-positive stray cats for the swine pathogens were as follows: 62.5% for Leptospira, 25% for Brucella, 12.5% for Salmonella, 12.5% for L. intracellularis and 4.2% for PEDV. These results may be helpful for developing control measures to prevent the spread of infectious diseases of pigs.

  12. Recent viral pathogen in acute gastroenteritis: a retrospective study at a tertiary hospital for 1 year

    PubMed Central

    Jin, Hye Il; Lee, Yoo Mi; Choi, You Jin

    2016-01-01

    Purpose Viral gastroenteritis among children is mainly caused by rotavirus, norovirus, astrovirus, or adenovirus strains. However, changing socioeconomic conditions and a rotavirus vaccination program may be affecting the prevalence of these viral infections. Therefore, we aimed to elucidate the season-specific trends in viral infections for facilitating prophylaxis and surveillance in our region. Methods We evaluated 345 pediatric patients (203 males, 142 females; age, 1 month to 16 years) who visited the CHA Bundang Medical Center because of gastroenteric symptoms between June 2014 and May 2015. The specimens were simultaneously tested for norovirus, rotavirus, astrovirus, and adenovirus via multiplex reverse transcription polymerase chain reaction. Clinical characteristics of patients were analyzed retrospectively. Results The most common virus was norovirus, followed by rotavirus, adenovirus, and astrovirus. Of all viral infections, 45.2% occurred mainly between 6 and 24 months of age; in particular, norovirus infection mostly occurred in all age groups except those below 6 months of age, when rotavirus was most prevalent. In addition, seasonal variation was observed, such as norovirus infection from December to February, rotavirus infection from February to April, and adenovirus infection from July to October. Conclusion Our results showed that the most common cause of acute pediatric viral gastroenteritis had changed from rotavirus to norovirus in our patients, because of effective rotaviral vaccination. We recommend the management of food and personal hygiene in accordance with age or seasons as well as active vaccination for preventing viral gastroenteritis. PMID:27186218

  13. Replacement of a dominant viral pathogen by a fungal pathogen does not alter the collapse of a regional forest insect outbreak.

    PubMed

    Hajek, Ann E; Tobin, Patrick C; Haynes, Kyle J

    2015-03-01

    Natural enemies and environmental factors likely both influence the population cycles of many forest-defoliating insect species. Previous work suggests precipitation influences the spatiotemporal patterns of gypsy moth outbreaks in North America, and it has been hypothesized that precipitation could act indirectly through effects on pathogens. We investigated the potential role of climatic and environmental factors in driving pathogen epizootics and parasitism at 57 sites over an area of ≈72,300 km(2) in four US mid-Atlantic states during the final year (2009) of a gypsy moth outbreak. Prior work has largely reported that the Lymantria dispar nucleopolyhedrovirus (LdNPV) was the principal mortality agent responsible for regional collapses of gypsy moth outbreaks. However, in the gypsy moth outbreak-prone US mid-Atlantic region, the fungal pathogen Entomophaga maimaiga has replaced the virus as the dominant source of mortality in dense host populations. The severity of the gypsy moth population crash, measured as the decline in egg mass densities from 2009 to 2010, tended to increase with the prevalence of E. maimaiga and larval parasitoids, but not LdNPV. A significantly negative spatial association was detected between rates of fungal mortality and parasitism, potentially indicating displacement of parasitoids by E. maimaiga. Fungal, viral, and parasitoid mortality agents differed in their associations with local abiotic and biotic conditions, but precipitation significantly influenced both fungal and viral prevalence. This study provides the first spatially robust evidence of the dominance of E. maimaiga during the collapse of a gypsy moth outbreak and highlights the important role played by microclimatic conditions. PMID:25510217

  14. Coinfection of tick cell lines has variable effects on replication of intracellular bacterial and viral pathogens.

    PubMed

    Moniuszko, Anna; Rückert, Claudia; Alberdi, M Pilar; Barry, Gerald; Stevenson, Brian; Fazakerley, John K; Kohl, Alain; Bell-Sakyi, Lesley

    2014-06-01

    Ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. Both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. Microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. In this preliminary study, cell lines derived from the ticks Ixodes scapularis and Ixodes ricinus were infected sequentially with 2 arthropod-borne pathogens, Borrelia burgdorferi s.s., Ehrlichia ruminantium, or Semliki Forest virus (SFV), and the effect of coinfection on the replication of these pathogens was measured. Prior infection of tick cell cultures with the spirochaete B. burgdorferi enhanced subsequent replication of the rickettsial pathogen E. ruminantium whereas addition of spirochaetes to cells infected with E. ruminantium had no effect on growth of the latter. Both prior and subsequent presence of B. burgdorferi also had a positive effect on SFV replication. Presence of E. ruminantium or SFV had no measurable effect on B. burgdorferi growth. In tick cells infected first with E. ruminantium and then with SFV, virus replication was significantly higher across all time points measured (24, 48, 72h post infection), while presence of the virus had no detectable effect on bacterial growth. When cells were infected first with SFV and then with E. ruminantium, there was no effect on replication of either pathogen. The results of this preliminary study indicate that interplay does occur between different pathogens during infection of tick cells. Further study is needed to determine if this results from direct pathogen-pathogen interaction or from effects on host cell defences, and to determine if these observations also apply in vivo in ticks. If presence of one pathogen in the tick vector results in increased replication of another, this could have implications for disease transmission and incidence.

  15. Rapid detection and identification of viral and bacterial fish pathogens using a DNA array-based multiplex assay.

    PubMed

    Lievens, B; Frans, I; Heusdens, C; Justé, A; Jonstrup, S P; Lieffrig, F; Willems, K A

    2011-11-01

    Fish diseases can be caused by a variety of diverse organisms, including bacteria, fungi, viruses and protozoa, and pose a universal threat to the ornamental fish industry and aquaculture. The lack of rapid, accurate and reliable means by which fish pathogens can be detected and identified has been one of the main limitations in fish pathogen diagnosis and fish disease management and has consequently stimulated the search for alternative diagnostic techniques. Here, we describe a method based on multiplex and broad-range PCR amplification combined with DNA array hybridization for the simultaneous detection and identification of all cyprinid herpesviruses (CyHV-1, CyHV-2 and CyHV-3) and some of the most important fish pathogenic Flavobacterium species, including F. branchiophilum, F. columnare and F. psychrophilum. For virus identification, the DNA polymerase and helicase genes were targeted. For bacterial identification, the ribosomal RNA gene was used. The developed methodology permitted 100% specificity for the identification of the target species. Detection sensitivity was equivalent to 10 viral genomes or less than a picogram of bacterial DNA. The utility and power of the array for sensitive pathogen detection and identification in complex samples such as infected tissue is demonstrated in this study. PMID:21988358

  16. Rapid detection and identification of viral and bacterial fish pathogens using a DNA array-based multiplex assay.

    PubMed

    Lievens, B; Frans, I; Heusdens, C; Justé, A; Jonstrup, S P; Lieffrig, F; Willems, K A

    2011-11-01

    Fish diseases can be caused by a variety of diverse organisms, including bacteria, fungi, viruses and protozoa, and pose a universal threat to the ornamental fish industry and aquaculture. The lack of rapid, accurate and reliable means by which fish pathogens can be detected and identified has been one of the main limitations in fish pathogen diagnosis and fish disease management and has consequently stimulated the search for alternative diagnostic techniques. Here, we describe a method based on multiplex and broad-range PCR amplification combined with DNA array hybridization for the simultaneous detection and identification of all cyprinid herpesviruses (CyHV-1, CyHV-2 and CyHV-3) and some of the most important fish pathogenic Flavobacterium species, including F. branchiophilum, F. columnare and F. psychrophilum. For virus identification, the DNA polymerase and helicase genes were targeted. For bacterial identification, the ribosomal RNA gene was used. The developed methodology permitted 100% specificity for the identification of the target species. Detection sensitivity was equivalent to 10 viral genomes or less than a picogram of bacterial DNA. The utility and power of the array for sensitive pathogen detection and identification in complex samples such as infected tissue is demonstrated in this study.

  17. Coinfection of tick cell lines has variable effects on replication of intracellular bacterial and viral pathogens

    PubMed Central

    Moniuszko, Anna; Rückert, Claudia; Alberdi, M. Pilar; Barry, Gerald; Stevenson, Brian; Fazakerley, John K.; Kohl, Alain; Bell-Sakyi, Lesley

    2014-01-01

    Ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. Both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. Microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. In this preliminary study, cell lines derived from the ticks Ixodes scapularis and Ixodes ricinus were infected sequentially with 2 arthropod-borne pathogens, Borrelia burgdorferi s.s., Ehrlichia ruminantium, or Semliki Forest virus (SFV), and the effect of coinfection on the replication of these pathogens was measured. Prior infection of tick cell cultures with the spirochaete B. burgdorferi enhanced subsequent replication of the rickettsial pathogen E. ruminantium whereas addition of spirochaetes to cells infected with E. ruminantium had no effect on growth of the latter. Both prior and subsequent presence of B. burgdorferi also had a positive effect on SFV replication. Presence of E. ruminantium or SFV had no measurable effect on B. burgdorferi growth. In tick cells infected first with E. ruminantium and then with SFV, virus replication was significantly higher across all time points measured (24, 48, 72 h post infection), while presence of the virus had no detectable effect on bacterial growth. When cells were infected first with SFV and then with E. ruminantium, there was no effect on replication of either pathogen. The results of this preliminary study indicate that interplay does occur between different pathogens during infection of tick cells. Further study is needed to determine if this results from direct pathogen–pathogen interaction or from effects on host cell defences, and to determine if these observations also apply in vivo in ticks. If presence of one pathogen in the tick vector results in increased replication of another, this could have implications for disease transmission and incidence

  18. Capture and concentration of viral and bacterial foodborne pathogens using apolipoprotein H.

    PubMed

    Almand, Erin A; Goulter, Rebecca M; Jaykus, Lee-Ann

    2016-09-01

    The need for improved pathogen separation and concentration methods to reduce time-to-detection for foodborne pathogens is well recognized. Apolipoprotein H (ApoH) is an acute phase human plasma protein that has been previously shown to interact with viruses, lipopolysaccharides (LPS) and bacterial proteins. The purpose of this study was to determine if ApoH was capable of binding and efficiently capturing two representative human norovirus strains (GI.1 and GII.4), a cultivable surrogate, and four bacterial pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus). Experiments were carried out using an ApoH-conjugated magnetic bead-based capture followed by pathogen detection using nucleic acid amplification. For all three viruses studied, >10% capture efficiency (<1 Log10 loss in RT-qPCR amplifiable units) was observed. The same capture efficiencies were observed for the bacterial pathogens tested, with the exception of E. coli O157:H7 (approximately 1% capture efficiency, or 2 Log10 loss in CFU equivalents). The efficiency of the capture steps did not vary as a consequence of input target concentration or in the presence of an abundance of background microflora. A complementary plate-based capture assay showed that ApoH bound to a variety of human norovirus virus-like particles. ApoH has the potential to be a broadly reactive ligand for separating and concentrating representative foodborne pathogens, both bacteria and viruses. PMID:27439140

  19. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part I: Overview, vaccines for enteric viruses and Vibrio cholerae

    PubMed Central

    O’Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Salazar, Juan Carlos; Montero, David

    2015-01-01

    Efforts to develop vaccines for prevention of acute diarrhea have been going on for more than 40 y with partial success. The myriad of pathogens, more than 20, that have been identified as a cause of acute diarrhea throughout the years pose a significant challenge for selecting and further developing the most relevant vaccine candidates. Based on pathogen distribution as identified in epidemiological studies performed mostly in low-resource countries, rotavirus, Cryptosporidium, Shigella, diarrheogenic E. coli and V. cholerae are predominant, and thus the main targets for vaccine development and implementation. Vaccination against norovirus is most relevant in middle/high-income countries and possibly in resource-deprived countries, pending a more precise characterization of disease impact. Only a few licensed vaccines are currently available, of which rotavirus vaccines have been the most outstanding in demonstrating a significant impact in a short time period. This is a comprehensive review, divided into 2 articles, of nearly 50 vaccine candidates against the most relevant viral and bacterial pathogens that cause acute gastroenteritis. In order to facilitate reading, sections for each pathogen are organized as follows: i) a discussion of the main epidemiological and pathogenic features; and ii) a discussion of vaccines based on their stage of development, moving from current licensed vaccines to vaccines in advanced stage of development (in phase IIb or III trials) to vaccines in early stages of clinical development (in phase I/II) or preclinical development in animal models. In this first article we discuss rotavirus, norovirus and Vibrio cholerae. In the following article we will discuss Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic), and Campylobacter jejuni. PMID:25715048

  20. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part I: Overview, vaccines for enteric viruses and Vibrio cholerae.

    PubMed

    O'Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Salazar, Juan Carlos; Montero, David

    2015-01-01

    Efforts to develop vaccines for prevention of acute diarrhea have been going on for more than 40 y with partial success. The myriad of pathogens, more than 20, that have been identified as a cause of acute diarrhea throughout the years pose a significant challenge for selecting and further developing the most relevant vaccine candidates. Based on pathogen distribution as identified in epidemiological studies performed mostly in low-resource countries, rotavirus, Cryptosporidium, Shigella, diarrheogenic E. coli and V. cholerae are predominant, and thus the main targets for vaccine development and implementation. Vaccination against norovirus is most relevant in middle/high-income countries and possibly in resource-deprived countries, pending a more precise characterization of disease impact. Only a few licensed vaccines are currently available, of which rotavirus vaccines have been the most outstanding in demonstrating a significant impact in a short time period. This is a comprehensive review, divided into 2 articles, of nearly 50 vaccine candidates against the most relevant viral and bacterial pathogens that cause acute gastroenteritis. In order to facilitate reading, sections for each pathogen are organized as follows: i) a discussion of the main epidemiological and pathogenic features; and ii) a discussion of vaccines based on their stage of development, moving from current licensed vaccines to vaccines in advanced stage of development (in phase IIb or III trials) to vaccines in early stages of clinical development (in phase I/II) or preclinical development in animal models. In this first article we discuss rotavirus, norovirus and Vibrio cholerae. In the following article we will discuss Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic), and Campylobacter jejuni.

  1. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part I: Overview, vaccines for enteric viruses and Vibrio cholerae.

    PubMed

    O'Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Salazar, Juan Carlos; Montero, David

    2015-01-01

    Efforts to develop vaccines for prevention of acute diarrhea have been going on for more than 40 y with partial success. The myriad of pathogens, more than 20, that have been identified as a cause of acute diarrhea throughout the years pose a significant challenge for selecting and further developing the most relevant vaccine candidates. Based on pathogen distribution as identified in epidemiological studies performed mostly in low-resource countries, rotavirus, Cryptosporidium, Shigella, diarrheogenic E. coli and V. cholerae are predominant, and thus the main targets for vaccine development and implementation. Vaccination against norovirus is most relevant in middle/high-income countries and possibly in resource-deprived countries, pending a more precise characterization of disease impact. Only a few licensed vaccines are currently available, of which rotavirus vaccines have been the most outstanding in demonstrating a significant impact in a short time period. This is a comprehensive review, divided into 2 articles, of nearly 50 vaccine candidates against the most relevant viral and bacterial pathogens that cause acute gastroenteritis. In order to facilitate reading, sections for each pathogen are organized as follows: i) a discussion of the main epidemiological and pathogenic features; and ii) a discussion of vaccines based on their stage of development, moving from current licensed vaccines to vaccines in advanced stage of development (in phase IIb or III trials) to vaccines in early stages of clinical development (in phase I/II) or preclinical development in animal models. In this first article we discuss rotavirus, norovirus and Vibrio cholerae. In the following article we will discuss Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic), and Campylobacter jejuni. PMID:25715048

  2. Outbreak of ranavirus infection in sheatfish, Silurus glanis (L.), in Poland.

    PubMed

    Borzym, E; Karpińska, T A; Reichert, M

    2015-01-01

    Ranavirus was detected in adult sheatfish, with clinical signs, on a Polish fish farm in February. Farm isolates induced a strong cytopathic effect in vitro and were identified by electron microscopy and PCR amplification of the ranavirus specific gene fragment. Restriction analysis with the Acc I enzyme showed that isolated ranaviruses were different from the epizootic heamatopoietic necrosis virus (EHNV). We sequenced a fragment of the major capsid protein (MCP) gene and found that isolates were similar to other strains of ranaviruses, available in GenBank.

  3. Outbreak of ranavirus infection in sheatfish, Silurus glanis (L.), in Poland.

    PubMed

    Borzym, E; Karpińska, T A; Reichert, M

    2015-01-01

    Ranavirus was detected in adult sheatfish, with clinical signs, on a Polish fish farm in February. Farm isolates induced a strong cytopathic effect in vitro and were identified by electron microscopy and PCR amplification of the ranavirus specific gene fragment. Restriction analysis with the Acc I enzyme showed that isolated ranaviruses were different from the epizootic heamatopoietic necrosis virus (EHNV). We sequenced a fragment of the major capsid protein (MCP) gene and found that isolates were similar to other strains of ranaviruses, available in GenBank. PMID:26618594

  4. Comparative study of CXC chemokines modulation in brown trout (Salmo trutta) following infection with a bacterial or viral pathogen.

    PubMed

    Gorgoglione, Bartolomeo; Zahran, Eman; Taylor, Nick G H; Feist, Stephen W; Zou, Jun; Secombes, Christopher J

    2016-03-01

    Chemokine modulation in response to pathogens still needs to be fully characterised in fish, in view of the recently described novel chemokines present. This paper reports the first comparative study of CXC chemokine genes transcription in salmonids (brown trout), with a particular focus on the fish specific CXC chemokines (CXCL_F). Adopting new primer sets, optimised to specifically target mRNA, a RT-qPCR gene screening was carried out. Constitutive gene expression was assessed first in six tissues from SPF brown trout. Transcription modulation was next investigated in kidney and spleen during septicaemic infection induced by a RNA virus (Viral Haemorrhagic Septicaemia virus, genotype Ia) or by a Gram negative bacterium (Yersinia ruckeri, ser. O1/biot. 2). From each target organ specific pathogen burden, measured detecting VHSV-glycoprotein or Y. ruckeri 16S rRNA, and IFN-γ gene expression were analysed for their correlation to chemokine transcription. Both pathogens modulated CXC chemokine gene transcript levels, with marked up-regulation seen in some cases, and with both temporal and tissue specific effects apparent. For example, Y. ruckeri strongly induced chemokine transcription in spleen within 24h, whilst VHS generally induced the largest increases at 3d.p.i. in both tissues. This study gives clues to the role of the novel CXC chemokines, in comparison to the other known CXC chemokines in salmonids. PMID:26866873

  5. Distribution of an invasive aquatic pathogen (viral hemorrhagic septicemia virus) in the Great Lakes and its relationship to shipping

    USGS Publications Warehouse

    Bain, Mark B.; Cornwell, Emily R.; Hope, Kristine M.; Eckerlin, Geofrey E.; Casey, Rufina N.; Groocock, Geoffrey H.; Getchell, Rodman G.; Bowser, Paul R.; Winton, James R.; Batts, William N.; Cangelosi, Allegra; Casey, James W.

    2010-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus found in fish from oceans of the northern hemisphere and freshwaters of Europe. It has caused extensive losses of cultured and wild fish and has become established in the North American Great Lakes. Large die-offs of wild fish in the Great Lakes due to VHSV have alarmed the public and provoked government attention on the introduction and spread of aquatic animal pathogens in freshwaters. We investigated the relations between VHSV dispersion and shipping and boating activity in the Great Lakes by sampling fish and water at sites that were commercial shipping harbors, recreational boating centers, and open shorelines. Fish and water samples were individually analyzed for VHSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell culture assays. Of 1,221 fish of 17 species, 55 were VHSV positive with highly varied qRT-PCR titers (1 to 5,950,000 N gene copies). The detections of VHSV in fish and water samples were closely associated and the virus was detected in 21 of 30 sites sampled. The occurrence of VHSV was not related to type of site or shipping related invasion hotspots. Our results indicate that VHSV is widely dispersed in the Great Lakes and is both an enzootic and epizootic pathogen. We demonstrate that pathogen distribution information could be developed quickly and is clearly needed for aquatic ecosystem conservation, management of affected populations, and informed regulation of the worldwide trade of aquatic organisms.

  6. Distribution of an Invasive Aquatic Pathogen (Viral Hemorrhagic Septicemia Virus) in the Great Lakes and Its Relationship to Shipping

    PubMed Central

    Bain, Mark B.; Cornwell, Emily R.; Hope, Kristine M.; Eckerlin, Geofrey E.; Casey, Rufina N.; Groocock, Geoffrey H.; Getchell, Rodman G.; Bowser, Paul R.; Winton, James R.; Batts, William N.; Cangelosi, Allegra; Casey, James W.

    2010-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus found in fish from oceans of the northern hemisphere and freshwaters of Europe. It has caused extensive losses of cultured and wild fish and has become established in the North American Great Lakes. Large die-offs of wild fish in the Great Lakes due to VHSV have alarmed the public and provoked government attention on the introduction and spread of aquatic animal pathogens in freshwaters. We investigated the relations between VHSV dispersion and shipping and boating activity in the Great Lakes by sampling fish and water at sites that were commercial shipping harbors, recreational boating centers, and open shorelines. Fish and water samples were individually analyzed for VHSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell culture assays. Of 1,221 fish of 17 species, 55 were VHSV positive with highly varied qRT-PCR titers (1 to 5,950,000 N gene copies). The detections of VHSV in fish and water samples were closely associated and the virus was detected in 21 of 30 sites sampled. The occurrence of VHSV was not related to type of site or shipping related invasion hotspots. Our results indicate that VHSV is widely dispersed in the Great Lakes and is both an enzootic and epizootic pathogen. We demonstrate that pathogen distribution information could be developed quickly and is clearly needed for aquatic ecosystem conservation, management of affected populations, and informed regulation of the worldwide trade of aquatic organisms. PMID:20405014

  7. Comparative study of CXC chemokines modulation in brown trout (Salmo trutta) following infection with a bacterial or viral pathogen.

    PubMed

    Gorgoglione, Bartolomeo; Zahran, Eman; Taylor, Nick G H; Feist, Stephen W; Zou, Jun; Secombes, Christopher J

    2016-03-01

    Chemokine modulation in response to pathogens still needs to be fully characterised in fish, in view of the recently described novel chemokines present. This paper reports the first comparative study of CXC chemokine genes transcription in salmonids (brown trout), with a particular focus on the fish specific CXC chemokines (CXCL_F). Adopting new primer sets, optimised to specifically target mRNA, a RT-qPCR gene screening was carried out. Constitutive gene expression was assessed first in six tissues from SPF brown trout. Transcription modulation was next investigated in kidney and spleen during septicaemic infection induced by a RNA virus (Viral Haemorrhagic Septicaemia virus, genotype Ia) or by a Gram negative bacterium (Yersinia ruckeri, ser. O1/biot. 2). From each target organ specific pathogen burden, measured detecting VHSV-glycoprotein or Y. ruckeri 16S rRNA, and IFN-γ gene expression were analysed for their correlation to chemokine transcription. Both pathogens modulated CXC chemokine gene transcript levels, with marked up-regulation seen in some cases, and with both temporal and tissue specific effects apparent. For example, Y. ruckeri strongly induced chemokine transcription in spleen within 24h, whilst VHS generally induced the largest increases at 3d.p.i. in both tissues. This study gives clues to the role of the novel CXC chemokines, in comparison to the other known CXC chemokines in salmonids.

  8. Production of transgenic rainbow trout resistant to infection by bacterial and viral pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exploiting the natural microbe-defense (innate defense) mechanism, originally discovered in insects and subsequently found in many animal species, may lead to the development of a novel approach for protecting commercially important finfish and crustacean species from infection by microbial pathogen...

  9. DEVELOPMENT OF A BIOMARKER SYSTEM FOR DETECTING EXPOSURE TO WATERBORNE VIRAL PATHOGENS

    EPA Science Inventory

    EPA has published a drinking water contaminant candidate list (CCL) that includes waterborne pathogens and chemicals that may be considered for regulation at a future date. For each contaminant on the CCL, the Agency will need sufficient data to conduct analyses on the extent of...

  10. Detection of viral and bacterial pathogens in hospitalized children with acute respiratory illnesses, Chongqing, 2009-2013.

    PubMed

    Wei, Lan; Liu, Wei; Zhang, Xiao-Ai; Liu, En-Mei; Wo, Yin; Cowling, Benjamin J; Cao, Wu-Chun

    2015-04-01

    Acute respiratory infections (ARIs) cause large disease burden each year. The codetection of viral and bacterial pathogens is quite common; however, the significance for clinical severity remains controversial. We aimed to identify viruses and bacteria in hospitalized children with ARI and the impact of mixed detections.Hospitalized children with ARI aged ≤16 were recruited from 2009 to 2013 at the Children's Hospital of Chongqing Medical University, Chongqing, China. Nasopharyngeal aspirates (NPAs) were collected for detection of common respiratory viruses by reverse transcription polymerase chain reaction (RT-PCR) or PCR. Bacteria were isolated from NPAs by routine culture methods. Detection and codetection frequencies and clinical features and severity were compared.Of the 3181 hospitalized children, 2375 (74.7%) were detected with ≥1 virus and 707 (22.2%) with ≥1 bacteria, 901 (28.3%) with ≥2 viruses, 57 (1.8%) with ≥2 bacteria, and 542 (17.0%) with both virus and bacteria. The most frequently detected were Streptococcus pneumoniae, respiratory syncytial virus, parainfluenza virus, and influenza virus. Clinical characteristics were similar among different pathogen infections for older group (≥6 years old), with some significant difference for the younger. Cases with any codetection were more likely to present with fever; those with ≥2 virus detections had higher prevalence of cough; cases with virus and bacteria codetection were more likely to have cough and sputum. No significant difference in the risk of pneumonia, severe pneumonia, and intensive care unit admission were found for any codetection than monodetection.There was a high codetection rate of common respiratory pathogens among hospitalized pediatric ARI cases, with fever as a significant predictor. Cases with codetection showed no significant difference in severity than those with single pathogens. PMID:25906103

  11. Seroprevalence of respiratory viral pathogens of indigenous calves in Western Kenya.

    PubMed

    Callaby, R; Toye, P; Jennings, A; Thumbi, S M; Coetzer, J A W; Conradie Van Wyk, I C; Hanotte, O; Mbole-Kariuki, M N; Bronsvoort, B M de C; Kruuk, L E B; Woolhouse, M E J; Kiara, H

    2016-10-01

    Most studies of infectious diseases in East African cattle have concentrated on gastro-intestinal parasites and vector-borne diseases. As a result, relatively little is known about viral diseases, except for those that are clinically symptomatic or which affect international trade such as foot and mouth disease, bluetongue and epizootic haemorrhagic disease. Here, we investigate the seroprevalence, distribution and relationship between the viruses involved in respiratory disease, infectious bovine rhinotracheitis virus (IBR), bovine parainfluenza virus Type 3 (PIV3) and bovine viral diarrhoea virus (BVDV) in East African Shorthorn Zebu calves. These viruses contribute to the bovine respiratory disease complex (BRD) which is responsible for major economic losses in cattle from intensive farming systems as a result of pneumonia. We found that calves experience similar risks of infection for IBR, PIV3, and BVDV with a seroprevalence of 20.9%, 20.1% and 19.8% respectively. We confirm that positive associations exist between IBR, PIV3 and BVDV; being seropositive for any one of these three viruses means that an individual is more likely to be seropositive for the other two viruses than expected by chance. PMID:27663380

  12. Bacterial and Viral Pathogens in Live Oysters: 2007 United States Market Survey ▿

    PubMed Central

    DePaola, Angelo; Jones, Jessica L.; Woods, Jacquelina; Burkhardt, William; Calci, Kevin R.; Krantz, Jeffrey A.; Bowers, John C.; Kasturi, Kuppuswamy; Byars, Robin H.; Jacobs, Emily; Williams-Hill, Donna; Nabe, Khamphet

    2010-01-01

    Two samples of market oysters, primarily from retail establishments, were collected twice each month in each of nine states during 2007. Samples were shipped refrigerated overnight to five U.S. Food and Drug Administration laboratories on a rotating basis and analyzed by most probable number (MPN) for total and pathogenic Vibrio parahaemolyticus and V. vulnificus numbers and for the presence of toxigenic V. cholerae, Salmonella spp., norovirus (NoV), and hepatitis A virus (HAV). Levels of indicator organisms, including fecal coliforms (MPN), Escherichia coli (MPN), male-specific bacteriophage, and aerobic plate counts, were also determined. V. parahaemolyticus and V. vulnificus levels were distributed seasonally and geographically by harvest region and were similar to levels observed in a previous study conducted in 1998-1999. Levels of pathogenic V. parahaemolyticus were typically several logs lower than total V. parahaemolyticus levels regardless of season or region. Pathogenic V. parahaemolyticus levels in the Gulf and Mid-Atlantic regions were about two logs greater than the levels observed in the Pacific and North Atlantic regions. Pathogens generally associated with fecal pollution were detected sporadically or not at all (toxigenic V. cholerae, 0%; Salmonella, 1.5%; NoV, 3.9%; HAV, 4.4%). While seasonal prevalences of NoV and HAV were generally greater in oysters harvested from December to March, the low detection frequency obscured any apparent seasonal effects. Overall, there was no relationship between the levels of indicator microorganisms and the presence of enteric viruses. These data provide a baseline that can be used to further validate risk assessment predictions, determine the effectiveness of new control measures, and compare the level of protection provided by the U.S. shellfish sanitation system to those in other countries. PMID:20190085

  13. Is There Still Room for Novel Viral Pathogens in Pediatric Respiratory Tract Infections?

    PubMed Central

    Taboada, Blanca; Espinoza, Marco A.; Isa, Pavel; Aponte, Fernando E.; Arias-Ortiz, María A.; Monge-Martínez, Jesús; Rodríguez-Vázquez, Rubén; Díaz-Hernández, Fidel; Zárate-Vidal, Fernando; Wong-Chew, Rosa María; Firo-Reyes, Verónica; del Río-Almendárez, Carlos N.; Gaitán-Meza, Jesús; Villaseñor-Sierra, Alberto; Martínez-Aguilar, Gerardo; Salas-Mier, Ma. del Carmen; Noyola, Daniel E.; Pérez-Gónzalez, Luis F.; López, Susana; Santos-Preciado, José I.; Arias, Carlos F.

    2014-01-01

    Viruses are the most frequent cause of respiratory disease in children. However, despite the advanced diagnostic methods currently in use, in 20 to 50% of respiratory samples a specific pathogen cannot be detected. In this work, we used a metagenomic approach and deep sequencing to examine respiratory samples from children with lower and upper respiratory tract infections that had been previously found negative for 6 bacteria and 15 respiratory viruses by PCR. Nasal washings from 25 children (out of 250) hospitalized with a diagnosis of pneumonia and nasopharyngeal swabs from 46 outpatient children (out of 526) were studied. DNA reads for at least one virus commonly associated to respiratory infections was found in 20 of 25 hospitalized patients, while reads for pathogenic respiratory bacteria were detected in the remaining 5 children. For outpatients, all the samples were pooled into 25 DNA libraries for sequencing. In this case, in 22 of the 25 sequenced libraries at least one respiratory virus was identified, while in all other, but one, pathogenic bacteria were detected. In both patient groups reads for respiratory syncytial virus, coronavirus-OC43, and rhinovirus were identified. In addition, viruses less frequently associated to respiratory infections were also found. Saffold virus was detected in outpatient but not in hospitalized children. Anellovirus, rotavirus, and astrovirus, as well as several animal and plant viruses were detected in both groups. No novel viruses were identified. Adding up the deep sequencing results to the PCR data, 79.2% of 250 hospitalized and 76.6% of 526 ambulatory patients were positive for viruses, and all other children, but one, had pathogenic respiratory bacteria identified. These results suggest that at least in the type of populations studied and with the sampling methods used the odds of finding novel, clinically relevant viruses, in pediatric respiratory infections are low. PMID:25412469

  14. Viral pneumonia.

    PubMed

    Greenberg, S B

    1991-09-01

    Viral pneumonias are common in infants and young children but rare in adults. Respiratory syncytial virus (RSV) and para-influenza viruses are the most frequent viral pathogens in infants and children. Influenza virus types A and B account for over one half of viral pneumonias in adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus (CMV) and other herpesviruses, as well as rubeola and adenovirus. Diagnosis of viral pneumonia depends on appropriate viral cultures and acute and convalescent sera for specific antibodies. Superinfection with bacteria is common in adults. Anti-viral therapy is available for several respiratory viruses. Ribavirin, amantadine/rimantadine, interferon alpha, and acyclovir are antiviral drugs that may be of benefit in treatment and prophylaxis. Prevention of viral pneumonia will depend upon improved viral immunization practices.

  15. Canine Enteric Coronaviruses: Emerging Viral Pathogens with Distinct Recombinant Spike Proteins

    PubMed Central

    Licitra, Beth N.; Duhamel, Gerald E.; Whittaker, Gary R.

    2014-01-01

    Canine enteric coronavirus (CCoV) is an alphacoronavirus infecting dogs that is closely related to enteric coronaviruses of cats and pigs. While CCoV has traditionally caused mild gastro-intestinal clinical signs, there are increasing reports of lethal CCoV infections in dogs, with evidence of both gastrointestinal and systemic viral dissemination. Consequently, CCoV is now considered to be an emerging infectious disease of dogs. In addition to the two known serotypes of CCoV, novel recombinant variants of CCoV have been found containing spike protein N-terminal domains (NTDs) that are closely related to those of feline and porcine strains. The increase in disease severity in dogs and the emergence of novel CCoVs can be attributed to the high level of recombination within the spike gene that can occur during infection by more than one CCoV type in the same host. PMID:25153347

  16. In Search of Pathogens: Transcriptome-Based Identification of Viral Sequences from the Pine Processionary Moth (Thaumetopoea pityocampa)

    PubMed Central

    Jakubowska, Agata K.; Nalcacioglu, Remziye; Millán-Leiva, Anabel; Sanz-Carbonell, Alejandro; Muratoglu, Hacer; Herrero, Salvador; Demirbag, Zihni

    2015-01-01

    Thaumetopoea pityocampa (pine processionary moth) is one of the most important pine pests in the forests of Mediterranean countries, Central Europe, the Middle East and North Africa. Apart from causing significant damage to pinewoods, T. pityocampa occurrence is also an issue for public and animal health, as it is responsible for dermatological reactions in humans and animals by contact with its irritating hairs. High throughput sequencing technologies have allowed the fast and cost-effective generation of genetic information of interest to understand different biological aspects of non-model organisms as well as the identification of potential pathogens. Using these technologies, we have obtained and characterized the transcriptome of T. pityocampa larvae collected in 12 different geographical locations in Turkey. cDNA libraries for Illumina sequencing were prepared from four larval tissues, head, gut, fat body and integument. By pooling the sequences from Illumina platform with those previously published using the Roche 454-FLX and Sanger methods we generated the largest reference transcriptome of T. pityocampa. In addition, this study has also allowed identification of possible viral pathogens with potential application in future biocontrol strategies. PMID:25626148

  17. Complete Genome Sequence of a Ranavirus Isolated from Chinese Giant Salamander (Andrias davidianus).

    PubMed

    Wang, Na; Zhang, Min; Zhang, Lifeng; Jing, Hongli; Jiang, Yulin; Wu, Shaoqiang; Lin, Xiangmei

    2014-01-09

    A ranavirus (RV) was isolated from Chinese giant salamanders (Andrias davidianus) in China in 2010 and provisionally designated Andrias davidianus ranavirus (ADRV). The complete genome sequence is 106,719 nucleotides long. Genomic sequence and phylogenetic analyses showed that ADRV has a high degree of conservation with other RVs.

  18. Human Sentinel Surveillance of Influenza and Other Respiratory Viral Pathogens in Border Areas of Western Cambodia.

    PubMed

    Timmermans, Ans; Melendrez, Melanie C; Se, Youry; Chuang, Ilin; Samon, Nou; Uthaimongkol, Nichapat; Klungthong, Chonticha; Manasatienkij, Wudtichai; Thaisomboonsuk, Butsaya; Tyner, Stuart D; Rith, Sareth; Horm, Viseth Srey; Jarman, Richard G; Bethell, Delia; Chanarat, Nitima; Pavlin, Julie; Wongstitwilairoong, Tippa; Saingam, Piyaporn; El, But Sam; Fukuda, Mark M; Touch, Sok; Sovann, Ly; Fernandez, Stefan; Buchy, Philippe; Chanthap, Lon; Saunders, David

    2016-01-01

    Little is known about circulation of influenza and other respiratory viruses in remote populations along the Thai-Cambodia border in western Cambodia. We screened 586 outpatients (median age 5, range 1-77) presenting with influenza-like-illness (ILI) at 4 sentinel sites in western Cambodia between May 2010 and December 2012. Real-time reverse transcriptase (rRT) PCR for influenza was performed on combined nasal and throat specimens followed by viral culture, antigenic analysis, antiviral susceptibility testing and full genome sequencing for phylogenetic analysis. ILI-specimens negative for influenza were cultured, followed by rRT-PCR for enterovirus and rhinovirus (EV/RV) and EV71. Influenza was found in 168 cases (29%) and occurred almost exclusively in the rainy season from June to November. Isolated influenza strains had close antigenic and phylogenetic relationships, matching vaccine and circulating strains found elsewhere in Cambodia. Influenza vaccination coverage was low (<20%). Western Cambodian H1N1(2009) isolate genomes were more closely related to 10 earlier Cambodia isolates (94.4% genome conservation) than to 13 Thai isolates (75.9% genome conservation), despite sharing the majority of the amino acid changes with the Thai references. Most genes showed signatures of purifying selection. Viral culture detected only adenovirus (5.7%) and parainfluenza virus (3.8%), while non-polio enteroviruses (10.3%) were detected among 164 culture-negative samples including coxsackievirus A4, A6, A8, A9, A12, B3, B4 and echovirus E6 and E9 using nested RT-PCR methods. A single specimen of EV71 was found. Despite proximity to Thailand, influenza epidemiology of these western Cambodian isolates followed patterns observed elsewhere in Cambodia, continuing to support current vaccine and treatment recommendations from the Cambodian National Influenza Center. Amino acid mutations at non-epitope sites, particularly hemagglutinin genes, require further investigation in light

  19. Human Sentinel Surveillance of Influenza and Other Respiratory Viral Pathogens in Border Areas of Western Cambodia.

    PubMed

    Timmermans, Ans; Melendrez, Melanie C; Se, Youry; Chuang, Ilin; Samon, Nou; Uthaimongkol, Nichapat; Klungthong, Chonticha; Manasatienkij, Wudtichai; Thaisomboonsuk, Butsaya; Tyner, Stuart D; Rith, Sareth; Horm, Viseth Srey; Jarman, Richard G; Bethell, Delia; Chanarat, Nitima; Pavlin, Julie; Wongstitwilairoong, Tippa; Saingam, Piyaporn; El, But Sam; Fukuda, Mark M; Touch, Sok; Sovann, Ly; Fernandez, Stefan; Buchy, Philippe; Chanthap, Lon; Saunders, David

    2016-01-01

    Little is known about circulation of influenza and other respiratory viruses in remote populations along the Thai-Cambodia border in western Cambodia. We screened 586 outpatients (median age 5, range 1-77) presenting with influenza-like-illness (ILI) at 4 sentinel sites in western Cambodia between May 2010 and December 2012. Real-time reverse transcriptase (rRT) PCR for influenza was performed on combined nasal and throat specimens followed by viral culture, antigenic analysis, antiviral susceptibility testing and full genome sequencing for phylogenetic analysis. ILI-specimens negative for influenza were cultured, followed by rRT-PCR for enterovirus and rhinovirus (EV/RV) and EV71. Influenza was found in 168 cases (29%) and occurred almost exclusively in the rainy season from June to November. Isolated influenza strains had close antigenic and phylogenetic relationships, matching vaccine and circulating strains found elsewhere in Cambodia. Influenza vaccination coverage was low (<20%). Western Cambodian H1N1(2009) isolate genomes were more closely related to 10 earlier Cambodia isolates (94.4% genome conservation) than to 13 Thai isolates (75.9% genome conservation), despite sharing the majority of the amino acid changes with the Thai references. Most genes showed signatures of purifying selection. Viral culture detected only adenovirus (5.7%) and parainfluenza virus (3.8%), while non-polio enteroviruses (10.3%) were detected among 164 culture-negative samples including coxsackievirus A4, A6, A8, A9, A12, B3, B4 and echovirus E6 and E9 using nested RT-PCR methods. A single specimen of EV71 was found. Despite proximity to Thailand, influenza epidemiology of these western Cambodian isolates followed patterns observed elsewhere in Cambodia, continuing to support current vaccine and treatment recommendations from the Cambodian National Influenza Center. Amino acid mutations at non-epitope sites, particularly hemagglutinin genes, require further investigation in light

  20. Human Sentinel Surveillance of Influenza and Other Respiratory Viral Pathogens in Border Areas of Western Cambodia

    PubMed Central

    Chuang, Ilin; Samon, Nou; Uthaimongkol, Nichapat; Klungthong, Chonticha; Manasatienkij, Wudtichai; Thaisomboonsuk, Butsaya; Tyner, Stuart D.; Rith, Sareth; Horm, Viseth Srey; Jarman, Richard G.; Bethell, Delia; Chanarat, Nitima; Pavlin, Julie; Wongstitwilairoong, Tippa; Saingam, Piyaporn; El, But Sam; Fukuda, Mark M.; Touch, Sok; Sovann, Ly; Fernandez, Stefan; Buchy, Philippe; Chanthap, Lon; Saunders, David

    2016-01-01

    Little is known about circulation of influenza and other respiratory viruses in remote populations along the Thai-Cambodia border in western Cambodia. We screened 586 outpatients (median age 5, range 1–77) presenting with influenza-like-illness (ILI) at 4 sentinel sites in western Cambodia between May 2010 and December 2012. Real-time reverse transcriptase (rRT) PCR for influenza was performed on combined nasal and throat specimens followed by viral culture, antigenic analysis, antiviral susceptibility testing and full genome sequencing for phylogenetic analysis. ILI-specimens negative for influenza were cultured, followed by rRT-PCR for enterovirus and rhinovirus (EV/RV) and EV71. Influenza was found in 168 cases (29%) and occurred almost exclusively in the rainy season from June to November. Isolated influenza strains had close antigenic and phylogenetic relationships, matching vaccine and circulating strains found elsewhere in Cambodia. Influenza vaccination coverage was low (<20%). Western Cambodian H1N1(2009) isolate genomes were more closely related to 10 earlier Cambodia isolates (94.4% genome conservation) than to 13 Thai isolates (75.9% genome conservation), despite sharing the majority of the amino acid changes with the Thai references. Most genes showed signatures of purifying selection. Viral culture detected only adenovirus (5.7%) and parainfluenza virus (3.8%), while non-polio enteroviruses (10.3%) were detected among 164 culture-negative samples including coxsackievirus A4, A6, A8, A9, A12, B3, B4 and echovirus E6 and E9 using nested RT-PCR methods. A single specimen of EV71 was found. Despite proximity to Thailand, influenza epidemiology of these western Cambodian isolates followed patterns observed elsewhere in Cambodia, continuing to support current vaccine and treatment recommendations from the Cambodian National Influenza Center. Amino acid mutations at non-epitope sites, particularly hemagglutinin genes, require further investigation in light

  1. An Acute Immune Response to Middle East Respiratory Syndrome Coronavirus Replication Contributes to Viral Pathogenicity.

    PubMed

    Baseler, Laura J; Falzarano, Darryl; Scott, Dana P; Rosenke, Rebecca; Thomas, Tina; Munster, Vincent J; Feldmann, Heinz; de Wit, Emmie

    2016-03-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in a human with severe pneumonia in 2012. Since then, infections have been detected in >1500 individuals, with disease severity ranging from asymptomatic to severe, fatal pneumonia. To elucidate the pathogenesis of this virus and investigate mechanisms underlying disease severity variation in the absence of autopsy data, a rhesus macaque and common marmoset model of MERS-CoV disease were analyzed. Rhesus macaques developed mild disease, and common marmosets exhibited moderate to severe, potentially lethal, disease. Both nonhuman primate species exhibited respiratory clinical signs after inoculation, which were more severe and of longer duration in the marmosets, and developed bronchointerstitial pneumonia. In marmosets, the pneumonia was more extensive, with development of severe airway lesions. Quantitative analysis showed significantly higher levels of pulmonary neutrophil infiltration and higher amounts of pulmonary viral antigen in marmosets. Pulmonary expression of the MERS-CoV receptor, dipeptidyl peptidase 4, was similar in marmosets and macaques. These results suggest that increased virus replication and the local immune response to MERS-CoV infection likely play a role in pulmonary pathology severity. Together, the rhesus macaque and common marmoset models of MERS-CoV span the wide range of disease severity reported in MERS-CoV-infected humans, which will aid in investigating MERS-CoV disease pathogenesis. PMID:26724387

  2. Human Monoclonal Antibodies Against a Plethora of Viral Pathogens From Single Combinatorial Libraries

    NASA Astrophysics Data System (ADS)

    Williamson, R. Anthony; Burioni, Roberto; Sanna, Pietro P.; Partridge, Lynda J.; Barbas, Carlos F., III; Burton, Dennis R.

    1993-05-01

    Conventional antibody generation usually requires active immunization with antigen immediately prior to the preparation procedure. Combinatorial antibody library technology offers the possibility of cloning a range of antibody specificities at a single point in time and then accessing these specificities at will. Here we show that human monoclonal antibody Fab fragments against a plethora of infectious agents can be readily derived from a single library. Further examination of a number of libraries shows that whenever antibody against a pathogen can be detected in the serum of the donor, then specific antibodies can be derived from the corresponding library. We describe the generation of human Fab fragments against herpes simplex virus types 1 and 2, human cytomegalovirus, varicella zoster virus, rubella, human immunodeficiency virus type 1, and respiratory syncytial virus. The antibodies are shown to be highly specific and a number are effective in neutralizing virus in vitro.

  3. The population genetics of drug resistance evolution in natural populations of viral, bacterial and eukaryotic pathogens.

    PubMed

    Wilson, Benjamin A; Garud, Nandita R; Feder, Alison F; Assaf, Zoe J; Pennings, Pleuni S

    2016-01-01

    Drug resistance is a costly consequence of pathogen evolution and a major concern in public health. In this review, we show how population genetics can be used to study the evolution of drug resistance and also how drug resistance evolution is informative as an evolutionary model system. We highlight five examples from diverse organisms with particular focus on: (i) identifying drug resistance loci in the malaria parasite Plasmodium falciparum using the genomic signatures of selective sweeps, (ii) determining the role of epistasis in drug resistance evolution in influenza, (iii) quantifying the role of standing genetic variation in the evolution of drug resistance in HIV, (iv) using drug resistance mutations to study clonal interference dynamics in tuberculosis and (v) analysing the population structure of the core and accessory genome of Staphylococcus aureus to understand the spread of methicillin resistance. Throughout this review, we discuss the uses of sequence data and population genetic theory in studying the evolution of drug resistance.

  4. Direct metagenomic detection of viral pathogens in nasal and fecal specimens using an unbiased high-throughput sequencing approach.

    PubMed

    Nakamura, Shota; Yang, Cheng-Song; Sakon, Naomi; Ueda, Mayo; Tougan, Takahiro; Yamashita, Akifumi; Goto, Naohisa; Takahashi, Kazuo; Yasunaga, Teruo; Ikuta, Kazuyoshi; Mizutani, Tetsuya; Okamoto, Yoshiko; Tagami, Michihira; Morita, Ryoji; Maeda, Norihiro; Kawai, Jun; Hayashizaki, Yoshihide; Nagai, Yoshiyuki; Horii, Toshihiro; Iida, Tetsuya; Nakaya, Takaaki

    2009-01-01

    With the severe acute respiratory syndrome epidemic of 2003 and renewed attention on avian influenza viral pandemics, new surveillance systems are needed for the earlier detection of emerging infectious diseases. We applied a "next-generation" parallel sequencing platform for viral detection in nasopharyngeal and fecal samples collected during seasonal influenza virus (Flu) infections and norovirus outbreaks from 2005 to 2007 in Osaka, Japan. Random RT-PCR was performed to amplify RNA extracted from 0.1-0.25 ml of nasopharyngeal aspirates (N = 3) and fecal specimens (N = 5), and more than 10 microg of cDNA was synthesized. Unbiased high-throughput sequencing of these 8 samples yielded 15,298-32,335 (average 24,738) reads in a single 7.5 h run. In nasopharyngeal samples, although whole genome analysis was not available because the majority (>90%) of reads were host genome-derived, 20-460 Flu-reads were detected, which was sufficient for subtype identification. In fecal samples, bacteria and host cells were removed by centrifugation, resulting in gain of 484-15,260 reads of norovirus sequence (78-98% of the whole genome was covered), except for one specimen that was under-detectable by RT-PCR. These results suggest that our unbiased high-throughput sequencing approach is useful for directly detecting pathogenic viruses without advance genetic information. Although its cost and technological availability make it unlikely that this system will very soon be the diagnostic standard worldwide, this system could be useful for the earlier discovery of novel emerging viruses and bioterrorism, which are difficult to detect with conventional procedures. PMID:19156205

  5. A sodium channel variant in Aedes aegypti as a candidate pathogen sensor for viral-associated molecular patterns.

    PubMed

    Lee, Cara; Jones, Alexis; Kainz, Danielle; Khan, Faatima; Carrithers, Michael D

    2015-08-01

    Recent work demonstrated that a splice variant of a human macrophage voltage-gated sodium channel expressed on endosomes acts as an intracellular sensor for dsRNA, a viral-associated molecular pattern. Here our goal was to identify a candidate gene in a clinically relevant invertebrate model with related cellular and pattern recognition properties. The para gene in drosophila and other insects encodes voltage-gated sodium channels with similar electrophysiological properties to those found in vertebrate excitable membranes. A database search revealed that the AAEL006019 gene in Aedes aegypti, the yellow fever mosquito, encodes a voltage-gated sodium channel that is distinct from genes that encode para-like sodium channels. As compared to para-like channels, the protein products from this gene have deletions in the N-terminus and in the DII-DIII linker region. When over-expressed in an Aedes aegypti cell line, CCL-125, the AAEL006019 channel demonstrated cytoplasmic expression on vesicular-like organelles. Electrophysiologic analysis revealed that the channel mediates small inward currents that are enhanced by synthetic mimics of viral-derived ssRNA, R848 and ORN02, but not the dsRNA mimic, poly I:C. R848 treatment of CCL-125 cells that express high levels of the channels led to increased expression of RelA and Ago2, two mediators of insect innate immunity. These results suggest that the AAEL006019 channel acts as an intracellular pathogen sensor for ssRNA molecular patterns. PMID:26086103

  6. Direct Metagenomic Detection of Viral Pathogens in Nasal and Fecal Specimens Using an Unbiased High-Throughput Sequencing Approach

    PubMed Central

    Sakon, Naomi; Ueda, Mayo; Tougan, Takahiro; Yamashita, Akifumi; Goto, Naohisa; Takahashi, Kazuo; Yasunaga, Teruo; Ikuta, Kazuyoshi; Mizutani, Tetsuya; Okamoto, Yoshiko; Tagami, Michihira; Morita, Ryoji; Maeda, Norihiro; Kawai, Jun; Hayashizaki, Yoshihide; Nagai, Yoshiyuki; Horii, Toshihiro; Iida, Tetsuya; Nakaya, Takaaki

    2009-01-01

    With the severe acute respiratory syndrome epidemic of 2003 and renewed attention on avian influenza viral pandemics, new surveillance systems are needed for the earlier detection of emerging infectious diseases. We applied a “next-generation” parallel sequencing platform for viral detection in nasopharyngeal and fecal samples collected during seasonal influenza virus (Flu) infections and norovirus outbreaks from 2005 to 2007 in Osaka, Japan. Random RT-PCR was performed to amplify RNA extracted from 0.1–0.25 ml of nasopharyngeal aspirates (N = 3) and fecal specimens (N = 5), and more than 10 µg of cDNA was synthesized. Unbiased high-throughput sequencing of these 8 samples yielded 15,298–32,335 (average 24,738) reads in a single 7.5 h run. In nasopharyngeal samples, although whole genome analysis was not available because the majority (>90%) of reads were host genome–derived, 20–460 Flu-reads were detected, which was sufficient for subtype identification. In fecal samples, bacteria and host cells were removed by centrifugation, resulting in gain of 484–15,260 reads of norovirus sequence (78–98% of the whole genome was covered), except for one specimen that was under-detectable by RT-PCR. These results suggest that our unbiased high-throughput sequencing approach is useful for directly detecting pathogenic viruses without advance genetic information. Although its cost and technological availability make it unlikely that this system will very soon be the diagnostic standard worldwide, this system could be useful for the earlier discovery of novel emerging viruses and bioterrorism, which are difficult to detect with conventional procedures. PMID:19156205

  7. Source identification of bacterial and viral pathogens and their survival/fading in the process of wastewater treatment, reclamation, and environmental reuse.

    PubMed

    Zhou, Jinhong; Wang, Xiaochang C; Ji, Zheng; Xu, Limei; Yu, Zhenzhen

    2015-01-01

    Pathogenic safety is drawing wide concern in water reclamation and reuse. In order to elucidate survive/fade of pathogens during the processes of wastewater treatment and reclamation, general indicators (fecal coliform and Escherichia coli), pathogenic bacteria (Salmonella and Shigella) and viruses (enterovirus, rotavirus and norovirus) were investigated in an A(2)O-MBR system. Attention was paid to their strengths from different sources, at various stages of the treatment, and in the product water. According to findings, black water was the main source for pathogens-at least 1-2-log higher in concentration than those from other sources. The preliminary treatment of wastewater by fine screens could bring about 0.2-0.4-log removal for almost all pathogens. The biological treatment units achieved almost identical removal (1.3-1.7-log) for bacteria and viruses. However, subsequent treatment in the membrane bioreactor showed varied removal for fecal coliform (4.7-log), E. coli (2.6-log) and the other pathogens (0.7-1.0-log), indicating that a high reduction of indicator bacteria may not imply equivalent removal of bacterial and viral pathogens. Chlorination was proved to be effective for eliminating all pathogens. In the artificial lake where the product water was stored, fecal coliform was not detected during the study period, but E. coli and pathogens were frequently detected, indicating that these bacterial and viral pathogens may be originating from non-fecal sources. On sunny summer days, the lake water could be bacteria-free due to sunlight radiation, but viruses were still detectable. Therefore, secondary disinfection may have to be adopted when the reclaimed water stored in such an open reservoir is supplied for strict reuse purposes.

  8. Source identification of bacterial and viral pathogens and their survival/fading in the process of wastewater treatment, reclamation, and environmental reuse.

    PubMed

    Zhou, Jinhong; Wang, Xiaochang C; Ji, Zheng; Xu, Limei; Yu, Zhenzhen

    2015-01-01

    Pathogenic safety is drawing wide concern in water reclamation and reuse. In order to elucidate survive/fade of pathogens during the processes of wastewater treatment and reclamation, general indicators (fecal coliform and Escherichia coli), pathogenic bacteria (Salmonella and Shigella) and viruses (enterovirus, rotavirus and norovirus) were investigated in an A(2)O-MBR system. Attention was paid to their strengths from different sources, at various stages of the treatment, and in the product water. According to findings, black water was the main source for pathogens-at least 1-2-log higher in concentration than those from other sources. The preliminary treatment of wastewater by fine screens could bring about 0.2-0.4-log removal for almost all pathogens. The biological treatment units achieved almost identical removal (1.3-1.7-log) for bacteria and viruses. However, subsequent treatment in the membrane bioreactor showed varied removal for fecal coliform (4.7-log), E. coli (2.6-log) and the other pathogens (0.7-1.0-log), indicating that a high reduction of indicator bacteria may not imply equivalent removal of bacterial and viral pathogens. Chlorination was proved to be effective for eliminating all pathogens. In the artificial lake where the product water was stored, fecal coliform was not detected during the study period, but E. coli and pathogens were frequently detected, indicating that these bacterial and viral pathogens may be originating from non-fecal sources. On sunny summer days, the lake water could be bacteria-free due to sunlight radiation, but viruses were still detectable. Therefore, secondary disinfection may have to be adopted when the reclaimed water stored in such an open reservoir is supplied for strict reuse purposes. PMID:25374337

  9. Interferometric biosensing platform for multiplexed digital detection of viral pathogens and biomarkers

    NASA Astrophysics Data System (ADS)

    Daaboul, George

    Label-free optical biosensors have been established as proven tools for monitoring specific biomolecular interactions. However, compact and robust embodiments of such instruments have yet to be introduced in order to provide sensitive, quantitative, and high-throughput biosensing for low-cost research and clinical applications. Here we present the interferometric reflectance-imaging sensor (IRIS). IRIS allows sensitive label free analysis using an inexpensive and durable multi-color LED illumination source on a silicon based surface. IRIS monitors biomolecular interaction through measurement of biomass addition to the sensor's surface. We demonstrate the capability of this system to dynamically monitor antigen---antibody interactions with a noise floor of 5.2 pg/mm 2 and DNA single mismatch detection under isothermal melting conditions in an array format. Ensemble detection of binding events using IRIS did not provide the sensitivity needed for detection of infectious disease and biomarkers at clinically relevant concentrations. Therefore, a new approach was adapted to the IRIS platform that allowed the detection and identification of individual nanoparticles on the sensor's surface. The new detection method was termed single-particle IRIS (SP-IRIS). We developed two detection modalities for SP-IRIS. The first modality is when the target is a nanoparticle such as a virus. We verified that SP-IRIS can accurately detect and size individual viral particles. Then we demonstrated that single nanoparticle counting and sizing methodology on SP-IRIS leads to a specific and sensitive virus sensor that can be multiplexed. Finally, we developed an assay for the detection of Ebola and Marburg. A detection limit of 3 x 103 PFU/ml was demonstrated for vesicular stomatitis virus (VSV) pseudotyped with Ebola or Marburg virus glycoprotein. We have demonstrated that virus detection can be done in human whole blood directly without the need for sample preparation. The second modality

  10. A Homolog Pentameric Complex Dictates Viral Epithelial Tropism, Pathogenicity and Congenital Infection Rate in Guinea Pig Cytomegalovirus

    PubMed Central

    McGregor, Alistair

    2016-01-01

    In human cytomegalovirus (HCMV), tropism to epithelial and endothelial cells is dependent upon a pentameric complex (PC). Given the structure of the placenta, the PC is potentially an important neutralizing antibody target antigen against congenital infection. The guinea pig is the only small animal model for congenital CMV. Guinea pig cytomegalovirus (GPCMV) potentially encodes a UL128-131 HCMV PC homolog locus (GP128-GP133). In transient expression studies, GPCMV gH and gL glycoproteins interacted with UL128, UL130 and UL131 homolog proteins (designated GP129 and GP131 and GP133 respectively) to form PC or subcomplexes which were determined by immunoprecipitation reactions directed to gH or gL. A natural GP129 C-terminal deletion mutant (aa 107–179) and a chimeric HCMV UL128 C-terminal domain swap GP129 mutant failed to form PC with other components. GPCMV infection of a newly established guinea pig epithelial cell line required a complete PC and a GP129 mutant virus lacked epithelial tropism and was attenuated in the guinea pig for pathogenicity and had a low congenital transmission rate. Individual knockout of GP131 or 133 genes resulted in loss of viral epithelial tropism. A GP128 mutant virus retained epithelial tropism and GP128 was determined not to be a PC component. A series of GPCMV mutants demonstrated that gO was not strictly essential for epithelial infection whereas gB and the PC were essential. Ectopic expression of a GP129 cDNA in a GP129 mutant virus restored epithelial tropism, pathogenicity and congenital infection. Overall, GPCMV forms a PC similar to HCMV which enables evaluation of PC based vaccine strategies in the guinea pig model. PMID:27387220

  11. A Homolog Pentameric Complex Dictates Viral Epithelial Tropism, Pathogenicity and Congenital Infection Rate in Guinea Pig Cytomegalovirus.

    PubMed

    Coleman, Stewart; Choi, K Yeon; Root, Matthew; McGregor, Alistair

    2016-07-01

    In human cytomegalovirus (HCMV), tropism to epithelial and endothelial cells is dependent upon a pentameric complex (PC). Given the structure of the placenta, the PC is potentially an important neutralizing antibody target antigen against congenital infection. The guinea pig is the only small animal model for congenital CMV. Guinea pig cytomegalovirus (GPCMV) potentially encodes a UL128-131 HCMV PC homolog locus (GP128-GP133). In transient expression studies, GPCMV gH and gL glycoproteins interacted with UL128, UL130 and UL131 homolog proteins (designated GP129 and GP131 and GP133 respectively) to form PC or subcomplexes which were determined by immunoprecipitation reactions directed to gH or gL. A natural GP129 C-terminal deletion mutant (aa 107-179) and a chimeric HCMV UL128 C-terminal domain swap GP129 mutant failed to form PC with other components. GPCMV infection of a newly established guinea pig epithelial cell line required a complete PC and a GP129 mutant virus lacked epithelial tropism and was attenuated in the guinea pig for pathogenicity and had a low congenital transmission rate. Individual knockout of GP131 or 133 genes resulted in loss of viral epithelial tropism. A GP128 mutant virus retained epithelial tropism and GP128 was determined not to be a PC component. A series of GPCMV mutants demonstrated that gO was not strictly essential for epithelial infection whereas gB and the PC were essential. Ectopic expression of a GP129 cDNA in a GP129 mutant virus restored epithelial tropism, pathogenicity and congenital infection. Overall, GPCMV forms a PC similar to HCMV which enables evaluation of PC based vaccine strategies in the guinea pig model.

  12. Emerging viral pathogens in long-term expatriates (II): Dengue virus.

    PubMed

    Jänisch, T; Preiser, W; Berger, A; Niedrig, M; Mikulicz, U; Thoma, B; Doerr, H W

    1997-10-01

    Dengue virus infections have been well known for many years; still dengue virus is regarded as an 'emerging' pathogen, as the disease profile is changing. Its geographical range and overall incidence, and the incidence of the associated complications, dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS), are on the increase. Modern-day travel and increasing urbanization seem to be the main contributing factors. In order to estimate the risk of infection during long-term stays in dengue-endemic countries, we tested sera obtained from 323 development aid workers and their family members who had spent on average 9.8 years in dengue-endemic regions for the presence of dengue virus antibodies. Dengue virus antibody screening was done by a commercially available immunofluorescence test (IF). Reactive samples were re-tested by an in-house IF and also tested for cross-reactivity to yellow fever virus using yellow fever IF and neutralization test (NT). Evaluation of the results revealed that the screening test has a specificity of at least 63.2%. In 12 of 19 initially positive cases crossreacting antibodies against yellow fever virus could be ruled out. Three cases remained indeterminable, whereas four of the reactive and 10 (out of 12) of the borderline reactive cases showed crossreactivity with yellow fever virus, probably due to previous vaccination. We found seroprevalence rates of 4.3% with no significant differences related to gender or area of upbringing. Seroprevalence rates were evaluated according to region of suspected or confirmed infection. In two cases the dengue infection had taken a classical clinical course; in another three cases an extraordinary febrile illness was reported in the history. None of the other seropositive individuals had a history of an illness possibly attributable to dengue virus infection. Our results show that there definitely is a risk for long-term expatriates to acquire (mostly non- or oligo-symptomatic) dengue infection

  13. Development of slide ELISA (SELISA) for detection of four poultry viral pathogens by direct heat fixation of viruses on glass slides.

    PubMed

    Desingu, P A; Singh, S D; Dhama, K; Kumar, O R Vinodh; Singh, R; Singh, R K

    2014-12-01

    The development of an easy and simpler method of slide enzyme-linked immunosorbent assay (SELISA) for the diagnosis of four economically important poultry viruses viz., Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV) and egg drop syndrome 76 virus (EDS 76) and the use of SELISA for semi quantitation of NDV are described. The positive signals for viral aggregates were detected under light microscope. This is the first report regarding the development of SELISA based on heat fixation for the diagnosis of viral pathogens. PMID:25218174

  14. Development of slide ELISA (SELISA) for detection of four poultry viral pathogens by direct heat fixation of viruses on glass slides.

    PubMed

    Desingu, P A; Singh, S D; Dhama, K; Kumar, O R Vinodh; Singh, R; Singh, R K

    2014-12-01

    The development of an easy and simpler method of slide enzyme-linked immunosorbent assay (SELISA) for the diagnosis of four economically important poultry viruses viz., Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV) and egg drop syndrome 76 virus (EDS 76) and the use of SELISA for semi quantitation of NDV are described. The positive signals for viral aggregates were detected under light microscope. This is the first report regarding the development of SELISA based on heat fixation for the diagnosis of viral pathogens.

  15. Viral infection

    PubMed Central

    Puigdomènech, Isabel; de Armas-Rillo, Laura; Machado, José-David

    2011-01-01

    Viruses have developed different survival strategies in host cells by crossing cell-membrane compartments, during different steps of their viral life cycle. In fact, the non-regenerative viral membrane of enveloped viruses needs to encounter the dynamic cell-host membrane, during early steps of the infection process, in which both membranes fuse, either at cell-surface or in an endocytic compartment, to promote viral entry and infection. Once inside the cell, many viruses accomplish their replication process through exploiting or modulating membrane traffic, and generating specialized compartments to assure viral replication, viral budding and spreading, which also serve to evade the immune responses against the pathogen. In this review, we have attempted to present some data that highlight the importance of membrane dynamics during viral entry and replicative processes, in order to understand how viruses use and move through different complex and dynamic cell-membrane structures and how they use them to persist. PMID:21966556

  16. Epidemiology of viral pathogens of free-ranging dogs and Indian foxes in a human-dominated landscape in central India.

    PubMed

    Belsare, A V; Vanak, A T; Gompper, M E

    2014-08-01

    There is an increasing concern that free-ranging domestic dog (Canis familiaris) populations may serve as reservoirs of pathogens which may be transmitted to wildlife. We documented the prevalence of antibodies to three viral pathogens, canine parvovirus (CPV), canine distemper virus (CDV) and canine adenovirus (CAV), in free-ranging dog and sympatric Indian fox (Vulpes bengalensis) populations in and around the Great Indian Bustard Wildlife Sanctuary, in Maharashtra, central India. A total of 219 dogs and 33 foxes were sampled during the study period. Ninety-three percentage of dogs and 87% of foxes were exposed to one or more of the three pathogens. Exposure rates in dogs were high: >88% for CPV, >72% for CDV and 71% for CAV. A large proportion of adult dogs had antibodies against these pathogens due to seroconversion following earlier natural infection. The high prevalence of exposure to these pathogens across the sampling sessions, significantly higher exposure rates of adults compared with juveniles, and seroconversion in some unvaccinated dogs documented during the study period suggests that these pathogens are enzootic. The prevalence of exposure to CPV, CDV and CAV in foxes was 48%, 18% and 52%, respectively. Further, a high rate of mortality was documented in foxes with serologic evidence of ongoing CDV infection. Dogs could be playing a role in the maintenance and transmission of these pathogens in the fox population, but our findings show that most dogs in the population are immune to these pathogens by virtue of earlier natural infection, and therefore, these individuals make little current or future contribution to viral maintenance. Vaccination of this cohort will neither greatly improve their collective immune status nor contribute to herd immunity. Our findings have potentially important implications for dog disease control programmes that propose using canine vaccination as a tool for conservation management of wild carnivore populations. PMID

  17. Epidemiology of viral pathogens of free-ranging dogs and Indian foxes in a human-dominated landscape in central India.

    PubMed

    Belsare, A V; Vanak, A T; Gompper, M E

    2014-08-01

    There is an increasing concern that free-ranging domestic dog (Canis familiaris) populations may serve as reservoirs of pathogens which may be transmitted to wildlife. We documented the prevalence of antibodies to three viral pathogens, canine parvovirus (CPV), canine distemper virus (CDV) and canine adenovirus (CAV), in free-ranging dog and sympatric Indian fox (Vulpes bengalensis) populations in and around the Great Indian Bustard Wildlife Sanctuary, in Maharashtra, central India. A total of 219 dogs and 33 foxes were sampled during the study period. Ninety-three percentage of dogs and 87% of foxes were exposed to one or more of the three pathogens. Exposure rates in dogs were high: >88% for CPV, >72% for CDV and 71% for CAV. A large proportion of adult dogs had antibodies against these pathogens due to seroconversion following earlier natural infection. The high prevalence of exposure to these pathogens across the sampling sessions, significantly higher exposure rates of adults compared with juveniles, and seroconversion in some unvaccinated dogs documented during the study period suggests that these pathogens are enzootic. The prevalence of exposure to CPV, CDV and CAV in foxes was 48%, 18% and 52%, respectively. Further, a high rate of mortality was documented in foxes with serologic evidence of ongoing CDV infection. Dogs could be playing a role in the maintenance and transmission of these pathogens in the fox population, but our findings show that most dogs in the population are immune to these pathogens by virtue of earlier natural infection, and therefore, these individuals make little current or future contribution to viral maintenance. Vaccination of this cohort will neither greatly improve their collective immune status nor contribute to herd immunity. Our findings have potentially important implications for dog disease control programmes that propose using canine vaccination as a tool for conservation management of wild carnivore populations.

  18. Comparison of a multiplex reverse transcription-PCR-enzyme hybridization assay with conventional viral culture and immunofluorescence techniques for the detection of seven viral respiratory pathogens.

    PubMed

    Liolios, L; Jenney, A; Spelman, D; Kotsimbos, T; Catton, M; Wesselingh, S

    2001-08-01

    A multiplex reverse transcription-PCR-enzyme hybridization assay (RT-PCR-EHA; Hexaplex; Prodesse Inc., Waukesha, Wis.) was used for the simultaneous detection of human parainfluenza virus types 1, 2, and 3, influenza virus types A and B, and respiratory syncytial virus types A and B. One hundred forty-three respiratory specimens from 126 patients were analyzed by RT-PCR-EHA, and the results were compared to those obtained by conventional viral culture and immunofluorescence (IF) methods. RT-PCR-EHA proved to be positive for 17 of 143 (11.9%) specimens, whereas 8 of 143 (5.6%) samples were positive by viral culture and/or IF. Eight samples were positive by both RT-PCR-EHA and conventional methods, while nine samples were RT-PCR-EHA positive and viral culture and IF negative. Eight of the nine samples with discordant results were then independently tested by a different multiplex RT-PCR assay for influenza virus types A and B, and all eight proved to be positive. In comparison to viral culture and IF methods, RT-PCR-EHA gave a sensitivity and a specificity of 100 and 93%, respectively. Since RT-PCR-EHA was able to detect more positive samples, which would otherwise have been missed by routine methods, we suggest that this multiplex RT-PCR-EHA provides a highly sensitive and specific means of diagnostic detection of major respiratory viruses.

  19. NS Reassortment of an H7-Type Highly Pathogenic Avian Influenza Virus Affects Its Propagation by Altering the Regulation of Viral RNA Production and Antiviral Host Response▿ †

    PubMed Central

    Wang, Zhongfang; Robb, Nicole C.; Lenz, Eva; Wolff, Thorsten; Fodor, Ervin; Pleschka, Stephan

    2010-01-01

    Highly pathogenic avian influenza viruses (HPAIV) with reassorted NS segments from H5- and H7-type avian virus strains placed in the genetic background of the A/FPV/Rostock/34 HPAIV (FPV; H7N1) were generated by reverse genetics. Virological characterizations demonstrated that the growth kinetics of the reassortant viruses differed from that of wild-type (wt) FPV and depended on whether cells were of mammalian or avian origin. Surprisingly, molecular analysis revealed that the different reassortant NS segments were not only responsible for alterations in the antiviral host response but also affected viral genome replication and transcription as well as nuclear ribonucleoprotein (RNP) export. RNP reconstitution experiments demonstrated that the effects on accumulation levels of viral RNA species were dependent on the specific NS segment as well as on the genetic background of the RNA-dependent RNA polymerase (RdRp). Beta interferon (IFN-β) expression and the induction of apoptosis were found to be inversely correlated with the magnitude of viral growth, while the NS allele, virus subtype, and nonstructural protein NS1 expression levels showed no correlation. Thus, these results demonstrate that the origin of the NS segment can have a dramatic effect on the replication efficiency and host range of HPAIV. Overall, our data suggest that the propagation of NS reassortant influenza viruses is affected at multiple steps of the viral life cycle as a result of the different effects of the NS1 protein on multiple viral and host functions. PMID:20739516

  20. Viral DNA sequences of genes encoding the ATPase and the major capsid protein of tropical iridovirus isolates which are pathogenic to fishes in Japan, South China Sea and Southeast Asian countries.

    PubMed

    Sudthongkong, C; Miyata, M; Miyazaki, T

    2002-11-01

    Tropical iridovirus infection causes severe epizootic resulting in mass mortalities and large economic losses in freshwater ornamental fishes cultured in Southeast Asian countries, in wild fish seedlings captured in South China Sea, and in marine fishes farmed in Japan, Singapore, and Thailand. All of tropical iridovirus-infected fishes histopathologically showed the systemic formation of inclusion body-bearing cells and necrosis of virus-infected splenocytes and hematopoietic cells. We designed primer sets for the ATPase gene and the major capsid protein (MCP) gene and sequenced the PCR products derived from 5 iridovirus isolates from sea bass in South China Sea, red sea bream in Japan, brown-spotted grouper with a grouper sleepy disease in Thailand, dwarf gourami from Malaysia and African lampeye from Sumatra Island, Indonesia. The ATPase gene and the MCP gene of these 5 viral isolates were highly homologous (> 95.8%, > 94.9% identity, respectively) and the deduced amino acid sequences of the ATPase and the MCP were also highly identical (> 98.1%, > 97.2% identity, respectively). Based on the high homology, these 5 isolates of tropical iridovirus from various fishes in geographically different regions were determined to have a single origin and to be native to Southeast Asian regions. However, these sequences were far different from those of members of the genera Ranavirus, Lymphocystivirus and Iridovirus in the Family Iridoviridae. We propose a new genus "Tropivirus" for tropical iridovirus in the Family Iridoviridae.

  1. Effects of ranavirus infection of red-eared sliders (Trachemys scripta elegans) on plasma proteins.

    PubMed

    Moore, A Russell; Allender, Matthew C; MacNeill, Amy L

    2014-06-01

    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 molecular testing for ranavirus. Validation of an inexpensive, clinically relevant, and reproducible diagnostic test that detects inflammation in turtles is needed. Although commonly used, plasma protein electrophoresis to detect an inflammatory acute-phase protein response has not been evaluated in a controlled environment in turtles with experimentally induced inflammatory disease. The objective of this study was to measure plasma protein fractions by electrophoresis to determine if an acute-phase protein response occurs in RES during infection with a frog virus 3-like ranavirus (FV3-like virus) isolated from a chelonian. A Bradford assay and agarose gel electrophoresis (AGE) were performed using plasma collected during a study of the effect of temperature on the pathogenesis of ranavirus in RES. In RES at the time of viremia, total albumin (ALB(mg/ml)) and albumin to globulin ratio were significantly lower and beta-globulin percentage was significantly higher in RES exposed to ranavirus (n = 4) as compared to matched, uninfected RES (n = 8). In the last sample collected prior to death, total protein (TP(mg/ml)), ALB(mg/ml), alpha-globulin percentage, and total alpha-globulin (alpha(mg/ml)) were significantly lower in RES exposed to ranavirus (n = 4) than control individuals (n = 8). In summary, FV3-like virus induces a decrease in plasma albumin concentration at the onset ofviremia and decreases in TP(mg/ml, ALB(mg/ml), and alpha(mg/ml) concentrations prior to death in

  2. Viral replication rate regulates clinical outcome and CD8 T cell responses during highly pathogenic H5N1 influenza virus infection in mice.

    PubMed

    Hatta, Yasuko; Hershberger, Karen; Shinya, Kyoko; Proll, Sean C; Dubielzig, Richard R; Hatta, Masato; Katze, Michael G; Kawaoka, Yoshihiro; Suresh, M

    2010-01-01

    Since the first recorded infection of humans with H5N1 viruses of avian origin in 1997, sporadic human infections continue to occur with a staggering mortality rate of >60%. Although sustained human-to-human transmission has not occurred yet, there is a growing concern that these H5N1 viruses might acquire this trait and raise the specter of a pandemic. Despite progress in deciphering viral determinants of pathogenicity, we still lack crucial information on virus/immune system interactions pertaining to severe disease and high mortality associated with human H5N1 influenza virus infections. Using two human isolates of H5N1 viruses that differ in their pathogenicity in mice, we have defined mechanistic links among the rate of viral replication, mortality, CD8 T cell responses, and immunopathology. The extreme pathogenicity of H5N1 viruses was directly linked to the ability of the virus to replicate rapidly, and swiftly attain high steady-state titers in the lungs within 48 hours after infection. The remarkably high replication rate of the highly pathogenic H5N1 virus did not prevent the induction of IFN-β or activation of CD8 T cells, but the CD8 T cell response was ineffective in controlling viral replication in the lungs and CD8 T cell deficiency did not affect viral titers or mortality. Additionally, BIM deficiency ameliorated lung pathology and inhibited T cell apoptosis without affecting survival of mice. Therefore, rapidly replicating, highly lethal H5N1 viruses could simply outpace and overwhelm the adaptive immune responses, and kill the host by direct cytopathic effects. However, therapeutic suppression of early viral replication and the associated enhancement of CD8 T cell responses improved the survival of mice following a lethal H5N1 infection. These findings suggest that suppression of early H5N1 virus replication is key to the programming of an effective host response, which has implications in treatment of this infection in humans. PMID:20949022

  3. The North American strain of viral hemorrhagic septicemia virus is highly pathogenic for laboratory-reared Pacific herring (Clupea pallasi)

    USGS Publications Warehouse

    Kocan, R.; Bradley, M.; Elder, N.; Meyers, T.; Batts, W.; Winton, J.

    1997-01-01

    Specific-pathogen-free Pacific herring Clupea pallasi were reared in the laboratory from eggs and then challenged at 5, 9, and 13 months of age by waterborne exposure to low (101.5–2.5 plaque-forming units [PFU] per milliliter), medium (103.5–4.5 PFU/mL), or high (105.5–6.5 PFU/mL) levels of a North American isolate of viral hemorrhagic septicemia virus (VHSV). The fish were extremely susceptible to the virus, showing clinical disease, mortality approaching 100%, and only a limited increase in resistance with age. Mortality began 4–6 d after exposure and peaked at approximately day 7 in fish exposed to high levels of virus. Whereas the mean time to death showed a significant dose response (P < 0.001), the percent mortality and virus titers in dead fish were generally high in all groups regardless of initial challenge dose. External signs of disease were usually limited to 1–2-mm hemorrhagic areas on the lower jaw and isthmus and around the eye, but 2 of 130 infected fish exhibited extensive cutaneous hemorrhaging. Histopathologic examination of tissues from moribund fish sampled at 2–8 d after exposure revealed multifocal coagulative necrosis of hepatocytes, diffuse necrosis of interstitial hematopoietic tissues in the kidney, diffuse necrosis of the spleen, epidermis, and subcutis, and occasional necrosis of pancreatic acinar cells. Virus titers in tissues of experimentally infected herring were first detected 48 h after exposure and peaked 6-8 d after exposure at 107.7 PFU/g. Fish began shedding virus at 48 h after exposure with titers in the flow-through aquaria reaching 102.5 PFU/mL at 4–5 d after exposure, just before peak mortality. When the water flow was turned off for 3 h, titers in the water rose to 103.5 PFU/mL, and the amount of virus shed by infected fish (on average, greater than 106.5 PFU/h per fish) appeared sufficient to sustain a natural epizootic among schooling herring. Taken together, these data suggest that VHSV could be a

  4. The 18S rDNA sequence of Synchytrium endobioticum and its utility in microarrays for the simultaneous detection of fungal and viral pathogens of potato.

    PubMed

    Abdullahi, Ismail; Koerbler, Marianne; Stachewicz, Hans; Winter, Stephan

    2005-08-01

    Resting spores extracted from wart (Synchytrium endobioticum)-infected potato tubers were used for DNA extraction and amplification of 18S rDNA. Analysis of the cloned, sequenced fragment revealed high similarity to members of the Chytridiomycota. Using this information, specific oligonucleotide probes were designed and arrayed onto glass slides for detection of the pathogen. Viral sequence information available in the databank was retrieved, or new viral sequences were generated, and used to design probes for specific detection of important quarantine viruses of potato. To determine the sensitivity and specificity of the oligonucleotide probes, total RNA from infected plants was reverse transcribed, labelled with Cyanine 5, and hybridised with the microarray. A significant number of the oligonucleotide probes exhibited high specificity to S. endobioticum, Andean potato latent virus, Andean potato mottle virus, Potato black ringspot virus, and Potato spindle tuber viroid. Hybridisation signals of sub-arrays within slides were reproducible (r = 0.79) with a high correlation coefficient of hybridisation repetitions (0.73). Our results demonstrate the potential of microarray-based hybridisation for identification of multiple pathogen targets, which will find application in quarantine laboratories, where parallel testing for diverse pathogens is essential. PMID:15800764

  5. Experimentally Infected Domestic Ducks Show Efficient Transmission of Indonesian H5N1 Highly Pathogenic Avian Influenza Virus, but Lack Persistent Viral Shedding

    PubMed Central

    Wibawa, Hendra; Bingham, John; Nuradji, Harimurti; Lowther, Sue; Payne, Jean; Harper, Jenni; Junaidi, Akhmad; Middleton, Deborah; Meers, Joanne

    2014-01-01

    Ducks are important maintenance hosts for avian influenza, including H5N1 highly pathogenic avian influenza viruses. A previous study indicated that persistence of H5N1 viruses in ducks after the development of humoral immunity may drive viral evolution following immune selection. As H5N1 HPAI is endemic in Indonesia, this mechanism may be important in understanding H5N1 evolution in that region. To determine the capability of domestic ducks to maintain prolonged shedding of Indonesian clade 2.1 H5N1 virus, two groups of Pekin ducks were inoculated through the eyes, nostrils and oropharynx and viral shedding and transmission investigated. Inoculated ducks (n = 15), which were mostly asymptomatic, shed infectious virus from the oral route from 1 to 8 days post inoculation, and from the cloacal route from 2–8 dpi. Viral ribonucleic acid was detected from 1–15 days post inoculation from the oral route and 1–24 days post inoculation from the cloacal route (cycle threshold <40). Most ducks seroconverted in a range of serological tests by 15 days post inoculation. Virus was efficiently transmitted during acute infection (5 inoculation-infected to all 5 contact ducks). However, no evidence for transmission, as determined by seroconversion and viral shedding, was found between an inoculation-infected group (n = 10) and contact ducks (n = 9) when the two groups only had contact after 10 days post inoculation. Clinical disease was more frequent and more severe in contact-infected (2 of 5) than inoculation-infected ducks (1 of 15). We conclude that Indonesian clade 2.1 H5N1 highly pathogenic avian influenza virus does not persist in individual ducks after acute infection. PMID:24392085

  6. Experimentally infected domestic ducks show efficient transmission of Indonesian H5N1 highly pathogenic avian influenza virus, but lack persistent viral shedding.

    PubMed

    Wibawa, Hendra; Bingham, John; Nuradji, Harimurti; Lowther, Sue; Payne, Jean; Harper, Jenni; Junaidi, Akhmad; Middleton, Deborah; Meers, Joanne

    2014-01-01

    Ducks are important maintenance hosts for avian influenza, including H5N1 highly pathogenic avian influenza viruses. A previous study indicated that persistence of H5N1 viruses in ducks after the development of humoral immunity may drive viral evolution following immune selection. As H5N1 HPAI is endemic in Indonesia, this mechanism may be important in understanding H5N1 evolution in that region. To determine the capability of domestic ducks to maintain prolonged shedding of Indonesian clade 2.1 H5N1 virus, two groups of Pekin ducks were inoculated through the eyes, nostrils and oropharynx and viral shedding and transmission investigated. Inoculated ducks (n = 15), which were mostly asymptomatic, shed infectious virus from the oral route from 1 to 8 days post inoculation, and from the cloacal route from 2-8 dpi. Viral ribonucleic acid was detected from 1-15 days post inoculation from the oral route and 1-24 days post inoculation from the cloacal route (cycle threshold <40). Most ducks seroconverted in a range of serological tests by 15 days post inoculation. Virus was efficiently transmitted during acute infection (5 inoculation-infected to all 5 contact ducks). However, no evidence for transmission, as determined by seroconversion and viral shedding, was found between an inoculation-infected group (n = 10) and contact ducks (n = 9) when the two groups only had contact after 10 days post inoculation. Clinical disease was more frequent and more severe in contact-infected (2 of 5) than inoculation-infected ducks (1 of 15). We conclude that Indonesian clade 2.1 H5N1 highly pathogenic avian influenza virus does not persist in individual ducks after acute infection.

  7. Anuran susceptibilities to ranaviruses: role of species identity, exposure route, and a novel virus isolate.

    PubMed

    Hoverman, Jason T; Gray, Matthew J; Miller, Debra L

    2010-03-01

    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 water bath were similarly lethal routes of transmission, and (3) quantify the effects of exposure duration on disease outcomes. We conducted our research in a controlled aquatic laboratory using a factorial combination of virus isolates, transmission routes, and exposure durations. While ranaviruses can affect many species, we found that larval anurans differ greatly in susceptibility to ranaviruses. Average mortality rates of Cope's gray tree frogs (66%) and pickerel frogs (68%) were similar but 3-fold higher than for eastern narrow-mouthed toads. Direct ingestion of the viruses increased mean infection and mortality rates by 30% and caused death about 2 times faster compared to water bath exposure. However, exposure duration did not impact mean infection or mortality rates. We also found that the ranaculture isolate increased mortality by > 34% compared to FV3. Our results suggest that ranaviruses can rapidly infect and cause disease in multiple amphibian species. Given the risk associated with introducing novel ranaviruses from ranaculture facilities, we recommend that all nations adopt the protocol set forth by the World Organization for Animal Health for testing and certifying that amphibians that are commercially shipped are negative for ranavirus infection. PMID:20402227

  8. Co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in Florida, USA.

    PubMed

    Landsberg, Jan H; Kiryu, Yasunari; Tabuchi, Maki; Waltzek, Thomas B; Enge, Kevin M; Reintjes-Tolen, Sarah; Preston, Asa; Pessier, Allan P

    2013-07-22

    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 parasites. The intensity of infection in bullfrog livers was high. Tadpoles were evaluated for frog virus 3 (FV3) by histology and PCR. For those southern leopard frog tadpoles (n = 2) whose livers had not been obscured by alveolate spore infection, neither a pathologic response nor intracytoplasmic inclusions typically associated with clinical infections of FV3-like ranavirus were noted. Sequencing of a portion (496 bp) of the viral major capsid protein gene confirmed FV3-like virus in bullfrogs (n = 1, plus n = 6 pooled) and southern leopard frogs (n = 1, plus n = 4 pooled). In July 2011, young-of-the-year bullfrog tadpoles (n = 7) were negative for alveolate parasites, but 1 gopher frog tadpole was positive. To our knowledge, this is the first confirmed mortality event for amphibians in Florida associated with FV3-like virus, but the extent to which the virus played a primary role is uncertain. Larval mortality was most likely caused by a combination of alveolate parasite infections, FV3-like ranavirus, and undetermined etiological factors.

  9. Co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in Florida, USA.

    PubMed

    Landsberg, Jan H; Kiryu, Yasunari; Tabuchi, Maki; Waltzek, Thomas B; Enge, Kevin M; Reintjes-Tolen, Sarah; Preston, Asa; Pessier, Allan P

    2013-07-22

    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 parasites. The intensity of infection in bullfrog livers was high. Tadpoles were evaluated for frog virus 3 (FV3) by histology and PCR. For those southern leopard frog tadpoles (n = 2) whose livers had not been obscured by alveolate spore infection, neither a pathologic response nor intracytoplasmic inclusions typically associated with clinical infections of FV3-like ranavirus were noted. Sequencing of a portion (496 bp) of the viral major capsid protein gene confirmed FV3-like virus in bullfrogs (n = 1, plus n = 6 pooled) and southern leopard frogs (n = 1, plus n = 4 pooled). In July 2011, young-of-the-year bullfrog tadpoles (n = 7) were negative for alveolate parasites, but 1 gopher frog tadpole was positive. To our knowledge, this is the first confirmed mortality event for amphibians in Florida associated with FV3-like virus, but the extent to which the virus played a primary role is uncertain. Larval mortality was most likely caused by a combination of alveolate parasite infections, FV3-like ranavirus, and undetermined etiological factors. PMID:23872853

  10. A reverse genetics system for the Great Lakes strain of viral hemorrhagic septicemia virus: the NV gene is required for pathogenicity

    USGS Publications Warehouse

    Ammayappan, Arun; Kurath, Gael; Thompson, Tarin M.; Vakharia, Vikram N.

    2011-01-01

    Viral hemorrhagic septicemia virus (VHSV), belonging to the genus Novirhabdovirus in the family of Rhabdoviridae, causes a highly contagious disease of fresh and saltwater fish worldwide. Recently, a novel genotype of VHSV, designated IVb, has invaded the Great Lakes in North America, causing large-scale epidemics in wild fish. An efficient reverse genetics system was developed to generate a recombinant VHSV of genotype IVb from cloned cDNA. The recombinant VHSV (rVHSV) was comparable to the parental wild-type strain both in vitro and in vivo, causing high mortality in yellow perch (Perca flavescens). A modified recombinant VHSV was generated in which the NV gene was substituted with an enhanced green fluorescent protein gene (rVHSV-ΔNV-EGFP), and another recombinant was made by inserting the EGFP gene into the full-length viral clone between the P and M genes (rVHSV-EGFP). The in vitro replication kinetics of rVHSV-EGFP was similar to rVHSV; however, the rVHSV-ΔNV-EGFP grew 2 logs lower. In yellow perch challenges, wtVHSV and rVHSV induced 82-100% cumulative per cent mortality (CPM), respectively, whereas rVHSV-EGFP produced 62% CPM and rVHSV-ΔNV-EGFP caused only 15% CPM. No reversion of mutation was detected in the recovered viruses and the recombinant viruses stably maintained the foreign gene after several passages. These results indicate that the NV gene of VHSV is not essential for viral replication in vitro and in vivo, but it plays an important role in viral replication efficiency and pathogenicity. This system will facilitate studies of VHSV replication, virulence, and production of viral vectored vaccines.

  11. Critical Role of K1685 and K1829 in the Large Protein of Rabies Virus in Viral Pathogenicity and Immune Evasion

    PubMed Central

    Tian, Dayong; Luo, Zhaochen; Zhou, Ming; Li, Mingming; Yu, Lan; Wang, Chong; Yuan, Jiaolong; Li, Fang; Tian, Bin; Sui, Baokun; Chen, Huanchun

    2015-01-01

    ABSTRACT Rabies, one of the oldest infectious diseases, still presents a public health threat in most parts of the world today. Its pathogen, rabies virus (RABV), can utilize its viral proteins, such as the nucleoprotein and phosphorylation protein, to subvert the host innate immune system. For a long time, the large (L) protein was believed to be essential for RABV transcription and replication, but its role in viral pathogenicity and immune evasion was not known. Recent studies have found that the conserved K-D-K-E tetrad motif in the L protein is related to the methyltransferase (MTase) activity in the viral mRNA process. In the present study, a series of RABV mutations in this motif was constructed with the recombinant CVS-B2c (rB2c) virus. Two of these mutants, rB2c-K1685A and rB2c-K1829A, were found to be stable and displayed an attenuated phenotype in both in vitro growth and in vivo pathogenicity in adult and suckling mice. Further studies demonstrated that these two mutants were more sensitive to the expression of the interferon-stimulated gene product IFIT2 than the parent virus. Taken together, our results suggest that K1685 and K1829 in the L protein play important roles in pathogenicity and immune evasion during RABV infection. IMPORTANCE Rabies continues to present a public health threat in most areas of the world, especially in the developing countries of Asia and Africa. The pathogenic mechanisms for rabies are not well understood. In the present study, it was found that the recombinant rabies viruses rB2c-K1685A and rB2c-K1829A, carrying mutations at the predicted MTase catalytic sites in the L protein, were highly attenuated both in vitro and in vivo. Further studies showed that these mutants were more sensitive to the expression of the interferon-stimulated gene product IFIT2 than the parent virus. These findings improve our understanding of rabies pathogenesis, which may help in developing potential therapeutics and an avirulent rabies vaccine

  12. Amphibian commerce as a likely source of pathogen pollution.

    PubMed

    Picco, Angela M; Collins, James P

    2008-12-01

    The commercial trade of wildlife occurs on a global scale. In addition to removing animals from their native populations, this trade may lead to the release and subsequent introduction of nonindigenous species and the pathogens they carry. Emerging infectious diseases, such as chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), and ranaviral disease have spread with global trade in amphibians and are linked to amphibian declines and die-offs worldwide, which suggests that the commercial trade in amphibians may be a source of pathogen pollution. We screened tiger salamanders involved in the bait trade in the western United States for both ranaviruses and Bd with polymerase chain reaction and used oral reports from bait shops and ranavirus DNA sequences from infected bait salamanders to determine how these animals and their pathogens are moved geographically by commerce. In addition, we conducted 2 surveys of anglers to determine how often tiger salamanders are used as bait and how often they are released into fishing waters by anglers, and organized bait-shop surveys to determine whether tiger salamanders are released back into the wild after being housed in bait shops. Ranaviruses were detected in the tiger salamander bait trade in Arizona, Colorado, and New Mexico, and Bd was detected in Arizona bait shops. Ranaviruses were spread geographically through the bait trade. All tiger salamanders in the bait trade were collected from the wild, and in general they moved east to west and north to south, bringing with them their multiple ranavirus strains. Finally, 26-73% of anglers used tiger salamanders as fishing bait, 26-67% of anglers released tiger salamanders bought as bait into fishing waters, and 4% of bait shops released tiger salamanders back into the wild after they were housed in shops with infected animals. The tiger salamander bait trade in the western United States is a useful model for understanding the consequences of the

  13. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands.

    PubMed

    Rijks, Jolianne M; Saucedo, Bernardo; Spitzen-van der Sluijs, Annemarieke; Wilkie, Gavin S; van Asten, Alphons J A M; van den Broek, Jan; Boonyarittichaikij, Roschong; Stege, Marisca; van der Sterren, Fleur; Martel, An; Pasmans, Frank; Hughes, Joseph; Gröne, Andrea; van Beurden, Steven J; Kik, Marja J L

    2016-01-01

    In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention.

  14. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands.

    PubMed

    Rijks, Jolianne M; Saucedo, Bernardo; Spitzen-van der Sluijs, Annemarieke; Wilkie, Gavin S; van Asten, Alphons J A M; van den Broek, Jan; Boonyarittichaikij, Roschong; Stege, Marisca; van der Sterren, Fleur; Martel, An; Pasmans, Frank; Hughes, Joseph; Gröne, Andrea; van Beurden, Steven J; Kik, Marja J L

    2016-01-01

    In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention. PMID:27315226

  15. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands

    PubMed Central

    Spitzen-van der Sluijs, Annemarieke; Wilkie, Gavin S.; van Asten, Alphons J. A. M.; van den Broek, Jan; Boonyarittichaikij, Roschong; Stege, Marisca; van der Sterren, Fleur; Martel, An; Pasmans, Frank; Hughes, Joseph; Gröne, Andrea; van Beurden, Steven J.; Kik, Marja J. L.

    2016-01-01

    In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention. PMID:27315226

  16. [Cases of West Nile fever in Novosibirsk region in 2004, and the genotyping of its viral pathogen].

    PubMed

    Ternovoĭ, V A; Protopopova, E V; Kononova, Iu V; Ol'khovikova, E A; Spiridonova, E A; Akopov, G D; Shestopalov, A M; Loktev, V B

    2007-01-01

    Three cases of West Nile fever were registered for the first time in Novosibirsk region in 2004. The diagnosis was confirmed by revealing IgG against West Nile virus (three cases) and viral RNA (two cases). Sequence analysis of fragments of E protein gene showed that the virus belonged to Ia genotype. PMID:17338376

  17. Simultaneous detection of viral and bacterial enteric pathogens using the Seeplex® Diarrhea ACE detection system.

    PubMed

    Coupland, L J; McElarney, I; Meader, E; Cowley, K; Alcock, L; Naunton, J; Gray, J

    2013-10-01

    A panel of 223 faecal samples was analysed to determine the clinical utility of the Seeplex® Diarrhea ACE Detection multiplex PCR system (Seeplex system; Seegene, Korea), a qualitative multiplexing PCR technology that enables simultaneous multi-pathogen detection of four viruses and/or ten bacteria associated with acute gastroenteritis. Conventional diagnostic methods and a norovirus-specific multiplex real-time RT–PCR detected 98 pathogens in 96 samples. The Seeplex system detected 81 pathogens in 75 samples. All samples positive for adenovirus, norovirus, Campylobacter spp., Escherichia coli O157, Shigella spp. or Vibrio spp. were detected by the Seeplex system. Rotavirus, Clostridium difficile toxin B, and Salmonella spp. were not detected in 12.5%, 50% and 15.8% of samples, respectively. Additional multiple infections were detected in 19 samples by the Seeplex system. The Seeplex system provides significant additional diagnostic capability for the syndromic diagnosis of acute gastroenteritis with increased sensitivity for the majority of pathogens.

  18. Ranavirus-associated mass mortality in wild amphibians, the Netherlands, 2010: a first report.

    PubMed

    Kik, Marja; Martel, An; Sluijs, Annemarieke Spitzen-van der; Pasmans, Frank; Wohlsein, Peter; Gröne, Andrea; Rijks, Jolianne M

    2011-11-01

    In 2010, a mass die-off of over 1000 wild water frogs (Pelophylax spp.) and at least 10 common newts (Lissotriton vulgaris) occurred in a pond in The Netherlands. Haemorrhagic disease with hepatomegaly and splenomegaly was evident. Microscopically, multiple organs presented cells with multifocal intracytoplasmic inclusion bodies, in which ranavirus-like particles were demonstrated ultrastructurally. All specimens examined tested positive for ranavirus by PCR. The sequence obtained showed a 100% identity with the one deposited for common midwife toad virus (CMTV). This is the first report of ranavirus-associated mortality in wild amphibian populations in The Netherlands. It is also the first time CMTV or a CMTV-like virus has been reported in these two species in the adult stage and outside of Spain.

  19. Age-related presence of selected viral and bacterial pathogens in paraffin-embedded lung samples of dogs with pneumonia.

    PubMed

    Wöhrer, Daniela; Spergser, Joachim; Bagrinovschi, Gabriela; Möstl, Karin; Weissenböck, Herbert

    2016-03-01

    The aim of this retrospective study was to detect selected pathogens in pneumonic lung tissue of dogs of different age groups by immunohistochemistry (IHC), in situ hybridisation (ISH) or polymerase chain reaction (PCR) in order to get information about their involvement in pneumonia formation. In archived formalin-fixed and paraffin wax-embedded lung samples from 68 cases with the clinical and histologic diagnosis of pneumonia the histological pattern of pneumonia was re-evaluated and the samples were further investigated for the following infectious agents: canine distemper virus (CDV), canine adenovirus type 2 (CAV-2), canine respiratory coronavirus (CRCoV), Bordetella (B.) bronchiseptica, Pasteurella (P.) multocida, Mycoplasma spp., and Pneumocystis spp. In 47.1% of the samples at least one of the featured respiratory pathogens was detected. In 31.3% of these positive samples more than one pathogen could be found. The correct detection of CDV had been achieved in ten out of eleven positive cases (90.9%) upon initial investigation, but the presence of bacterial pathogens, like B. bronchiseptica (10 cases) and P. multocida (17 cases) had been missed in all but one case. While CDV and CRCoV infections were exclusively found in dogs younger than one year, the vast majority of infections with P. multocida and B. bronchiseptica were both common either in dogs younger than 4 months or older than one year. Thus, this retrospective approach yielded valuable data on the presence, absence and prevalence of certain respiratory pathogens in dogs with pneumonia. PMID:26919147

  20. Incidence of Norovirus and Other Viral Pathogens That Cause Acute Gastroenteritis (AGE) among Kaiser Permanente Member Populations in the United States, 2012-2013.

    PubMed

    Grytdal, Scott P; DeBess, Emilio; Lee, Lore E; Blythe, David; Ryan, Patricia; Biggs, Christianne; Cameron, Miriam; Schmidt, Mark; Parashar, Umesh D; Hall, Aron J

    2016-01-01

    Noroviruses and other viral pathogens are increasingly recognized as frequent causes of acute gastroenteritis (AGE). However, few laboratory-based data are available on the incidence of AGE caused by viral pathogens in the U.S. This study examined stool specimens submitted for routine clinical diagnostics from patients enrolled in Kaiser Permanente (KP) health plans in metro Portland, OR, and the Maryland, District of Columbia, and northern Virginia geographic areas to estimate the incidence of viral enteropathogens in these populations. Over a one-year study period, participating laboratories randomly selected stools submitted for routine clinical diagnostics for inclusion in the study along with accompanying demographic and clinical data. Selected stools were tested for norovirus, rotavirus, sapovirus, and astrovirus using standardized real-time RT-PCR protocols. Each KP site provided administrative data which were used in conjunction with previously published data on healthcare utilization to extrapolate pathogen detection rates into population-based incidence rates. A total of 1,099 specimens collected during August 2012 to September 2013 were included. Mean age of patients providing stool specimens was 46 years (range: 0-98 years). Noroviruses were the most common viral pathogen identified among patients with AGE (n = 63 specimens, 6% of specimens tested). In addition, 22 (2%) of specimens were positive for rotavirus; 19 (2%) were positive for sapovirus; and 7 (1%) were positive for astrovirus. Incidence of norovirus-associated outpatient visits was 5.6 per 1,000 person-years; incidence of norovirus disease in the community was estimated to be 69.5 per 1,000 person-years. Norovirus incidence was highest among children <5 years of age (outpatient incidence = 25.6 per 1,000 person-years; community incidence = 152.2 per 1,000 person-years), followed by older adults aged >65 years (outpatient incidence = 7.8 per 1,000 person-years; community incidence = 75.8 per 1

  1. A new ranavirus isolated from Pseudacris clarkii tadpoles in playa wetlands in the southern High Plains, Texas.

    PubMed

    Torrence, Shannon M; Green, D Earl; Benson, Catherine J; Ip, Hon S; Smith, Loren M; McMurry, Scott T

    2010-06-01

    Mass die-offs of amphibian populations pose a challenging problem for conservation biologists. Ranaviruses often cause systemic infections in amphibians and, in North America, are especially virulent and lethal to larvae and metamorphs. In this paper we describe a novel ranavirus isolate as well as the first recorded occurrence of ranavirus in the southern High Plains of Texas and in associated populations of the spotted chorus frog Pseudacris clarkii. The breeding sites were playas, that is, wetlands that fill via isolated thunderstorms that can occur infrequently; thus, not every playa has water or breeding amphibians annually. We did not detect ranavirus in sympatric anurans, but other reports document ranaviruses in Pseudacris spp. elsewhere. The occurrence of multiple isolates of ranavirus in a number of Pseudacris species suggests that this genus of frogs is highly susceptible to ranaviruses and may experience exceptionally high mortality rates from infection. Thus, the virus may contribute to substantial seasonal population declines and low seasonal recruitment, with negative impacts on populations of breeding adults in successive years. PMID:20848879

  2. A new ranavirus isolated from Pseudacris clarkii tadpoles in playa wetlands in the southern High Plains, Texas.

    PubMed

    Torrence, Shannon M; Green, D Earl; Benson, Catherine J; Ip, Hon S; Smith, Loren M; McMurry, Scott T

    2010-06-01

    Mass die-offs of amphibian populations pose a challenging problem for conservation biologists. Ranaviruses often cause systemic infections in amphibians and, in North America, are especially virulent and lethal to larvae and metamorphs. In this paper we describe a novel ranavirus isolate as well as the first recorded occurrence of ranavirus in the southern High Plains of Texas and in associated populations of the spotted chorus frog Pseudacris clarkii. The breeding sites were playas, that is, wetlands that fill via isolated thunderstorms that can occur infrequently; thus, not every playa has water or breeding amphibians annually. We did not detect ranavirus in sympatric anurans, but other reports document ranaviruses in Pseudacris spp. elsewhere. The occurrence of multiple isolates of ranavirus in a number of Pseudacris species suggests that this genus of frogs is highly susceptible to ranaviruses and may experience exceptionally high mortality rates from infection. Thus, the virus may contribute to substantial seasonal population declines and low seasonal recruitment, with negative impacts on populations of breeding adults in successive years.

  3. Integrated DNA and RNA extraction and purification on an automated microfluidic cassette from bacterial and viral pathogens causing community-acquired lower respiratory tract infections.

    PubMed

    Van Heirstraeten, Liesbet; Spang, Peter; Schwind, Carmen; Drese, Klaus S; Ritzi-Lehnert, Marion; Nieto, Benjamin; Camps, Marta; Landgraf, Bryan; Guasch, Francesc; Corbera, Antoni Homs; Samitier, Josep; Goossens, Herman; Malhotra-Kumar, Surbhi; Roeser, Tina

    2014-05-01

    In this paper, we describe the development of an automated sample preparation procedure for etiological agents of community-acquired lower respiratory tract infections (CA-LRTI). The consecutive assay steps, including sample re-suspension, pre-treatment, lysis, nucleic acid purification, and concentration, were integrated into a microfluidic lab-on-a-chip (LOC) cassette that is operated hands-free by a demonstrator setup, providing fluidic and valve actuation. The performance of the assay was evaluated on viral and Gram-positive and Gram-negative bacterial broth cultures previously sampled using a nasopharyngeal swab. Sample preparation on the microfluidic cassette resulted in higher or similar concentrations of pure bacterial DNA or viral RNA compared to manual benchtop experiments. The miniaturization and integration of the complete sample preparation procedure, to extract purified nucleic acids from real samples of CA-LRTI pathogens to, and above, lab quality and efficiency, represent important steps towards its application in a point-of-care test (POCT) for rapid diagnosis of CA-LRTI. PMID:24615272

  4. A multiplexed reverse transcriptase PCR assay for identification of viral respiratory pathogens at point-of-care

    SciTech Connect

    Letant, S E; .Ortiz, J I; Tammero, L; Birch, J M; Derlet, R W; Cohen, S; Manning, D; McBride, M T

    2007-04-11

    We have developed a nucleic acid-based assay that is rapid, sensitive, specific, and can be used for the simultaneous detection of 5 common human respiratory pathogens including influenza A, influenza B, parainfluenza type 1 and 3, respiratory syncytial virus, and adenovirus group B, C, and E. Typically, diagnosis on an un-extracted clinical sample can be provided in less than 3 hours, including sample collection, preparation, and processing, as well as data analysis. Such a multiplexed panel would enable rapid broad-spectrum pathogen testing on nasal swabs, and therefore allow implementation of infection control measures, and timely administration of antiviral therapies. This article presents a summary of the assay performance in terms of sensitivity and specificity. Limits of detection are provided for each targeted respiratory pathogen, and result comparisons are performed on clinical samples, our goal being to compare the sensitivity and specificity of the multiplexed assay to the combination of immunofluorescence and shell vial culture currently implemented at the UCDMC hospital. Overall, the use of the multiplexed RT-PCR assay reduced the rate of false negatives by 4% and reduced the rate of false positives by up to 10%. The assay correctly identified 99.3% of the clinical negatives, 97% of adenovirus, 95% of RSV, 92% of influenza B, and 77% of influenza A without any extraction performed on the clinical samples. The data also showed that extraction will be needed for parainfluenza virus, which was only identified correctly 24% of the time on un-extracted samples.

  5. Concurrent Phaeohyphomycosis and Ranavirus Infection in an Eastern Box Turtle ( Terrapene carolina ) in Athens, Georgia, USA.

    PubMed

    Perpiñán, David; Blas-Machado, Uriel; Sánchez, Susan; Miller, Debra L

    2016-07-01

    An eastern box turtle (Terrapene carolina) was found in a stream in the southeastern US, with a mass affecting the distal right forelimb. The turtle developed complications during hospitalization, including lethargy and oral caseous plaques and eventually died. Postmortem analyses diagnosed a mixed infection of phaeohyphomycosis and Ranavirus.

  6. Concurrent Phaeohyphomycosis and Ranavirus Infection in an Eastern Box Turtle ( Terrapene carolina ) in Athens, Georgia, USA.

    PubMed

    Perpiñán, David; Blas-Machado, Uriel; Sánchez, Susan; Miller, Debra L

    2016-07-01

    An eastern box turtle (Terrapene carolina) was found in a stream in the southeastern US, with a mass affecting the distal right forelimb. The turtle developed complications during hospitalization, including lethargy and oral caseous plaques and eventually died. Postmortem analyses diagnosed a mixed infection of phaeohyphomycosis and Ranavirus. PMID:27310167

  7. The origin of the PB1 segment of swine influenza A virus subtype H1N2 determines viral pathogenicity in mice.

    PubMed

    Metreveli, Giorgi; Gao, Qinshan; Mena, Ignacio; Schmolke, Mirco; Berg, Mikael; Albrecht, Randy A; García-Sastre, Adolfo

    2014-08-01

    Swine appear to be a key species in the generation of novel human influenza pandemics. Previous pandemic viruses are postulated to have evolved in swine by reassortment of avian, human, and swine influenza viruses. The human pandemic influenza viruses that emerged in 1957 and 1968 as well as swine viruses circulating since 1998 encode PB1 segments derived from avian influenza viruses. Here we investigate the possible role in viral replication and virulence of the PB1 gene segments present in two swine H1N2 influenza A viruses, A/swine/Sweden/1021/2009(H1N2) (sw 1021) and A/swine/Sweden/9706/2010(H1N2) (sw 9706), where the sw 1021 virus has shown to be more pathogenic in mice. By using reverse genetics, we swapped the PB1 genes of these two viruses. Similar to the sw 9706 virus, chimeric sw 1021 virus carrying the sw 9706 PB1 gene was not virulent in mice. In contrast, replacement of the PB1 gene of the sw 9706 virus by that from sw 1021 virus resulted in increased pathogenicity. Our study demonstrated that differences in virulence of swine influenza virus subtype H1N2 are attributed at least in part to the PB1 segment.

  8. Two single amino acid substitutions in the intervening region of Newcastle disease virus HN protein attenuate viral replication and pathogenicity

    PubMed Central

    Liu, Bin; Ji, Yanhong; Lin, Zhongqing; Fu, Yuguang; Muhammad Dafallah, Rihab; Zhu, Qiyun

    2015-01-01

    Among the proteins encoded by Newcastle disease virus (NDV), the attachment protein (HN) is an important determinant of virulence and pathogenicity. HN has been molecularly characterized at the protein level; however, the relationship between the molecular character of HN and the animal pathotype it causes has not been well explored. Here, we revisited the intervening region (IR) of the HN stalk and extended the known biological functions of HN. Three distinct substitutions (A89Q, P93A, and L94A) in the IR of genotype VII NDV (G7 strain) HN protein were analyzed. The A89Q and L94A mutations weakened the fusion promotion activity of HN to 44% and 41% of that of wild type, respectively, whereas P93A decreased the neuraminidase activity to 21% of the parental level. At the virus level, P93A and L94A-bearing viruses displayed impaired receptor recognition ability, neuraminidase activity, and fusion-promoting activity, all of which led to virus attenuation. In addition, the L94A-mutated virus showed a dramatic decline in replication and was attenuated in cells and in chickens. Our data demonstrate that the HN biological activities and functions modulated by these specific amino acids in the IR are associated with NDV replication and pathogenicity. PMID:26267791

  9. A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus

    PubMed Central

    Das, Sanchita; Rundell, Mark S.; Mirza, Aashiq H.; Pingle, Maneesh R.; Shigyo, Kristi; Garrison, Aura R.; Paragas, Jason; Smith, Scott K.; Olson, Victoria A.; Larone, Davise H.; Spitzer, Eric D.; Barany, Francis; Golightly, Linnie M.

    2015-01-01

    CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus). PMID:26381398

  10. A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.

    PubMed

    Das, Sanchita; Rundell, Mark S; Mirza, Aashiq H; Pingle, Maneesh R; Shigyo, Kristi; Garrison, Aura R; Paragas, Jason; Smith, Scott K; Olson, Victoria A; Larone, Davise H; Spitzer, Eric D; Barany, Francis; Golightly, Linnie M

    2015-01-01

    CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus).

  11. The presence of viral subpopulations in an infectious bronchitis virus vaccine with differing pathogenicity--a preliminary study.

    PubMed

    Hewson, Kylie A; Scott, Peter C; Devlin, Joanne M; Ignjatovic, Jagoda; Noormohammadi, Amir H

    2012-06-13

    There are currently four commercially available vaccines in Australia to protect chickens against infectious bronchitis virus (IBV). Predominantly, IBV causes clinical signs associated with respiratory or kidney disease, which subsequently cause an increase in mortality rate. Three of the current vaccines belong to the same subgroup (subgroup 1), however, the VicS vaccine has been reported to cause an increased vaccinal reaction compared to the other subgroup 1 vaccines. Molecular anomalies detected in VicS suggested the presence of two major subspecies, VicS-v and VicS-del, present in the commercial preparation of VicS. The most notable anomaly is the absence of a 40 bp sequence in the 3'UTR of VicS-del. In this investigation, the two subspecies were isolated and shown to grow independently and to similar titres in embryonated chicken eggs. An in vivo investigation involved 5 groups of 20 chickens each and found that VicS-del grew to a significantly lesser extent in the chicken tissues collected than did VicS-v. The group inoculated with an even ratio of the isolated subspecies scored the most severe clinical signs, with the longest duration. These results indicate the potential for a cooperative, instead of an expected competitive, relationship between VicS-v and VicS-del to infect a host, which is reminiscent of RNA viral quasi-species.

  12. Viral Hemorrhagic Fevers

    MedlinePlus

    ... Related Links About VSPB (Viral Special Pathogens Branch) File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel ...

  13. Loss of Anti-Viral Immunity by Infection with a Virus Encoding a Cross-Reactive Pathogenic Epitope

    PubMed Central

    Chen, Alex T.; Cornberg, Markus; Gras, Stephanie; Guillonneau, Carole; Rossjohn, Jamie; Trees, Andrew; Emonet, Sebastien; de la Torre, Juan C.; Welsh, Raymond M.; Selin, Liisa K.

    2012-01-01

    T cell cross-reactivity between different strains of the same virus, between different members of the same virus group, and even between unrelated viruses is a common occurrence. We questioned here how an intervening infection with a virus containing a sub-dominant cross-reactive T cell epitope would affect protective immunity to a previously encountered virus. Pichinde virus (PV) and lymphocytic choriomeningitis virus (LCMV) encode subdominant cross-reactive NP205–212 CD8 T cell epitopes sharing 6 of 8 amino acids, differing only in the MHC anchoring regions. These pMHC epitopes induce cross-reactive but non-identical T cell receptor (TCR) repertoires, and structural studies showed that the differing anchoring amino acids altered the conformation of the MHC landscape presented to the TCR. PV-immune mice receiving an intervening infection with wild type but not NP205-mutant LCMV developed severe immunopathology in the form of acute fatty necrosis on re-challenge with PV, and this pathology could be predicted by the ratio of NP205-specific to the normally immunodominant PV NP38–45 -specific T cells. Thus, cross-reactive epitopes can exert pathogenic properties that compromise protective immunity by impairing more protective T cell responses. PMID:22536152

  14. Occurrence of Bacterial and Viral Pathogens in Common and Noninvasive Diagnostic Sampling from Parrots and Racing Pigeons in Slovenia.

    PubMed

    Dovč, Alenka; Jereb, Gregor; Krapež, Uroš; Gregurić-Gračner, Gordana; Pintarič, Štefan; Slavec, Brigita; Knific, Renata Lindtner; Kastelic, Marjan; Kvapil, Pavel; Mićunović, Jasna; Vadnjal, Stanka; Ocepek, Matjaž; Zadravec, Marko; Zorman-Rojs, Olga

    2016-06-01

    Airborne pathogens can cause infections within parrot (Psittaciformes) and pigeon (Columbiformes) holdings and, in the case of zoonoses, can even spread to humans. Air sampling is a useful, noninvasive method which can enhance the common sampling methods for detection of microorganisms in bird flocks. In this study, fecal and air samples were taken from four parrot holdings. Additionally, cloacal and oropharyngeal swabs as well as air samples were taken from 15 racing pigeon holdings. Parrots were examined for psittacine beak and feather disease virus (PBFDV), proventricular dilatation disease virus (PDDV), adenoviruses (AdVs), avian paramyxovirus type-1 (APMV-1), avian influenza virus (AIV), Chlamydia psittaci (CP), and Mycobacterium avium complex (MAC). MAC and AdVs were detected in three parrot holdings, CP was detected in two parrot holdings, and PBFDV and PDDV were each detected in one parrot holding. Pigeons were examined for the pigeon circovirus (PiCV), AdVs, and CP; PiCV and AdVs were detected in all investigated pigeon holdings and CP was detected in five pigeon holdings.

  15. One time intranasal vaccination with a modified vaccinia Tiantan strain MVTT(ZCI) protects animals against pathogenic viral challenge.

    PubMed

    Yu, Wenbo; Fang, Qing; Zhu, Weijun; Wang, Haibo; Tien, Po; Zhang, Linqi; Chen, Zhiwei

    2010-02-25

    To combat variola virus in bioterrorist attacks, it is desirable to develop a noninvasive vaccine. Based on the vaccinia Tiantan (VTT) strain, which was historically used to eradicate the smallpox in China, we generated a modified VTT (MVTT(ZCI)) by removing the hemagglutinin gene and an 11,944bp genomic region from HindIII fragment C2L to F3L. MVTT(ZCI) was characterized for its host cell range in vitro and preclinical safety and efficacy profiles in mice. Despite replication-competency in some cell lines, unlike VTT, MVTT(ZCI) did not cause death after intracranial injection or body weight loss after intranasal inoculation. MVTT(ZCI) did not replicate in mouse brain and was safe in immunodeficient mice. MVTT(ZCI) induced neutralizing antibodies via the intranasal route of immunization. One time intranasal immunization protected animals from the challenge of the pathogenic vaccinia WR strain. This study established proof-of-concept that the attenuated replicating MVTT(ZCI) may serve as a safe noninvasive smallpox vaccine candidate.

  16. Occurrence of Bacterial and Viral Pathogens in Common and Noninvasive Diagnostic Sampling from Parrots and Racing Pigeons in Slovenia.

    PubMed

    Dovč, Alenka; Jereb, Gregor; Krapež, Uroš; Gregurić-Gračner, Gordana; Pintarič, Štefan; Slavec, Brigita; Knific, Renata Lindtner; Kastelic, Marjan; Kvapil, Pavel; Mićunović, Jasna; Vadnjal, Stanka; Ocepek, Matjaž; Zadravec, Marko; Zorman-Rojs, Olga

    2016-06-01

    Airborne pathogens can cause infections within parrot (Psittaciformes) and pigeon (Columbiformes) holdings and, in the case of zoonoses, can even spread to humans. Air sampling is a useful, noninvasive method which can enhance the common sampling methods for detection of microorganisms in bird flocks. In this study, fecal and air samples were taken from four parrot holdings. Additionally, cloacal and oropharyngeal swabs as well as air samples were taken from 15 racing pigeon holdings. Parrots were examined for psittacine beak and feather disease virus (PBFDV), proventricular dilatation disease virus (PDDV), adenoviruses (AdVs), avian paramyxovirus type-1 (APMV-1), avian influenza virus (AIV), Chlamydia psittaci (CP), and Mycobacterium avium complex (MAC). MAC and AdVs were detected in three parrot holdings, CP was detected in two parrot holdings, and PBFDV and PDDV were each detected in one parrot holding. Pigeons were examined for the pigeon circovirus (PiCV), AdVs, and CP; PiCV and AdVs were detected in all investigated pigeon holdings and CP was detected in five pigeon holdings. PMID:27309292

  17. BIOMARKERS OF VIRAL EXPOSURE

    EPA Science Inventory

    Viral and protozoan pathogens associated with raw sludge can cause encephalitis, gastroenteritis, hepatitis, myocarditis, and a number of other diseases. Raw sludge that has been treated to reduce these pathogens can be used for land application according to the regulations spec...

  18. Low detection of ranavirus DNA in wild postmetamorphic green frogs, Rana (Lithobates) clamitans, despite previous or concurrent tadpole mortality.

    PubMed

    Forzán, María J; Wood, John

    2013-10-01

    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 hepatic fine needle aspirates (FNAs) as further alternatives, and explore the adequacy of using green frogs as a target-sampling species when searching for ranavirus infection in the wild. Samples were obtained from 190 postmetamorphic (≥1-yr-old) green frogs from five ponds on Prince Edward Island (PEI), Canada. Three of the ponds had contemporary or recent tadpole mortalities due to Frog Virus 3 (FV3) ranavirus. PCR testing for ranavirus DNA was performed on 190 toe clips, 188 blood samples, 72 hepatic FNAs, and 72 liver tissue samples. Only two frogs were ranavirus-positive: liver and toe clip were positive in one, liver only was positive in the other; all blood and FNAs, including those from the two positive frogs, were negative. Results did not yield a definitive answer on the efficacy of testing each type of sample, but resemble what is found in salamanders infected with Ambystoma tigrinum (rana)virus. Findings indicate a low prevalence of FV3 in postmetamorphic green frogs on PEI (≤2.78%) and suggest that green frogs are poor reservoirs (carriers) for the virus.

  19. Exosomes in Viral Disease.

    PubMed

    Anderson, Monique R; Kashanchi, Fatah; Jacobson, Steven

    2016-07-01

    Viruses have evolved many mechanisms by which to evade and subvert the immune system to ensure survival and persistence. However, for each method undertaken by the immune system for pathogen removal, there is a counteracting mechanism utilized by pathogens. The new and emerging role of microvesicles in immune intercellular communication and function is no different. Viruses across many different families have evolved to insert viral components in exosomes, a subtype of microvesicle, with many varying downstream effects. When assessed cumulatively, viral antigens in exosomes increase persistence through cloaking viral genomes, decoying the immune system, and even by increasing viral infection in uninfected cells. Exosomes therefore represent a source of viral antigen that can be used as a biomarker for disease and targeted for therapy in the control and eradication of these disorders. With the rise in the persistence of new and reemerging viruses like Ebola and Zika, exploring the role of exosomes become more important than ever. PMID:27324390

  20. Viral Entry into Cells

    NASA Astrophysics Data System (ADS)

    D'Orsogna, Maria R.

    2010-09-01

    Successful viral infection of a healthy cell requires complex host-pathogen interactions. In this talk we focus on the dynamics specific to the HIV virus entering a eucaryotic cell. We model viral entry as a stochastic engagement of receptors and coreceptors on the cell surface. We also consider the transport of virus material to the cell nucleus by coupling microtubular motion to the concurrent biochemical transformations that render the viral material competent for nuclear entry. We discuss both mathematical and biological consequences of our model, such as the formulation of an effective integrodifferential boundary condition embodying a memory kernel and optimal timing in maximizing viral probabilities.

  1. Infection studies with two highly pathogenic avian influenza strains (Vietnamese and Indonesian) in Pekin ducks (Anas platyrhynchos), with particular reference to clinical disease, tissue tropism and viral shedding.

    PubMed

    Bingham, John; Green, Diane J; Lowther, Sue; Klippel, Jessica; Burggraaf, Simon; Anderson, Danielle E; Wibawa, Hendra; Hoa, Dong Manh; Long, Ngo Thanh; Vu, Pham Phong; Middleton, Deborah J; Daniels, Peter W

    2009-08-01

    Pekin ducks were infected by the mucosal route (oral, nasal, ocular) with one of two strains of Eurasian lineage H5N1 highly pathogenic avian influenza virus: A/Muscovy duck/Vietnam/453/2004 and A/duck/Indramayu/BBVW/109/2006 (from Indonesia). Ducks were killed humanely on days 1, 2, 3, 5 and 7 after challenge, or whenever morbidity was severe enough to justify euthanasia. Morbidity was recorded by observation of clinical signs and cloacal temperatures; the disease was characterized by histopathology; tissue tropism was studied by immunohistochemistry and virus titration on tissue samples; and viral shedding patterns were determined by virus isolation and titration of oral and cloacal swabs. The Vietnamese strain caused severe morbidity with fever and depression; the Indonesian strain caused only transient fever. Both viruses had a predilection for a similar range of tissue types, but the quantity of tissue antigen and tissue virus titres were considerably higher with the Vietnamese strain. The Vietnamese strain caused severe myocarditis and skeletal myositis; both strains caused non-suppurative encephalitis and a range of other inflammatory reactions of varying severity. The principal epithelial tissue infected was that of the air sacs, but antigen was not abundant. Epithelium of the turbinates, trachea and bronchi had only rare infection with virus. Virus was shed from both the oral and cloacal routes; it was first detected 24 h after challenge and persisted until day 5 after challenge. The higher prevalence of virus from swabs from ducks infected with the Vietnamese strain indicates that this strain may be more adapted to ducks than the Indonesia strain.

  2. Widespread co-occurrence of virulent pathogens within California amphibian communities.

    PubMed

    Hoverman, Jason T; Mihaljevic, Joseph R; Richgels, Katherine L D; Kerby, Jacob L; Johnson, Pieter T J

    2012-09-01

    The chytrid fungus Batrachochytrium dendrobatidis, ranaviruses, and trematodes (Ribeiroia ondatrae and echinostomes) are highly virulent pathogens known to infect amphibians, yet the extent to which they co-occur within amphibian communities remains poorly understood. Using field surveillance of 85 wetlands in the East Bay region of California, USA, we found that 68% of wetlands had ≥2 pathogens and 36% had ≥3 pathogens. Wetlands with high pathogen species richness also tended to cluster spatially. Our results underscore the need for greater integration of multiple pathogens and their interactions into amphibian disease research and conservation efforts.

  3. Ranavirus infection in a group of wild-caught Lake Urmia newts Neurergus crocatus imported from Iraq into Germany.

    PubMed

    Stöhr, Anke C; Fleck, Jürgen; Mutschmann, Frank; Marschang, Rachel E

    2013-04-11

    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 frog virus 3 genome. This is the first description of a ranavirus in Lake Urmia newts and in wild-caught amphibians from Iraq, as well as the first description of ranavirus infection in a urodele from the Middle East.

  4. Concurrent ranavirus and Batrachochytrium dendrobatidis infection in captive frogs (Phyllobates and Dendrobates species), The Netherlands, 2012: a first report.

    PubMed

    Kik, Marja; Stege, Marisca; Boonyarittichaikij, Roschong; van Asten, Alphons

    2012-11-01

    A ranavirus infection with concurrent Batrachochytrium dendrobatidis infection and mortality in captive Phyllobates and Dendrobates species is reported. Greyish skin with hepato- and reno-megaly were evident. Microscopically, Batrachochytrium dendrobatidis was present in the stratum corneum of the hyperkeratotic skin. Intracytoplasmic inclusion bodies were present in erythrocytes and multiple organs. All samples examined tested positive using PCR for the major capsid protein (MCP) gene of ranavirus and the ITS-1-5.8S region of B. dendrobatidis. The sequence obtained showed a 99% identity with the deposited sequence of the MCP gene of the common midwife toad virus (CMTV). This is the first report of mortality in captivity in poison dart frogs caused by a ranavirus, CMTV or like virus, and Batrachochytrium dendrobatidis infection.

  5. Concurrent ranavirus and Batrachochytrium dendrobatidis infection in captive frogs (Phyllobates and Dendrobates species), The Netherlands, 2012: a first report.

    PubMed

    Kik, Marja; Stege, Marisca; Boonyarittichaikij, Roschong; van Asten, Alphons

    2012-11-01

    A ranavirus infection with concurrent Batrachochytrium dendrobatidis infection and mortality in captive Phyllobates and Dendrobates species is reported. Greyish skin with hepato- and reno-megaly were evident. Microscopically, Batrachochytrium dendrobatidis was present in the stratum corneum of the hyperkeratotic skin. Intracytoplasmic inclusion bodies were present in erythrocytes and multiple organs. All samples examined tested positive using PCR for the major capsid protein (MCP) gene of ranavirus and the ITS-1-5.8S region of B. dendrobatidis. The sequence obtained showed a 99% identity with the deposited sequence of the MCP gene of the common midwife toad virus (CMTV). This is the first report of mortality in captivity in poison dart frogs caused by a ranavirus, CMTV or like virus, and Batrachochytrium dendrobatidis infection. PMID:23102620

  6. Outbreak of common midwife toad virus in alpine newts (Mesotriton alpestris cyreni) and common midwife toads (Alytes obstetricans) in northern Spain: a comparative pathological study of an emerging ranavirus.

    PubMed

    Balseiro, Ana; Dalton, Kevin P; del Cerro, Ana; Márquez, Isabel; Parra, Francisco; Prieto, José M; Casais, R

    2010-11-01

    This report describes the isolation and characterisation of the common midwife toad virus (CMTV) from juvenile alpine newts (Mesotriton alpestris cyreni) and common midwife toad (CMT) tadpoles (Alytes obstetricans) in the Picos de Europa National Park in Northern Spain in August 2008. A comparative pathological and immunohistochemical study was carried out using anti-CMTV polyclonal serum. In the kidneys, glomeruli had the most severe histological lesions in CMT tadpoles, while both glomeruli and renal tubular epithelial cells exhibited foci of necrosis in juvenile alpine newts. Viral antigens were detected by immunohistochemical labelling mainly in the kidneys of CMT tadpoles and in ganglia of juvenile alpine newts. This is the first report of ranavirus infection in the alpine newt, the second known species to be affected by CMTV in the past 2 years.

  7. PCR prevalence of Ranavirus in free-ranging eastern box turtles (Terrapene carolina carolina) at rehabilitation centers in three southeastern US states.

    PubMed

    Allender, Matthew C; Abd-Eldaim, Mohamed; Schumacher, Juergen; McRuer, David; Christian, Larry S; Kennedy, Melissa

    2011-07-01

    Ranaviruses (genus Ranavirus) have been observed in disease epidemics and mass mortality events in free-ranging amphibian, turtle, and tortoise populations worldwide. Infection is highly fatal in turtles, and the potential impact on endangered populations could be devastating. Our objectives were to determine the prevalence of ranavirus DNA in blood and oral swabs, report associated clinical signs of infection, and determine spatial distribution of infected turtles. Blood and oral swabs were taken from 140 eastern box turtles (Terrapene carolina carolina) that were presented to the wildlife centers at the University of Tennessee (UT; n=39), Wildlife Center of Virginia (WCV; n=34), and North Carolina State University (NCSU; n=36), as well as a free-ranging nonrehabilitation population near Oak Ridge, Tennessee (OR; n=39) March-November 2007. Samples were evaluated for ranavirus infection using polymerase chain reaction (PCR) targeting a conserved portion of the major capsid protein. Two turtles, one from UT and one from NCSU, had evidence of ranavirus infection; sequences of PCR products were 100% homologous to Frog Virus 3. Prevalence of ranavirus DNA in blood was 3, 0, 3, and 0% for UT, WCV, NCSU, and OR, respectively. Prevalence in oral swab samples was 3, 0, and 0% for UT, WCV, and NCSU, respectively. Wildlife centers may be useful in detection of Ranavirus infection and may serve as a useful early monitoring point for regional disease outbreaks.

  8. Efficacy of an inactivated and a fowlpox-vectored vaccine in Muscovy ducks against an Asian H5N1 highly pathogenic avian influenza viral challenge.

    PubMed

    Steensels, M; Van Borm, S; Lambrecht, B; De Vriese, J; Le Gros, F X; Bublot, M; van den Berg, T

    2007-03-01

    The efficacy of an inactivated vaccine containing the Eurasian isolate A/chicken/Italy/22A/98 H5N9 (H5N9-It) was compared with that of the fowlpox-vectored TROVACTM-AIV H5 (rFP-AIV-H5) vaccine against an H5N1 highly pathogenic avian influenza challenge. Five-week-old Muscovy ducks were vaccinated with either H5N9-It (0.5 ml) or rFP-AIV-H5 (5 log10 50% tissue culture infectious dose (TCID50)/dose), followed by a boost at 7 wk of age with the same vaccine (1.0 ml of H5N9-It or 5 log10 TCID50/dose rFP-AIV-H5), and a challenge at 9 wk of age with 10(7) egg infectious dose (lethality 50%) of A/crested eagle/ Belgium/01/2004 (H5N1). All unvaccinated challenged birds showed severe nervous signs (loss of balance, torticollis) starting 7 days postinfection (dpi). None of the vaccinated ducks showed these nervous signs. Shedding was measured in oropharyngeal and cloacal swabs, sampled from 3 to 19 dpi by titration in chicken embryo fibroblasts and by real-time reverse transcription-polymerase chain reaction. Virus shedding was significantly higher in oropharyngeal compared to cloacal swabs. Both vaccines reduced the percentage of positive swabs and the viral load in the swabs, but the reduction was higher with the H5N9-It vaccine. The inactivated vaccine induced hemagglutination inhibition (HI) titers (5.4 log2) that were boosted after the second administration (7.5 log2). rFP-AIV-H5-induced HI titers were lower (3 log2 only after the second administration), most probably because the fowlpox vector does not replicate in ducks. Altogether, these results indicate that significant protection from clinical signs and reduction in virus shedding may be achieved in ducks with conventional inactivated or fowlpox-vectored vaccine as compared with nonvaccinated challenged control birds.

  9. Viral Hepatitis

    MedlinePlus

    ... Public Home » For Veterans and the Public Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... the Public Veterans and Public Home How is Hepatitis C Treated? Find the facts about the newest ...

  10. Viral apoptotic mimicry.

    PubMed

    Amara, Ali; Mercer, Jason

    2015-08-01

    As opportunistic pathogens, viruses have evolved many elegant strategies to manipulate host cells for infectious entry and replication. Viral apoptotic mimicry, defined by the exposure of phosphatidylserine - a marker for apoptosis - on the pathogen surface, is emerging as a common theme used by enveloped viruses to promote infection. Focusing on the four best described examples (vaccinia virus, dengue virus, Ebola virus and pseudotyped lentivirus), we summarize our current understanding of apoptotic mimicry as a mechanism for virus entry, binding and immune evasion. We also describe recent examples of non-enveloped viruses that use this mimicry strategy, and discuss future directions and how viral apoptotic mimicry could be targeted therapeutically.

  11. Viruses and viral proteins

    PubMed Central

    Verdaguer, Nuria; Ferrero, Diego; Murthy, Mathur R. N.

    2014-01-01

    For more than 30 years X-ray crystallography has been by far the most powerful approach for determining the structures of viruses and viral proteins at atomic resolution. The information provided by these structures, which covers many important aspects of the viral life cycle such as cell-receptor recognition, viral entry, nucleic acid transfer and genome replication, has extensively enriched our vision of the virus world. Many of the structures available correspond to potential targets for antiviral drugs against important human pathogens. This article provides an overview of the current knowledge of different structural aspects of the above-mentioned processes. PMID:25485129

  12. A member of the cathelicidin family of antimicrobial peptides is produced in the upper airway of the chinchilla and its mRNA expression is altered by common viral and bacterial co-pathogens of otitis media.

    PubMed

    McGillivary, Glen; Ray, William C; Bevins, Charles L; Munson, Robert S; Bakaletz, Lauren O

    2007-03-01

    Cationic antimicrobial peptides (AMPs), a component of the innate immune system, play a major role in defense of mucosal surfaces against a wide spectrum of microorganisms such as viral and bacterial co-pathogens of the polymicrobial disease otitis media (OM). To further understand the role of AMPs in OM, we cloned a cDNA encoding a cathelicidin homolog (cCRAMP) from upper respiratory tract (URT) mucosae of the chinchilla, the predominant host used to model experimental OM. Recombinant cCRAMP exhibited alpha-helical secondary structure and killed the three main bacterial pathogens of OM. In situ hybridization showed cCRAMP mRNA production in epithelium of the chinchilla Eustachian tube and RT-PCR was used to amplify cCRAMP mRNA from several other tissues of the chinchilla URT. Quantitative RT-PCR analysis of chinchilla middle ear epithelial cells (CMEEs) incubated with either viral (influenza A virus, adenovirus, or RSV) or bacterial (nontypeable H. influenzae, M. catarrhalis, or S. pneumoniae) pathogens associated with OM demonstrated distinct microbe-specific patterns of altered expression. Collectively, these data showed that viruses and bacteria modulate AMP messages in the URT, which likely contributes to the disease course of OM.

  13. First case of ranavirus and associated morbidity and mortality in an eastern mud turtle Kinosternon subrubrum in South Carolina.

    PubMed

    Winzeler, Megan E; Hamilton, Matthew T; Tuberville, Tracey D; Lance, Stacey L

    2015-05-11

    Ranaviruses are double-stranded DNA viruses that infect amphibians, fish, and reptiles, causing global epidemics in some amphibian populations. It is important to identify new species that may be susceptible to the disease, particularly if they reside in the same habitat as other at-risk species. On the Savannah River Site (SRS) in Aiken, South Carolina, USA, ranaviruses are present in several amphibian populations, but information is lacking on the presence, prevalence, and morbidity of the virus in reptile species. An eastern mud turtle Kinosternon subrubrum captured on the SRS in April 2014 exhibited clinical signs of a ranaviral infection, including oral plaque and conjunctivitis. Quantitative PCR analyses of DNA from liver tissue, ocular, oral, nasal, and cloacal swabs were all positive for ranavirus, and sequencing of the template confirmed infection with a FV3-like ranavirus. Histopathologic examination of postmortem tissue samples revealed ulceration of the oral and tracheal mucosa, intracytoplasmic epithelial inclusions in the oral mucosa and tongue sections, individualized and clusters of melanomacrophages in the liver, and bacterial rods located in the liver, kidney, heart, stomach, and small intestine. This is the first report of morbidity and mortality of a mud turtle with a systemic ranaviral infection.

  14. First case of ranavirus and associated morbidity and mortality in an eastern mud turtle Kinosternon subrubrum in South Carolina.

    PubMed

    Winzeler, Megan E; Hamilton, Matthew T; Tuberville, Tracey D; Lance, Stacey L

    2015-05-11

    Ranaviruses are double-stranded DNA viruses that infect amphibians, fish, and reptiles, causing global epidemics in some amphibian populations. It is important to identify new species that may be susceptible to the disease, particularly if they reside in the same habitat as other at-risk species. On the Savannah River Site (SRS) in Aiken, South Carolina, USA, ranaviruses are present in several amphibian populations, but information is lacking on the presence, prevalence, and morbidity of the virus in reptile species. An eastern mud turtle Kinosternon subrubrum captured on the SRS in April 2014 exhibited clinical signs of a ranaviral infection, including oral plaque and conjunctivitis. Quantitative PCR analyses of DNA from liver tissue, ocular, oral, nasal, and cloacal swabs were all positive for ranavirus, and sequencing of the template confirmed infection with a FV3-like ranavirus. Histopathologic examination of postmortem tissue samples revealed ulceration of the oral and tracheal mucosa, intracytoplasmic epithelial inclusions in the oral mucosa and tongue sections, individualized and clusters of melanomacrophages in the liver, and bacterial rods located in the liver, kidney, heart, stomach, and small intestine. This is the first report of morbidity and mortality of a mud turtle with a systemic ranaviral infection. PMID:25958808

  15. Comparative Genomics of Amphibian-like Ranaviruses, Nucleocytoplasmic Large DNA Viruses of Poikilotherms

    PubMed Central

    Price, Stephen J.

    2015-01-01

    Recent research on genome evolution of large DNA viruses has highlighted a number of incredibly dynamic processes that can facilitate rapid adaptation. The genomes of amphibian-like ranaviruses – double-stranded DNA viruses infecting amphibians, reptiles, and fish (family Iridoviridae) – were examined to assess variation in genome content and evolutionary processes. The viruses studied were closely related, but their genome content varied considerably, with 29 genes identified that were not present in all of the major clades. Twenty-one genes had evidence of recombination, while a virus isolated from a captive reptile appeared to be a mosaic of two divergent parents. Positive selection was also found to be acting on more than a quarter of Ranavirus genes and was found most frequently in the Spanish common midwife toad virus, which has had a severe impact on amphibian host communities. Efforts to resolve the root of this group by inclusion of an outgroup were inconclusive, but a set of core genes were identified, which recovered a well-supported species tree. PMID:27812275

  16. Evolution of 2009 H1N1 influenza viruses during the pandemic correlates with increased viral pathogenicity and transmissibility in the ferret model.

    PubMed

    Otte, Anna; Marriott, Anthony C; Dreier, Carola; Dove, Brian; Mooren, Kyra; Klingen, Thorsten R; Sauter, Martina; Thompson, Katy-Anne; Bennett, Allan; Klingel, Karin; van Riel, Debby; McHardy, Alice C; Carroll, Miles W; Gabriel, Gülsah

    2016-06-24

    There is increasing evidence that 2009 pandemic H1N1 influenza viruses have evolved after pandemic onset giving rise to severe epidemics in subsequent waves. However, it still remains unclear which viral determinants might have contributed to disease severity after pandemic initiation. Here, we show that distinct mutations in the 2009 pandemic H1N1 virus genome have occurred with increased frequency after pandemic declaration. Among those, a mutation in the viral hemagglutinin was identified that increases 2009 pandemic H1N1 virus binding to human-like α2,6-linked sialic acids. Moreover, these mutations conferred increased viral replication in the respiratory tract and elevated respiratory droplet transmission between ferrets. Thus, our data show that 2009 H1N1 influenza viruses have evolved after pandemic onset giving rise to novel virus variants that enhance viral replicative fitness and respiratory droplet transmission in a mammalian animal model. These findings might help to improve surveillance efforts to assess the pandemic risk by emerging influenza viruses.

  17. Evolution of 2009 H1N1 influenza viruses during the pandemic correlates with increased viral pathogenicity and transmissibility in the ferret model

    PubMed Central

    Otte, Anna; Marriott, Anthony C.; Dreier, Carola; Dove, Brian; Mooren, Kyra; Klingen, Thorsten R.; Sauter, Martina; Thompson, Katy-Anne; Bennett, Allan; Klingel, Karin; van Riel, Debby; McHardy, Alice C.; Carroll, Miles W.; Gabriel, Gülsah

    2016-01-01

    There is increasing evidence that 2009 pandemic H1N1 influenza viruses have evolved after pandemic onset giving rise to severe epidemics in subsequent waves. However, it still remains unclear which viral determinants might have contributed to disease severity after pandemic initiation. Here, we show that distinct mutations in the 2009 pandemic H1N1 virus genome have occurred with increased frequency after pandemic declaration. Among those, a mutation in the viral hemagglutinin was identified that increases 2009 pandemic H1N1 virus binding to human-like α2,6-linked sialic acids. Moreover, these mutations conferred increased viral replication in the respiratory tract and elevated respiratory droplet transmission between ferrets. Thus, our data show that 2009 H1N1 influenza viruses have evolved after pandemic onset giving rise to novel virus variants that enhance viral replicative fitness and respiratory droplet transmission in a mammalian animal model. These findings might help to improve surveillance efforts to assess the pandemic risk by emerging influenza viruses. PMID:27339001

  18. Genetic diversification of an emerging pathogen: A decade of mutation by the fish Viral Hemorrhagic Septicemia (VHS) virus in the Laurentian Great Lakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viral Hemorrhagic Septicemia virus (VHSv) is an RNA rhabdovirus, which causes one of the world's most serious fish diseases, infecting >80 freshwater and marine species across the Northern Hemisphere. A new, novel, and especially virulent substrain - VHSv-IVb - first appeared in the Laurentian Gre...

  19. First Dominique Dormont international conference on "Host-pathogen interactions in chronic infections – viral and host determinants of HCV, HCMV, and HIV infections"

    PubMed Central

    Menu, Elisabeth; Müller-Trutwin, Mickaela C; Pancino, Gianfranco; Saez-Cirion, Asier; Bain, Christine; Inchauspé, Geneviève; Gras, Gabriel S; Mabondzo, Aloïse M; Samri, Assia; Boutboul, Françoise; Grand, Roger Le

    2005-01-01

    The first Dominique Dormont International Conference on "Viral and host determinantsof HCV, HCMV, and HIV infections "was held in Paris, Val-de-Grâce, on December 3–4, 2004. The following is a summary of the scientific sessions of this meeting (). PMID:15813969

  20. Bovine viral diarrhea viruses (BVDV) and their cousins the HoBi-like viruses: Multi symptom, multi host, multi tasking pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The term bovine viral diarrhea (BVD) has come to refer to a diverse collection of clinical presentations that include respiratory, enteric and reproductive symptoms accompanied by immunosuppression. While the majority of cases are subclinical in nature two forms exist, mucosal disease and hemorrhag...

  1. 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.

    PubMed

    De Jesús Andino, Francisco; Chen, Guangchun; Li, Zhenghui; Grayfer, Leon; Robert, Jacques

    2012-10-25

    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 adults, leukocytes and tissues of infected tadpoles exhibited modest (10-100 time lower than adult) and delayed (3 day later than adult) increase in expression of inflammation-associated (TNF-α, IL-1β and IFN-γ) and antiviral (Mx1) genes. In contrast, these genes were readily and robustly upregulated in tadpoles upon bacterial stimulation. Furthermore, greater proportions of larval than adult PLs were infected by FV3. Our study suggests that tadpole susceptibility to FV3 infection is partially due to poor virus-elicited innate immune responses.

  2. Viral pneumonia

    MedlinePlus

    ... Names Pneumonia - viral; "Walking pneumonia" - viral Images Lungs Respiratory system References Lee FE, Treanor J. Viral infections. In: Mason RJ, VC Broaddus, Martin TR, et al, eds. Murray and Nadel’s Textbook of Respiratory Medicine . 5th ed. Philadelphia, PA: Saunders Elsevier; 2010: ...

  3. Comparison of Illumina de novo assembled and Sanger sequenced viral genomes: A case study for RNA viruses recovered from the plant pathogenic fungus Sclerotinia sclerotiorum.

    PubMed

    Khalifa, Mahmoud E; Varsani, Arvind; Ganley, Austen R D; Pearson, Michael N

    2016-07-01

    The advent of 'next generation sequencing' (NGS) technologies has led to the discovery of many novel mycoviruses, the majority of which are sufficiently different from previously sequenced viruses that there is no appropriate reference sequence on which to base the sequence assembly. Although many new genome sequences are generated by NGS, confirmation of the sequence by Sanger sequencing is still essential for formal classification by the International Committee for the Taxonomy of Viruses (ICTV), although this is currently under review. To empirically test the validity of de novo assembled mycovirus genomes from dsRNA extracts, we compared the results from Illumina sequencing with those from random cloning plus targeted PCR coupled with Sanger sequencing for viruses from five Sclerotinia sclerotiorum isolates. Through Sanger sequencing we detected nine viral genomes while through Illumina sequencing we detected the same nine viruses plus one additional virus from the same samples. Critically, the Illumina derived sequences share >99.3 % identity to those obtained by cloning and Sanger sequencing. Although, there is scope for errors in de novo assembled viral genomes, our results demonstrate that by maximising the proportion of viral sequence in the data and using sufficiently rigorous quality controls, it is possible to generate de novo genome sequences of comparable accuracy from Illumina sequencing to those obtained by Sanger sequencing. PMID:26581665

  4. Complete genome sequence and construction of infectious full-length cDNA clones of tobacco ringspot Nepovirus, a viral pathogen causing bud blight in soybean.

    PubMed

    Zhao, Fumei; Hwang, Un Sun; Lim, Seungmo; Yoo, Ran Hee; Igori, Davaajargal; Lee, Su-Heon; Lim, Hyoun-Sub; Moon, Jae Sun

    2015-08-01

    Tobacco ringspot virus (TRSV, genus Nepovirus), causes severe diseases in soybean and tobacco plants. TRSV-induced bud blight disease significantly reduced both the yield and quality of soybeans. The function of the encoded viral gene product involved in TRSV infection was unclear due to the limitation of reverse genetics studies on the viral genome. Here, we represent the successful construction of infectious full-length cDNA clones of TRSV genome (RNA1 and RNA2). The cDNAs of TRSV RNA1 and RNA2 were cloned into the binary vector pPZP211 immediately downstream of a double cauliflower mosaic virus 35S promoter and upstream of the nopaline synthase terminator. Seven days after agrobacterium-mediated co-inoculation of these two constructs, Nicotiana benthamiana plants developed a systemic infection with necrotic ringspot symptoms and weak stunting of the leaves, similar to that induced by natural TRSV. The systemic infection was confirmed by transmission electron microscopy and Western blot analysis. Simultaneously, soybean, tomato, and Arabidopsis ecotype Estland were mechanically inoculated with sap prepared from TRSV-agroinfiltrated N. benthamiana leaves, showing typical symptoms of bud blight, necrotic spots, and lethal systemic necrosis, respectively. The system developed herein will be an appealing way to determine TRSV viral gene functions and study host-TRSV interactions. PMID:26159876

  5. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part II: Vaccines for Shigella, Salmonella, enterotoxigenic E. coli (ETEC) enterohemorragic E. coli (EHEC) and Campylobacter jejuni.

    PubMed

    O'Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Carlos Salazar, Juan; Montero, David

    2015-01-01

    In Part II we discuss the following bacterial pathogens: Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic) and Campylobacter jejuni. In contrast to the enteric viruses and Vibrio cholerae discussed in Part I of this series, for the bacterial pathogens described here there is only one licensed vaccine, developed primarily for Vibrio cholerae and which provides moderate protection against enterotoxigenic E. coli (ETEC) (Dukoral(®)), as well as a few additional candidates in advanced stages of development for ETEC and one candidate for Shigella spp. Numerous vaccine candidates in earlier stages of development are discussed.

  6. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part II: Vaccines for Shigella, Salmonella, enterotoxigenic E. coli (ETEC) enterohemorragic E. coli (EHEC) and Campylobacter jejuni.

    PubMed

    O'Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Carlos Salazar, Juan; Montero, David

    2015-01-01

    In Part II we discuss the following bacterial pathogens: Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic) and Campylobacter jejuni. In contrast to the enteric viruses and Vibrio cholerae discussed in Part I of this series, for the bacterial pathogens described here there is only one licensed vaccine, developed primarily for Vibrio cholerae and which provides moderate protection against enterotoxigenic E. coli (ETEC) (Dukoral(®)), as well as a few additional candidates in advanced stages of development for ETEC and one candidate for Shigella spp. Numerous vaccine candidates in earlier stages of development are discussed. PMID:25715096

  7. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part II: Vaccines for Shigella, Salmonella, enterotoxigenic E. coli (ETEC) enterohemorragic E. coli (EHEC) and Campylobacter jejuni

    PubMed Central

    O’Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Carlos Salazar, Juan; Montero, David

    2015-01-01

    In Part II we discuss the following bacterial pathogens: Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic) and Campylobacter jejuni. In contrast to the enteric viruses and Vibrio cholerae discussed in Part I of this series, for the bacterial pathogens described here there is only one licensed vaccine, developed primarily for Vibrio cholerae and which provides moderate protection against enterotoxigenic E. coli (ETEC) (Dukoral®), as well as a few additional candidates in advanced stages of development for ETEC and one candidate for Shigella spp. Numerous vaccine candidates in earlier stages of development are discussed. PMID:25715096

  8. Ranavirus-associated mass mortality in imported red tailed knobby newts (Tylototriton kweichowensis): a case report.

    PubMed

    Pasmans, Frank; Blahak, Silvia; Martel, An; Pantchev, Nikola; Zwart, Peer

    2008-05-01

    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 marked pathology was noticed and the virus could not be re-isolated at 9weeks post-inoculation. Apart from the possibility of exposure of a non-sensitive host, the mortality episode in the newts may be related to stress resulting from the importation of the newts in breeding condition. This possibility is supported by the presence of degenerating egg-follicles in the females.

  9. A loop-mediated isothermal amplification method for the detection of members of the genus Ranavirus.

    PubMed

    Min, Zhang; Hongli, Jing; Lifeng, Zhang; Na, Wang; Shaoqiang, Wu; Xiangmei, Lin

    2013-10-01

    A loop-mediated isothermal amplification (LAMP) method was developed for detection of members of the genus Ranavirus. The optimum reaction mixture contained 2.5 μL of each inner primer, RV-FIP (20 pmol/μL) and RV-BIP (20 pmol/μL), 0.5 μL of each outer primer, RV-F3 (10 pmol/μL) and RV-B3 (10 pmol/μL), 1.25 μL of each loop primer, RV-LF (20 pmol/μL) and RV-LB (20 pmol/μL), 3.5 μL dNTP mix (10 mM each), 8 μL MgSO4 (25 mM), 1 μL of Bst DNA polymerase (8 U/mL, large fragment; New England Biolabs Inc., Beverly, MA, USA), 2.5 μL 10 × supplied buffer, and 1 μL of template DNA in a final volume of 25 μL. The optimum reaction conditions were 63 °C for 60 min. This LAMP method could detect Andrias davidianus iridovirus (ADIV), soft-shelled turtle iridovirus (STIV), and epizootic hematopoietic necrosis virus (EHNV), all of which belong to the genus Ranavirus, but it could not detect other viruses such as koi herpes virus (KHV), channel catfish virus (CCV), infectious spleen and kidney necrosis virus (ISKNV) and white spot syndrome virus (WSSV). The detection limit of the LAMP method was 100 copies of STIV DNA segment, and the sensitivity was 10 times higher than that of the polymerase chain reaction (PCR) assay. The results could be estimated visually by eye when calcein was added.

  10. Optimizing Viral Discovery in Bats

    PubMed Central

    Young, Cristin C. W.; Olival, Kevin J.

    2016-01-01

    Viral discovery studies in bats have increased dramatically over the past decade, yet a rigorous synthesis of the published data is lacking. We extract and analyze data from 93 studies published between 2007–2013 to examine factors that increase success of viral discovery in bats, and specific trends and patterns of infection across host taxa and viral families. Over the study period, 248 novel viruses from 24 viral families have been described. Using generalized linear models, at a study level we show the number of host species and viral families tested best explained number of viruses detected. We demonstrate that prevalence varies significantly across viral family, specimen type, and host taxonomy, and calculate mean PCR prevalence by viral family and specimen type across all studies. Using a logistic model, we additionally identify factors most likely to increase viral detection at an individual level for the entire dataset and by viral families with sufficient sample sizes. Our analysis highlights major taxonomic gaps in recent bat viral discovery efforts and identifies ways to improve future viral pathogen detection through the design of more efficient and targeted sample collection and screening approaches. PMID:26867024

  11. Optimizing Viral Discovery in Bats.

    PubMed

    Young, Cristin C W; Olival, Kevin J

    2016-01-01

    Viral discovery studies in bats have increased dramatically over the past decade, yet a rigorous synthesis of the published data is lacking. We extract and analyze data from 93 studies published between 2007-2013 to examine factors that increase success of viral discovery in bats, and specific trends and patterns of infection across host taxa and viral families. Over the study period, 248 novel viruses from 24 viral families have been described. Using generalized linear models, at a study level we show the number of host species and viral families tested best explained number of viruses detected. We demonstrate that prevalence varies significantly across viral family, specimen type, and host taxonomy, and calculate mean PCR prevalence by viral family and specimen type across all studies. Using a logistic model, we additionally identify factors most likely to increase viral detection at an individual level for the entire dataset and by viral families with sufficient sample sizes. Our analysis highlights major taxonomic gaps in recent bat viral discovery efforts and identifies ways to improve future viral pathogen detection through the design of more efficient and targeted sample collection and screening approaches. PMID:26867024

  12. Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian Influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV)

    PubMed Central

    2009-01-01

    Background Influenza virus (IV) infections are a major threat to human welfare and animal health worldwide. Anti-viral therapy includes vaccines and a few anti-viral drugs. However vaccines are not always available in time, as demonstrated by the emergence of the new 2009 H1N1-type pandemic strain of swine origin (S-OIV) in April 2009, and the acquisition of resistance to neuraminidase inhibitors such as Tamiflu® (oseltamivir) is a potential problem. Therefore the prospects for the control of IV by existing anti-viral drugs are limited. As an alternative approach to the common anti-virals we studied in more detail a commercial standardized extract of the widely used herb Echinacea purpurea (Echinaforce®, EF) in order to elucidate the nature of its anti-IV activity. Results Human H1N1-type IV, highly pathogenic avian IV (HPAIV) of the H5- and H7-types, as well as swine origin IV (S-OIV, H1N1), were all inactivated in cell culture assays by the EF preparation at concentrations ranging from the recommended dose for oral consumption to several orders of magnitude lower. Detailed studies with the H5N1 HPAIV strain indicated that direct contact between EF and virus was required, prior to infection, in order to obtain maximum inhibition in virus replication. Hemagglutination assays showed that the extract inhibited the receptor binding activity of the virus, suggesting that the extract interferes with the viral entry into cells. In sequential passage studies under treatment in cell culture with the H5N1 virus no EF-resistant variants emerged, in contrast to Tamiflu®, which produced resistant viruses upon passaging. Furthermore, the Tamiflu®-resistant virus was just as susceptible to EF as the wild type virus. Conclusion As a result of these investigations, we believe that this standard Echinacea preparation, used at the recommended dose for oral consumption, could be a useful, readily available and affordable addition to existing control options for IV replication and

  13. Equine herpesvirus type 1 tegument protein VP22 is not essential for pathogenicity in a hamster model, but is required for efficient viral growth in cultured cells

    PubMed Central

    OKADA, Ayaka; IZUME, Satoko; OHYA, Kenji; FUKUSHI, Hideto

    2015-01-01

    VP22 is a major tegument protein of Equine herpesvirus type 1 (EHV-1) that is a conserved protein among alphaherpesviruses. However, the roles of VP22 differ among each virus, and the roles of EHV-1 VP22 are still unclear. Here, we constructed an EHV-1 VP22 deletion mutant and a revertant virus to clarify the role of VP22. We found that EHV-1 VP22 was required for efficient viral growth in cultured cells, but not for virulence in a hamster model. PMID:25948053

  14. The VP1 S154D mutation of type Asia1 foot-and-mouth disease virus enhances viral replication and pathogenicity.

    PubMed

    Lian, Kaiqi; Yang, Fan; Zhu, Zixiang; Cao, Weijun; Jin, Ye; Liu, Huanan; Li, Dan; Zhang, Keshan; Guo, Jianhong; Liu, Xiangtao; Zheng, Haixue

    2016-04-01

    One of the proteins encoded by the foot-and-mouth disease virus (FMDV), the VP1 protein, a capsid protein, plays an important role in integrin receptor attachment and humoral immunity-mediated host responses. The integrin receptor recognition motif and an important antigenic epitope exist within the G-H loop, which is comprised of amino acids 134-160 of the VP1 protein. FMDV strain, Asia1/HN/CHA/06, isolated from a pig, was passaged four times in suckling mice and sequenced. Sequencing analyses showed that there was a mutation of the integrin receptor recognition motif Arg-Gly-Asp/Arg-Asp-Asp (RGD/RDD, VP1 143-145) and a VP1 154 serine/Asp (VP1 S154D) mutation in the G-H loop of the VP1 protein. The influence of the RGD/RDD mutation on Asia1 FMDV disease phenotype has been previously studied. In this study, to determine the influence of the VP1 S154D mutation on FMDV Asia1 replication and pathogenicity, two recombinant FMDVs with different residues only at the VP1 154 site were rescued by reverse genetics techniques and their infectious potential in host cells and pathogenicity in pigs were compared. Our data indicates that the VP1 S154D mutation increases the replication level of FMDV Asia1/HN/CHA/06 in BHK-21, IB-RS-2, and PK-15 cells and enhances pathogenicity in pigs. Through the transient transfection-infection assay to compare integrin receptor usage of two recombinant viruses, the result shows that the VP1 S154D mutation markedly increases the ability of type Asia1 FMDV to use the integrin receptors αυβ6 and αυβ8 from pig. This study identifies a key research target for illuminating the role of residues located at G-H loop in FMDV pathogenicity. PMID:26792712

  15. Viral hepatitis: Indian scenario.

    PubMed

    Satsangi, Sandeep; Chawla, Yogesh K

    2016-07-01

    Viral hepatitis is a cause for major health care burden in India and is now equated as a threat comparable to the "big three" communicable diseases - HIV/AIDS, malaria and tuberculosis. Hepatitis A virus and Hepatitis E virus are predominantly enterically transmitted pathogens and are responsible to cause both sporadic infections and epidemics of acute viral hepatitis. Hepatitis B virus and Hepatitis C virus are predominantly spread via parenteral route and are notorious to cause chronic hepatitis which can lead to grave complications including cirrhosis of liver and hepatocellular carcinoma. Around 400 million people all over the world suffer from chronic hepatitis and the Asia-Pacific region constitutes the epicentre of this epidemic. The present article would aim to cover the basic virologic aspects of these viruses and highlight the present scenario of viral hepatitis in India. PMID:27546957

  16. Gene Diversification of an Emerging Pathogen: A Decade of Mutation in a Novel Fish Viral Hemorrhagic Septicemia (VHS) Substrain since Its First Appearance in the Laurentian Great Lakes

    PubMed Central

    Leaman, Douglas W.; Niner, Megan D.; Shepherd, Brian S.

    2015-01-01

    Viral Hemorrhagic Septicemia virus (VHSv) is an RNA rhabdovirus, which causes one of the world's most serious fish diseases, infecting >80 freshwater and marine species across the Northern Hemisphere. A new, novel, and especially virulent substrain—VHSv-IVb—first appeared in the Laurentian Great Lakes about a decade ago, resulting in massive fish kills. It rapidly spread and has genetically diversified. This study analyzes temporal and spatial mutational patterns of VHSv-IVb across the Great Lakes for the novel non-virion (Nv) gene that is unique to this group of novirhabdoviruses, in relation to its glycoprotein (G), phosphoprotein (P), and matrix (M) genes. Results show that the Nv-gene has been evolving the fastest (k = 2.0x10-3 substitutions/site/year), with the G-gene at ~1/7 that rate (k = 2.8x10-4). Most (all but one) of the 12 unique Nv- haplotypes identified encode different amino acids, totaling 26 changes. Among the 12 corresponding G-gene haplotypes, seven vary in amino acids with eight total changes. The P- and M- genes are more evolutionarily conserved, evolving at just ~1/15 (k = 1.2x10-4) of the Nv-gene’s rate. The 12 isolates contained four P-gene haplotypes with two amino acid changes, and six M-gene haplotypes with three amino acid differences. Patterns of evolutionary changes coincided among the genes for some of the isolates, but appeared independent in others. New viral variants were discovered following the large 2006 outbreak; such differentiation may have been in response to fish populations developing resistance, meriting further investigation. Two 2012 variants were isolated by us from central Lake Erie fish that lacked classic VHSv symptoms, having genetically distinctive Nv-, G-, and M-gene sequences (with one of them also differing in its P-gene); they differ from each other by a G-gene amino acid change and also differ from all other isolates by a shared Nv-gene amino acid change. Such rapid evolutionary differentiation may

  17. Gene Diversification of an Emerging Pathogen: A Decade of Mutation in a Novel Fish Viral Hemorrhagic Septicemia (VHS) Substrain since Its First Appearance in the Laurentian Great Lakes.

    PubMed

    Stepien, Carol A; Pierce, Lindsey R; Leaman, Douglas W; Niner, Megan D; Shepherd, Brian S

    2015-01-01

    Viral Hemorrhagic Septicemia virus (VHSv) is an RNA rhabdovirus, which causes one of the world's most serious fish diseases, infecting >80 freshwater and marine species across the Northern Hemisphere. A new, novel, and especially virulent substrain-VHSv-IVb-first appeared in the Laurentian Great Lakes about a decade ago, resulting in massive fish kills. It rapidly spread and has genetically diversified. This study analyzes temporal and spatial mutational patterns of VHSv-IVb across the Great Lakes for the novel non-virion (Nv) gene that is unique to this group of novirhabdoviruses, in relation to its glycoprotein (G), phosphoprotein (P), and matrix (M) genes. Results show that the Nv-gene has been evolving the fastest (k = 2.0 x 10-3 substitutions/site/year), with the G-gene at ~1/7 that rate (k = 2.8 x 10-4). Most (all but one) of the 12 unique Nv- haplotypes identified encode different amino acids, totaling 26 changes. Among the 12 corresponding G-gene haplotypes, seven vary in amino acids with eight total changes. The P- and M- genes are more evolutionarily conserved, evolving at just ~1/15 (k = 1.2 x 10-4) of the Nv-gene's rate. The 12 isolates contained four P-gene haplotypes with two amino acid changes, and six M-gene haplotypes with three amino acid differences. Patterns of evolutionary changes coincided among the genes for some of the isolates, but appeared independent in others. New viral variants were discovered following the large 2006 outbreak; such differentiation may have been in response to fish populations developing resistance, meriting further investigation. Two 2012 variants were isolated by us from central Lake Erie fish that lacked classic VHSv symptoms, having genetically distinctive Nv-, G-, and M-gene sequences (with one of them also differing in its P-gene); they differ from each other by a G-gene amino acid change and also differ from all other isolates by a shared Nv-gene amino acid change. Such rapid evolutionary differentiation may

  18. The pathogenicity determinant of Citrus tristeza virus causing the seedling yellows syndrome maps at the 3'-terminal region of the viral genome.

    PubMed

    Albiach-Marti, Maria R; Robertson, Cecile; Gowda, Siddarame; Tatineni, Satyanarayana; Belliure, Belén; Garnsey, Stephen M; Folimonova, Svetlana Y; Moreno, Pedro; Dawson, William O

    2010-01-01

    Citrus tristeza virus (CTV) (genus Closterovirus, family Closteroviridae) causes some of the more important viral diseases of citrus worldwide. The ability to map disease-inducing determinants of CTV is needed to develop better diagnostic and disease control procedures. A distinctive phenotype of some isolates of CTV is the ability to induce seedling yellows (SY) in sour orange, lemon and grapefruit seedlings. In Florida, the decline isolate of CTV, T36, induces SY, whereas a widely distributed mild isolate, T30, does not. To delimit the viral sequences associated with the SY syndrome, we created a number of T36/T30 hybrids by substituting T30 sequences into different regions of the 3' half of the genome of an infectious cDNA of T36. Eleven T36/T30 hybrids replicated in Nicotiana benthamiana protoplasts. Five of these hybrids formed viable virions that were mechanically transmitted to Citrus macrophylla, a permissive host for CTV. All induced systemic infections, similar to that of the parental T36 clone. Tissues from these C. macrophylla source plants were then used to graft inoculate sour orange and grapefruit seedlings. Inoculation with three of the T30/T36 hybrid constructs induced SY symptoms identical to those of T36; however, two hybrids with T30 substitutions in the p23-3' nontranslated region (NTR) (nucleotides 18 394-19 296) failed to induce SY. Sour orange seedlings infected with a recombinant non-SY p23-3' NTR hybrid also remained symptomless when challenged with the parental virus (T36), demonstrating the potential feasibility of using engineered constructs of CTV to mitigate disease.

  19. Survey on viral pathogens in wild red foxes (Vulpes vulpes) in Germany with emphasis on parvoviruses and analysis of a DNA sequence from a red fox parvovirus.

    PubMed Central

    Truyen, U.; Müller, T.; Heidrich, R.; Tackmann, K.; Carmichael, L. E.

    1998-01-01

    The seroprevalence of canine parvovirus (CPV), canine distemper virus (CDV), canine adenovirus (CAV) and canine herpesvirus (CHV) infections in red foxes (Vulpes vulpes) was determined in fox sera collected between 1991 and 1995. A total of 500 sera were selected and the seroprevalences were estimated to be 13% (65 of 500 sera) for CPV, 4.4% (17 of 383 sera) for CDV, 35% (17 of 485 sera) for CAV, and 0.4% (2 of 485 sera) for CHV, respectively. No statistically significant differences were observed between the two (rural and suburban) areas under study. Parvovirus DNA sequences were amplified from tissues of free-ranging foxes and compared to those of prototype viruses from dogs and cats. We report here a parvovirus sequence indicative of a true intermediate between the feline panleukopenia virus-like viruses and the canine parvovirus-like viruses. The red fox parvoviral sequence, therefore, appears to represent a link between those viral groups. The DNA sequence together with a significant seroprevalence of parvovirus infections in foxes supports the hypothesis that the sudden emergence of canine parvovirus in the domestic dog population may have involved the interspecies transmission between wild and domestic carnivores. PMID:9825797

  20. Pathogenicity in six Australian reptile species following experimental inoculation with Bohle iridovirus.

    PubMed

    Ariel, E; Wirth, W; Burgess, G; Scott, J; Owens, L

    2015-08-20

    Ranaviruses are able to infect multiple species of fish, amphibian and reptile, and some strains are capable of interclass transmission. These numerous potential carriers and reservoir species compound efforts to control and contain infections in cultured and wild populations, and a comprehensive knowledge of susceptible species and life stage is necessary to inform such processes. Here we report on the challenge of 6 water-associated reptiles with Bohle iridovirus (BIV) to investigate its potential pathogenicity in common native reptiles of the aquatic and riparian fauna of northern Queensland, Australia. Adult tortoises Elseya latisternum and Emydura krefftii, snakes Boiga irregularis, Dendrelaphis punctulatus and Amphiesma mairii, and yearling crocodiles Crocodylus johnstoni were exposed via intracoelomic inoculation or co-habitation with infected con-specifics, but none were adversely affected by the challenge conditions applied here. Bohle iridovirus was found to be extremely virulent in hatchling tortoises E. latisternum and E. krefftii via intracoelomic challenge, as demonstrated by distinct lesions in multiple organs associated with specific immunohistochemistry staining and a lethal outcome (10/17) of the challenge. Virus was re-isolated from 2/5 E. latisternum, 4/12 E. krefftii and 1/3 brown tree snakes B. irregularis. Focal necrosis, haemorrhage and infiltration of granulocytes were frequently observed histologically in the pancreas, liver and sub-mucosa of the intestine of challenged tortoise hatchlings. Immunohistochemistry demonstrated the presence of ranavirus antigens in the necrotic lesions and in individual cells of the vascular endothelium, the connective tissue and in granulocytes associated with necrosis or present along serosal surfaces. The outcome of this study confirms hatchling tortoises are susceptible to BIV, thereby adding Australian reptiles to the host range of ranaviruses. Additionally, given that BIV was originally isolated from an

  1. Routine clinical inspections in Norwegian marine salmonid sites: A key role in surveillance for freedom from pathogenic viral haemorrhagic septicaemia (VHS).

    PubMed

    Lyngstad, Trude Marie; Hellberg, Hege; Viljugrein, Hildegunn; Bang Jensen, Britt; Brun, Edgar; Sergeant, Evan; Tavornpanich, Saraya

    2016-02-01

    Since the mid-1980s, clinical inspections of aquaculture sites carried out on a regular basis by authorized veterinarians and fish health biologists (known as fish health services: FHS) have been an essential part of aquatic animal health surveillance in Norway. The aims of the present study were (1) to evaluate the performance of FHS routine clinical inspections for the detection of VHS and (2) to explore the effectiveness of risk-based prioritisation of FHS inspections for demonstrating freedom from VHS in marine salmonid sites in Norway. A stochastic simulation model was developed to estimate site sensitivity (SeS), population sensitivity (SeP), and probability of freedom (PFree). The estimation of SeS takes into consideration the probability that FHS submit samples if a site is infected, the probability that a sample is tested if submitted, the effective probability of infection in fish with clinical signs, laboratory test sensitivity, and the number of tested samples. SeP and PFree were estimated on a monthly basis over a 12 month period for six alternative surveillance scenarios and included the risk factors: region, species, area production density, and biosecurity level. Model results indicate that the current surveillance system, based on routine inspections by the FHS has a high capability for detecting VHS and that there is a high probability of freedom from VHS in Norwegian marine farmed salmonids (PFree >95%). Sensitivity analysis identified the probabilities that samples are submitted and submitted samples are tested, as the most influential input variables. The model provides a supporting tool for evaluation of potential changes in the surveillance strategy, and can be viewed as a platform for similar exotic viral infectious diseases in marine salmonid farming in Norway, if they share similar risk factors. PMID:26754927

  2. STAT2 Knockout Syrian Hamsters Support Enhanced Replication and Pathogenicity of Human Adenovirus, Revealing an Important Role of Type I Interferon Response in Viral Control.

    PubMed

    Toth, Karoly; Lee, Sang R; Ying, Baoling; Spencer, Jacqueline F; Tollefson, Ann E; Sagartz, John E; Kong, Il-Keun; Wang, Zhongde; Wold, William S M

    2015-08-01

    Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models.

  3. STAT2 Knockout Syrian Hamsters Support Enhanced Replication and Pathogenicity of Human Adenovirus, Revealing an Important Role of Type I Interferon Response in Viral Control

    PubMed Central

    Spencer, Jacqueline F.; Tollefson, Ann E.; Sagartz, John E.; Kong, Il-Keun; Wang, Zhongde; Wold, William S. M.

    2015-01-01

    Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models. PMID

  4. Serological survey of selected canine viral pathogens and zoonoses in grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) from Alaska.

    PubMed

    Chomel, B B; Kasten, R W; Chappuis, G; Soulier, M; Kikuchi, Y

    1998-12-01

    Between 1988 and 1991, 644 serum samples were collected from 480 grizzly bears (Ursus arctos horribilis) and 40 black bears (Ursus americanus) from Alaska, United States of America, and were tested for selected canine viral infections and zoonoses. Antibody prevalence in grizzly bears was 0% for parvovirus, 8.3% (40/480) for distemper, 14% (68/480) for infectious hepatitis, 16.5% (79/480) for brucellosis, 19% (93/480) for tularaemia and 47% (225/478) for trichinellosis. In black bears, prevalence ranged from 0% for distemper and parvovirus to 27.5% for trichinellosis and 32% for tularaemia. Antibody prevalence for brucellosis (2.5%) and tularaemia (32%) were identical for grizzly bears and black bears from the geographical area of interior Alaska. Links between differences in prevalence and the origin of the grizzly bears were observed. Antibodies to canine distemper virus and infectious hepatitis virus were mainly detected in grizzly bears from Kodiak Island and the Alaskan Peninsula. Brucellosis antibodies were prevalent in grizzly bears from western and northern Alaska, whereas tularaemia antibodies were detected in grizzly bears from interior Alaska and the Arctic. There was a strong gradient for antibodies to Trichinella spp. from southern to northern Alaska. For most diseases, antibody prevalence increased with age. However, for several infections, no antibodies were detected in grizzly bears aged from 0 to 2 years, in contrast to the presence of those infections in black bears. Grizzly bears served as excellent sentinels for surveillance of zoonotic infections in wildlife in Alaska.

  5. Viral Gastroenteritis

    MedlinePlus

    ... stomach, small intestine, and large intestine. Several different viruses can cause viral gastroenteritis, which is highly contagious ... and last for 1 to 3 days. Some viruses cause symptoms that last longer. [ Top ] What are ...

  6. Viral arthritis

    MedlinePlus

    Infectious arthritis - viral ... Ohl CA, Forster D. Infectious arthritis of native joints. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious ...

  7. Highly pathogenic H5N1 influenza A virus strains provoke heterogeneous IFN-α/β responses that distinctively affect viral propagation in human cells.

    PubMed

    Matthaei, Markus; Budt, Matthias; Wolff, Thorsten

    2013-01-01

    The fatal transmissions of highly pathogenic avian influenza A viruses (IAV) of the H5N1 subtype to humans and high titer replication in the respiratory tract indicate that these pathogens can overcome the bird-to-human species barrier. While type I interferons (IFN-α/β) are well described to contribute to the species barrier of many zoonotic viruses, current data to the role of these antiviral cytokines during human H5N1 IAV infections is limited and contradictory. We hypothesized an important role for the IFN system in limiting productive infection of avian H5N1 strains in human cells. Hence, we examined IFN-α/β gene activation by different avian and human H5N1 isolates, if the IFN-α/β response restricts H5N1 growth and whether the different strains were equally capable to regulate the IFN-α/β system via their IFN-antagonistic NS1 proteins. Two human H5N1 isolates and a seasonal H3N2 strain propagated efficiently in human respiratory cells and induced little IFN-β, whereas three purely avian H5N1 strains were attenuated for replication and provoked higher IFN secretion. Replication of avian viruses was significantly enhanced on interferon-deficient cells, and exogenous IFN potently limited the growth of all strains in human cells. Moreover, IFN-α/β activation by all strains depended on retinoic acid-inducible gene I excluding principal differences in receptor activation between the different viruses. Interestingly, all H5N1 NS1 proteins suppressed IFN-α/β induction comparably well to the NS1 of seasonal IAV. Thus, our study shows that H5N1 strains are heterogeneous in their capacity to activate human cells in an NS1-independent manner. Our findings also suggest that H5N1 viruses need to acquire adaptive changes to circumvent strong IFN-α/β activation in human host cells. Since no single amino acid polymorphism could be associated with a respective high- or low induction phenotype we propose that the necessary adaptations to overcome the human IFN

  8. Exploring the viral world through metagenomics.

    PubMed

    Rosario, Karyna; Breitbart, Mya

    2011-10-01

    Viral metagenomics, or shotgun sequencing of purified viral particles, has revolutionized the field of environmental virology by allowing the exploration of viral communities in a variety of sample types throughout the biosphere. The introduction of viral metagenomics has demonstrated that dominant viruses in environmental communities are not well-represented by the cultured viruses in existing sequence databases. Viral metagenomic studies have provided insights into viral ecology by elucidating the genetic potential, community structure, and biogeography of environmental viruses. In addition, viral metagenomics has expanded current knowledge of virus-host interactions by uncovering genes that may allow viruses to manipulate their hosts in unexpected ways. The intrinsic potential for virus discovery through viral metagenomics can help advance a wide array of disciplines including evolutionary biology, pathogen surveillance, and biotechnology.

  9. Metagenomic Detection of Viral Pathogens in Spanish Honeybees: Co-Infection by Aphid Lethal Paralysis, Israel Acute Paralysis and Lake Sinai Viruses

    PubMed Central

    Rubio-Guerri, Consuelo; Karlsson, Oskar E.; Kukielka, Deborah; Belák, Sándor; Sánchez-Vizcaíno, José Manuel

    2013-01-01

    The situation in Europe concerning honeybees has in recent years become increasingly aggravated with steady decline in populations and/or catastrophic winter losses. This has largely been attributed to the occurrence of a variety of known and “unknown”, emerging novel diseases. Previous studies have demonstrated that colonies often can harbour more than one pathogen, making identification of etiological agents with classical methods difficult. By employing an unbiased metagenomic approach, which allows the detection of both unexpected and previously unknown infectious agents, the detection of three viruses, Aphid Lethal Paralysis Virus (ALPV), Israel Acute Paralysis Virus (IAPV), and Lake Sinai Virus (LSV), in honeybees from Spain is reported in this article. The existence of a subgroup of ALPV with the ability to infect bees was only recently reported and this is the first identification of such a strain in Europe. Similarly, LSV appear to be a still unclassified group of viruses with unclear impact on colony health and these viruses have not previously been identified outside of the United States. Furthermore, our study also reveals that these bees carried a plant virus, Turnip Ringspot Virus (TuRSV), potentially serving as important vector organisms. Taken together, these results demonstrate the new possibilities opened up by high-throughput sequencing and metagenomic analysis to study emerging new diseases in domestic and wild animal populations, including honeybees. PMID:23460860

  10. Outbreak of H5N2 highly pathogenic avian Influenza A virus infection in two commercial layer facilities: lesions and viral antigen distribution.

    PubMed

    Arruda, Paulo H E; Stevenson, Gregory W; Killian, Mary L; Burrough, Eric R; Gauger, Phillip C; Harmon, Karen M; Magstadt, Drew R; Yoon, Kyoung-Jin; Zhang, Jianqiang; Madson, Darin M; Piñeyro, Pablo; Derscheid, Rachel J; Schwartz, Kent J; Cooper, Vickie L; Halbur, Patrick G; Main, Rodger G; Sato, Yuko; Arruda, Bailey L

    2016-09-01

    The largest outbreak of highly pathogenic avian Influenza A virus (HPAIV) infection in U.S. history began in December 2014 resulting in the euthanasia of millions of birds and collateral economic consequences to the U.S. poultry industry. We describe 2 cases of H5N2 HPAIV infection in laying hens in Iowa. Following a sharp increase in mortality with minimal clinical signs, 15 dead birds, from 2 unrelated farms, were submitted to the Iowa State University Veterinary Diagnostic Laboratory. Common lesions included diffuse edema and multifocal hemorrhage of the comb, catarrhal exudate in the oropharynx, and multifocal tracheal hemorrhage. Less common lesions included epicardial petechiae, splenic hemorrhage, and pancreatic necrosis. Influenza A virus nucleoprotein was detected by immunohistochemistry in multiple cell types including ependymal cells, the choroid plexus, neurons, respiratory epithelium and macrophages in the lung, cardiac myocytes, endothelial cells, necrotic foci in the spleen, Kupffer cells in the liver, and necrotic acinar cells in the pancreas. Real-time polymerase chain reaction and sequencing confirmed H5N2 HPAIV with molecular characteristics similar to other contemporary U.S. H5N2 HPAIVs in both cases. PMID:27423731

  11. [DNA vaccination via in vivo electroporation can elicit specific immune response against highly pathogenic H5N1 influenza viral structural antigens in mice].

    PubMed

    Wang, Wen; Chen, Hong; Tan, Wen-jie; Deng, Yao; Wang, Min; Liu, Yuan; Yin, Xiao; Zhang, Ke; Guan, Jie; Zhou, Jian-fang; Shu, Yue-long; Ruan, Li

    2010-05-01

    This study aims to develop inexpensive and effective experimental vaccines against highly pathogenic H5N1 Avian Influenza (HPAI) virus and to optimize their immunization programs. To this end, we first synthesized the codon-optimized hemagglutinin gene (HAop) and neuraminidase gene (NAop), both of which were derived from a H5N1 virus (Anhui strain), and constructed successfully the DNA vaccines containing a single cistronic construct (HAwt, HAop, or NAop) or a bicistronic construct (HAop/M2 or NAop/M1) of H5N1 influenza virus origin. Their expression was confirmed by indirect immunofluorescent assay (IFA) and Western blotting. Then twice vaccination of mice with the DNA vaccines by injection intramuscularly or in vivo electroporation (EP) via two different routes was evaluated and analyzed by hemagglutination inhibition (HI) assay, NA-specific antibody detection, micro-neutralizing antibody test and IFN-gamma ELISpot assay. Our results showed that the DNA vaccines with coden-optimized HAop and NAop constructs could quickly elicit a strong immune response by in vivo EP, especially the cellular immune response against HA and NA; the in vivo EP via intradermal route induced stronger humoral immune responses than those via intramuscular route. Our findings will pave a way for further development of novel DNA-based H5N1 vaccine and for the optimization of the immunization programs of DNA vaccine. PMID:20572336

  12. Present and future projections of habitat suitability of the Asian tiger mosquito, a vector of viral pathogens, from global climate simulation.

    PubMed

    Proestos, Y; Christophides, G K; Ergüler, K; Tanarhte, M; Waldock, J; Lelieveld, J

    2015-04-01

    Climate change can influence the transmission of vector-borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian tiger mosquito (Aedes albopictus), which can transmit pathogens that cause chikungunya, dengue fever, yellow fever and various encephalitides. Using a general circulation model at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the twenty-first century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that approximately 2.4 billion individuals in a land area of nearly 20 million km(2) will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making.

  13. Present and future projections of habitat suitability of the Asian tiger mosquito, a vector of viral pathogens, from global climate simulation

    PubMed Central

    Proestos, Y.; Christophides, G. K.; Ergüler, K.; Tanarhte, M.; Waldock, J.; Lelieveld, J.

    2015-01-01

    Climate change can influence the transmission of vector-borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian tiger mosquito (Aedes albopictus), which can transmit pathogens that cause chikungunya, dengue fever, yellow fever and various encephalitides. Using a general circulation model at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the twenty-first century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that approximately 2.4 billion individuals in a land area of nearly 20 million km2 will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making. PMID:25688015

  14. Present and future projections of habitat suitability of the Asian tiger mosquito, a vector of viral pathogens, from global climate simulation.

    PubMed

    Proestos, Y; Christophides, G K; Ergüler, K; Tanarhte, M; Waldock, J; Lelieveld, J

    2015-04-01

    Climate change can influence the transmission of vector-borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian tiger mosquito (Aedes albopictus), which can transmit pathogens that cause chikungunya, dengue fever, yellow fever and various encephalitides. Using a general circulation model at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the twenty-first century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that approximately 2.4 billion individuals in a land area of nearly 20 million km(2) will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making. PMID:25688015

  15. Present and Future Projections of Habitat Suitability of the Asian Tiger Mosquito, a Vector of Viral Pathogens, from Global Climate Simulations.

    NASA Astrophysics Data System (ADS)

    Proestos, Y.; Christophides, G.; Erguler, K.; Tanarhte, M.; Waldock, J.; Lelieveld, J.

    2014-12-01

    Climate change can influence the transmission of vector borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian Tiger mosquito (Aedes albopictus), which can transmit pathogens that cause Chikungunya, Dengue fever, yellow fever and various encephalitides. Using a general circulation model (GCM) at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the 21st century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that about 2.4 billion individuals in a land area of nearly 20 million square kilometres will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making.

  16. Viral arthritis

    PubMed Central

    Marks, Michael; Marks, Jonathan L

    2016-01-01

    Acute-onset arthritis is a common clinical problem facing both the general clinician and the rheumatologist. A viral aetiology is though to be responsible for approximately 1% of all cases of acute arthritis with a wide range of causal agents recognised. The epidemiology of acute viral arthritis continues to evolve, with some aetiologies, such as rubella, becoming less common due to vaccination, while some vector-borne viruses have become more widespread. A travel history therefore forms an important part of the assessment of patients presenting with an acute arthritis. Worldwide, parvovirus B19, hepatitis B and C, HIV and the alphaviruses are among the most important causes of virally mediated arthritis. Targeted serological testing may be of value in establishing a diagnosis, and clinicians must also be aware that low-titre autoantibodies, such as rheumatoid factor and antinuclear antibody, can occur in the context of acute viral arthritis. A careful consideration of epidemiological, clinical and serological features is therefore required to guide clinicians in making diagnostic and treatment decisions. While most virally mediated arthritides are self-limiting some warrant the initiation of specific antiviral therapy. PMID:27037381

  17. Molecular basis of viral and microbial pathogenesis

    SciTech Connect

    Rott, R.; Goebel, W.

    1988-01-01

    The contents of this book are: Correlation Between Viroid Structure and Pathogenicty; Antigenicity of the Influenza Haemagglutinia Membrane Glycoprotein; Viral Glycoproteins as Determinants of Pathogenicity; Virus Genes Involved in Host Range and Pathogenicity; Molecular Heterogenetiy of Pathogenic Herpus Viruses; Recombination of Foreign (Viral) DNA with Host Genome: Studies in Vivo and in a Cell-Free system; Disorders of Cellular Neuro-Functions by Persistent Viral Infection; Pathogenic Aspects of Measles Virus-Persistent Infections in Man; Analysis of the Dual Lineage Specificity of E26 Avian Leukemia Virus; Mx Gene Control of Influenza Virus Susceptibility; Shiga and Shika-Like Toxins: A Family of Related Cytokinons; and Molecular Mechanisms of Pathogenicity in Shigella Flexneri.

  18. Complete genome sequence of a common midwife toad virus-like ranavirus associated with mass mortalities in wild amphibians in the Netherlands.

    PubMed

    van Beurden, Steven J; Hughes, Joseph; Saucedo, Bernardo; Rijks, Jolianne; Kik, Marja; Haenen, Olga L M; Engelsma, Marc Y; Gröne, Andrea; Verheije, M Helene; Wilkie, Gavin

    2014-12-24

    A ranavirus associated with mass mortalities in wild water frogs (Pelophylax spp.) and other amphibians in the Netherlands since 2010 was isolated, and its complete genome sequence was determined. The virus has a genome of 107,772 bp and shows 96.5% sequence identity with the common midwife toad virus from Spain.

  19. Complete Genome Sequence of a Common Midwife Toad Virus-Like Ranavirus Associated with Mass Mortalities in Wild Amphibians in the Netherlands

    PubMed Central

    Hughes, Joseph; Saucedo, Bernardo; Rijks, Jolianne; Kik, Marja; Haenen, Olga L. M.; Engelsma, Marc Y.; Gröne, Andrea; Verheije, M. Helene; Wilkie, Gavin

    2014-01-01

    A ranavirus associated with mass mortalities in wild water frogs (Pelophylax spp.) and other amphibians in the Netherlands since 2010 was isolated, and its complete genome sequence was determined. The virus has a genome of 107,772 bp and shows 96.5% sequence identity with the common midwife toad virus from Spain. PMID:25540340

  20. The role of amphibian antimicrobial peptides in protection of amphibians from pathogens linked to global amphibian declines.

    PubMed

    Rollins-Smith, Louise A

    2009-08-01

    Amphibian species have experienced population declines and extinctions worldwide that are unprecedented in recent history. Many of these recent declines have been linked to a pathogenic skin fungus, Batrachochytrium dendrobatidis, or to iridoviruses of the genus Ranavirus. One of the first lines of defense against pathogens that enter by way of the skin are antimicrobial peptides synthesized and stored in dermal granular glands and secreted into the mucus following alarm or injury. Here, I review what is known about the capacity of amphibian antimicrobial peptides from diverse amphibians to inhibit B. dendrobatidis or ranavirus infections. When multiple species were compared for the effectiveness of their in vitro antimicrobial peptides defenses against B. dendrobatidis, non-declining species of rainforest amphibians had more effective antimicrobial peptides than species in the same habitat that had recently experienced population declines. Further, there was a significant correlation between the effectiveness of the antimicrobial peptides and resistance of the species to experimental infection. These studies support the hypothesis that antimicrobial peptides are an important component of innate defenses against B. dendrobatidis. Some amphibian antimicrobial peptides inhibit ranavirus infections and infection of human T lymphocytes by the human immunodeficiency virus (HIV). An effective antimicrobial peptide defense against skin pathogens appears to depend on a diverse array of genes expressing antimicrobial peptides. The production of antimicrobial peptides may be regulated by signals from the pathogens. However, this defense must also accommodate potentially beneficial microbes on the skin that compete or inhibit growth of the pathogens. How this delicate balancing act is accomplished is an important area of future research.

  1. Viral Hepatitis

    MedlinePlus

    ... with hepatitis? How does a pregnant woman pass hepatitis B virus to her baby? If I have hepatitis B, what does my baby need so that she ... Can I breastfeed my baby if I have hepatitis B? More information on viral hepatitis What is hepatitis? ...

  2. Ocular manifestations of feline viral diseases.

    PubMed

    Stiles, Jean

    2014-08-01

    Feline viral diseases are common and cats can be presented with a variety of clinical manifestations. Ocular disease associated with viral pathogens is not unusual, particularly with viruses causing upper respiratory tract disease in cats, such as feline herpesvirus type 1 and feline calicivirus. These agents mainly cause ocular surface disease. Other viruses, such as feline immunodeficiency virus and feline coronavirus, can cause uveitis, while feline leukemia virus can induce ocular lymphosarcoma. This review covers the most common viral pathogens of cats that cause ocular manifestations, the specific features of the ocular diseases caused by these viruses and therapeutic recommendations.

  3. Antisense approaches for elucidating ranavirus gene function in an infected fish cell line.

    PubMed

    Whitley, D S; Sample, R C; Sinning, A R; Henegar, J; Chinchar, V G

    2011-09-01

    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 process we have targeted several structural and catalytic genes using antisense morpholino oligonucleotides (asMO) and small, interfering RNAs (siRNA). In proof of concept experiments we show the feasibility of this approach and describe recent work targeting five frog virus 3 genes. Our results indicate that both 46K and 32R, two immediate-early viral proteins, are essential for replication in vitro, and confirm earlier findings that the major capsid protein, the largest subunit of the viral homolog of RNA polymerase II, and the viral DNA methyltransferase are also essential for replication in cell culture.

  4. Neutrophil Extracellular Traps Go Viral

    PubMed Central

    Schönrich, Günther; Raftery, Martin J.

    2016-01-01

    Neutrophils are the most numerous immune cells. Their importance as the first line of defense against bacterial and fungal pathogens is well described. In contrast, the role of neutrophils in controlling viral infections is less clear. Bacterial and fungal pathogens can stimulate neutrophils extracellular traps (NETs) in a process called NETosis. Although NETosis has previously been described as a special form of programmed cell death, there are forms of NET production that do not end with the demise of neutrophils. As an end result of NETosis, genomic DNA complexed with microbicidal proteins is expelled from neutrophils. These structures can kill pathogens or at least prevent their local spread within host tissue. On the other hand, disproportionate NET formation can cause local or systemic damage. Only recently, it was recognized that viruses can also induce NETosis. In this review, we discuss the mechanisms by which NETs are produced in the context of viral infection and how this may contribute to both antiviral immunity and immunopathology. Finally, we shed light on viral immune evasion mechanisms targeting NETs. PMID:27698656

  5. Neutrophil Extracellular Traps Go Viral

    PubMed Central

    Schönrich, Günther; Raftery, Martin J.

    2016-01-01

    Neutrophils are the most numerous immune cells. Their importance as the first line of defense against bacterial and fungal pathogens is well described. In contrast, the role of neutrophils in controlling viral infections is less clear. Bacterial and fungal pathogens can stimulate neutrophils extracellular traps (NETs) in a process called NETosis. Although NETosis has previously been described as a special form of programmed cell death, there are forms of NET production that do not end with the demise of neutrophils. As an end result of NETosis, genomic DNA complexed with microbicidal proteins is expelled from neutrophils. These structures can kill pathogens or at least prevent their local spread within host tissue. On the other hand, disproportionate NET formation can cause local or systemic damage. Only recently, it was recognized that viruses can also induce NETosis. In this review, we discuss the mechanisms by which NETs are produced in the context of viral infection and how this may contribute to both antiviral immunity and immunopathology. Finally, we shed light on viral immune evasion mechanisms targeting NETs.

  6. Viral quasispecies evolution.

    PubMed

    Domingo, Esteban; Sheldon, Julie; Perales, Celia

    2012-06-01

    Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.

  7. Viral Quasispecies Evolution

    PubMed Central

    Sheldon, Julie; Perales, Celia

    2012-01-01

    Summary: Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory. PMID:22688811

  8. Unexpected rarity of the pathogen Batrachochytrium dendrobatidis in Appalachian Plethodon Salamanders: 1957-2011.

    PubMed

    Muletz, Carly; Caruso, Nicholas M; Fleischer, Robert C; McDiarmid, Roy W; Lips, Karen R

    2014-01-01

    Widespread population declines in terrestrial Plethodon salamanders occurred by the 1980s throughout the Appalachian Mountains, the center of global salamander diversity, with no evident recovery. We tested the hypothesis that the historic introduction and spread of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) into the eastern US was followed by Plethodon population declines. We expected to detect elevated prevalence of Bd prior to population declines as observed for Central American plethodontids. We tested 1,498 Plethodon salamanders of 12 species (892 museum specimens, 606 wild individuals) for the presence of Bd, and tested 94 of those for Batrachochytrium salamandrivorans (Bs) and for ranavirus. Field samples were collected in 2011 from 48 field sites across a 767 km transect. Historic samples from museum specimens were collected at five sites with the greatest number and longest duration of collection (1957-987), four of which were sampled in the field in 2011. None of the museum specimens were positive for Bd, but four P. cinereus from field surveys were positive. The overall Bd prevalence from 1957-2011 for 12 Plethodon species sampled across a 757 km transect was 0.2% (95% CI 0.1-0.7%). All 94 samples were negative for Bs and ranavirus. We conclude that known amphibian pathogens are unlikely causes for declines in these Plethodon populations. Furthermore, these exceptionally low levels of Bd, in a region known to harbor Bd, may indicate that Plethodon specific traits limit Bd infection. PMID:25084159

  9. Unexpected Rarity of the Pathogen Batrachochytrium dendrobatidis in Appalachian Plethodon Salamanders: 1957–2011

    PubMed Central

    Muletz, Carly; Caruso, Nicholas M.; Fleischer, Robert C.; McDiarmid, Roy W.; Lips, Karen R.

    2014-01-01

    Widespread population declines in terrestrial Plethodon salamanders occurred by the 1980s throughout the Appalachian Mountains, the center of global salamander diversity, with no evident recovery. We tested the hypothesis that the historic introduction and spread of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) into the eastern US was followed by Plethodon population declines. We expected to detect elevated prevalence of Bd prior to population declines as observed for Central American plethodontids. We tested 1,498 Plethodon salamanders of 12 species (892 museum specimens, 606 wild individuals) for the presence of Bd, and tested 94 of those for Batrachochytrium salamandrivorans (Bs) and for ranavirus. Field samples were collected in 2011 from 48 field sites across a 767 km transect. Historic samples from museum specimens were collected at five sites with the greatest number and longest duration of collection (1957–987), four of which were sampled in the field in 2011. None of the museum specimens were positive for Bd, but four P. cinereus from field surveys were positive. The overall Bd prevalence from 1957–2011 for 12 Plethodon species sampled across a 757 km transect was 0.2% (95% CI 0.1–0.7%). All 94 samples were negative for Bs and ranavirus. We conclude that known amphibian pathogens are unlikely causes for declines in these Plethodon populations. Furthermore, these exceptionally low levels of Bd, in a region known to harbor Bd, may indicate that Plethodon specific traits limit Bd infection. PMID:25084159

  10. Unexpected rarity of the pathogen Batrachochytrium dendrobatidis in Appalachian Plethodon Salamanders: 1957-2011.

    PubMed

    Muletz, Carly; Caruso, Nicholas M; Fleischer, Robert C; McDiarmid, Roy W; Lips, Karen R

    2014-01-01

    Widespread population declines in terrestrial Plethodon salamanders occurred by the 1980s throughout the Appalachian Mountains, the center of global salamander diversity, with no evident recovery. We tested the hypothesis that the historic introduction and spread of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) into the eastern US was followed by Plethodon population declines. We expected to detect elevated prevalence of Bd prior to population declines as observed for Central American plethodontids. We tested 1,498 Plethodon salamanders of 12 species (892 museum specimens, 606 wild individuals) for the presence of Bd, and tested 94 of those for Batrachochytrium salamandrivorans (Bs) and for ranavirus. Field samples were collected in 2011 from 48 field sites across a 767 km transect. Historic samples from museum specimens were collected at five sites with the greatest number and longest duration of collection (1957-987), four of which were sampled in the field in 2011. None of the museum specimens were positive for Bd, but four P. cinereus from field surveys were positive. The overall Bd prevalence from 1957-2011 for 12 Plethodon species sampled across a 757 km transect was 0.2% (95% CI 0.1-0.7%). All 94 samples were negative for Bs and ranavirus. We conclude that known amphibian pathogens are unlikely causes for declines in these Plethodon populations. Furthermore, these exceptionally low levels of Bd, in a region known to harbor Bd, may indicate that Plethodon specific traits limit Bd infection.

  11. Viral metagenomics and blood safety.

    PubMed

    Sauvage, V; Eloit, M

    2016-02-01

    The characterization of the human blood-associated viral community (also called blood virome) is essential for epidemiological surveillance and to anticipate new potential threats for blood transfusion safety. Currently, the risk of blood-borne agent transmission of well-known viruses (HBV, HCV, HIV and HTLV) can be considered as under control in high-resource countries. However, other viruses unknown or unsuspected may be transmitted to recipients by blood-derived products. This is particularly relevant considering that a significant proportion of transfused patients are immunocompromised and more frequently subjected to fatal outcomes. Several measures to prevent transfusion transmission of unknown viruses have been implemented including the exclusion of at-risk donors, leukocyte reduction of donor blood, and physicochemical treatment of the different blood components. However, up to now there is no universal method for pathogen inactivation, which would be applicable for all types of blood components and, equally effective for all viral families. In addition, among available inactivation procedures of viral genomes, some of them are recognized to be less effective on non-enveloped viruses, and inadequate to inactivate higher viral titers in plasma pools or derivatives. Given this, there is the need to implement new methodologies for the discovery of unknown viruses that may affect blood transfusion. Viral metagenomics combined with High Throughput Sequencing appears as a promising approach for the identification and global surveillance of new and/or unexpected viruses that could impair blood transfusion safety. PMID:26778104

  12. Viral Parkinsonism

    PubMed Central

    Jang, Haeman; Boltz, David A.; Webster, Robert G.; Smeyne, Richard Jay

    2015-01-01

    Parkinson's disease is a debilitating neurological disorder characterized that affects 1-2% of the adult population over 55 years of age. For the vast majority of cases, the etiology of this disorder is unknown, although it is generally accepted that there is a genetic susceptibility to any number of environmental agents. One such agent may be viruses. It has been shown that numerous viruses can enter the nervous system, i.e. they are neurotropic, and induce a number of encephalopathies. One of the secondary consequences of these encephalopathies can be parkinsonism, that is both transient as well as permanent. One of the most highlighted and controversial cases of viral parkinsonism is that which followed the 1918 influenza outbreak and the subsequent induction of von Economo's encephalopathy. In this review, we discuss the neurological sequelae of infection by influenza virus as well as that of other viruses known to induce parkinsonism including Coxsackie, Japanese encephalitis B, St. Louis, West Nile and HIV viruses. PMID:18760350

  13. Viral evolution

    PubMed Central

    Nasir, Arshan; Kim, Kyung Mo; Caetano-Anollés, Gustavo

    2012-01-01

    Explaining the origin of viruses remains an important challenge for evolutionary biology. Previous explanatory frameworks described viruses as founders of cellular life, as parasitic reductive products of ancient cellular organisms or as escapees of modern genomes. Each of these frameworks endow viruses with distinct molecular, cellular, dynamic and emergent properties that carry broad and important implications for many disciplines, including biology, ecology and epidemiology. In a recent genome-wide structural phylogenomic analysis, we have shown that large-to-medium-sized viruses coevolved with cellular ancestors and have chosen the evolutionary reductive route. Here we interpret these results and provide a parsimonious hypothesis for the origin of viruses that is supported by molecular data and objective evolutionary bioinformatic approaches. Results suggest two important phases in the evolution of viruses: (1) origin from primordial cells and coexistence with cellular ancestors, and (2) prolonged pressure of genome reduction and relatively late adaptation to the parasitic lifestyle once virions and diversified cellular life took over the planet. Under this evolutionary model, new viral lineages can evolve from existing cellular parasites and enhance the diversity of the world’s virosphere. PMID:23550145

  14. Long-term study of an infection with ranaviruses in a group of edible frogs (Pelophylax kl. esculentus) and partial characterization of two viruses based on four genomic regions.

    PubMed

    Stöhr, Anke C; Hoffmann, Alexandra; Papp, Tibor; Robert, Nadia; Pruvost, Nicolas B M; Reyer, Heinz-Ulrich; Marschang, Rachel E

    2013-08-01

    Several edible frogs (Pelophylax kl. esculentus) collected into a single group from various ponds in Europe died suddenly with reddening of the skin (legs, abdomen) and haemorrhages in the gastrointestinal tract. Ranavirus was detected in some of the dead frogs using PCR, and virus was also isolated in cell culture. Over the following 3 years, another two outbreaks occurred with low to high mortality in between asymptomatic periods. In the first 2 years, the same ranavirus was detected repeatedly, but a new ranavirus was isolated in association with the second mass-mortality event. The two different ranaviruses were characterized based on nucleotide sequences from four genomic regions, namely, major capsid protein, DNA polymerase, ribonucleoside diphosphate reductase alpha and beta subunit genes. The sequences showed slight variations to each other or GenBank entries and both clustered to the Rana esculenta virus (REV-like) clade in the phylogenetic analysis. Furthermore, a quiescent infection was demonstrated in two individuals. By comparing samples taken before and after transport and caging in groups it was possible to identify the pond of origin and a ranavirus was detected for the first time in wild amphibians in Germany.

  15. Viral hepatitis*

    PubMed Central

    Deinhardt, F.; Gust, I. D.

    1982-01-01

    Three forms of viral hepatitis can be recognized: hepatitis A, hepatitis B, and hepatitis non-A, non-B. Hepatitis A is caused by a picornavirus, is transmitted by the faceal—oral route, does not become chronic, and no chronic virus carriers exist. The virus can be grown in cell cultures, and killed as well as live attenuated virus vaccines are under development. Hepatitis B is caused by an enveloped virus containing a circular, double-stranded form of DNA. The disease is transmitted parenterally through inoculation of blood or blood products containing virus or through close personal contact with a virus-positive person. Hepatitis B becomes chronic in a certain number of cases and can lead to cirrhosis and primary liver cell carcinoma. The blood and certain body secretions of individuals with a persistent or chronic infection may remain infectious for many years. The hepatitis B virus cannot be grown in cell cultures but the entire genome has been sequenced and cloned in bacterial and eukaryotic cells. An inactivated virus vaccine has been prepared from hepatitis B surface antigen present in the plasma of hepatitis B virus carriers and further vaccines are under development. The agents of hepatitis non-A, non-B have not been identified. It is possible to distinguish between a predominantly parenterally transmitted and an orally transmitted form of hepatitis non-A, non-B. The latter is reported to be caused by a picornavirus that does not, however, have any antigenic relationship with hepatitis A virus. PMID:6817933

  16. Viral subversion of nucleocytoplasmic trafficking.

    PubMed

    Yarbrough, Melanie L; Mata, Miguel A; Sakthivel, Ramanavelan; Fontoura, Beatriz M A

    2014-02-01

    Trafficking of proteins and RNA into and out of the nucleus occurs through the nuclear pore complex (NPC). Because of its critical function in many cellular processes, the NPC and transport factors are common targets of several viruses that disrupt key constituents of the machinery to facilitate viral replication. Many viruses such as poliovirus and severe acute respiratory syndrome (SARS) virus inhibit protein import into the nucleus, whereas viruses such as influenza A virus target and disrupt host mRNA nuclear export. Current evidence indicates that these viruses may employ such strategies to avert the host immune response. Conversely, many viruses co-opt nucleocytoplasmic trafficking to facilitate transport of viral RNAs. As viral proteins interact with key regulators of the host nuclear transport machinery, viruses have served as invaluable tools of discovery that led to the identification of novel constituents of nuclear transport pathways. This review explores the importance of nucleocytoplasmic trafficking to viral pathogenesis as these studies revealed new antiviral therapeutic strategies and exposed previously unknown cellular mechanisms. Further understanding of nuclear transport pathways will determine whether such therapeutics will be useful treatments for important human pathogens.

  17. Viral Subversion of Nucleocytoplasmic Trafficking

    PubMed Central

    Yarbrough, Melanie L.; Mata, Miguel A.; Sakthivel, Ramanavelan; Fontoura, Beatriz M. A.

    2014-01-01

    Trafficking of proteins and RNA into and out of the nucleus occurs through the nuclear pore complex (NPC). Due to its critical function in many cellular processes, the NPC and transport factors are common targets of several viruses that disrupt key constituents of the machinery to facilitate viral replication. Many viruses such as poliovirus and severe acute respiratory syndrome (SARS) virus inhibit protein import into the nucleus, while viruses such as influenza A virus target and disrupt host mRNA nuclear export. Current evidence indicates that these viruses may employ such strategies to avert the host immune response. Conversely, many viruses co-opt nucleocytoplasmic trafficking to facilitate transport of viral RNAs. Since viral proteins interact with key regulators of the host nuclear transport machinery, viruses have served as invaluable tools of discovery that led to the identification of novel constituents of nuclear transport pathways. In addition, this review explores the importance of nucleocytoplasmic trafficking to viral pathogenesis as these studies revealed new antiviral therapeutic strategies and exposed previously unknown cellular mechanisms. Further understanding of nuclear transport pathways will determine whether such therapeutics will be useful treatments for important human pathogens. PMID:24289861

  18. MARINE MAMMAL DISEASES: PATHOGENS AND PROCESSES

    EPA Science Inventory

    The purpose of this chapter is to provide a concise overview of the pathogens and processes that alter the health of marine mammals. Viral disease is the most common etiology of significant mortality events in marine mammals. Discussion of viral disease focuses on effects in the ...

  19. [Viral superantigens].

    PubMed

    Us, Dürdal

    2016-07-01

    , expression of endogenous SAgs leads to thymic deletion of responding T cells (bearing Vβ6-9+ TCR) due to self-tolerance induction during the fetal life, and protects the host against future exogenous MMTV infections. The SAg of rabies virus is the N protein found in nucleocapsid structure and stimulates Vβ8+TCR-bearing T cells. The SAg-induced polyclonal activation of T cells leads to turn-off the specific immune response, to enhance the immunopathogenesis and facilitates viral transmission from the initial site of infection (the muscle tissue) to the nerve endings. In case of EBV-associated SAg that activates Vβ13+TCR-bearing T cells, it was detected that the SAg activity was not encoded by EBV itself, but instead was due to the transactivation of HERV-K18 by EBV latent membrane proteins, whose env gene encodes the SAg (Sutkowski, et al. 2001). It has been denoted that EBV-induced SAg expression plays a role in the long-term persistence and latency of virus in memory B cells, in the development of autoimmune diseases and in the oncogenesis mechanisms. The proteins which are identified as SAgs of HIV are Nef and gp120. It is believed that, the massive activation of CD4+ T cells (selectively with Vβ-12+, Vβ-5.3+ and Vβ-18+ TCRs) in early stages of infection and clonal deletion, anergy and apoptosis of bystander T cells in the late stages may be due to SAg property of Nef protein, as well as the other mechanisms. However there are some studies indicating that Nef does not act as a SAg (Lapatschek, et al. 2001). HIV gp120 glycoprotein is a B-cell SAg that binds to VH3-expressing B cell receptors and causes polyclonal B cell activation. In addition, binding of gp120 to IgE on the surface of basophiles and mast cells causes activation of those cells, secretion of high level proinflammatory mediators leading to allergic reactions and tissue damage. In a recent study, the depletion (anergy or deletion) of T cell populations bearing Vβ12+, Vβ13+ and Vβ17+ TCR have been

  20. Bioterrorism: pathogens as weapons.

    PubMed

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern.

  1. Bioterrorism: pathogens as weapons.

    PubMed

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern. PMID:23011963

  2. Pathogene Mikroorganismen

    NASA Astrophysics Data System (ADS)

    Wagner, Martin

    Infektionen, die vom Tier auf den Menschen übertragen werden, werden als Zoonosen bezeichnet. Pathogene Mikroorganismen können entweder durch Mensch-Mensch, Mensch-Tier-Kontakt oder durch Kontakt mit kontaminierten Vektoren übertragen werden [39]. Vektoren können einerseits belebt (z. B. blutsaugende Insekten), andererseits unbelebt sein. Kontaminierte Lebensmittel und Wasser gehören zu den wichtigsten unbelebten Vektoren. Neben Lebensmitteln können aber auch kontaminierte Gegenstände oder der Kontakt mit Kontaminationsquellen in der Umwelt Auslöser von Krankheitsfällen sein. Weltweit sind mehr als 1400 krankheitsverursachende biologische Agentien bekannt, von denen über 60 % ein zoonotisches Potenzial aufweisen. Als Ergebnis von Expertengesprächen wurde kürzlich berichtet, dass etwa 3 bis 4, meist virale, neu auftretende Infektionskrankheiten ("emerging diseases“) pro Jahr erwartet werden können [15]. Es handelt sich bei diesen Vorgängen aber nicht nur um das Auftauchen vollkommen neuer oder unbeschriebener Spezies, sondern auch um evolutionsbedingte Anpassungen von mikrobiellen Populationen an neue Bedingungen in ihrem Ökosystem [7]. Molekulare Analysen an Umweltchlamydien erbrachten Hinweise, dass die Evolution erste genetische Pathogenitätsmerkmale in dieser Spezies schon vor 700 Mio. Jahren entstehen ließ [14]. Viele Faktoren befeuern den Prozess der Anpassung, unter anderem auch alle Strategien, mit denen der Mensch seit Jahrtausenden versucht, Lebensmittel sicher und haltbar zu machen. Als die treibenden Kräfte des Auftretens neuer Krankheitserreger werden in der Gegenwart vor allem das sich ändernde Weltklima, die globalen Warenströme und die sich verändernden Konsumgewohnheiten genannt. Es steht auch außer Zweifel, dass viele dieser Erreger Tiere als ihr natürliches Reservoir haben werden, d. h. Zoonosen im klassischen Sinne sind [15].

  3. Viral Skin Diseases.

    PubMed

    Ramdass, Priya; Mullick, Sahil; Farber, Harold F

    2015-12-01

    In the vast world of skin diseases, viral skin disorders account for a significant percentage. Most viral skin diseases present with an exanthem (skin rash) and, oftentimes, an accompanying enanthem (lesions involving the mucosal membrane). In this article, the various viral skin diseases are explored, including viral childhood exanthems (measles, rubella, erythema infectiosum, and roseola), herpes viruses (herpes simplex virus, varicella zoster virus, Kaposi sarcoma herpes virus, viral zoonotic infections [orf, monkeypox, ebola, smallpox]), and several other viral skin diseases, such as human papilloma virus, hand, foot, and mouth disease, molluscum contagiosum, and Gianotti-Crosti syndrome.

  4. Viral Skin Diseases.

    PubMed

    Ramdass, Priya; Mullick, Sahil; Farber, Harold F

    2015-12-01

    In the vast world of skin diseases, viral skin disorders account for a significant percentage. Most viral skin diseases present with an exanthem (skin rash) and, oftentimes, an accompanying enanthem (lesions involving the mucosal membrane). In this article, the various viral skin diseases are explored, including viral childhood exanthems (measles, rubella, erythema infectiosum, and roseola), herpes viruses (herpes simplex virus, varicella zoster virus, Kaposi sarcoma herpes virus, viral zoonotic infections [orf, monkeypox, ebola, smallpox]), and several other viral skin diseases, such as human papilloma virus, hand, foot, and mouth disease, molluscum contagiosum, and Gianotti-Crosti syndrome. PMID:26612372

  5. Viral population dynamics and virulence thresholds.

    PubMed

    Lancaster, Karen Z; Pfeiffer, Julie K

    2012-08-01

    Viral factors and host barriers influence virally induced disease, and asymptomatic versus symptomatic infection is governed by a 'virulence threshold'. Understanding modulation of virulence thresholds could lend insight into disease outcome and aid in rational therapeutic and vaccine design. RNA viruses are an excellent system to study virulence thresholds in the context of quasispecies population dynamics. RNA viruses have high error frequencies and our understanding of viral population dynamics has been shaped by quasispecies evolutionary theory. In turn, research using RNA viruses as replicons with short generation times and high mutation rates has been an invaluable tool to test models of quasispecies theory. The challenge and new frontier of RNA virus population dynamics research is to combine multiple theoretical models and experimental data to describe viral population behavior as it changes, moving within and between hosts, to predict disease and pathogen emergence. Several excellent studies have begun to undertake this challenge using novel approaches.

  6. Assembly of viral genomes from metagenomes

    PubMed Central

    Smits, Saskia L.; Bodewes, Rogier; Ruiz-Gonzalez, Aritz; Baumgärtner, Wolfgang; Koopmans, Marion P.; Osterhaus, Albert D. M. E.; Schürch, Anita C.

    2014-01-01

    Viral infections remain a serious global health issue. Metagenomic approaches are increasingly used in the detection of novel viral pathogens but also to generate complete genomes of uncultivated viruses. In silico identification of complete viral genomes from sequence data would allow rapid phylogenetic characterization of these new viruses. Often, however, complete viral genomes are not recovered, but rather several distinct contigs derived from a single entity are, some of which have no sequence homology to any known proteins. De novo assembly of single viruses from a metagenome is challenging, not only because of the lack of a reference genome, but also because of intrapopulation variation and uneven or insufficient coverage. Here we explored different assembly algorithms, remote homology searches, genome-specific sequence motifs, k-mer frequency ranking, and coverage profile binning to detect and obtain viral target genomes from metagenomes. All methods were tested on 454-generated sequencing datasets containing three recently described RNA viruses with a relatively large genome which were divergent to previously known viruses from the viral families Rhabdoviridae and Coronaviridae. Depending on specific characteristics of the target virus and the metagenomic community, different assembly and in silico gap closure strategies were successful in obtaining near complete viral genomes. PMID:25566226

  7. Cellular and humoral mediated immunity and distribution of viral antigen in chickens after infection with a low pathogenic avian influenza virus (H4N6) isolated from wild ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four-week-old commercial chickens were intranasally inoculated with an H4N6 low pathogenicity avian influenza virus (LPAIV) isolated from a duck in Ukraine. Cecum, spleen, lung, and trachea samples were collected from birds from 1 to 21 days post inoculation (dpi) and examined by immunohistochemica...

  8. HIV suppression by host restriction factors and viral immune evasion.

    PubMed

    Jia, Xiaofei; Zhao, Qi; Xiong, Yong

    2015-04-01

    Antiviral restriction factors are an integral part of the host innate immune system that protects cells from viral pathogens, such as human immunodeficiency virus (HIV). Studies of the interactions between restriction factors and HIV have greatly advanced our understanding of both the viral life cycle and basic cell biology, as well as provided new opportunities for therapeutic intervention of viral infection. Here we review the recent developments towards establishing the structural and biochemical bases of HIV inhibition by, and viral countermeasures of, the restriction factors TRIM5, MxB, APOBEC3, SAMHD1, and BST2/tetherin.

  9. Pediatric Asthma and Viral Infection.

    PubMed

    Garcia-Garcia, M Luz; Calvo Rey, Cristina; Del Rosal Rabes, Teresa

    2016-05-01

    Respiratory viral infections, particularly respiratory syncytial virus (RSV) and rhinovirus, are the most importance risk factors for the onset of wheezing in infants and small children. Bronchiolitis is the most common acute respiratory infection in children under 1year of age, and the most common cause of hospitalization in this age group. RSV accounts for approximately 70% of all these cases, followed by rhinovirus, adenovirus, metapneumovirus and bocavirus. The association between bronchiolitis caused by RSV and the development of recurrent wheezing and/or asthma was first described more than 40years ago, but it is still unclear whether bronchiolitis causes chronic respiratory symptoms, or if it is a marker for children with a genetic predisposition for developing asthma in the medium or long term. In any case, sufficient evidence is available to corroborate the existence of this association, which is particularly strong when the causative agent of bronchiolitis is rhinovirus. The pathogenic role of respiratory viruses as triggers for exacerbations in asthmatic patients has not been fully characterized. However, it is clear that respiratory viruses, and in particular rhinovirus, are the most common causes of exacerbation in children, and some type of respiratory virus has been identified in over 90% of children hospitalized for an episode of wheezing. Changes in the immune response to viral infections in genetically predisposed individuals are very likely to be the main factors involved in the association between viral infection and asthma. PMID:26766408

  10. Recycling Endosomes and Viral Infection

    PubMed Central

    Vale-Costa, Sílvia; Amorim, Maria João

    2016-01-01

    Many viruses exploit specific arms of the endomembrane system. The unique composition of each arm prompts the development of remarkably specific interactions between viruses and sub-organelles. This review focuses on the viral–host interactions occurring on the endocytic recycling compartment (ERC), and mediated by its regulatory Ras-related in brain (Rab) GTPase Rab11. This protein regulates trafficking from the ERC and the trans-Golgi network to the plasma membrane. Such transport comprises intricate networks of proteins/lipids operating sequentially from the membrane of origin up to the cell surface. Rab11 is also emerging as a critical factor in an increasing number of infections by major animal viruses, including pathogens that provoke human disease. Understanding the interplay between the ERC and viruses is a milestone in human health. Rab11 has been associated with several steps of the viral lifecycles by unclear processes that use sophisticated diversified host machinery. For this reason, we first explore the state-of-the-art on processes regulating membrane composition and trafficking. Subsequently, this review outlines viral interactions with the ERC, highlighting current knowledge on viral-host binding partners. Finally, using examples from the few mechanistic studies available we emphasize how ERC functions are adjusted during infection to remodel cytoskeleton dynamics, innate immunity and membrane composition. PMID:27005655

  11. Pediatric Asthma and Viral Infection.

    PubMed

    Garcia-Garcia, M Luz; Calvo Rey, Cristina; Del Rosal Rabes, Teresa

    2016-05-01

    Respiratory viral infections, particularly respiratory syncytial virus (RSV) and rhinovirus, are the most importance risk factors for the onset of wheezing in infants and small children. Bronchiolitis is the most common acute respiratory infection in children under 1year of age, and the most common cause of hospitalization in this age group. RSV accounts for approximately 70% of all these cases, followed by rhinovirus, adenovirus, metapneumovirus and bocavirus. The association between bronchiolitis caused by RSV and the development of recurrent wheezing and/or asthma was first described more than 40years ago, but it is still unclear whether bronchiolitis causes chronic respiratory symptoms, or if it is a marker for children with a genetic predisposition for developing asthma in the medium or long term. In any case, sufficient evidence is available to corroborate the existence of this association, which is particularly strong when the causative agent of bronchiolitis is rhinovirus. The pathogenic role of respiratory viruses as triggers for exacerbations in asthmatic patients has not been fully characterized. However, it is clear that respiratory viruses, and in particular rhinovirus, are the most common causes of exacerbation in children, and some type of respiratory virus has been identified in over 90% of children hospitalized for an episode of wheezing. Changes in the immune response to viral infections in genetically predisposed individuals are very likely to be the main factors involved in the association between viral infection and asthma.

  12. Bloodborne pathogens

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000453.htm Bloodborne pathogens To use the sharing features on this page, please enable JavaScript. A pathogen is something that causes disease. Germs that can ...

  13. [Cell analogs of viral proteins].

    PubMed

    Blinov, V M; Gaĭsler, V; Krasnov, G S; Shargunov, A V; Shurdov, M A; Zverev, V V

    2014-01-01

    Horizontal transfer of genes between viruses and their hosts played an important role in the evolution of various eukaryotes including contemporary mammals as well as the pathogens themselves. Elements of viruses of various types can be found in the genome of animals. Endogenous retroviral elements composing up to 8% of human genome length not only determine its high flexibility and rapid adaptation potential. Many of virus genes such as Fv1, Lv1, Lv2 being analogues of capsid and other proteins determine effective suppression of viral replication after cell penetration by the causative agent. Introduction of these elements into genome of a wide variety of animals from fish to primates could have taken place against the background of global natural cataclysms of viral origin. Integration of retrovirus genes coding surface glycoproteins with immunosuppressing domains into genetic apparatus of animals served as an impetus to the development of viviparity and spread ofplacental mammals. Their cell analogs syncytins perform a dual function: take direct part in the formation of syncytiotrophoblast layer of placenta and ensure tolerance of immune system of mother to embryo. The acquisition of cell genes by viruses also played an important role in their evolution: various interleukins and other modulators of immune response introduced into viral genome from cell genetic apparatus became one of the most important factors of pathogenicity of a wide variety of causative agents including poxviruses, cytomegalovirus, Epstein-Barr virus and many others. Evolutionary pathways of the virus and host are thus inseparable from each other, and character of one of these directions is largely dictated by the vector of another. PMID:25051706

  14. Broad-Spectrum Drugs Against Viral Agents

    PubMed Central

    Christopher, Mary E.; Wong, Jonathan P.

    2008-01-01

    Development of antivirals has focused primarily on vaccines and on treatments for specific viral agents. Although effective, these approaches may be limited in situations where the etiologic agent is unknown or when the target virus has undergone mutation, recombination or reassortment. Augmentation of the innate immune response may be an effective alternative for disease amelioration. Nonspecific, broad-spectrum immune responses can be induced by double-stranded (ds)RNAs such as poly (ICLC), or oligonucleotides (ODNs) containing unmethylated deocycytidyl-deoxyguanosinyl (CpG) motifs. These may offer protection against various bacterial and viral pathogens regardless of their genetic makeup, zoonotic origin or drug resistance. PMID:19325820

  15. Viral immunity. Transkingdom control of viral infection and immunity in the mammalian intestine.

    PubMed

    Pfeiffer, Julie K; Virgin, Herbert W

    2016-01-15

    Viruses that infect the intestine include major human pathogens (retroviruses, noroviruses, rotaviruses, astroviruses, picornaviruses, adenoviruses, herpesviruses) that constitute a serious public health problem worldwide. These viral pathogens are members of a large, complex viral community inhabiting the intestine termed "the enteric virome." Enteric viruses have intimate functional and genetic relationships with both the host and other microbial constituents that inhabit the intestine, such as the bacterial microbiota, their associated phages, helminthes, and fungi, which together constitute the microbiome. Emerging data indicate that enteric viruses regulate, and are in turn regulated by, these other microbes through a series of processes termed "transkingdom interactions." This represents a changing paradigm in intestinal immunity to viral infection. Here we review recent advances in the field and propose new ways in which to conceptualize this important area.

  16. Immunogens of bovine viral diarrhea virus.

    PubMed

    Bolin, S R

    1993-11-01

    Bovine viral diarrhea virus (BVDV) is a ubiquitous pathogen of cattle that induces economically important diseases affecting multiple organ systems. In the United States, over 150 biological products are licensed for control of BVDV. These products contain live or killed BVDV, and many products contain other viruses or bacteria. Potency tests for these vaccines are based on animal inoculation and serology. For live virus vaccines, titration of viral infectivity in cell culture is an accepted alternative to animal inoculation. The immunogens in a killed virus vaccine may be measured by enzyme linked immunoabsorbent assay. Immunogens of BVDV that stimulate a protective immune response have not been conclusively identified. Epitopes on a putative viral envelope glycoprotein, gp53, are involved in viral neutralization. Other viral glycoproteins, gp48 and gp25, are immunogenic but epitopes on these proteins do not stimulate production of antibodies that efficiently neutralize virus. Progress in developing meaningful in vitro assays for quantitation of BVDV immunogens awaits identification of viral proteins that stimulate a protective immunity.

  17. The PA and HA gene-mediated high viral load and intense innate immune response in the brain contribute to the high pathogenicity of H5N1 avian influenza virus in mallard ducks.

    PubMed

    Hu, Jiao; Hu, Zenglei; Mo, Yiqun; Wu, Qiwen; Cui, Zhu; Duan, Zhiqiang; Huang, Junqing; Chen, Hongzhi; Chen, Yuxin; Gu, Min; Wang, Xiaoquan; Hu, Shunlin; Liu, Huimou; Liu, Wenbo; Liu, Xiaowen; Liu, Xiufan

    2013-10-01

    Most highly pathogenic avian influenza A viruses cause only mild clinical signs in ducks, serving as an important natural reservoir of influenza A viruses. However, we isolated two H5N1 viruses that are genetically similar but differ greatly in virulence in ducks. A/Chicken/Jiangsu/k0402/2010 (CK10) is highly pathogenic, whereas A/Goose/Jiangsu/k0403/2010 (GS10) is low pathogenic. To determine the genetic basis for the high virulence of CK10 in ducks, we generated a series of single-gene reassortants between CK10 and GS10 and tested their virulence in ducks. Expression of the CK10 PA or hemagglutinin (HA) gene in the GS10 context resulted in increased virulence and virus replication. Conversely, inclusion of the GS10 PA or HA gene in the CK10 background attenuated the virulence and virus replication. Moreover, the PA gene had a greater contribution. We further determined that residues 101G and 237E in the PA gene contribute to the high virulence of CK10. Mutations at these two positions produced changes in virulence, virus replication, and polymerase activity of CK10 or GS10. Position 237 plays a greater role in determining these phenotypes. Moreover, the K237E mutation in the GS10 PA gene increased PA nuclear accumulation. Mutant GS10 viruses carrying the CK10 HA gene or the PA101G or PA237E mutation induced an enhanced innate immune response. A sustained innate response was detected in the brain rather than in the lung and spleen. Our results suggest that the PA and HA gene-mediated high virus replication and the intense innate immune response in the brain contribute to the high virulence of H5N1 virus in ducks.

  18. Pathogenicity of reassortant H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks has increased over time. These changes in virulence have been reported with viruses from countries with high population of domestic ducks, including Egypt. In order to understand which viral genes are contri...

  19. A proteomics perspective on viral DNA sensors in host defense and viral immune evasion mechanisms.

    PubMed

    Crow, Marni S; Javitt, Aaron; Cristea, Ileana M

    2015-06-01

    The sensing of viral DNA is an essential step of cellular immune response to infections with DNA viruses. These human pathogens are spread worldwide, triggering a wide range of virus-induced diseases, and are associated with high levels of morbidity and mortality. Despite similarities between DNA molecules, mammalian cells have the remarkable ability to distinguish viral DNA from their own DNA. This detection is carried out by specialized antiviral proteins, called DNA sensors. These sensors bind to foreign DNA to activate downstream immune signaling pathways and alert neighboring cells by eliciting the expression of antiviral cytokines. The sensing of viral DNA was shown to occur both in the cytoplasm and in the nucleus of infected cells, disproving the notion that sensing occurred by simple spatial separation of viral and host DNA. A number of omic approaches, in particular, mass-spectrometry-based proteomic methods, have significantly contributed to the constantly evolving field of viral DNA sensing. Here, we review the impact of omic methods on the identification of viral DNA sensors, as well as on the characterization of mechanisms involved in host defense or viral immune evasion.

  20. Cytoplasmic sensing of viral nucleic acids.

    PubMed

    Habjan, Matthias; Pichlmair, Andreas

    2015-04-01

    Viruses are the most abundant pathogens on earth. A fine-tuned framework of intervening pathways is in place in mammalian cells to orchestrate the cellular defence against these pathogens. Key for this system is sensor proteins that recognise specific features associated with nucleic acids of incoming viruses. Here we review the current knowledge on cytoplasmic sensors for viral nucleic acids. These sensors induce expression of cytokines, affect cellular functions required for virus replication and directly target viral nucleic acids through degradation or sequestration. Their ability to respond to a given nucleic acid is based on both the differential specificity of the individual proteins and the downstream signalling or adaptor proteins. The cooperation of these multiple proteins and pathways plays a key role in inducing successful immunity against virus infections.

  1. Coagulation, Protease Activated Receptors and Viral Myocarditis

    PubMed Central

    Antoniak, Silvio; Mackman, Nigel

    2013-01-01

    The coagulation protease cascade plays an essential role in hemostasis. In addition, a clot contributes to host defense by limiting the spread of pathogens. Coagulation proteases induce intracellular signaling by cleavage of cell surface receptors called protease-activated receptors (PARs). These receptors allow cells to sense changes in the extracellular environment, such as infection. Viruses activate the coagulation cascade by inducing tissue factor expression and by disrupting the endothelium. Virus infection of the heart can cause myocarditis, cardiac remodeling and heart failure. Recent studies using a mouse model have shown that tissue factor, thrombin and PAR-1 signaling all positively regulate the innate immune during viral myocarditis. In contrast, PAR-2 signaling was found to inhibit interferon-β expression and the innate immune response. These observations suggest that anticoagulants may impair the innate immune response to viral infection and that inhibition of PAR-2 may be a new target to reduce viral myocarditis.. PMID:24203054

  2. Diagnosis and treatment of viral diseases in recipients of allogeneic hematopoietic stem cell transplantation

    PubMed Central

    2013-01-01

    Viral infections are important causes of morbidity and mortality after allogeneic stem cell hematopoietic transplantation (allo-HSCT). Although most viral infections present with asymptomatic or subclinical manifestations, viruses may result in fatal complications in severe immunocompromised recipients. Reactivation of latent viruses, such as herpesviruses, is frequent during the immunosuppression that occurs with allo-HSCT. Viruses acquired from community, such as the respiratory and gastrointestinal viruses, are also important pathogens of post-transplant viral diseases. Currently, molecular diagnostic methods have replaced or supplemented traditional methods, such as viral culture and antigen detection, in diagnosis of viral infections. The utilization of polymerase chain reaction facilitates the early diagnosis. In view of lacking efficacious agents for treatment of viral diseases, prevention of viral infections is extremely valuable. Application of prophylactic strategies including preemptive therapy reduces viral infections and diseases. Adoptive cellular therapy for restoring virus-specific immunity is a promising method in the treatment of viral diseases. PMID:24341630

  3. Viral Disease Networks?

    NASA Astrophysics Data System (ADS)

    Gulbahce, Natali; Yan, Han; Vidal, Marc; Barabasi, Albert-Laszlo

    2010-03-01

    Viral infections induce multiple perturbations that spread along the links of the biological networks of the host cells. Understanding the impact of these cascading perturbations requires an exhaustive knowledge of the cellular machinery as well as a systems biology approach that reveals how individual components of the cellular system function together. Here we describe an integrative method that provides a new approach to studying virus-human interactions and its correlations with diseases. Our method involves the combined utilization of protein - protein interactions, protein -- DNA interactions, metabolomics and gene - disease associations to build a ``viraldiseasome''. By solely using high-throughput data, we map well-known viral associated diseases and predict new candidate viral diseases. We use microarray data of virus-infected tissues and patient medical history data to further test the implications of the viral diseasome. We apply this method to Epstein-Barr virus and Human Papillomavirus and shed light into molecular development of viral diseases and disease pathways.

  4. Viral niche construction alters hosts and ecosystems at multiple scales.

    PubMed

    Hamblin, Steven R; White, Peter A; Tanaka, Mark M

    2014-11-01

    The classical picture of viruses focuses on pathogenic viruses damaging the host's cells and physiology and host-pathogen immune coevolution. However, a broader picture of viruses is emerging that includes weakly pathogenic, commensal, or even mutualistic viruses and includes gross behavioural manipulations and viral effects on ecosystems. In this paper, we argue for niche construction as a unifying perspective on viral evolution. As obligate intracellular parasites, viruses are always modifying their environment, and these modifications drive evolutionary feedback between the virus and its environment across multiple scales from cells to ecosystems. We argue that niche construction will provide new insights into viral evolution, and that virology is a powerful source of empirical tests for niche construction.

  5. Emerging viral diseases in kidney transplant recipients.

    PubMed

    Moal, Valérie; Zandotti, Christine; Colson, Philippe

    2013-01-01

    Viruses are the most important cause of infections and a major source of mortality in Kidney Transplant Recipients (KTRs). These patients may acquire viral infections through exogenous routes including community exposure, donor organs, and blood products or by endogenous reactivation of latent viruses. Beside major opportunistic infections due to CMV and EBV and viral hepatitis B and C, several viral diseases have recently emerged in KTRs. New medical practices or technologies, implementation of new diagnostic tools, and improved medical information have contributed to the emergence of these viral diseases in this special population. The purpose of this review is to summarize the current knowledge on emerging viral diseases and newly discovered viruses in KTRs over the last two decades. We identified viruses in the field of KT that had shown the greatest increase in numbers of citations in the NCBI PubMed database. BKV was the most cited in the literature and linked to an emerging disease that represents a great clinical concern in KTRs. HHV-8, PVB19, WNV, JCV, H1N1 influenza virus A, HEV, and GB virus were the main other emerging viruses. Excluding HHV8, newly discovered viruses have been infrequently linked to clinical diseases in KTRs. Nonetheless, pathogenicity can emerge long after the discovery of the causative agent, as has been the case for BKV. Overall, antiviral treatments are very limited, and reducing immunosuppressive therapy remains the cornerstone of management. PMID:23132728

  6. Raw Sewage Harbors Diverse Viral Populations

    PubMed Central

    Cantalupo, Paul G.; Calgua, Byron; Zhao, Guoyan; Hundesa, Ayalkibet; Wier, Adam D.; Katz, Josh P.; Grabe, Michael; Hendrix, Roger W.; Girones, Rosina; Wang, David; Pipas, James M.

    2011-01-01

    ABSTRACT At this time, about 3,000 different viruses are recognized, but metagenomic studies suggest that these viruses are a small fraction of the viruses that exist in nature. We have explored viral diversity by deep sequencing nucleic acids obtained from virion populations enriched from raw sewage. We identified 234 known viruses, including 17 that infect humans. Plant, insect, and algal viruses as well as bacteriophages were also present. These viruses represented 26 taxonomic families and included viruses with single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), positive-sense ssRNA [ssRNA(+)], and dsRNA genomes. Novel viruses that could be placed in specific taxa represented 51 different families, making untreated wastewater the most diverse viral metagenome (genetic material recovered directly from environmental samples) examined thus far. However, the vast majority of sequence reads bore little or no sequence relation to known viruses and thus could not be placed into specific taxa. These results show that the vast majority of the viruses on Earth have not yet been characterized. Untreated wastewater provides a rich matrix for identifying novel viruses and for studying virus diversity. Importance At this time, virology is focused on the study of a relatively small number of viral species. Specific viruses are studied either because they are easily propagated in the laboratory or because they are associated with disease. The lack of knowledge of the size and characteristics of the viral universe and the diversity of viral genomes is a roadblock to understanding important issues, such as the origin of emerging pathogens and the extent of gene exchange among viruses. Untreated wastewater is an ideal system for assessing viral diversity because virion populations from large numbers of individuals are deposited and because raw sewage itself provides a rich environment for the growth of diverse host species and thus their viruses. These studies suggest that

  7. Simultaneous Extraction of Viral and Bacterial Nucleic Acids for Molecular Diagnostic Applications

    PubMed Central

    Kajiura, Lauren N.; Stewart, Scott D.; Dresios, John; Uyehara, Catherine F. T.

    2015-01-01

    Molecular detection of microbial pathogens in clinical samples requires the application of efficient sample lysis protocols and subsequent extraction and isolation of their nucleic acids. Here, we describe a simple and time-efficient method for simultaneous extraction of genomic DNA from gram-positive and -negative bacteria, as well as RNA from viral agents present in a sample. This method compared well with existing bacterial- and viral-specialized extraction protocols, worked reliably on clinical samples, and was not pathogen specific. This method may be used to extract DNA and RNA concurrently from viral and bacterial pathogens present in a sample and effectively detect coinfections in routine clinical diagnostics. PMID:26543438

  8. Viral epidemiology of acute exacerbations of chronic obstructive pulmonary disease.

    PubMed

    Dimopoulos, G; Lerikou, M; Tsiodras, S; Chranioti, Aik; Perros, E; Anagnostopoulou, U; Armaganidis, A; Karakitsos, P

    2012-02-01

    The role of viruses in Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD) needs further elucidation. The aim of the present study was to evaluate the molecular epidemiology of viral pathogens in AECOPD. Patients presenting to the Emergency Room with AECOPD needing hospitalization were recruited. Oropharyngeal and sputum samples were collected in order to perform microarrays-based viral testing for the detection of respiratory viruses. A total of 200 (100%) patients were analyzed and from them in 107 (53.5%) a virus was detected. The commonest identified viruses were the human Respiratory Syncytial Virus (subtypes A and B) (40.5%), influenza virus (subtypes A, B, C) (11%), rhinovirus (8%) and human Parainfluenza Virus (subtypes A and B) (7.5%). A bacterial pathogen was isolated in 27 (14%) patients and a dual infection due to a bacterial and a viral pathogen was recognised in 14/107 patients. Patients with AECOPD and a viral infection had a lengthier hospital stay (9.2 ± 4.6 vs 7.6 ± 4.3, p < 0.01) while the severity of the disease was no related with significant differences among the groups of the study population. In conclusion, the isolation of a virus was strongly associated with AECOPD in the examined population. The stage of COPD appeared to have no relation with the frequency of the isolated viruses while dual infection with a viral and a bacterial pathogen was not rare.

  9. Control Measures for Human Respiratory Viral Infection.

    PubMed

    Bennett, Lesley; Waterer, Grant

    2016-08-01

    New viral respiratory pathogens are emerging with increasing frequency and have potentially devastating impacts on the population worldwide. Recent examples of newly emerged threats include severe acute respiratory syndrome coronavirus, the 2009 H1N1 influenza pandemic, and Middle East respiratory syndrome coronavirus. Experiences with these pathogens have shown up major deficiencies in how we deal globally with emerging pathogens and taught us salient lessons in what needs to be addressed for future pandemics. This article reviews the lessons learnt from past experience and current knowledge on the range of measures required to limit the impact of emerging respiratory infections from public health responses down to individual patient management. Key areas of interest are surveillance programs, political limitations on our ability to respond quickly enough to emerging threats, media management, public information dissemination, infection control, prophylaxis, and individual patient management. Respiratory physicians have a crucial role to play in many of these areas and need to be aware of how to respond as new viral pathogens emerge. PMID:27486741

  10. Genomic Basis of Plant Pathogen Suppression by Biocontrol Pseudomonas Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various plant commensal bacterial species, which naturally colonize the plant rhizosphere, are able to suppress fungal, bacterial, viral and even insect plant pathogens. These biocontrol activities are elicited primarily through the production of secreted exoenzymes and secondary metabolites that ma...

  11. Antivirals for Respiratory Viral Infections: Problems and Prospects.

    PubMed

    Liu, Qiang; Zhou, Yuan-Hong; Ye, Feng; Yang, Zhan-Qiu

    2016-08-01

    In the past two decades, several newly emerging and reemerging viral respiratory pathogens including several influenza viruses (avian influenza and pandemic influenza), severe acute respiratory syndrome coronavirus (SARS-CoV), and Middle East respiratory syndrome coronavirus (MERS-CoV), have continued to challenge medical and public health systems. Thereafter, the development of cost-effective, broad-spectrum antiviral agents is the urgent mission of both virologists and pharmacologists. Current antiviral developments have focused targets on viral entry, replication, release, and intercellular pathways essential for viral life cycle. Here, we review the current literature on challenges and prospects in the development of these antivirals. PMID:27486742

  12. Countermeasures against viral diseases of farmed fish.

    PubMed

    Kibenge, Frederick S B; Godoy, Marcos G; Fast, Mark; Workenhe, Samuel; Kibenge, Molly J T

    2012-09-01

    Farmed fish provide an increasing fraction of the human food supply, and are of major economic importance in many countries. As in the case of terrestrial agriculture, bringing together large numbers of animals of a single species (i.e., monoculture) increases the risk of infectious disease outbreaks, including viral infections. Aquaculture, in which farmed fish are kept at high population densities in close proximity with wild fish reservoirs, is ideal for the emergence of wild-type pathogens that exist benignly in local wild fish and/or the spreading of aquatic pathogens to wild fish that enter into or come into close proximity with net cages and with fish escaping from them. This paper provides a general review for the nonspecialist of viral diseases of farmed fish and how they could be prevented or treated. It has five principal objectives: (1) to provide an update on the most important and emerging viral diseases of salmonid aquaculture; (2) to review general aspects of innate antiviral defense against virus infections in fish, including recent advances in antiviral signaling; (3) to discuss current principles and practices of vaccinating fish; (4) to review antiviral drugs that have activity against viruses of farmed fish, and current barriers to employing them in aquaculture; and (5) to discuss the growing use of "functional feeds" in salmonid aquaculture to mitigate viral diseases. In conclusion, despite the challenging aquatic environment, it is expected that well thought-out combinations of vaccination and immunostimulants and/or antiviral drugs could provide solid protection against viral diseases of farmed fish.

  13. Identification of a Natural Viral RNA Motif That Optimizes Sensing of Viral RNA by RIG-I

    PubMed Central

    Xu, Jie; Mercado-López, Xiomara; Grier, Jennifer T.; Kim, Won-keun; Chun, Lauren F.; Irvine, Edward B.; Del Toro Duany, Yoandris; Kell, Alison; Hur, Sun; Gale, Michael; Raj, Arjun

    2015-01-01

    ABSTRACT Stimulation of the antiviral response depends on the sensing of viral pathogen-associated molecular patterns (PAMPs) by specialized cellular proteins. During infection with RNA viruses, 5′-di- or -triphosphates accompanying specific single or double-stranded RNA motifs trigger signaling of intracellular RIG-I-like receptors (RLRs) and initiate the antiviral response. Although these molecular signatures are present during the replication of many viruses, it is unknown whether they are sufficient for strong activation of RLRs during infection. Immunostimulatory defective viral genomes (iDVGs) from Sendai virus (SeV) are among the most potent natural viral triggers of antiviral immunity. Here we describe an RNA motif (DVG70-114) that is essential for the potent immunostimulatory activity of 5′-triphosphate-containing SeV iDVGs. DVG70-114 enhances viral sensing by the host cell independently of the long stretches of complementary RNA flanking the iDVGs, and it retains its stimulatory potential when transferred to otherwise inert viral RNA. In vitro analysis showed that DVG70-114 augments the binding of RIG-I to viral RNA and promotes enhanced RIG-I polymerization, thereby facilitating the onset of the antiviral response. Together, our results define a new natural viral PAMP enhancer motif that promotes viral recognition by RLRs and confers potent immunostimulatory activity to viral RNA. PMID:26443454

  14. Viral metagenomics: a tool for virus discovery and diversity in aquaculture.

    PubMed

    Alavandi, S V; Poornima, M

    2012-09-01

    Viruses are abundant biological entities on earth and the emergence of viral pathogens has become a serious threat to aquaculture and fisheries worldwide. However, our response to viral pathogens has been largely reactive, in the sense that a new pathogen is usually not discovered until it has already reached epidemic proportions. Current diagnostic methods such as PCR, immunological assays and pan-viral microarrays are limited in their ability to identify novel viruses. In this context, the knowledge on the diversity of viruses in healthy and disease situations becomes important for understanding their role on the health of animals in aquaculture species. Viral metagenomics, which involves viral purification and shotgun sequencing, has proven to be useful for understanding viral diversity and describing novel viruses in new diseases and has been recognized as an important tool for discovering novel viruses in human and veterinary medicine. With the advancements in sequencing technology and development of bioinformatics tools for nucleic acid sequence assembly and annotation, information on novel viruses and diversity of viruses in marine ecosystems has been rapidly expanding through viral metagenomics. Novel circoviruses and RNA viruses in Tampa bay pink shrimp, annelovirus in sea lion, picornavirus in ringed seals and several new viruses of marine animals have been recently described using viral metagenomics and this tool has been also recently used in describing viral diversity in aquaculture ponds. Further, a large amount of information has been generated on the diversity of viruses in the marine environment using viral metagenomics during the last decade. There exists a great potential with viral metagenomics for discovering novel viruses in asymptomatic marine candidate animals of aquaculture/mariculture, some of which may assume pathogenic status under high density culture and stress. Additionally, viral metagenomics can help our understanding of viruses

  15. Viral infections during pregnancy.

    PubMed

    Silasi, Michelle; Cardenas, Ingrid; Kwon, Ja-Young; Racicot, Karen; Aldo, Paula; Mor, Gil

    2015-03-01

    Viral infections during pregnancy have long been considered benign conditions with a few notable exceptions, such as herpes virus. The recent Ebola outbreak and other viral epidemics and pandemics show how pregnant women suffer worse outcomes (such as preterm labor and adverse fetal outcomes) than the general population and non-pregnant women. New knowledge about the ways the maternal-fetal interface and placenta interact with the maternal immune system may explain these findings. Once thought to be 'immunosuppressed', the pregnant woman actually undergoes an immunological transformation, where the immune system is necessary to promote and support the pregnancy and growing fetus. When this protection is breached, as in a viral infection, this security is weakened and infection with other microorganisms can then propagate and lead to outcomes, such as preterm labor. In this manuscript, we review the major viral infections relevant to pregnancy and offer potential mechanisms for the associated adverse pregnancy outcomes. PMID:25582523

  16. VIRAL INFECTIONS DURING PREGNANCY

    PubMed Central

    Silasi, Michelle; Cardenas, Ingrid; Racicot, Karen; Kwon, Ja-Young; Aldo, Paula; Mor, Gil

    2015-01-01

    Viral infections during pregnancy have long been considered benign conditions with a few notable exceptions, such as herpes virus. The recent Ebola outbreak and other viral epidemics and pandemics show how pregnant women suffer worse outcomes (such as preterm labor and adverse fetal outcomes) than the general population and non-pregnant women. New knowledge about the ways the maternal-fetal interface and placenta interact with the maternal immune system may explain these findings. Once thought to be “immunosuppressed”, the pregnant woman actually undergoes an immunological transformation, where the immune system is necessary to promote and support the pregnancy and growing fetus. When this protection is breached, as in a viral infection, this security is weakened and infection with other microorganisms can then propagate and lead to outcomes, such as preterm labor. In this manuscript, we review the major viral infections relevant to pregnancy, and offer potential mechanisms for the associated adverse pregnancy outcomes. PMID:25582523

  17. HIV and Viral Hepatitis

    MedlinePlus

    ... prevalent among blacks as among whites. Viral Hepatitis Transmission People can be infected with the three most ... risk for HAV. • • New data suggest that sexual transmission of HCV among MSM with HIV occurs more ...

  18. Viral miRNAs.

    PubMed

    Plaisance-Bonstaff, Karlie; Renne, Rolf

    2011-01-01

    Since 2004, more than 200 microRNAs (miRNAs) have been discovered in double-stranded DNA viruses, mainly herpesviruses and polyomaviruses (Nucleic Acids Res 32:D109-D111, 2004). miRNAs are short 22  ±  3 nt RNA molecules that posttranscriptionally regulate gene expression by binding to 3'-untranslated regions (3'UTR) of target mRNAs, thereby inducing translational silencing and/or transcript degradation (Nature 431:350-355, 2004; Cell 116:281-297, 2004). Since miRNAs require only limited complementarity for binding, miRNA targets are difficult to determine (Mol Cell 27:91-105, 2007). To date, targets have only been experimentally verified for relatively few viral miRNAs, which either target viral or host cellular gene expression: For example, SV40 and related polyomaviruses encode miRNAs which target viral large T antigen expression (Nature 435:682-686, 2005; J Virol 79:13094-13104, 2005; Virology 383:183-187, 2009; J Virol 82:9823-9828, 2008) and miRNAs of α-, β-, and γ-herpesviruses have been implicated in regulating the transition from latent to lytic gene expression, a key step in the herpesvirus life cycle. Viral miRNAs have also been shown to target various host cellular genes. Although this field is just beginning to unravel the multiple roles of viral miRNA in biology and pathogenesis, the current data strongly suggest that virally encoded miRNAs are able to regulate fundamental biological processes such as immune recognition, promotion of cell survival, angiogenesis, proliferation, and cell differentiation. This chapter aims to summarize our current knowledge of viral miRNAs, their targets and function, and the challenges lying ahead to decipher their role in viral biology, pathogenesis, and for γ-herepsvirus-encoded miRNAs, potentially tumorigenesis. PMID:21431678

  19. NCBI viral genomes resource.

    PubMed

    Brister, J Rodney; Ako-Adjei, Danso; Bao, Yiming; Blinkova, Olga

    2015-01-01

    Recent technological innovations have ignited an explosion in virus genome sequencing that promises to fundamentally alter our understanding of viral biology and profoundly impact public health policy. Yet, any potential benefits from the billowing cloud of next generation sequence data hinge upon well implemented reference resources that facilitate the identification of sequences, aid in the assembly of sequence reads and provide reference annotation sources. The NCBI Viral Genomes Resource is a reference resource designed to bring order to this sequence shockwave and improve usability of viral sequence data. The resource can be accessed at http://www.ncbi.nlm.nih.gov/genome/viruses/ and catalogs all publicly available virus genome sequences and curates reference genome sequences. As the number of genome sequences has grown, so too have the difficulties in annotating and maintaining reference sequences. The rapid expansion of the viral sequence universe has forced a recalibration of the data model to better provide extant sequence representation and enhanced reference sequence products to serve the needs of the various viral communities. This, in turn, has placed increased emphasis on leveraging the knowledge of individual scientific communities to identify important viral sequences and develop well annotated reference virus genome sets.

  20. Immigration and viral hepatitis.

    PubMed

    Sharma, Suraj; Carballo, Manuel; Feld, Jordan J; Janssen, Harry L A

    2015-08-01

    WHO estimates reveal that the global prevalence of viral hepatitis may be as high as 500 million, with an annual mortality rate of up to 1.3 million individuals. The majority of this global burden of disease is borne by nations of the developing world with high rates of vertical and iatrogenic transmission of HBV and HCV, as well as poor access to healthcare. In 2013, 3.2% of the global population (231 million individuals) migrated into a new host nation. Migrants predominantly originate from the developing countries of the south, into the developed economies of North America and Western Europe. This mass migration of individuals from areas of high-prevalence of viral hepatitis poses a unique challenge to the healthcare systems of the host nations. Due to a lack of universal standards for screening, vaccination and treatment of viral hepatitis, the burden of chronic liver disease and hepatocellular carcinoma continues to increase among migrant populations globally. Efforts to increase case identification and treatment among migrants have largely been limited to small outreach programs in urban centers, such that the majority of migrants with viral hepatitis continue to remain unaware of their infection. This review summarizes the data on prevalence of viral hepatitis and burden of chronic liver disease among migrants, current standards for screening and treatment of immigrants and refugees, and efforts to improve the identification and treatment of viral hepatitis among migrants. PMID:25962882

  1. Immigration and viral hepatitis.

    PubMed

    Sharma, Suraj; Carballo, Manuel; Feld, Jordan J; Janssen, Harry L A

    2015-08-01

    WHO estimates reveal that the global prevalence of viral hepatitis may be as high as 500 million, with an annual mortality rate of up to 1.3 million individuals. The majority of this global burden of disease is borne by nations of the developing world with high rates of vertical and iatrogenic transmission of HBV and HCV, as well as poor access to healthcare. In 2013, 3.2% of the global population (231 million individuals) migrated into a new host nation. Migrants predominantly originate from the developing countries of the south, into the developed economies of North America and Western Europe. This mass migration of individuals from areas of high-prevalence of viral hepatitis poses a unique challenge to the healthcare systems of the host nations. Due to a lack of universal standards for screening, vaccination and treatment of viral hepatitis, the burden of chronic liver disease and hepatocellular carcinoma continues to increase among migrant populations globally. Efforts to increase case identification and treatment among migrants have largely been limited to small outreach programs in urban centers, such that the majority of migrants with viral hepatitis continue to remain unaware of their infection. This review summarizes the data on prevalence of viral hepatitis and burden of chronic liver disease among migrants, current standards for screening and treatment of immigrants and refugees, and efforts to improve the identification and treatment of viral hepatitis among migrants.

  2. The Fecal Viral Flora of Wild Rodents

    PubMed Central

    Phan, Tung G.; Kapusinszky, Beatrix; Wang, Chunlin; Rose, Robert K.; Lipton, Howard L.; Delwart, Eric L.

    2011-01-01

    The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae, Iridoviridae, Polydnaviridae, Dicistroviriade, Bromoviridae, and Virgaviridae families followed by plant virus-related sequences in the Nanoviridae, Geminiviridae, Phycodnaviridae, Secoviridae, Partitiviridae, Tymoviridae, Alphaflexiviridae, and Tombusviridae families reflecting the largely insect and plant rodent diet. Phylogenetic analyses of full and partial viral genomes therefore revealed many previously unreported viral species, genera, and families. The close genetic similarities noted between some rodent and human viruses might reflect past zoonoses. This study increases our understanding of the viral diversity in wild rodents and highlights the large number of still uncharacterized viruses in mammals. PMID:21909269

  3. Correlates of viral richness in bats (order Chiroptera).

    PubMed

    Turmelle, Amy S; Olival, Kevin J

    2009-12-01

    Historic and contemporary host ecology and evolutionary dynamics have profound impacts on viral diversity, virulence, and associated disease emergence. Bats have been recognized as reservoirs for several emerging viral pathogens, and are unique among mammals in their vagility, potential for long-distance dispersal, and often very large, colonial populations. We investigate the relative influences of host ecology and population genetic structure for predictions of viral richness in relevant reservoir species. We test the hypothesis that host geographic range area, distribution, population genetic structure, migratory behavior, International Union for Conservation of Nature and Natural Resources (IUCN) threat status, body mass, and colony size, are associated with known viral richness in bats. We analyze host traits and viral richness in a generalized linear regression model framework, and include a correction for sampling effort and phylogeny. We find evidence that sampling effort, IUCN status, and population genetic structure correlate with observed viral species richness in bats, and that these associations are independent of phylogeny. This study is an important first step in understanding the mechanisms that promote viral richness in reservoir species, and may aid in predicting the emergence of viral zoonoses from bats.

  4. Pathogen intelligence.

    PubMed

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  5. Pathogen intelligence

    PubMed Central

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  6. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG).

    PubMed

    Chen, Robert T; Carbery, Baevin; Mac, Lisa; Berns, Kenneth I; Chapman, Louisa; Condit, Richard C; Excler, Jean-Louis; Gurwith, Marc; Hendry, Michael; Khan, Arifa S; Khuri-Bulos, Najwa; Klug, Bettina; Robertson, James S; Seligman, Stephen J; Sheets, Rebecca; Williamson, Anna-Lise

    2015-01-01

    Recombinant viral vectors provide an effective means for heterologous antigen expression in vivo and thus represent promising platforms for developing novel vaccines against human pathogens from Ebola to tuberculosis. An increasing number of candidate viral vector vaccines are entering human clinical trials. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to improve our ability to anticipate potential safety issues and meaningfully assess or interpret safety data, thereby facilitating greater public acceptance when licensed.

  7. Broad-spectrum antivirals against viral fusion

    PubMed Central

    Vigant, Frederic; Santos, Nuno C.; Lee, Benhur

    2015-01-01

    Effective antivirals have been developed against specific viruses, such as HIV, Hepatitis C virus and influenza virus. This ‘one bug–one drug’ approach to antiviral drug development can be successful, but it may be inadequate for responding to an increasing diversity of viruses that cause significant diseases in humans. The majority of viral pathogens that cause emerging and re-emerging infectious diseases are membrane-enveloped viruses, which require the fusion of viral and cell membranes for virus entry. Therefore, antivirals that target the membrane fusion process represent new paradigms for broad-spectrum antiviral discovery. In this Review, we discuss the mechanisms responsible for the fusion between virus and cell membranes and explore how broad-spectrum antivirals target this process to prevent virus entry. PMID:26075364

  8. Statistical Mechanics and Thermodynamics of Viral Evolution

    NASA Astrophysics Data System (ADS)

    Jones, Barbara; Kaufman, James

    Using methods drawn from physics we study the life cycle of viruses. We analyze a model of viral infection and evolution using the ``grand canonical ensemble'' and formalisms from statistical mechanics and thermodynamics. Using this approach we determine possible genetic states of a model virus and host as a function of two independent pressures-immune response and system temperature. We show the system has a real thermodynamic temperature, and discover a new phase transition between a positive temperature regime of normal replication and a negative temperature ``disordered'' phase of the virus. We distinguish this from previous observations of a phase transition that arises as a function of mutation rate. From an evolutionary biology point of view, at steady state the viruses naturally evolve to distinct quasispecies. The approach used here could be refined to apply to real biological systems, perhaps providing insight into immune escape, the emergence of novel pathogens and other results of viral evolution.

  9. Viral evasion of intracellular DNA and RNA sensing.

    PubMed

    Chan, Ying Kai; Gack, Michaela U

    2016-06-01

    The co-evolution of viruses with their hosts has led to the emergence of viral pathogens that are adept at evading or actively suppressing host immunity. Pattern recognition receptors (PRRs) are key components of antiviral immunity that detect conserved molecular features of viral pathogens and initiate signalling that results in the expression of antiviral genes. In this Review, we discuss the strategies that viruses use to escape immune surveillance by key intracellular sensors of viral RNA or DNA, with a focus on RIG-I-like receptors (RLRs), cyclic GMP-AMP synthase (cGAS) and interferon-γ (IFNγ)-inducible protein 16 (IFI16). Such viral strategies include the sequestration or modification of viral nucleic acids, interference with specific post-translational modifications of PRRs or their adaptor proteins, the degradation or cleavage of PRRs or their adaptors, and the sequestration or relocalization of PRRs. An understanding of viral immune-evasion mechanisms at the molecular level may guide the development of vaccines and antivirals. PMID:27174148

  10. Viral evasion of intracellular DNA and RNA sensing.

    PubMed

    Chan, Ying Kai; Gack, Michaela U

    2016-06-01

    The co-evolution of viruses with their hosts has led to the emergence of viral pathogens that are adept at evading or actively suppressing host immunity. Pattern recognition receptors (PRRs) are key components of antiviral immunity that detect conserved molecular features of viral pathogens and initiate signalling that results in the expression of antiviral genes. In this Review, we discuss the strategies that viruses use to escape immune surveillance by key intracellular sensors of viral RNA or DNA, with a focus on RIG-I-like receptors (RLRs), cyclic GMP-AMP synthase (cGAS) and interferon-γ (IFNγ)-inducible protein 16 (IFI16). Such viral strategies include the sequestration or modification of viral nucleic acids, interference with specific post-translational modifications of PRRs or their adaptor proteins, the degradation or cleavage of PRRs or their adaptors, and the sequestration or relocalization of PRRs. An understanding of viral immune-evasion mechanisms at the molecular level may guide the development of vaccines and antivirals.

  11. Nosocomial viral respiratory infections.

    PubMed

    Graman, P S; Hall, C B

    1989-12-01

    Nosocomial infections with respiratory tract viruses, particularly influenza and respiratory syncytial viruses, account for the majority of serious nosocomial viral disease. Chronically ill, immunocompromised, elderly, and very young hosts are especially vulnerable to potentially life-threatening involvement of the lower respiratory tract. Effective preventive strategies are based upon early accurate viral diagnosis and an appreciation of the epidemiology and mechanisms of transmission for each viral agent. Influenza viruses spread via airborne dispersion of small particle aerosols, resulting in explosive outbreaks; control measures emphasize immunization and chemoprophylaxis of susceptible patients and personnel, and isolation of those already infected. Transmission of respiratory syncytial virus, in contrast, seems to require closer contact, with virus passed on hands, fomites, or in large droplets inoculated into the eyes and nose at close range. Strategies for control of nosocomial respiratory syncytial virus are designed to interrupt hand carriage and inoculation of virus onto mucous membranes.

  12. Modeling Viral Capsid Assembly

    PubMed Central

    2014-01-01

    I present a review of the theoretical and computational methodologies that have been used to model the assembly of viral capsids. I discuss the capabilities and limitations of approaches ranging from equilibrium continuum theories to molecular dynamics simulations, and I give an overview of some of the important conclusions about virus assembly that have resulted from these modeling efforts. Topics include the assembly of empty viral shells, assembly around single-stranded nucleic acids to form viral particles, and assembly around synthetic polymers or charged nanoparticles for nanotechnology or biomedical applications. I present some examples in which modeling efforts have promoted experimental breakthroughs, as well as directions in which the connection between modeling and experiment can be strengthened. PMID:25663722

  13. Analysis of host genetic diversity and viral entry as sources of between-host variation in viral load

    USGS Publications Warehouse

    Wargo, Andrew R.; Kell, Alison M.; Scott, Robert J.; Thorgaard, Gary H.; Kurath, Gael

    2012-01-01

    Little is known about the factors that drive the high levels of between-host variation in pathogen burden that are frequently observed in viral infections. Here, two factors thought to impact viral load variability, host genetic diversity and stochastic processes linked with viral entry into the host, were examined. This work was conducted with the aquatic vertebrate virus, Infectious hematopoietic necrosis virus (IHNV), in its natural host, rainbow trout. It was found that in controlled in vivo infections of IHNV, a suggestive trend of reduced between-fish viral load variation was observed in a clonal population of isogenic trout compared to a genetically diverse population of out-bred trout. However, this trend was not statistically significant for any of the four viral genotypes examined, and high levels of fish-to-fish variation persisted even in the isogenic trout population. A decrease in fish-to-fish viral load variation was also observed in virus injection challenges that bypassed the host entry step, compared to fish exposed to the virus through the natural water-borne immersion route of infection. This trend was significant for three of the four virus genotypes examined and suggests host entry may play a role in viral load variability. However, high levels of viral load variation also remained in the injection challenges. Together, these results indicate that although host genetic diversity and viral entry may play some role in between-fish viral load variation, they are not major factors. Other biological and non-biological parameters that may influence viral load variation are discussed.

  14. Viral vaccines: selected topics.

    PubMed

    Kańtoch, M

    1996-01-01

    Significant role of viruses in pathology, their dominating position in etiology of infectious diseases point at the special position of active prophylactic procedures based on vaccination. The real role and value of viral vaccines of classic and modern generations, the limitation of immune potency in suppression of defence mechanisms, some problems of immunization against virus vertical transmission are presented in the paper. The reader may find tables which cumulate selected but significant patterns of viral vaccines and vaccinations, and selected papers devoted to topics discussed. PMID:9017153

  15. Viral meningitis and encephalitis.

    PubMed

    Tuppeny, Misti

    2013-09-01

    Meningitis is an inflammation of the meninges, whereas encephalitis is inflammation of the parenchymal brain tissue. The single distinguishing element between the 2 diagnoses is the altered state of consciousness, focal deficits, and seizures found in encephalitis. Consequently meningoencephalitis is a term used when both findings are present in the patient. Viral meningitis is not necessarily reported as it is often underdiagnosed, whereas encephalitis cases are on the increase in various areas of North America. Improved imaging and viral diagnostics, as well as enhanced neurocritical care management, have improved patient outcomes to date.

  16. Viral infections in pigeons.

    PubMed

    Marlier, D; Vindevogel, H

    2006-07-01

    This review provides a current update on the major viral diseases of the domestic pigeon (Columba livia domestica), based on scientific reports and clinical experience. Paramyxovirus 1, adenovirus, rotavirus, herpesvirus 1, poxvirus and circovirus infections are described according to common clinical signs and target tissues. Since pigeons are sometimes treated as if they were poultry, the review also summarises the common viral infections of poultry for which pigeons are considered resistant. It is hoped that the review will provide a useful reference for veterinarians and others and offer advice on the diagnosis, treatment and prevention of the major infectious diseases of pigeons.

  17. Failure of Viral Shells

    NASA Astrophysics Data System (ADS)

    Klug, William S.; Bruinsma, Robijn F.; Michel, Jean-Philippe; Knobler, Charles M.; Ivanovska, Irena L.; Schmidt, Christoph F.; Wuite, Gijs J. L.

    2006-12-01

    We report a combined theoretical and experimental study of the structural failure of viral shells under mechanical stress. We find that discontinuities in the force-indentation curve associated with failure should appear when the so-called Föppl von Kármán (FvK) number exceeds a critical value. A nanoindentation study of a viral shell subject to a soft-mode instability, where the stiffness of the shell decreases with increasing pH, confirms the predicted onset of failure as a function of the FvK number.

  18. Dengue viral infection.

    PubMed

    Sarin, Y K; Singh, S; Singh, T

    1998-02-01

    Dengue viral infection produces a spectrum of disease. For example, mild dengue disease is characterized by biphasic fever, myalgia, arthralgia, leukopenia, and lymphadenopathy, while dengue hemorrhagic fever is an often fatal disease characterized by hemorrhages and shock syndrome. The disease, especially in its severe form, is seen more often among children than among adults. With focus upon India, dengue's etiology, epidemiology, pathology, pathogenesis of dengue hemorrhagic fever, clinical manifestations of both the mild and severe forms of dengue viral infection, diagnosis, differential diagnosis, treatment, prevention, and prognosis are discussed.

  19. Emerging viral infections.

    PubMed

    Bale, James F

    2012-09-01

    Unique disorders appear episodically in human populations and cause life-threatening systemic or neurological disease. Historical examples of such disorders include von Economo encephalitis, a disorder of presumed viral etiology; acquired immune deficiency syndrome, caused by the human immunodeficiency virus; and severe acute respiratory syndrome, caused by a member of the coronavirus family. This article describes the factors that contribute to the emergence of infectious diseases and focuses on selected recent examples of emerging viral infections that can affect the nervous system of infants, children, and adolescents.

  20. Global trends in emerging viral diseases of wildlife origin

    USGS Publications Warehouse

    Sleeman, Jonathan M.; Ip, Hon S.

    2015-01-01

    The following article provides examples of recently emerged viral diseases of wildlife origin. The examples have been selected to illustrate the drivers of emerging viral diseases, both novel pathogens and previously known diseases, the impacts of these diseases, as well as the role of wildlife both as “villains” or reservoirs as well as “victims” of these viral diseases. The article also discusses potential management strategies for emerging viral diseases in wildlife populations and future science directions in wildlife health to prevent, prepare, respond to, and recover from these disease events. Finally, the concept of One Health and its potential role in developing solutions to these issues of mutual concern is discussed.

  1. Viral Space Situational Awareness

    NASA Astrophysics Data System (ADS)

    Gleckler, A.; Butterfield, M. C.

    2012-09-01

    Viral SSA takes advantage of the amateur astronomy community to provide an extremely low-cost and geographically-diverse network of optical SSA sites. In the spirit of programs such as DARPA's Grand Challenge and the National Weather Service's program of providing amateur meteorologists with weather stations linked to a central professional meteorological facility, we form a cooperative bond with a willing community of technically-minded individuals. We term this program "viral" because we will qualify an initial set of astronomers for SSA operation and then use word of mouth in the astronomy community, as well as an outreach program, to pull in new observers. The use of modern remote controlled telescopes allows the incorporation of certified amateur, university, and commercial telescope systems. The availability of the local Viral SSA member for troubleshooting eliminates most significant costs of operating a large network. In this talk, we discuss the key concepts of Viral SSA and the route to a network of 100+ sites in a three year or less timeframe.

  2. Computational tools for viral metagenomics and their application in clinical research.

    PubMed

    Fancello, L; Raoult, D; Desnues, C

    2012-12-20

    There are 100 times more virions than eukaryotic cells in a healthy human body. The characterization of human-associated viral communities in a non-pathological state and the detection of viral pathogens in cases of infection are essential for medical care and epidemic surveillance. Viral metagenomics, the sequenced-based analysis of the complete collection of viral genomes directly isolated from an organism or an ecosystem, bypasses the "single-organism-level" point of view of clinical diagnostics and thus the need to isolate and culture the targeted organism. The first part of this review is dedicated to a presentation of past research in viral metagenomics with an emphasis on human-associated viral communities (eukaryotic viruses and bacteriophages). In the second part, we review more precisely the computational challenges posed by the analysis of viral metagenomes, and we illustrate the problem of sequences that do not have homologs in public databases and the possible approaches to characterize them.

  3. KSHV Rta Promoter Specification and Viral Reactivation.

    PubMed

    Guito, Jonathan; Lukac, David M

    2012-01-01

    Viruses are obligate intracellular pathogens whose biological success depends upon replication and packaging of viral genomes, and transmission of progeny viruses to new hosts. The biological success of herpesviruses is enhanced by their ability to reproduce their genomes without producing progeny viruses or killing the host cells, a process called latency. Latency permits a herpesvirus to remain undetected in its animal host for decades while maintaining the potential to reactivate, or switch, to a productive life cycle when host conditions are conducive to generating viral progeny. Direct interactions between many host and viral molecules are implicated in controlling herpesviral reactivation, suggesting complex biological networks that control the decision. One viral protein that is necessary and sufficient to switch latent Kaposi's sarcoma-associated herpesvirus (KSHV) into the lytic infection cycle is called K-Rta. K-Rta is a transcriptional activator that specifies promoters by binding DNA directly and interacting with cellular proteins. Among these cellular proteins, binding of K-Rta to RBP-Jk is essential for viral reactivation. In contrast to the canonical model for Notch signaling, RBP-Jk is not uniformly and constitutively bound to the latent KSHV genome, but rather is recruited to DNA by interactions with K-Rta. Stimulation of RBP-Jk DNA binding requires high affinity binding of Rta to repetitive and palindromic "CANT DNA repeats" in promoters, and formation of ternary complexes with RBP-Jk. However, while K-Rta expression is necessary for initiating KSHV reactivation, K-Rta's role as the switch is inefficient. Many factors modulate K-Rta's function, suggesting that KSHV reactivation can be significantly regulated post-Rta expression and challenging the notion that herpesviral reactivation is bistable. This review analyzes rapidly evolving research on KSHV K-Rta to consider the role of K-Rta promoter specification in regulating the progression of KSHV

  4. Irradiation as a means to minimize public health risks from sludge-borne pathogens

    SciTech Connect

    Yeager, J.G.; O'Brien, R.T.

    1983-01-01

    Bacterial, parasitic and fungal pathogens should be eliminated from sludge by the 1-Mrad PFRP (Processes to Further Reduce Pathogens) dose required by EPA regulations. While viruses are much more radiation resistant than the other pathogen types, the 1-Mrad PFRP dose of gamma radiation given in conjunction with a required PSRP (Processes to Significantly Reduce Pathogens) should effectively eliminate the health hazard posed by viral pathogens in sludge. 2 figures, 9 tables.

  5. Avian Diagnostic and Therapeutic Antibodies to Viral Emerging Pathogens

    SciTech Connect

    David Bradley

    2011-03-31

    During the current period the following key objectives were achieved: demonstration of high titer antibody production by geese following immunization with inactived H1N1 virus; completion of the epitope mapping of West Nile Virus-specific goose antibodies and initiation of epitope mapping of H1N1 flu-specific goose antibodies; advancement in scalable purification of goose antibodies.

  6. Controls on pathogen species richness in plants introduced and native ranges: roles of residence time, range size and host traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction of hosts to new geographic regions allows them to escape many pathogens, raising two questions. How quickly do introduced hosts accumulate pathogens? Do the same factors control pathogen accumulation as in the native range? We analyzed fungal and viral pathogen species richness on 124 p...

  7. Inducible viral receptor, A possible concept to induce viral protection in primitive immune animals.

    PubMed

    Pasharawipas, Tirasak

    2011-01-01

    A pseudolysogen (PL) is derived from the lysogenic Vibrio harveyi (VH) which is infected with the VHS1 (Vibrio harveyi Siphoviridae-like 1) bacteriophage. The lysogenic Vibrio harveyi undergoes an unequivalent division of the extra-chromosomal VHS1 phage genome and its VH host chromosome and produces a true lysogen (TL) and pseudolysogen (PL). The PL is tolerant to super-infection of VHS1, as is of the true lysogen (TL), but the PL does not contain the VHS1 phage genome while the TL does. However, the PL can become susceptible to VHS1 phage infection if the physiological state of the PL is changed. It is postulated that this is due to a phage receptor molecule which can be inducible to an on-and-off regulation influence by an alternating condition of the bacterial host cell. This characteristic of the PL leads to speculate that this phenomenon can also occur in high organisms with low immunity such as shrimp. This article proposes a hypothesis that the viral receptor molecule on the target cell can play a crucial role in which the invertebrate aquaculture animals can become tolerant to viral infection. A possible mechanism may be that the target cell disrupts the viral receptor molecule to prevent super infection. This concept can explain a mechanism for the prevention of viral infection in invertebrate animals which do not have acquired immunity in response to pathogens. It can guide us to develop a mechanism of immunity to viral infection in low-evolved-immune animals. Also, it can be an additional mechanism that exists in high immune organism, as in human for the prevention of viral infection. PMID:21711515

  8. Viral Membrane Scission

    PubMed Central

    Rossman, Jeremy S.; Lamb, Robert A.

    2014-01-01

    Virus budding is a complex, multistep process in which viral proteins make specific alterations in membrane curvature. Many different viral proteins can deform the membrane and form a budding virion, but very few can mediate membrane scission to complete the budding process. As a result, enveloped viruses have developed numerous ways of facilitating membrane scission, including hijacking host cellular scission machinery and expressing their own scission proteins. These proteins mediate scission in very different ways, though the biophysical mechanics underlying their actions may be similar. In this review, we explore the mechanisms of membrane scission and the ways in which enveloped viruses use these systems to mediate the release of budding virions. PMID:24099087

  9. Viral membrane fusion.

    PubMed

    Harrison, Stephen C

    2015-05-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.

  10. Anti-Viral Antibody Profiling by High Density Protein Arrays

    PubMed Central

    Bian, Xiaofang; Wiktor, Peter; Kahn, Peter; Brunner, Al; Khela, Amritpal; Karthikeyan, Kailash; Barker, Kristi; Yu, Xiaobo; Magee, Mitch; Wasserfall, Clive H.; Gibson, David; Rooney, Madeleine E; Qiu, Ji; LaBaer, Joshua

    2015-01-01

    Viral infections elicit anti-viral antibodies and have been associated with various chronic diseases. Detection of these antibodies can facilitate diagnosis, treatment of infection and understanding of the mechanisms of virus associated diseases. In this work, we assayed anti-viral antibodies using a novel high density-nucleic acid programmable protein array (HD-NAPPA) platform. Individual viral proteins were expressed in situ directly from plasmids encoding proteins in an array of microscopic reaction chambers. Quality of protein display and serum response was assured by comparing intra- and inter- array correlation within or between printing batches with average correlation coefficients of 0.91 and 0.96, respectively. HD-NAPPA showed higher signal to background (S/B) ratio compared with standard NAPPA on planar glass slides and ELISA. Antibody responses to 761 antigens from 25 different viruses were profiled among patients with juvenile idiopathic arthritis (JIA) and type 1 diabetes (T1D). Common as well as unique antibody reactivity patterns were detected between patients and healthy controls. We believe HD-viral-NAPPA will enable the study of host-pathogen interactions at unprecedented dimensions and elucidate the role of pathogen infections in disease development. PMID:25758251

  11. Viral membrane fusion

    SciTech Connect

    Harrison, Stephen C.

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

  12. Viral epidemiology of acute exacerbations of chronic obstructive pulmonary disease.

    PubMed

    Dimopoulos, G; Lerikou, M; Tsiodras, S; Chranioti, Aik; Perros, E; Anagnostopoulou, U; Armaganidis, A; Karakitsos, P

    2012-02-01

    The role of viruses in Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD) needs further elucidation. The aim of the present study was to evaluate the molecular epidemiology of viral pathogens in AECOPD. Patients presenting to the Emergency Room with AECOPD needing hospitalization were recruited. Oropharyngeal and sputum samples were collected in order to perform microarrays-based viral testing for the detection of respiratory viruses. A total of 200 (100%) patients were analyzed and from them in 107 (53.5%) a virus was detected. The commonest identified viruses were the human Respiratory Syncytial Virus (subtypes A and B) (40.5%), influenza virus (subtypes A, B, C) (11%), rhinovirus (8%) and human Parainfluenza Virus (subtypes A and B) (7.5%). A bacterial pathogen was isolated in 27 (14%) patients and a dual infection due to a bacterial and a viral pathogen was recognised in 14/107 patients. Patients with AECOPD and a viral infection had a lengthier hospital stay (9.2 ± 4.6 vs 7.6 ± 4.3, p < 0.01) while the severity of the disease was no related with significant differences among the groups of the study population. In conclusion, the isolation of a virus was strongly associated with AECOPD in the examined population. The stage of COPD appeared to have no relation with the frequency of the isolated viruses while dual infection with a viral and a bacterial pathogen was not rare. PMID:21983132

  13. Pathogenic human viruses in coastal waters

    USGS Publications Warehouse

    Griffin, Dale W.; Donaldson, Kim A.; Paul, J.H.; Rose, Joan B.

    2003-01-01

    This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and

  14. Pathogenic Human Viruses in Coastal Waters

    PubMed Central

    Griffin, Dale W.; Donaldson, Kim A.; Paul, John H.; Rose, Joan B.

    2003-01-01

    This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and important field. PMID:12525429

  15. Resistant Pathogens, Fungi, and Viruses

    PubMed Central

    Guidry, Christopher A.; Mansfield, Sara A.; Sawyer, Robert G.; Cook, Charles H.

    2014-01-01

    The first reports of antibiotic pathogens occurred a few short years after the introduction of these powerful new agents, heralding a new kind of war between medicine and pathogens. Although originally described in Staphylococcus aureus, resistance among bacteria has now become a grim race to determine which classes of bacteria will become more resistant, pitting the Gram positive staphylococci, enterococci, and streptococci against the increasingly resistant Gram negative pathogens, e. g., carbapenemase-resistant enterobacteriaceae. In addition, the availability of antibacterial agents has allowed the development of whole new kinds of diseases caused by non-bacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. All of these organisms are becoming more prevalent and, ultimately, more clinically relevant for surgeons. It is ironic that despite their ubiquity in our communities, there is seldom a second thought given to viral infections in patients with surgical illness. The extent of most surgeon’s interest in viral infections ends with hepatitis and HIV, no doubt related to transmissibility as well as the implications that these viruses might have in a patient’s hepatic or immune functions. There are chapters and even textbooks written about these viruses so these will not be considered here. Instead, we will present the growing body of knowledge of the herpes family viruses and their occurrence and consequences in patients with concomitant surgical disease or critical illness. We have also chosen to focus this chapter on previously immune competent patients, as the impact of herpes family viruses in immunosuppressed patients such as transplant or AIDS patients has received thorough treatment elsewhere. PMID:25440119

  16. Phylodynamic analysis of a viral infection network

    PubMed Central

    Shiino, Teiichiro

    2012-01-01

    Viral infections by sexual and droplet transmission routes typically spread through a complex host-to-host contact network. Clarifying the transmission network and epidemiological parameters affecting the variations and dynamics of a specific pathogen is a major issue in the control of infectious diseases. However, conventional methods such as interview and/or classical phylogenetic analysis of viral gene sequences have inherent limitations and often fail to detect infectious clusters and transmission connections. Recent improvements in computational environments now permit the analysis of large datasets. In addition, novel analytical methods have been developed that serve to infer the evolutionary dynamics of virus genetic diversity using sample date information and sequence data. This type of framework, termed “phylodynamics,” helps connect some of the missing links on viral transmission networks, which are often hard to detect by conventional methods of epidemiology. With sufficient number of sequences available, one can use this new inference method to estimate theoretical epidemiological parameters such as temporal distributions of the primary infection, fluctuation of the pathogen population size, basic reproductive number, and the mean time span of disease infectiousness. Transmission networks estimated by this framework often have the properties of a scale-free network, which are characteristic of infectious and social communication processes. Network analysis based on phylodynamics has alluded to various suggestions concerning the infection dynamics associated with a given community and/or risk behavior. In this review, I will summarize the current methods available for identifying the transmission network using phylogeny, and present an argument on the possibilities of applying the scale-free properties to these existing frameworks. PMID:22993510

  17. MHC class I antigen presentation: learning from viral evasion strategies.

    PubMed

    Hansen, Ted H; Bouvier, Marlene

    2009-07-01

    The cell surface display of peptides by MHC class I molecules to lymphocytes provides the host with an important surveillance mechanism to protect against invading pathogens. However, in turn, viruses have evolved elegant strategies to inhibit various stages of the MHC class I antigen presentation pathway and prevent the display of viral peptides. This Review highlights how the elucidation of mechanisms of viral immune evasion is important for advancing our understanding of virus-host interactions and can further our knowledge of the MHC class I presentation pathway as well as other cellular pathways.

  18. Involvement of the PI3K and ERK signaling pathways in largemouth bass virus-induced apoptosis and viral replication.

    PubMed

    Huang, Xiaohong; Wang, Wei; Huang, Youhua; Xu, Liwen; Qin, Qiwei

    2014-12-01

    Increased reports demonstrated that largemouth Bass, Micropterus salmoides in natural and artificial environments were always suffered from an emerging iridovirus disease, largemouth Bass virus (LMBV). However, the underlying mechanism of LMBV pathogenesis remained largely unknown. Here, we investigated the cell signaling events involved in virus induced cell death and viral replication in vitro. We found that LMBV infection in epithelioma papulosum cyprini (EPC) cells induced typical apoptosis, evidenced by the appearance of apoptotic bodies, cytochrome c release, mitochondrial membrane permeabilization (MMP) destruction and reactive oxygen species (ROS) generation. Two initiators of apoptosis, caspase-8 and caspase-9, and the executioner of apoptosis, caspase-3, were all significantly activated with the infection time, suggested that not only mitochondrion-mediated, but also death receptor-mediated apoptosis were involved in LMBV infection. Reporter gene assay showed that the promoter activity of transcription factors including p53, NF-κB, AP-1 and cAMP response element-binding protein (CREB) were decreased during LMBV infection. After treatment with different signaling pathway inhibitors, virus production were significantly suppressed by the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway and extracellular-signal-regulated kinases (ERK) signaling pathway. Furthermore, LMBV infection induced apoptosis was enhanced by PI3K inhibitor LY294002, but decreased by addition of ERK inhibitor UO126. Therefore, we speculated that apoptosis was sophisticatedly regulated by a series of cell signaling events for efficient virus propagation. Taken together, our results provided new insights into the molecular mechanism of ranavirus infection. PMID:25260912

  19. Involvement of the PI3K and ERK signaling pathways in largemouth bass virus-induced apoptosis and viral replication.

    PubMed

    Huang, Xiaohong; Wang, Wei; Huang, Youhua; Xu, Liwen; Qin, Qiwei

    2014-12-01

    Increased reports demonstrated that largemouth Bass, Micropterus salmoides in natural and artificial environments were always suffered from an emerging iridovirus disease, largemouth Bass virus (LMBV). However, the underlying mechanism of LMBV pathogenesis remained largely unknown. Here, we investigated the cell signaling events involved in virus induced cell death and viral replication in vitro. We found that LMBV infection in epithelioma papulosum cyprini (EPC) cells induced typical apoptosis, evidenced by the appearance of apoptotic bodies, cytochrome c release, mitochondrial membrane permeabilization (MMP) destruction and reactive oxygen species (ROS) generation. Two initiators of apoptosis, caspase-8 and caspase-9, and the executioner of apoptosis, caspase-3, were all significantly activated with the infection time, suggested that not only mitochondrion-mediated, but also death receptor-mediated apoptosis were involved in LMBV infection. Reporter gene assay showed that the promoter activity of transcription factors including p53, NF-κB, AP-1 and cAMP response element-binding protein (CREB) were decreased during LMBV infection. After treatment with different signaling pathway inhibitors, virus production were significantly suppressed by the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway and extracellular-signal-regulated kinases (ERK) signaling pathway. Furthermore, LMBV infection induced apoptosis was enhanced by PI3K inhibitor LY294002, but decreased by addition of ERK inhibitor UO126. Therefore, we speculated that apoptosis was sophisticatedly regulated by a series of cell signaling events for efficient virus propagation. Taken together, our results provided new insights into the molecular mechanism of ranavirus infection.

  20. Rapid Detection of Pathogens

    SciTech Connect

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  1. Innate immune system activation by viral RNA: How to predict it?

    PubMed

    Kondili, M; Roux, M; Vabret, N; Bailly-Bechet, M

    2016-01-15

    The immune system is able to identify foreign pathogens via different pathways. In the case of viral infection, recognition of the viral RNA is a crucial step, and many efforts have been made to understand which features of viral RNA are detected by the immune system. The biased viral RNA composition, measured as host-virus nucleotidic divergence, or CpG enrichment, has been proposed as salient signal. Peculiar structural features of these RNA could also be related to the immune system activation. Here, we gather multiple datasets and proceed to a meta-analysis to uncover the best predictors of immune system activation by viral RNA. "A" nucleotide content and Minimum Folding Energy are good predictors, and are more easily generalized than more complex indicators suggested previously. As RNA composition and structure are highly correlated, we suggest further experiments on synthetic sequences to identify the viral RNA sensing mechanisms by immune system receptors.

  2. Innate immune system activation by viral RNA: How to predict it?

    PubMed

    Kondili, M; Roux, M; Vabret, N; Bailly-Bechet, M

    2016-01-15

    The immune system is able to identify foreign pathogens via different pathways. In the case of viral infection, recognition of the viral RNA is a crucial step, and many efforts have been made to understand which features of viral RNA are detected by the immune system. The biased viral RNA composition, measured as host-virus nucleotidic divergence, or CpG enrichment, has been proposed as salient signal. Peculiar structural features of these RNA could also be related to the immune system activation. Here, we gather multiple datasets and proceed to a meta-analysis to uncover the best predictors of immune system activation by viral RNA. "A" nucleotide content and Minimum Folding Energy are good predictors, and are more easily generalized than more complex indicators suggested previously. As RNA composition and structure are highly correlated, we suggest further experiments on synthetic sequences to identify the viral RNA sensing mechanisms by immune system receptors. PMID:26650692

  3. Vaccines 87, modern approaches to new vaccines: Prevention of AIDS and other viral, bacterial and parasitic diseases

    SciTech Connect

    Chanock, R.M.; Lerner, R.A.; Brown, F.; Ginsberg, H.

    1987-01-01

    This book contains five sections and a summary. Each section consists of several papers. The section titles are: Immunology, AIDS, Pathogenic Bacteria and Viral Glycoproteins, Pathogenesis and Attenuation, and Recombinant Vectors and Paraviruses.

  4. Combating emerging viral threats

    PubMed Central

    Bekerman, Elena; Einav, Shirit

    2015-01-01

    Synopsis Most approved antiviral therapeutics selectively inhibit proteins encoded by a single virus, thereby providing a “one drug-one bug” solution. As a result of this narrow spectrum of coverage and the high cost of drug development, therapies are currently approved for fewer than ten viruses out of the hundreds known to cause human disease. This perspective summarizes progress and challenges in the development of broad-spectrum antiviral therapies. These strategies include targeting enzymatic functions shared by multiple viruses and host cell machinery by newly discovered compounds or by repurposing approved drugs. These approaches offer new practical means for developing therapeutics against existing and emerging viral threats. PMID:25883340

  5. Viral complement regulatory proteins.

    PubMed

    Rosengard, A M; Ahearn, J M

    1999-05-01

    The inactivation of complement provides cells and tissues critical protection from complement-mediated attack and decreases the associated recruitment of other inflammatory mediators. In an attempt to evade the host immune response, viruses have evolved two mechanisms to acquire complement regulatory proteins. They can directly seize the host cell complement regulators onto their outer envelope and/or they can produce their own proteins which are either secreted into the neighboring intercellular space or expressed as membrane-bound proteins on the infected host cell. The following review will concentrate on the viral homologues of the mammalian complement regulatory proteins, specifically those containing complement control protein (CCP) repeats. PMID:10408371

  6. [Viral exanthematic childhood diseases].

    PubMed

    Allwinn, R; Doerr, H W

    1997-01-01

    Exanthem is defined as multiple, inflammatory skin alteration with a hematogenic, lymphogenic or neurogenic origin. Typically, so called exanthematic children's diseases are measles, mumps, rubella, varicella, erythema infectiosum (fifth disease) and in the past small pox. The pathogenesis of the viral-caused diseases primarily occurs in the vascular connective tissue. The cytopathogenetic effects result in inflammatory tissue reactions with activation of defence mechanism and producing of immune complexes. First symptoms are hyperemia, edema and inflammatory infiltrates with itchy swellings. Virological laboratory diagnosis are necessary especially for the progress of atypical infectious diseases, for persons with immunological or chronical illness and under chemotherapeutical or immunosuppressival treatment.

  7. Viral surveillance and discovery

    PubMed Central

    Lipkin, Walter Ian; Firth, Cadhla

    2014-01-01

    The field of virus discovery has burgeoned with the advent of high throughput sequencing platforms and bioinformatics programs that enable rapid identification and molecular characterization of known and novel agents, investments in global microbial surveillance that include wildlife and domestic animals as well as humans, and recognition that viruses may be implicated in chronic as well as acute diseases. Here we review methods for viral surveillance and discovery, strategies and pitfalls in linking discoveries to disease, and identify opportunities for improvements in sequencing instrumentation and analysis, the use of social media and medical informatics that will further advance clinical medicine and public health. PMID:23602435

  8. Equine viral arteritis.

    PubMed

    Balasuriya, Udeni B R

    2014-12-01

    Equine arteritis virus (EAV), the causative agent of equine viral arteritis (EVA), is a respiratory and reproductive disease that occurs throughout the world. EAV infection is highly species-specific and exclusively limited to members of the family Equidae, which includes horses, donkeys, mules, and zebras. EVA is an economically important disease and outbreaks could cause significant losses to the equine industry. The primary objective of this article is to summarize current understanding of EVA, specifically the disease, pathogenesis, epidemiology, host immune response, vaccination and treatment strategies, prevention and control measures, and future directions.

  9. Vaccines and viral antigenic diversity.

    PubMed

    Mumford, J A

    2007-04-01

    examine the significance of viral evolution in relation to vaccine strains. This method is highly applicable to other important pathogens displaying antigenic diversity, such as FMD. PMID:17633294

  10. Assessment of Virally Vectored Autoimmunity as a Biocontrol Strategy for Cane Toads

    PubMed Central

    Robinson, Anthony J.; Venables, Daryl; Voysey, Rhonda D.; Boyle, Donna G.; Shanmuganathan, Thayalini; Hardy, Christopher M.; Siddon, Nicole A.; Hyatt, Alex D.

    2011-01-01

    Background The cane toad, Bufo (Chaunus) marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. Methodology/Principal Findings The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs), developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin) and genetic (adult globin mRNA levels) measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. Conclusions/Significance While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach. PMID:21283623

  11. Human viral gastroenteritis.

    PubMed Central

    Christensen, M L

    1989-01-01

    During the last 15 years, several different groups of fastidious viruses that are responsible for a large proportion of acute viral gastroenteritis cases have been discovered by the electron microscopic examination of stool specimens. This disease is one of the most prevalent and serious clinical syndromes seen around the world, especially in children. Rotaviruses, in the family Reoviridae, and fastidious fecal adenoviruses account for much of the viral gastroenteritis in infants and young children, whereas the small caliciviruses and unclassified astroviruses, and possibly enteric coronaviruses, are responsible for significantly fewer cases overall. In addition to electron microscopy, enzyme immunoassays and other rapid antigen detection systems have been developed to detect rotaviruses and fastidious fecal adenoviruses in the stool specimens of both nonhospitalized patients and those hospitalized for dehydration and electrolyte imbalance. Experimental rotavirus vaccines have also been developed, due to the prevalence and seriousness of rotavirus infection. The small, unclassified Norwalk virus and morphologically similar viruses are responsible for large and small outbreaks of acute gastroenteritis in older children, adolescents, and adults. Hospitalization of older patients infected with these viruses is usually not required, and their laboratory diagnoses have been limited primarily to research laboratories. Images PMID:2644024

  12. [Emergent viral infections].

    PubMed

    Galama, J M

    2001-03-31

    The emergence and re-emergence of viral infections is an ongoing process. Large-scale vaccination programmes led to the eradication or control of some viral infections in the last century, but new viruses are always emerging. Increased travel is leading to a rise in the importation of exotic infections such as dengue and hepatitis E, but also of hepatitis A, which is no longer endemic. Apart from import diseases new viruses have appeared (Nipah-virus and transfusion-transmitted virus). Existing viruses may suddenly cause more severe diseases, e.g. infection by enterovirus 71. The distribution area of a virus may change, e.g. in case of West Nile virus, an Egyptian encephalitis virus that appears to have established itself in the USA. Furthermore, there is no such thing as a completely new virus; it is always an existing virus that has adapted itself to another host or that was already present in humans but has only recently been discovered. A number of factors facilitate the emergence of new infectious diseases. These include intensive animal husbandry and the transport of animals. The unexpected appearance of West Nile virus in the western hemisphere was possibly due to animal transportation.

  13. Bovine Viral Diarrhea Virus-Associated Disease in Feedlot Cattle.

    PubMed

    Larson, Robert L

    2015-11-01

    Bovine viral diarrhea virus (BVDv) is associated with bovine respiratory disease complex and other diseases of feedlot cattle. Although occasionally a primary pathogen, BVDv's impact on cattle health is through the immunosuppressive effects of the virus and its synergism with other pathogens. The simple presence or absence of BVDv does not result in consistent health outcomes because BVDv is only one of many risk factors that contribute to disease syndromes. Current interventions have limitations and the optimum strategy for their uses to limit the health, production, and economic costs associated with BVDv have to be carefully considered for optimum cost-effectiveness.

  14. Viral noncoding RNAs: more surprises

    PubMed Central

    Tycowski, Kazimierz T.; Guo, Yang Eric; Lee, Nara; Moss, Walter N.; Vallery, Tenaya K.; Xie, Mingyi

    2015-01-01

    Eukaryotic cells produce several classes of long and small noncoding RNA (ncRNA). Many DNA and RNA viruses synthesize their own ncRNAs. Like their host counterparts, viral ncRNAs associate with proteins that are essential for their stability, function, or both. Diverse biological roles—including the regulation of viral replication, viral persistence, host immune evasion, and cellular transformation—have been ascribed to viral ncRNAs. In this review, we focus on the multitude of functions played by ncRNAs produced by animal viruses. We also discuss their biogenesis and mechanisms of action. PMID:25792595

  15. Going viral: a review of replication-selective oncolytic adenoviruses

    PubMed Central

    Larson, Christopher; Oronsky, Bryan; Scicinski, Jan; Fanger, Gary R.; Stirn, Meaghan; Oronsky, Arnold; Reid, Tony R.

    2015-01-01

    Oncolytic viruses have had a tumultuous course, from the initial anecdotal reports of patients having antineoplastic effects after natural viral infections a century ago to the development of current cutting-edge therapies in clinical trials. Adenoviruses have long been the workhorse of virotherapy, and we review both the scientific and the not-so-scientific forces that have shaped the development of these therapeutics from wild-type viral pathogens, turning an old foe into a new friend. After a brief review of the mechanics of viral replication and how it has been modified to engineer tumor selectivity, we give particular attention to ONYX-015, the forerunner of virotherapy with extensive clinical testing that pioneered the field. The findings from those as well as other oncolytic trials have shaped how we now view these viruses, which our immune system has evolved to vigorously attack, as promising immunotherapy agents. PMID:26280277

  16. Antiviral defense in shrimp: from innate immunity to viral infection.

    PubMed

    Wang, Pei-Hui; Huang, Tianzhi; Zhang, Xiaobo; He, Jian-Guo

    2014-08-01

    The culture of penaeid shrimp is rapidly developing as a major business endeavor worldwide. However, viral diseases have caused huge economic loss in penaeid shrimp culture industries. Knowledge of shrimp innate immunity and antiviral responses has made important progress in recent years, allowing the design of better strategies for the prevention and control of shrimp diseases. In this study, we have updated information on shrimp antiviral immunity and interactions between shrimp hosts and viral pathogens. Current knowledge and recent progress in immune signaling pathways (e.g., Toll/IMD-NF-κB and JAK-STAT signaling pathways), RNAi, phagocytosis, and apoptosis in shrimp antiviral immunity are discussed. The mechanism of viral infection in shrimp hosts and the interactions between viruses and shrimp innate immune systems are also analyzed.

  17. Current Approaches on Viral Infection: Proteomics and Functional Validations

    PubMed Central

    Zheng, Jie; Tan, Boon Huan; Sugrue, Richard; Tang, Kai

    2012-01-01

    Viruses could manipulate cellular machinery to ensure their continuous survival and thus become parasites of living organisms. Delineation of sophisticated host responses upon virus infection is a challenging task. It lies in identifying the repertoire of host factors actively involved in the viral infectious cycle and characterizing host responses qualitatively and quantitatively during viral pathogenesis. Mass spectrometry based proteomics could be used to efficiently study pathogen-host interactions and virus-hijacked cellular signaling pathways. Moreover, direct host and viral responses upon infection could be further investigated by activity-based functional validation studies. These approaches involve drug inhibition of secretory pathway, immunofluorescence staining, dominant negative mutant of protein target, real-time PCR, small interfering siRNA-mediated knockdown, and molecular cloning studies. In this way, functional validation could gain novel insights into the high-content proteomic dataset in an unbiased and comprehensive way. PMID:23162545

  18. Viral Interference and Persistence in Mosquito-Borne Flaviviruses

    PubMed Central

    Salas-Benito, Juan Santiago; De Nova-Ocampo, Mónica

    2015-01-01

    Mosquito-borne flaviviruses are important pathogens for humans, and the detection of two or more flaviviruses cocirculating in the same geographic area has often been reported. However, the epidemiological impact remains to be determined. Mosquito-borne flaviviruses are primarily transmitted through Aedes and Culex mosquitoes; these viruses establish a life-long or persistent infection without apparent pathological effects. This establishment requires a balance between virus replication and the antiviral host response. Viral interference is a phenomenon whereby one virus inhibits the replication of other viruses, and this condition is frequently associated with persistent infections. Viral interference and persistent infection are determined by several factors, such as defective interfering particles, competition for cellular factors required for translation/replication, and the host antiviral response. The interaction between two flaviviruses typically results in viral interference, indicating that these viruses share common features during the replicative cycle in the vector. The potential mechanisms involved in these processes are reviewed here. PMID:26583158

  19. Viral Interference and Persistence in Mosquito-Borne Flaviviruses.

    PubMed

    Salas-Benito, Juan Santiago; De Nova-Ocampo, Mónica

    2015-01-01

    Mosquito-borne flaviviruses are important pathogens for humans, and the detection of two or more flaviviruses cocirculating in the same geographic area has often been reported. However, the epidemiological impact remains to be determined. Mosquito-borne flaviviruses are primarily transmitted through Aedes and Culex mosquitoes; these viruses establish a life-long or persistent infection without apparent pathological effects. This establishment requires a balance between virus replication and the antiviral host response. Viral interference is a phenomenon whereby one virus inhibits the replication of other viruses, and this condition is frequently associated with persistent infections. Viral interference and persistent infection are determined by several factors, such as defective interfering particles, competition for cellular factors required for translation/replication, and the host antiviral response. The interaction between two flaviviruses typically results in viral interference, indicating that these viruses share common features during the replicative cycle in the vector. The potential mechanisms involved in these processes are reviewed here.

  20. Zika Fetal Neuropathogenesis: Etiology of a Viral Syndrome.

    PubMed

    Klase, Zachary A; Khakhina, Svetlana; Schneider, Adriano De Bernardi; Callahan, Michael V; Glasspool-Malone, Jill; Malone, Robert

    2016-08-01

    The ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain-Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of "TORCH" viral pathogenesis to provide context. By drawing parallels to other viral infections of the fetus, we identify common themes and mechanisms that may illuminate the observed pathology. The existing data on the susceptibility of various cells to both Zika and other flavivirus infections are summarized. Finally, we highlight relevant aspects of the known molecular mechanisms of flavivirus replication.

  1. Zika Fetal Neuropathogenesis: Etiology of a Viral Syndrome

    PubMed Central

    Klase, Zachary A.; Khakhina, Svetlana; Schneider, Adriano De Bernardi; Callahan, Michael V.; Glasspool-Malone, Jill

    2016-01-01

    The ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain–Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of “TORCH” viral pathogenesis to provide context. By drawing parallels to other viral infections of the fetus, we identify common themes and mechanisms that may illuminate the observed pathology. The existing data on the susceptibility of various cells to both Zika and other flavivirus infections are summarized. Finally, we highlight relevant aspects of the known molecular mechanisms of flavivirus replication. PMID:27560129

  2. Zika Fetal Neuropathogenesis: Etiology of a Viral Syndrome.

    PubMed

    Klase, Zachary A; Khakhina, Svetlana; Schneider, Adriano De Bernardi; Callahan, Michael V; Glasspool-Malone, Jill; Malone, Robert

    2016-08-01

    The ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain-Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of "TORCH" viral pathogenesis to provide context. By drawing parallels to other viral infections of the fetus, we identify common themes and mechanisms that may illuminate the observed pathology. The existing data on the susceptibility of various cells to both Zika and other flavivirus infections are summarized. Finally, we highlight relevant aspects of the known molecular mechanisms of flavivirus replication. PMID:27560129

  3. Effectiveness of irradiation in killing pathogens. [Treatment of sewage sludge for land application

    SciTech Connect

    Yeager, J.G.; Ward, R.L.

    1980-01-01

    United States Environmental Protection Agency regulations include gamma ray irradiation of sludge as an approved Process to Further Reduce Pathogens (PFRP) prior to land application. Research at Sandia National Laboratories on pathogen inactivation in sludge by gamma irradiation has demonstrated that the 1 Mrad PFRP dose is capable, by itself, of eliminating bacterial, fungal, and parasitic pathogens from sludge. Gamma irradiation of sludge in conjunction with the required Processes to Significantly Reduce Pathogens (PSRP) should also eliminate the viral hazard from wastewater sludges.

  4. Comparison of innate immune responses to pathogenic and putative non-pathogenic hantaviruses in vitro.

    PubMed

    Shim, So Hee; Park, Man-Seong; Moon, Sungsil; Park, Kwang Sook; Song, Jin-Won; Song, Ki-Joon; Baek, Luck Ju

    2011-09-01

    Hantaviruses are human pathogens that cause hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. The mechanisms accounting for the differences in virulence between pathogenic and non-pathogenic hantaviruses are not well known. We have examined the pathogenesis of different hantavirus groups by comparing the innate immune responses induced in the host cell following infection by pathogenic (Sin Nombre, Hantaan, and Seoul virus) and putative non-pathogenic (Prospect Hill, Tula, and Thottapalayam virus) hantaviruses. Pathogenic hantaviruses were found to replicate more efficiently in interferon-competent A549 cells than putative non-pathogenic hantaviruses. The former also suppressed the expression of the interferon-β and myxovirus resistance protein genes, while the transcription level of both genes increased rapidly within 24 h post-infection in the latter. In addition, the induction level of interferon correlated with the activation level of interferon regulatory factor-3. Taken together, these results suggest that the observed differences are correlated with viral pathogenesis and further indicate that pathogenic and putative non-pathogenic hantaviruses differ in terms of early interferon induction via activation of the interferon regulatory factor-3 in infected host cells.

  5. Innate immune sensing of nucleic acids from pathogens.

    PubMed

    Oliveira, Sergio C

    2014-12-01

    The innate immune system is important as the first line of defense to sense invading pathogens. Nucleic acids represent critical pathogen signatures that trigger a host proinflammatory immune response. Much progress has been made in understanding how DNA and RNA trigger host defense countermeasures, however, several aspects of how cytosolic nucleic acids are sensed remain unclear. This special issue reviews how the host innate immune system senses nucleic acids from Brucella abortus, Mycobacterium sp and Legionella pneumophila, viral DNA, the role of STING in DNA sensing and inflammatory diseases and the mechanism of viral RNA recognition by the small interfering RNA pathway in Drosophila melanogaster.

  6. Viral etiology in infants hospitalized for acute bronchiolitis.

    PubMed

    Azkur, Dilek; Özaydın, Eda; Dibek-Mısırlıoğlu, Emine; Vezir, Emine; Tombuloğlu, Duygu; Köse, Gülşen; Kocabaş, Can N

    2014-01-01

    Acute bronchiolitis is predominantly a viral disease. Respiratory syncytial virus is the most common agent, but other newly identified viruses have also been considered as causes. The aim of the present study is to determine the respiratory viruses causing acute bronchiolitis in hospitalized infants. Infants younger than 2 years of age who were hospitalized for acute viral bronchiolitis in a children's hospital between November 2011 and May 2012 were evaluated for the presence of viruses as etiologic agents using a realtime polymerase chain reaction method.A total of 55 infants were included in this study. The mean age of the children was 6.98±5.53 months, and 63.6% were male. In the 55 children, 63 viruses were detected. A single viral pathogen was detected in 47 (85.5%) patients, and two viruses were co-detected in 8 (14.6%) patients. Respiratory syncytial virus was the most common virus identified, accounting for 25 (45.5%) cases, followed by rhinovirus (n=9, 16.4%), and human metapneumovirus (n = 8, 14.5%).Although respiratory syncytial virus remains the major viral pathogen in infants hospitalized for acute broncholitis, more than half of bronchiolitis cases are associated with other respiratory viruses.

  7. Immunologic special forces: anti-pathogen cytotoxic T-lymphocyte immunotherapy following hematopoietic stem cell transplantation

    PubMed Central

    Keller, Michael D; Bollard, Catherine M

    2014-01-01

    Anti-pathogen adoptive T-cell immunotherapy has been proven to be highly effective in preventing or controlling viral infections following hematopoietic stem cell transplantation. Recent advances in manufacturing protocols allow an increased number of targeted pathogens, eliminate the need for viral transduction, broaden the potential donor pool to include pathogen-naïve sources, and reduce the time requirement for production. Early studies suggest that anti-fungal immunotherapy may also have clinical benefit. Future advances include further broadening of the pathogens that can be targeted and development of T-cells with resistance to pharmacologic immunosuppression. PMID:27274983

  8. Endolysosomal trafficking of viral G protein-coupled receptor functions in innate immunity and control of viral oncogenesis.

    PubMed

    Dong, Xiaonan; Cheng, Adam; Zou, Zhongju; Yang, Yih-Sheng; Sumpter, Rhea M; Huang, Chou-Long; Bhagat, Govind; Virgin, Herbert W; Lira, Sergio A; Levine, Beth

    2016-03-15

    The ubiquitin-proteasome system degrades viral oncoproteins and other microbial virulence factors; however, the role of endolysosomal degradation pathways in these processes is unclear. Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma, and a constitutively active viral G protein-coupled receptor (vGPCR) contributes to the pathogenesis of KSHV-induced tumors. We report that a recently discovered autophagy-related protein, Beclin 2, interacts with KSHV GPCR, facilitates its endolysosomal degradation, and inhibits vGPCR-driven oncogenic signaling. Furthermore, monoallelic loss of Becn2 in mice accelerates the progression of vGPCR-induced lesions that resemble human Kaposi's sarcoma. Taken together, these findings indicate that Beclin 2 is a host antiviral molecule that protects against the pathogenic effects of KSHV GPCR by facilitating its endolysosomal degradation. More broadly, our data suggest a role for host endolysosomal trafficking pathways in regulating viral pathogenesis and oncogenic signaling.

  9. Endolysosomal trafficking of viral G protein-coupled receptor functions in innate immunity and control of viral oncogenesis.

    PubMed

    Dong, Xiaonan; Cheng, Adam; Zou, Zhongju; Yang, Yih-Sheng; Sumpter, Rhea M; Huang, Chou-Long; Bhagat, Govind; Virgin, Herbert W; Lira, Sergio A; Levine, Beth

    2016-03-15

    The ubiquitin-proteasome system degrades viral oncoproteins and other microbial virulence factors; however, the role of endolysosomal degradation pathways in these processes is unclear. Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma, and a constitutively active viral G protein-coupled receptor (vGPCR) contributes to the pathogenesis of KSHV-induced tumors. We report that a recently discovered autophagy-related protein, Beclin 2, interacts with KSHV GPCR, facilitates its endolysosomal degradation, and inhibits vGPCR-driven oncogenic signaling. Furthermore, monoallelic loss of Becn2 in mice accelerates the progression of vGPCR-induced lesions that resemble human Kaposi's sarcoma. Taken together, these findings indicate that Beclin 2 is a host antiviral molecule that protects against the pathogenic effects of KSHV GPCR by facilitating its endolysosomal degradation. More broadly, our data suggest a role for host endolysosomal trafficking pathways in regulating viral pathogenesis and oncogenic signaling. PMID:26929373

  10. [Update chronic viral hepatitis].

    PubMed

    Ziegenhagen, D J

    2016-03-01

    More than 500,000 people in Germany have chronic viral hepatitis. The interferon-based treatments formerly used in hepatitis B have been widely replaced by life-long oral medication with nucleoside or nucleotide analogues. Treatment for chronic hepatitis C has been improved substantially by the development of new and very expensive drug combinations. Up to 90% of patients can now be cured with certainty, and one to two years after successful treatment there is no relevant risk of recurrence. These individuals expect to receive insurance cover under appropriate conditions. Vaccination programmes are very efficient at decreasing the incidence of hepatitis B, but no vaccine against hepatitis C is likely to become available in the next decade. PMID:27111951

  11. Dengue viral infections

    PubMed Central

    Malavige, G; Fernando, S; Fernando, D; Seneviratne, S

    2004-01-01

    Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections. PMID:15466994

  12. Dengue viral infections.

    PubMed

    Malavige, G N; Fernando, S; Fernando, D J; Seneviratne, S L

    2004-10-01

    Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections.

  13. [Viral hemorrhagic fever].

    PubMed

    Kager, P A

    1998-02-28

    Viral haemorrhagic fevers, such as Lassa fever and yellow fever, cause tens of thousands of deaths annually outside the Netherlands. The viruses are mostly transmitted by mosquitoes, ticks or via excreta of rodents. Important to travellers are yellow fever, dengue and Lassa and Ebola fever. For yellow fever there is an efficacious vaccine. Dengue is frequently observed in travellers; prevention consists in avoiding mosquito bites, the treatment is symptomatic. Lassa and Ebola fever are extremely rare among travellers; a management protocol can be obtained from the Netherlands Ministry of Health, Welfare and Sports. Diagnostics of a patient from the tropics with fever and haemorrhagic diathesis should be aimed at treatable disorders such as malaria, typhoid fever, rickettsiosis or bacterial sepsis, because the probability of such a disease is much higher than that of Lassa or Ebola fever.

  14. Host and viral ecology determine bat rabies seasonality and maintenance

    USGS Publications Warehouse

    George, D.B.; Webb, C.T.; Farnsworth, Matthew L.; O'Shea, T.J.; Bowen, R.A.; Smith, D.L.; Stanley, T.R.; Ellison, L.E.; Rupprecht, C.E.

    2011-01-01

    Rabies is an acute viral infection that is typically fatal. Most rabies modeling has focused on disease dynamics and control within terrestrial mammals (e.g., raccoons and foxes). As such, rabies in bats has been largely neglected until recently. Because bats have been implicated as natural reservoirs for several emerging zoonotic viruses, including SARS-like corona viruses, henipaviruses, and lyssaviruses, understanding how pathogens are maintained within a population becomes vital. Unfortunately, little is known about maintenance mechanisms for any pathogen in bat populations. We present a mathematical model parameterized with unique data from an extensive study of rabies in a Colorado population of big brown bats (Eptesicus fuscus) to elucidate general maintenance mechanisms. We propose that life history patterns of many species of temperate-zone bats, coupled with sufficiently long incubation periods, allows for rabies virus maintenance. Seasonal variability in bat mortality rates, specifically low mortality during hibernation, allows long-term bat population viability. Within viable bat populations, sufficiently long incubation periods allow enough infected individuals to enter hibernation and survive until the following year, and hence avoid an epizootic fadeout of rabies virus. We hypothesize that the slowing effects of hibernation on metabolic and viral activity maintains infected individuals and their pathogens until susceptibles from the annual birth pulse become infected and continue the cycle. This research provides a context to explore similar host ecology and viral dynamics that may explain seasonal patterns and maintenance of other bat-borne diseases.

  15. Host and viral ecology determine bat rabies seasonality and maintenance.

    PubMed

    George, Dylan B; Webb, Colleen T; Farnsworth, Matthew L; O'Shea, Thomas J; Bowen, Richard A; Smith, David L; Stanley, Thomas R; Ellison, Laura E; Rupprecht, Charles E

    2011-06-21

    Rabies is an acute viral infection that is typically fatal. Most rabies modeling has focused on disease dynamics and control within terrestrial mammals (e.g., raccoons and foxes). As such, rabies in bats has been largely neglected until recently. Because bats have been implicated as natural reservoirs for several emerging zoonotic viruses, including SARS-like corona viruses, henipaviruses, and lyssaviruses, understanding how pathogens are maintained within a population becomes vital. Unfortunately, little is known about maintenance mechanisms for any pathogen in bat populations. We present a mathematical model parameterized with unique data from an extensive study of rabies in a Colorado population of big brown bats (Eptesicus fuscus) to elucidate general maintenance mechanisms. We propose that life history patterns of many species of temperate-zone bats, coupled with sufficiently long incubation periods, allows for rabies virus maintenance. Seasonal variability in bat mortality rates, specifically low mortality during hibernation, allows long-term bat population viability. Within viable bat populations, sufficiently long incubation periods allow enough infected individuals to enter hibernation and survive until the following year, and hence avoid an epizootic fadeout of rabies virus. We hypothesize that the slowing effects of hibernation on metabolic and viral activity maintains infected individuals and their pathogens until susceptibles from the annual birth pulse become infected and continue the cycle. This research provides a context to explore similar host ecology and viral dynamics that may explain seasonal patterns and maintenance of other bat-borne diseases.

  16. Animal migration and risk of spread of viral infections: Chapter 9

    USGS Publications Warehouse

    Prosser, Diann J.; Nagel, Jessica; Takekawa, John Y.; Edited by Singh, Sunit K.

    2013-01-01

    The potential contribution of migration towards the spread of disease is as varied as the ecology of the pathogens themselves and their host populations. This chapter outlines multiple examples of viral diseases in animal populations and their mechanisms of viral spread. Many species of insects, mammals, fish, and birds exhibit migratory behavior and have the potential to disperse diseases over long distances. The majority of studies available on viral zoonoses have focused on birds and bats, due to their highly migratory life histories. A number of studies have reported evidence of changes in the timing of animal migrations in response to climate change. The majority indicate an advancement of spring migration, with few or inconclusive results for fall migration. Predicting the combined effects of climate change on migratory patterns of host species and epidemiology of viral pathogens is complex and not fully realistic.

  17. Viral Epitopes and Monoclonal Antibodies: Isolation of Blocking Antibodies that Inhibit Virus Neutralization

    NASA Astrophysics Data System (ADS)

    Massey, Richard J.; Schochetman, Gerald

    1981-07-01

    The inability of pathogenic animal viruses to be completely neutralized by antibodies can lead to chronic viral infections in which infectious virus persists even in the presence of excess neutralizing antibody. A mechanism that results in this nonneutralized fraction of virus was defined by the topographical relationships of viral epitopes identified with monoclonal antibodies wherein monoclonal antibodies bind to virus and sterically block the binding of neutralizing antibodies.

  18. Strain Variation and Disease Severity in Congenital Cytomegalovirus Infection: In Search of a Viral Marker.

    PubMed

    Arav-Boger, Ravit

    2015-09-01

    The wide spectrum of congenital cytomegalovirus (CMV) disease and known differences in the biology and in vitro growth of CMV strains continue to drive studies in search for specific viral genetic determinants that may predict severity of congenital CMV disease. Several CMV genes have been studied in detail in congenitally infected children, but the complexity of the viral genome and differences in the definition of symptomatic disease versus asymptomatic CMV infection continue to raise questions related to what constitutes a pathogenic CMV strain.

  19. Viral Diseases in Zebrafish: What Is Known and Unknown

    PubMed Central

    Crim, Marcus J.; Riley, Lela K.

    2013-01-01

    Naturally occurring viral infections have the potential to introduce confounding variability that leads to invalid and misinterpreted data. Whereas the viral diseases of research rodents are well characterized and closely monitored, no naturally occurring viral infections have been characterized for the laboratory zebrafish (Danio rerio), an increasingly important biomedical research model. Despite the ignorance about naturally occurring zebrafish viruses, zebrafish models are rapidly expanding in areas of biomedical research where the confounding effects of unknown infectious agents present a serious concern. In addition, many zebrafish research colonies remain linked to the ornamental (pet) zebrafish trade, which can contribute to the introduction of new pathogens into research colonies, whereas mice used for research are purpose bred, with no introduction of new mice from the pet industry. Identification, characterization, and monitoring of naturally occurring viruses in zebrafish are crucial to the improvement of zebrafish health, the reduction of unwanted variability, and the continued development of the zebrafish as a model organism. This article addresses the importance of identifying and characterizing the viral diseases of zebrafish as the scope of zebrafish models expands into new research areas and also briefly addresses zebrafish susceptibility to experimental viral infection and the utility of the zebrafish as an infection and immunology model. PMID:23382345

  20. Architecture and regulation of negative-strand viral enzymatic machinery

    PubMed Central

    Kranzusch, Philip J.; Whelan, Sean P.J.

    2012-01-01

    Negative-strand (NS) RNA viruses initiate infection with a unique polymerase complex that mediates both mRNA transcription and subsequent genomic RNA replication. For nearly all NS RNA viruses, distinct enzymatic domains catalyzing RNA polymerization and multiple steps of 5′ mRNA cap formation are contained within a single large polymerase protein (L). While NS RNA viruses include a variety of emerging human and agricultural pathogens, the enzymatic machinery driving viral replication and gene expression remains poorly understood. Recent insights with Machupo virus and vesicular stomatitis virus have provided the first structural information of viral L proteins, and revealed how the various enzymatic domains are arranged into a conserved architecture shared by both segmented and nonsegmented NS RNA viruses. In vitro systems reconstituting RNA synthesis from purified components provide new tools to understand the viral replicative machinery, and demonstrate the arenavirus matrix protein regulates RNA synthesis by locking a polymerase–template complex. Inhibition of gene expression by the viral matrix protein is a distinctive feature also shared with influenza A virus and nonsegmented NS RNA viruses, possibly illuminating a conserved mechanism for coordination of viral transcription and polymerase packaging PMID:22767259

  1. Architecture and regulation of negative-strand viral enzymatic machinery.

    PubMed

    Kranzusch, Philip J; Whelan, Sean P J

    2012-07-01

    Negative-strand (NS) RNA viruses initiate infection with a unique polymerase complex that mediates both mRNA transcription and subsequent genomic RNA replication. For nearly all NS RNA viruses, distinct enzymatic domains catalyzing RNA polymerization and multiple steps of 5' mRNA cap formation are contained within a single large polymerase protein (L). While NS RNA viruses include a variety of emerging human and agricultural pathogens, the enzymatic machinery driving viral replication and gene expression remains poorly understood. Recent insights with Machupo virus and vesicular stomatitis virus have provided the first structural information of viral L proteins, and revealed how the various enzymatic domains are arranged into a conserved architecture shared by both segmented and nonsegmented NS RNA viruses. In vitro systems reconstituting RNA synthesis from purified components provide new tools to understand the viral replicative machinery, and demonstrate the arenavirus matrix protein regulates RNA synthesis by locking a polymerase-template complex. Inhibition of gene expression by the viral matrix protein is a distinctive feature also shared with influenza A virus and nonsegmented NS RNA viruses, possibly illuminating a conserved mechanism for coordination of viral transcription and polymerase packaging.

  2. Clinical and experimental aspects of viral myocarditis.

    PubMed Central

    Leslie, K; Blay, R; Haisch, C; Lodge, A; Weller, A; Huber, S

    1989-01-01

    Picornaviruses are frequently implicated as the etiological agents of acute myocarditis. This association is based historically on serological evidence of rising antibody titers to specific pathogens and more recently on identification of viral genomic material in endocardial biopsy specimens through in situ hybridization. Only rarely is infectious virus isolated from either the patient or the heart during periods of maximum myocardial inflammation and injury. Thus, despite a probable viral etiology, much interest centers on the role of the immune system in cardiac damage and the likelihood that the infection triggers an autoimmune response to heart-specific antigens. Heart-reactive antibodies and T cells are found in most myocarditis patients, and immunosuppressive therapy has proven beneficial in many, though not all, cases. Furthermore, murine models of coxsackievirus group B type 3-induced myocarditis also demonstrate that virus infection initiates autoimmunity and that these autoimmune effectors are predominately responsible for tissue injury. How virus-host interactions overcome presumed self-tolerance to heart antigens is discussed, and evidence supporting various theories of virus-initiated autoimmunity and disease pathogenesis are delineated. PMID:2650861

  3. Detection of viral hemorrhagic septicemia virus

    USGS Publications Warehouse

    Winton, James; Kurath, Gael; Batts, William

    2007-01-01

    Viral hemorrhagic septicemia virus (VHSV) is considered to be one of the most important viral pathogens of finfish and is listed as reportable by many nations and international organizations (Office International des Epizooties 2006). Prior to 1988, VHSV was thought to be limited to Europe (Wolf 1988; Smail 1999). Subsequently, it was shown that the virus is endemic among many marine and anadromous fish species in both the Pacific and Atlantic Oceans (Meyers and Winton 1995; Skall et al. 2005). Genetic analysis reveals that isolates of VHSV can be divided into four genotypes that generally correlate with geographic location with the North American isolates generally falling into VHSV Genotype IV (Snow et al. 2004). In 2005-2006, reports from the Great Lakes region indicated that wild fish had experienced disease or, in some cases, very large die-offs from VHSV (Elsayed et al. 2006, Lumsden et al. 2007). The new strain from the Great Lakes, now identified as VHSV Genotype IVb, appears most closely related to isolates of VHSV from mortalities that occurred during 2000-2004 in rivers and near-shore areas of New Brunswick and Nova Scotia, Canada (Gagne et al. 2007). The type IVb isolate found in the Great Lakes region is the only strain outside of Europe that has been associated with significant mortality in freshwater species.

  4. An atomistic approach to viral mechanical oscillations

    NASA Astrophysics Data System (ADS)

    Sankey, Otto F.

    2009-03-01

    Viruses are the simplest ``life'' form. These parasites reproduce by borrowing the machinery of their host cell. Many are pathogenic to plants, animals, and humans. Viruses possess an outer protein coat (capsid) that protects its genomic material that resides inside. We have developed a theoretical technique to model the very low frequency mechanical modes of the viral capsid with atomic resolution. The method uses empirical force fields and a mathematical framework borrowed from electronic structure theory for finding low energy states. The low frequency modes can be ``pinged'' with an ultra-short laser pulse and the aim of the light/vibrational coupling is to interfere with the viral life cycle. The theoretical work here is motivated by the recent work of Tsen et al. [2] who have used ultra-short pulsed laser scattering to inactivate viruses. The methodology can be applied to many systems, and the coupled mechanical oscillations of other floppy biomolecules such as a complete ATP binding cassette (ABC transporter) will also be discussed. Co-authors of this work are Dr. Eric Dykeman, Prof. K.-T. Tsen and Daryn Benson. [4pt] [1] E.C. Dykeman et al., Phys. Rev. Lett., 100, 028101 (2008). [0pt] [2] K-T. Tsen et al., J. of Physics -- Cond. Mat. 19, 472201 (2007).

  5. Statistical Mechanics and Thermodynamics of Viral Evolution

    PubMed Central

    Jones, Barbara A.; Lessler, Justin; Bianco, Simone; Kaufman, James H.

    2015-01-01

    This paper uses methods drawn from physics to study the life cycle of viruses. The paper analyzes a model of viral infection and evolution using the "grand canonical ensemble" and formalisms from statistical mechanics and thermodynamics. Using this approach we enumerate all possible genetic states of a model virus and host as a function of two independent pressures–immune response and system temperature. We prove the system has a real thermodynamic temperature, and discover a new phase transition between a positive temperature regime of normal replication and a negative temperature “disordered” phase of the virus. We distinguish this from previous observations of a phase transition that arises as a function of mutation rate. From an evolutionary biology point of view, at steady state the viruses naturally evolve to distinct quasispecies. This paper also reveals a universal relationship that relates the order parameter (as a measure of mutational robustness) to evolvability in agreement with recent experimental and theoretical work. Given that real viruses have finite length RNA segments that encode proteins which determine virus fitness, the approach used here could be refined to apply to real biological systems, perhaps providing insight into immune escape, the emergence of novel pathogens and other results of viral evolution. PMID:26422205

  6. Viral Hepatitis: A through E and Beyond

    MedlinePlus

    Viral Hepatitis: A through E and Beyond NATIONAL INSTITUTES OF HEALTH U.S. Department of Health and Human Services National Digestive Diseases Information Clearinghouse What is viral hepatitis? Viral hepatitis is inflammation of the liver caused ...

  7. Immunization Against Viral Diseases

    PubMed Central

    Wehrle, Paul F.

    1965-01-01

    Means are now at hand, if properly employed, to virtually eliminate clinical poliomyelitis and measles from this country. If such control is to be accomplished, more effective means are required to reach virtually all of the four million infants born each year in this country. Influenza can be suppressed, and improvements in influenza vaccine have been achieved in recent years. It seems likely at this time that at least several of the more important viral diseases can be controlled by utilizing antigens based on the biologic characteristics of the agent, and directed toward the reservoir of infection and the conditions favoring transmission of the infection. The theoretical problem of the effects in man of viruses that are oncogenic in rodents and are derived from various tissue culture systems deserves serious attention. However, this consideration, that of antigenic potency, and other problems reviewed should not be allowed to subvert efforts to solve the real problems that face us, the disability and death resulting from these common infections. PMID:14347979

  8. DENGUE VIRAL INFECTIONS

    PubMed Central

    Gurugama, Padmalal; Garg, Pankaj; Perera, Jennifer; Wijewickrama, Ananda; Seneviratne, Suranjith L

    2010-01-01

    Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF) occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host, different serotypes, and favorable conditions for vector breeding have led to the virulence and spread of the infections. The manifestations of dengue infections are protean from being asymptomatic to undifferentiated fever, severe dengue infections, and unusual complications. Early recognition and prompt initiation of appropriate supportive treatment are often delayed resulting in unnecessarily high morbidity and mortality. Attempts are underway for the development of a vaccine for preventing the burden of this neglected disease. This review outlines the epidemiology, clinical features, pathophysiologic mechanisms, management, and control of dengue infections. PMID:20418983

  9. Dengue viral infections.

    PubMed

    Gurugama, Padmalal; Garg, Pankaj; Perera, Jennifer; Wijewickrama, Ananda; Seneviratne, Suranjith L

    2010-01-01

    Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF) occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host, different serotypes, and favorable conditions for vector breeding have led to the virulence and spread of the infections. The manifestations of dengue infections are protean from being asymptomatic to undifferentiated fever, severe dengue infections, and unusual complications. Early recognition and prompt initiation of appropriate supportive treatment are often delayed resulting in unnecessarily high morbidity and mortality. Attempts are underway for the development of a vaccine for preventing the burden of this neglected disease. This review outlines the epidemiology, clinical features, pathophysiologic mechanisms, management, and control of dengue infections.

  10. Metagenomics-based analysis of viral communities in dairy lagoon wastewater.

    PubMed

    Alhamlan, F S; Ederer, M M; Brown, C J; Coats, E R; Crawford, R L

    2013-02-15

    Microbial populations, especially those of viruses, are poorly studied in dairy wastewater treatment operations. Here we report signature nucleic acid metagenomic sequences obtained by pyrosequencing viromes of virus-like particles that were extracted from two dairy waste treatment lagoons. The lagoons are operated in series, with Lagoon I being used as the primary stage and Lagoon II as the secondary stage of wastewater treatment. An average of 2000 sequences was obtained from each lagoon. More than 300 signatures from each lagoon matched sequences in the virus database of the National Center for Biotechnology Information (NCBI). We utilized a bioinformatics approach and transmission electron microscopy (TEM) to characterize the viral diversity and presence of potential viral pathogens within the lagoons. Our results showed differences in viral community compositions between Lagoon I and Lagoon II, suggesting that the viral community changes significantly in the transition of water between the two lagoons. Furthermore, the diverse viral community in the lagoon samples contained signature sequences of a variety of bacterial, plant, and animal viruses. Bacteriophage sequences dominated the viral community metagenomes in both lagoons. Ultimately these results can be used to identify viral bioindicators to rapidly assess wastewater treatment quality and the potential impacts of dairy operations on watersheds. Our viral metagenomic sequences have been submitted to GenBank (GPID 65805) and can provide insight into the composition and structure of viral communities within wastewaters of dairy lagoon systems.

  11. Guidelines for the qualitative detection of viral genomes in dried blood spots.

    PubMed

    Gibellini, Davide; De Crignis, Elisa; Re, Maria Carla

    2012-01-01

    Dried blood spots (DBSs) are a useful alternative to blood sampling especially in children or for screening high-risk populations in developing countries. DBS blood collection can be employed in the diagnosis of viral infections by PCR or RT-PCR and also in viral genome sequencing. In addition, the advent of multiplex PCR approaches has led to further diagnostic and methodological improvements allowing simultaneous detection of two or more different viral genomes in the same sample and amplification reaction. This chapter describes general guidelines for the qualitative viral genome amplification and detection in DBS providing an example application of a qualitative real-time SYBR Green-based multiplex RT-PCR assay targeting two major viral pathogens, HIV-1 and HCV.

  12. Twenty years of psychoneuroimmunology and viral infections in Brain, Behavior, and Immunity.

    PubMed

    Bonneau, Robert H; Padgett, David A; Sheridan, John F

    2007-03-01

    For 20 years, Brain, Behavior, and Immunity has provided an important venue for the publication of studies in psychoneuroimmunology. During this time period, psychoneuroimmunology has matured into an important multidisciplinary science that has contributed significantly to our knowledge of mind, brain, and body interactions. This review will not only focus on the primary research papers dealing with psychoneuroimmunology, viral infections, and anti-viral vaccine responses in humans and animal models that have appeared on the pages of Brain, Behavior, and Immunity during the past 20 years, but will also outline a variety of strategies that could be used for expanding our understanding of the neuroimmune-viral pathogen relationship.

  13. Viral BLIP dynamics during HAART.

    SciTech Connect

    Markowitz, M.; Louie, M.; Hurley, A.; Ho, David D.; Perelson, Alan S.,; Di Mascio, M.

    2001-01-01

    Intermittent episodes of low-level viremia (blips) are often observed in well-suppressed, HAART-treated patients. It has been reported that viral blips do not correlate with the emergence of new HAART-related mutations; however, increased frequency of blips correlates with slower decay of latently infected cells. Since blips are transient and unpredictable, detailed knowledge about them is difficult to obtain. We present an analysis of the dynamics of viral blips from viral load (VL) measurements on 123 patients for a period of 809k480d (21-1817d) and sampled every 31{+-}12d for a total of 26{+-}15 samples per patient.

  14. Detection of highly pathogenic and low pathogenic avian influenza subtype H5 (Eurasian lineage) using NASBA.

    PubMed

    Collins, Richard A; Ko, Lung Sang; So, Ka Lun; Ellis, Trevor; Lau, Lok Ting; Yu, Albert Cheung Hoi

    2002-05-16

    Nucleic acid sequence-based amplification (NASBA) is a technique that allows the rapid amplification of specific regions of nucleic acid obtained from a diverse range of sources. It is especially suitable for amplifying RNA sequences. A NASBA technique has been developed that allows the detection of avian influenza A subtype H5 from allantoic fluid harvested from inoculated chick embryos. The amplified viral RNA is detected by electrochemiluminescence. The NASBA technique described below is rapid and specific for the identification of influenza A subtype H5 viruses of the Eurasian lineage. More importantly, it can be used to distinguish highly pathogenic and low pathogenic strains of the H5 subtype.

  15. Receptor use by pathogenic arenaviruses.

    PubMed

    Reignier, Therese; Oldenburg, Jill; Noble, Beth; Lamb, Erika; Romanowski, Victor; Buchmeier, Michael J; Cannon, Paula M

    2006-09-15

    The arenavirus family contains several important human pathogens including Lassa fever virus (LASV), lymphocytic choriomeningitis virus (LCMV) and the New World clade B viruses Junin (JUNV) and Machupo (MACV). Previously, alpha-dystroglycan (alpha-DG) was identified as a receptor recognized by LASV and certain strains of LCMV. However, other studies have suggested that alpha-DG is probably not used by the clade B viruses, and the receptor(s) for these pathogens is currently unknown. Using pseudotyped retroviral vectors displaying arenavirus glycoproteins (GPs), we are able to explore the role played by the GP in viral entry in the absence of other viral proteins. By examining the ability of the vectors to transduce DG knockout murine embryonic stem (ES) cells, we have confirmed that LASV has an absolute requirement for alpha-DG in these cells. However, the LCMV GP can still direct substantial entry into murine ES cells in the absence of alpha-DG, even when the GP from the clone 13 variant is used that has previously been reported to be highly dependent on alpha-DG for entry. We also found that neither LASV or LCMV pseudotyped vectors were able to transduce human or murine lymphocytes, presumably due to the glycosylation state of alpha-DG in these cells. In contrast, the JUNV and MACV GPs displayed broad tropism on human, murine and avian cell types, including lymphocytes, and showed no requirement for alpha-DG in murine ES cells. These findings highlight the importance of molecules other than alpha-DG for arenavirus entry. An alternate receptor is present on murine ES cells that can be used by LCMV but not by LASV, and which is not available on human or murine lymphocytes, while a distinct and widely expressed receptor(s) is used by the clade B viruses.

  16. Polycistronic viral vectors.

    PubMed

    de Felipe, P

    2002-09-01

    Traditionally, vectors for gene transfer/therapy experiments were mono- or bicistronic. In the latter case, vectors express the gene of interest coupled with a marker gene. An increasing demand for more complex polycistronic vectors has arisen in recent years to obtain complex gene transfer/therapy effects. In particular, this demand is stimulated by the hope of a more powerful effect from combined gene therapy than from single gene therapy in a process whose parallels lie in the multi-drug combined therapies for cancer or AIDS. In the 1980's we had only splicing signals and internal promoters to construct such vectors: now a new set of biotechnological tools enables us to design new and more reliable bicistronic and polycistronic vectors. This article focuses on the description and comparison of the strategies for co-expression of two genes in bicistronic vectors, from the oldest to the more recently described: internal promoters, splicing, reinitiation, IRES, self-processing peptides (e.g. foot-and-mouth disease virus 2A), proteolytic cleavable sites (e.g. fusagen) and fusion of genes. I propose a classification of these strategies based upon either the use of multiple transcripts (with transcriptional mechanisms), or single transcripts (using translational/post-translational mechanisms). I also examine the different attempts to utilize these strategies in the construction of polycistronic vectors and the main problems encountered. Several potential uses of these polycistronic vectors, both in basic research and in therapy-focused applications, are discussed. The importance of the study of viral gene expression strategies and the need to transfer this knowledge to vector design is highlighted.

  17. Neuroanatomy goes viral!

    PubMed

    Nassi, Jonathan J; Cepko, Constance L; Born, Richard T; Beier, Kevin T

    2015-01-01

    The nervous system is complex not simply because of the enormous number of neurons it contains but by virtue of the specificity with which they are connected. Unraveling this specificity is the task of neuroanatomy. In this endeavor, neuroanatomists have traditionally exploited an impressive array of tools ranging from the Golgi method to electron microscopy. An ideal method for studying anatomy would label neurons that are interconnected, and, in addition, allow expression of foreign genes in these neurons. Fortuitously, nature has already partially developed such a method in the form of neurotropic viruses, which have evolved to deliver their genetic material between synaptically connected neurons while largely eluding glia and the immune system. While these characteristics make some of these viruses a threat to human health, simple modifications allow them to be used in controlled experimental settings, thus enabling neuroanatomists to trace multi-synaptic connections within and across brain regions. Wild-type neurotropic viruses, such as rabies and alpha-herpes virus, have already contributed greatly to our understanding of brain connectivity, and modern molecular techniques have enabled the construction of recombinant forms of these and other viruses. These newly engineered reagents are particularly useful, as they can target genetically defined populations of neurons, spread only one synapse to either inputs or outputs, and carry instructions by which the targeted neurons can be made to express exogenous proteins, such as calcium sensors or light-sensitive ion channels, that can be used to study neuronal function. In this review, we address these uniquely powerful features of the viruses already in the neuroanatomist's toolbox, as well as the aspects of their biology that currently limit their utility. Based on the latter, we consider strategies for improving viral tracing methods by reducing toxicity, improving control of transsynaptic spread, and extending

  18. Neuroanatomy goes viral!

    PubMed Central

    Nassi, Jonathan J.; Cepko, Constance L.; Born, Richard T.; Beier, Kevin T.

    2015-01-01

    The nervous system is complex not simply because of the enormous number of neurons it contains but by virtue of the specificity with which they are connected. Unraveling this specificity is the task of neuroanatomy. In this endeavor, neuroanatomists have traditionally exploited an impressive array of tools ranging from the Golgi method to electron microscopy. An ideal method for studying anatomy would label neurons that are interconnected, and, in addition, allow expression of foreign genes in these neurons. Fortuitously, nature has already partially developed such a method in the form of neurotropic viruses, which have evolved to deliver their genetic material between synaptically connected neurons while largely eluding glia and the immune system. While these characteristics make some of these viruses a threat to human health, simple modifications allow them to be used in controlled experimental settings, thus enabling neuroanatomists to trace multi-synaptic connections within and across brain regions. Wild-type neurotropic viruses, such as rabies and alpha-herpes virus, have already contributed greatly to our understanding of brain connectivity, and modern molecular techniques have enabled the construction of recombinant forms of these and other viruses. These newly engineered reagents are particularly useful, as they can target genetically defined populations of neurons, spread only one synapse to either inputs or outputs, and carry instructions by which the targeted neurons can be made to express exogenous proteins, such as calcium sensors or light-sensitive ion channels, that can be used to study neuronal function. In this review, we address these uniquely powerful features of the viruses already in the neuroanatomist’s toolbox, as well as the aspects of their biology that currently limit their utility. Based on the latter, we consider strategies for improving viral tracing methods by reducing toxicity, improving control of transsynaptic spread, and

  19. Comparative Genomics of an Emerging Amphibian Virus.

    PubMed

    Epstein, Brendan; Storfer, Andrew

    2015-11-03

    Ranaviruses, a genus of the Iridoviridae, are large double-stranded DNA viruses that infect cold-blooded vertebrates worldwide. Ranaviruses have caused severe epizootics in commercial frog and fish populations, and are currently classified as notifiable pathogens in international trade. Previous work shows that a ranavirus that infects tiger salamanders throughout Western North America (Ambystoma tigrinum virus, or ATV) is in high prevalence among salamanders in the fishing bait trade. Bait ATV strains have elevated virulence and are transported long distances by humans, providing widespread opportunities for pathogen pollution. We sequenced the genomes of 15 strains of ATV collected from tiger salamanders across western North America and performed phylogenetic and population genomic analyses and tests for recombination. We find that ATV forms a monophyletic clade within the rest of the Ranaviruses and that it likely emerged within the last several thousand years, before human activities influenced its spread. We also identify several genes under strong positive selection, some of which appear to be involved in viral virulence and/or host immune evasion. In addition, we provide support for the pathogen pollution hypothesis with evidence of recombination among ATV strains, and potential bait-endemic strain recombination.

  20. Comparative Genomics of an Emerging Amphibian Virus

    PubMed Central

    Epstein, Brendan; Storfer, Andrew

    2015-01-01

    Ranaviruses, a genus of the Iridoviridae, are large double-stranded DNA viruses that infect cold-blooded vertebrates worldwide. Ranaviruses have caused severe epizootics in commercial frog and fish populations, and are currently classified as notifiable pathogens in international trade. Previous work shows that a ranavirus that infects tiger salamanders throughout Western North America (Ambystoma tigrinum virus, or ATV) is in high prevalence among salamanders in the fishing bait trade. Bait ATV strains have elevated virulence and are transported long distances by humans, providing widespread opportunities for pathogen pollution. We sequenced the genomes of 15 strains of ATV collected from tiger salamanders across western North America and performed phylogenetic and population genomic analyses and tests for recombination. We find that ATV forms a monophyletic clade within the rest of the Ranaviruses and that it likely emerged within the last several thousand years, before human activities influenced its spread. We also identify several genes under strong positive selection, some of which appear to be involved in viral virulence and/or host immune evasion. In addition, we provide support for the pathogen pollution hypothesis with evidence of recombination among ATV strains, and potential bait-endemic strain recombination. PMID:26530419

  1. Comparative Genomics of an Emerging Amphibian Virus.

    PubMed

    Epstein, Brendan; Storfer, Andrew

    2016-01-01

    Ranaviruses, a genus of the Iridoviridae, are large double-stranded DNA viruses that infect cold-blooded vertebrates worldwide. Ranaviruses have caused severe epizootics in commercial frog and fish populations, and are currently classified as notifiable pathogens in international trade. Previous work shows that a ranavirus that infects tiger salamanders throughout Western North America (Ambystoma tigrinum virus, or ATV) is in high prevalence among salamanders in the fishing bait trade. Bait ATV strains have elevated virulence and are transported long distances by humans, providing widespread opportunities for pathogen pollution. We sequenced the genomes of 15 strains of ATV collected from tiger salamanders across western North America and performed phylogenetic and population genomic analyses and tests for recombination. We find that ATV forms a monophyletic clade within the rest of the Ranaviruses and that it likely emerged within the last several thousand years, before human activities influenced its spread. We also identify several genes under strong positive selection, some of which appear to be involved in viral virulence and/or host immune evasion. In addition, we provide support for the pathogen pollution hypothesis with evidence of recombination among ATV strains, and potential bait-endemic strain recombination. PMID:26530419

  2. Understanding HIV-1 viral load.

    PubMed

    Paxton, W B

    1995-01-01

    HIV viral markers, such as p24 antigen and viral RNA, measure how much virus is present. Studies are showing a relationship between RNA levels and clinical outcomes, which can help doctors evaluate the efficacy of drug therapy. Eventually, it is believed, RNA will replace T-cell counts as the marker of choice. The challenge is to interpret what the results of a viral load test mean for a specific patient. Currently, the two main viral load tests commercially available do not have a one-to-one linear relationship, so tests should not be switched. Doctors are advised not to over-interpret minor changes because of the ten to thirty percent variation in individual test results. These tests are not FDA-approved but are available at commercial reference labs. PMID:11362660

  3. Aseptic meningitis and viral myelitis.

    PubMed

    Irani, David N

    2008-08-01

    Meningitis and myelitis represent common and very infrequent viral infections of the central nervous system, respectively. The number of cases of viral meningitis that occurs annually exceeds the total number of meningitis cases caused by all other etiologies combined. Focal central nervous system infections, such as occur in the spinal cord with viral myelitis, are much less common and may be confused with noninfectious disorders that cause acute flaccid paralysis. This article reviews some of the important clinical features, epidemiology, diagnostic approaches, and management strategies for patients with aseptic meningitis and viral myelitis. Particular focus is placed on the diseases caused by enteroviruses, which as a group account for most aseptic meningitis cases and many focal infections of the spinal cord.

  4. Statistical Mechanics of Viral Entry

    NASA Astrophysics Data System (ADS)

    Zhang, Yaojun; Dudko, Olga K.

    2015-01-01

    Viruses that have lipid-membrane envelopes infect cells by fusing with the cell membrane to release viral genes. Membrane fusion is known to be hindered by high kinetic barriers associated with drastic structural rearrangements—yet viral infection, which occurs by fusion, proceeds on remarkably short time scales. Here, we present a quantitative framework that captures the principles behind the invasion strategy shared by all enveloped viruses. The key to this strategy—ligand-triggered conformational changes in the viral proteins that pull the membranes together—is treated as a set of concurrent, bias field-induced activated rate processes. The framework results in analytical solutions for experimentally measurable characteristics of virus-cell fusion and enables us to express the efficiency of the viral strategy in quantitative terms. The predictive value of the theory is validated through simulations and illustrated through recent experimental data on influenza virus infection.

  5. Viral Control of Mitochondrial Apoptosis

    PubMed Central

    Morselli, Eugenia; Touat, Zahia; Kroemer, Guido

    2008-01-01

    Throughout the process of pathogen–host co-evolution, viruses have developed a battery of distinct strategies to overcome biochemical and immunological defenses of the host. Thus, viruses have acquired the capacity to subvert host cell apoptosis, control inflammatory responses, and evade immune reactions. Since the elimination of infected cells via programmed cell death is one of the most ancestral defense mechanisms against infection, disabling host cell apoptosis might represent an almost obligate step in the viral life cycle. Conversely, viruses may take advantage of stimulating apoptosis, either to kill uninfected cells from the immune system, or to induce the breakdown of infected cells, thereby favoring viral dissemination. Several viral polypeptides are homologs of host-derived apoptosis-regulatory proteins, such as members of the Bcl-2 family. Moreover, viral factors with no homology to host proteins specifically target key components of the apoptotic machinery. Here, we summarize the current knowledge on the viral modulation of mitochondrial apoptosis, by focusing in particular on the mechanisms by which viral proteins control the host cell death apparatus. PMID:18516228

  6. Viral RNAs Are Unusually Compact

    PubMed Central

    Gopal, Ajaykumar; Egecioglu, Defne E.; Yoffe, Aron M.; Ben-Shaul, Avinoam; Rao, Ayala L. N.; Knobler, Charles M.; Gelbart, William M.

    2014-01-01

    A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly. PMID:25188030

  7. Viral immune evasion: Lessons in MHC class I antigen presentation.

    PubMed

    van de Weijer, Michael L; Luteijn, Rutger D; Wiertz, Emmanuel J H J

    2015-03-01

    The MHC class I antigen presentation pathway enables cells infected with intracellular pathogens to signal the presence of the invader to the immune system. Cytotoxic T lymphocytes are able to eliminate the infected cells through recognition of pathogen-derived peptides presented by MHC class I molecules at the cell surface. In the course of evolution, many viruses have acquired inhibitors that target essential stages of the MHC class I antigen presentation pathway. Studies on these immune evasion proteins reveal fascinating strategies used by viruses to elude the immune system. Viral immunoevasins also constitute great research tools that facilitate functional studies on the MHC class I antigen presentation pathway, allowing the investigation of less well understood routes, such as TAP-independent antigen presentation and cross-presentation of exogenous proteins. Viral immunoevasins have also helped to unravel more general cellular processes. For instance, basic principles of ER-associated protein degradation via the ubiquitin-proteasome pathway have been resolved using virus-induced degradation of MHC class I as a model. This review highlights how viral immunoevasins have increased our understanding of MHC class I-restricted antigen presentation.

  8. [Neuropsychiatric sequelae of viral meningitis in adults].

    PubMed

    Damsgaard, Jesper; Hjerrild, Simon; Renvillard, Signe Groth; Leutscher, Peter Derek Christian

    2011-10-10

    Viral meningitis is considered to be a benign illness with only mild symptoms. In contrast to viral encephalitis and bacterial meningitis, the prognosis is usually good. However, retrospective studies have demonstrated that patients suffering from viral meningitis may experience cognitive impairment following the acute course of infection. Larger controlled studies are needed to elucidate the potential neuropsychiatric adverse outcome of viral meningitis.

  9. Clinical and Associated Immunological Manifestations of HFMD Caused by Different Viral Infections in Children.

    PubMed

    Wang, Jingjing; Pu, Jing; Liu, Longding; Che, Yanchun; Liao, Yun; Wang, Lichun; Guo, Lei; Feng, Min; Liang, Yan; Fan, Shengtao; Cai, Lukui; Zhang, Ying; Li, Qihan

    2016-01-01

    Hand, foot, and mouth disease (HFMD), with vesiculae on the hands, feet and mouth, is an infectious disease caused by many viral pathogens. However, the differences of immune response induced by these pathogens are unclear. We compared the clinical manifestations and the levels of immunologic indicators from 60 HFMD patients caused by different viral pathogens to analyze the differences in the immune response. It was shown that Th2 cytokines (IL-4 and IL-10) increased significantly in EV71-infected children; Th1 cytokines (IL-2 and IFN-γ) rose in CA16-infected children; both Th1 and Th2 cytokines elevated in non-EVG-infected children; only individual cytokines (such as IL-10) went up in EVG-infected children. Meanwhile, the antibodies induced by viral infection could not cross-interfere between the different pathogens. These differences might be due to variations in the immune response induced by the individual pathogens or to the pathogenesis of the infections by the individual pathogens. PMID:27336013

  10. Clinical and Associated Immunological Manifestations of HFMD Caused by Different Viral Infections in Children

    PubMed Central

    Wang, Jingjing; Pu, Jing; Liu, Longding; Che, Yanchun; Liao, Yun; Wang, Lichun; Guo, Lei; Feng, Min; Liang, Yan; Fan, Shengtao; Cai, Lukui; Zhang, Ying; Li, Qihan

    2016-01-01

    Hand, foot, and mouth disease (HFMD), with vesiculae on the hands, feet and mouth, is an infectious disease caused by many viral pathogens. However, the differences of immune response induced by these pathogens are unclear. We compared the clinical manifestations and the levels of immunologic indicators from 60 HFMD patients caused by different viral pathogens to analyze the differences in the immune response. It was shown that Th2 cytokines (IL-4 and IL-10) increased significantly in EV71-infected children; Th1 cytokines (IL-2 and IFN-γ) rose in CA16-infected children; both Th1 and Th2 cytokines elevated in non-EVG-infected children; only individual cytokines (such as IL-10) went up in EVG-infected children. Meanwhile, the antibodies induced by viral infection could not cross-interfere between the different pathogens. These differences might be due to variations in the immune response induced by the individual pathogens or to the pathogenesis of the infections by the individual pathogens. PMID:27336013

  11. Molecular Basis of Latency in Pathogenic Human Viruses

    NASA Astrophysics Data System (ADS)

    Garcia-Blanco, Mariano A.; Cullen, Bryan R.

    1991-11-01

    Several human viruses are able to latently infect specific target cell populations in vivo. Analysis of the replication cycles of herpes simplex virus, Epstein-Barr virus, and human immunodeficiency virus suggests that the latent infections established by these human pathogens primarily result from a lack of host factors critical for the expression of viral early gene products. The subsequent activation of specific cellular transcription factors in response to extracellular stimuli can induce the expression of these viral regulatory proteins and lead to a burst of lytic viral replication. Latency in these eukaryotic viruses therefore contrasts with latency in bacteriophage, which is maintained primarily by the expression of virally encoded repressors of lytic replication.

  12. Enteric pathogens through life stages

    PubMed Central

    Kolling, Glynis; Wu, Martin; Guerrant, Richard L.

    2012-01-01

    Enteric infections and diarrheal diseases constitute pervasive health burdens throughout the world, with rates being highest at the two ends of life. During the first 2–3 years of life, much of the disease burden may be attributed to infection with enteric pathogens including Salmonella, rotavirus, and many other bacterial, viral, and protozoan organisms; however, infections due to Clostridium difficile exhibit steady increases with age. Still others, like Campylobacter infections in industrialized settings are high in early life (<2 years old) and increase again in early adulthood (called the “second weaning” by some). The reasons for these differences undoubtedly reside in part in pathogen differences; however, host factors including the commensal intestinal microbial communities, immune responses (innate and acquired), and age-dependant shifts likely play important roles. Interplay of these factors is illustrated by studies examining changes in human gut microbiota with inflammatory bowel disease and irritable bowel syndrome. Recent gut microbial surveys have indicated dramatic shifts in gut microbial population structure from infants to young adults to the elders. An understanding of the evolution of these factors and their interactions (e.g., how does gut microbiota modulate the “inflamm-aging” process or vice versa) through the human life “cycle” will be important in better addressing and controlling these enteric infections and their consequences for both quality and quantity of life (often assessed as disability adjusted life-years or “DALYs”). PMID:22937528

  13. [Pathology and viral metagenomics, a recent history].

    PubMed

    Bernardo, Pauline; Albina, Emmanuel; Eloit, Marc; Roumagnac, Philippe

    2013-05-01

    Human, animal and plant viral diseases have greatly benefited from recent metagenomics developments. Viral metagenomics is a culture-independent approach used to investigate the complete viral genetic populations of a sample. During the last decade, metagenomics concepts and techniques that were first used by ecologists progressively spread into the scientific field of viral pathology. The sample, which was first for ecologists a fraction of ecosystem, became for pathologists an organism that hosts millions of microbes and viruses. This new approach, providing without a priori high resolution qualitative and quantitative data on the viral diversity, is now revolutionizing the way pathologists decipher viral diseases. This review describes the very last improvements of the high throughput next generation sequencing methods and discusses the applications of viral metagenomics in viral pathology, including discovery of novel viruses, viral surveillance and diagnostic, large-scale molecular epidemiology, and viral evolution.

  14. Pathogenic simian immunodeficiency virus infection is associated with expansion of the enteric virome

    PubMed Central

    Handley, Scott; Thackray, Larissa B.; Zhao, Guoyan; Presti, Rachel; Miller, Andrew; Droit, Lindsay; Abbink, Peter; Maxfield, Lori F.; Kambal, Amal; Duan, Erning; Stanley, Kelly; Kramer, Joshua; Macri, Sheila C.; Permar, Sallie R.; Schmitz, Joern E.; Mansfield, Keith; Brenchley, Jason M.; Veazey, Ronald S.; Stappenbeck, Thaddeus S.; Wang, David; Barouch, Dan H.; Virgin, Herbert W.

    2012-01-01

    SUMMARY Pathogenic simian immunodeficiency virus (SIV) infection is associated with enteropathy which likely contributes to AIDS progression. To identify candidate etiologies for AIDS enteropathy, we used next generation sequencing to define the enteric virome during SIV infection in nonhuman primates. Pathogenic, but not non-pathogenic, SIV infection was associated with significant expansion of the enteric virome. We identified at least 32 previously undescribed enteric viruses during pathogenic SIV infection and confirmed their presence using viral culture and PCR testing. We detected unsuspected mucosal adenovirus infection associated with enteritis as well as parvovirus viremia in animals with advanced AIDS, indicating the pathogenic potential of SIV-associated expansion of the enteric virome. No association between pathogenic SIV infection and the family-level taxonomy of enteric bacteria was detected. Thus, enteric viral infections may contribute to AIDS enteropathy and disease progression. These findings underline the importance of metagenomic analysis of the virome for understanding AIDS pathogenesis. PMID:23063120

  15. Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells

    PubMed Central

    Sun, Di; Chen, Shun; Cheng, Anchun; Wang, Mingshu

    2016-01-01

    The Picornaviridae family comprises a large group of non-enveloped viruses that have a major impact on human and veterinary health. The viral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteinases. The crucial 3C proteinases (3Cpros) of picornaviruses share similar spatial structures and it is becoming apparent that 3Cpro plays a significant role in the viral life cycle and virus host interaction. Importantly, the proteinase and RNA-binding activity of 3Cpro are involved in viral polyprotein processing and the initiation of viral RNA synthesis. In addition, 3Cpro can induce the cleavage of certain cellular factors required for transcription, translation and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Due to interactions between 3Cpro and these essential factors, 3Cpro is also involved in viral pathogenesis to support efficient infection. Furthermore, based on the structural conservation, the development of irreversible inhibitors and discovery of non-covalent inhibitors for 3Cpro are ongoing and a better understanding of the roles played by 3Cpro may provide insights into the development of potential antiviral treatments. In this review, the current knowledge regarding the structural features, multiple functions in the viral life cycle, pathogen host interaction, and development of antiviral compounds for 3Cpro is summarized. PMID:26999188

  16. Cellular sensing of viral DNA and viral evasion mechanisms.

    PubMed

    Orzalli, Megan H; Knipe, David M

    2014-01-01

    Mammalian cells detect foreign DNA introduced as free DNA or as a result of microbial infection, leading to the induction of innate immune responses that block microbial replication and the activation of mechanisms that epigenetically silence the genes encoded by the foreign DNA. A number of DNA sensors localized to a variety of sites within the cell have been identified, and this review focuses on the mechanisms that detect viral DNA and how the resulting responses affect viral infections. Viruses have evolved mechanisms that inhibit these host sensors and signaling pathways, and the study of these antagonistic viral strategies has provided insight into the mechanisms of these host responses. The field of cellular sensing of foreign DNA is in its infancy, but our currently limited knowledge has raised a number of important questions for study.

  17. Fc receptors in antibody-dependent enhancement of viral infections.

    PubMed

    Taylor, Adam; Foo, Suan-Sin; Bruzzone, Roberto; Dinh, Luan Vu; King, Nicholas J C; Mahalingam, Suresh

    2015-11-01

    Sensitization of the humoral immune response to invading viruses and production of antiviral antibodies forms part of the host antiviral repertoire. Paradoxically, for a number of viral pathogens, under certain conditions, antibodies provide an attractive means of enhanced virus entry and replication in a number of cell types. Known as antibody-dependent enhancement (ADE) of infection, the phenomenon occurs when virus-antibody immunocomplexes interact with cells bearing complement or Fc receptors, promoting internalization of the virus and increasing infection. Frequently associated with exacerbation of viral disease, ADE of infection presents a major obstacle to the prevention of viral disease by vaccination and is thought to be partly responsible for the adverse effects of novel antiviral therapeutics such as intravenous immunoglobulins. There is a growing body of work examining the intracellular signaling pathways and epitopes responsible for mediating ADE, with a view to aiding rational design of antiviral strategies. With in vitro studies also confirming ADE as a feature of infection for a growing number of viruses, challenges remain in understanding the multilayered molecular mechanisms of ADE and its effect on viral pathogenesis. PMID:26497532

  18. Prevention and control of viral diseases of salmonids

    USGS Publications Warehouse

    Amend, Donald F.

    1976-01-01

    Three viral diseases of salmonids are of worldwide concern: infectious pancreatic necrosis (IPN) viral hemorrhagic septicemia (VHS), and infectious hematopoietic necrosis (IHN). Six principal approaches are being used to prevent or control these diseases: 1) preventing contact o the pathogen with the host, 2) environmental manipulation, 3) immunization, 4) chemotherapy, 5 selective breeding for disease resistance, and 6) reducing stress conditions which augment disease conditions. Preventing the introduction of a pathogen into a new stock of fish has been accomplished mainly by implementing stringent laws to prevent transport of infected fish into uninfected areas. Stocks of fish already infected are sometimes destroyed, and the hatchery is disinfected and restocked with fish free of specific pathogens. Environmental manipulation (elevated water temperature) has been successfully used to control IHN. Chemotherapeutics such as povidone-iodine for IPN and benzipyrene for IHN show promise of controlling mortalities; however, the practicality of using these drugs to eliminate the carrier fish has not been evaluated. Salmonids are capable of developing immune responses to viruses; however, development of effective vaccines, selective breeding for disease resistance, and identification of stress conditions which augment disease are still in the experimental phase.

  19. Computational mechanics of viral capsids.

    PubMed

    Gibbons, Melissa M; Perotti, Luigi E; Klug, William S

    2015-01-01

    Viral capsids undergo significant mechanical deformations during their assembly, maturation, and infective life-span. In order to characterize the mechanics of viral capsids, their response to applied external forces is analyzed in several experimental studies using, for instance, Atomic Force Microscope (AFM) indentation experiments. In recent years, a broader approach to study the mechanics of viral capsids has leveraged the theoretical tools proper of continuum mechanics. Even though the theory of continuum elasticity is most commonly used to study deformable bodies at larger macroscopic length scales, it has been shown that this very rich theoretical field can still offer useful insights into the mechanics of viral structures at the nanometer scale. Here we show the construction of viral capsid continuum mechanics models starting from different forms of experimental data. We will discuss the kinematics assumptions, the issue of the reference configuration, the material constitutive laws, and the numerical discretization necessary to construct a complete Finite Element capsid mechanical model. Some examples in the second part of the chapter will show the predictive capabilities of the constructed models and underline useful practical aspects related to efficiency and accuracy. We conclude each example by collecting several key findings discovered by simulating AFM indentation experiments using the constructed numerical models.

  20. The role of autophagy in intracellular pathogen nutrient acquisition

    PubMed Central

    Steele, Shaun; Brunton, Jason; Kawula, Thomas

    2015-01-01

    Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates, and amino acids). It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral, and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells. PMID:26106587

  1. Neuroinvasion and Inflammation in Viral Central Nervous System Infections

    PubMed Central

    Schroten, Horst

    2016-01-01

    Neurotropic viruses can cause devastating central nervous system (CNS) infections, especially in young children and the elderly. The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) have been described as relevant sites of entry for specific viruses as well as for leukocytes, which are recruited during the proinflammatory response in the course of CNS infection. In this review, we illustrate examples of established brain barrier models, in which the specific reaction patterns of different viral families can be analyzed. Furthermore, we highlight the pathogen specific array of cytokines and chemokines involved in immunological responses in viral CNS infections. We discuss in detail the link between specific cytokines and chemokines and leukocyte migration profiles. The thorough understanding of the complex and interrelated inflammatory mechanisms as well as identifying universal mediators promoting CNS inflammation is essential for the development of new diagnostic and treatment strategies. PMID:27313404

  2. Recovering full-length viral genomes from metagenomes

    PubMed Central

    Smits, Saskia L.; Bodewes, Rogier; Ruiz-González, Aritz; Baumgärtner, Wolfgang; Koopmans, Marion P.; Osterhaus, Albert D. M. E.; Schürch, Anita C.

    2015-01-01

    Infectious disease metagenomics is driven by the question: “what is causing the disease?” in contrast to classical metagenome studies which are guided by “what is out there?” In case of a novel virus, a first step to eventually establishing etiology can be to recover a full-length viral genome from a metagenomic sample. However, retrieval of a full-length genome of a divergent virus is technically challenging and can be time-consuming and costly. Here we discuss different assembly and fragment linkage strategies such as iterative assembly, motif searches, k-mer frequency profiling, coverage profile binning, and other strategies used to recover genomes of potential viral pathogens in a timely and cost-effective manner. PMID:26483782

  3. Papillomaviruses: Viral evolution, cancer and evolutionary medicine.

    PubMed

    Bravo, Ignacio G; Félez-Sánchez, Marta

    2015-01-28

    Papillomaviruses (PVs) are a numerous family of small dsDNA viruses infecting virtually all mammals. PVs cause infections without triggering a strong immune response, and natural infection provides only limited protection against reinfection. Most PVs are part and parcel of the skin microbiota. In some cases, infections by certain PVs take diverse clinical presentations from highly productive self-limited warts to invasive cancers. We propose PVs as an excellent model system to study the evolutionary interactions between the immune system and pathogens causing chronic infections: genotypically, PVs are very diverse, with hundreds of different genotypes infecting skin and mucosa; phenotypically, they display extremely broad gradients and trade-offs between key phenotypic traits, namely productivity, immunogenicity, prevalence, oncogenicity and clinical presentation. Public health interventions have been launched to decrease the burden of PV-associated cancers, including massive vaccination against the most oncogenic human PVs, as well as systematic screening for PV chronic anogenital infections. Anti-PVs vaccines elicit protection against infection, induce cross-protection against closely related viruses and result in herd immunity. However, our knowledge on the ecological and intrapatient dynamics of PV infections remains fragmentary. We still need to understand how the novel anthropogenic selection pressures posed by vaccination and screening will affect viral circulation and epidemiology. We present here an overview of PV evolution and the connection between PV genotypes and the phenotypic, clinical manifestations of the diseases they cause. This differential link between viral evolution and the gradient cancer-warts-asymptomatic infections makes PVs a privileged playground for evolutionary medicine research.

  4. Discovery and initial analysis of novel viral genomes in the soybean cyst nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes are the most abundant multi-cellular animals on earth, yet little is known about their natural viral pathogens and no nematode virus genomes have been published. Consequently, nematode viruses have been overlooked as important biotic factors in the study of nematode ecology. Here we show t...

  5. Noncoding RNPs of viral origin.

    PubMed

    Steitz, Joan; Borah, Sumit; Cazalla, Demian; Fok, Victor; Lytle, Robin; Mitton-Fry, Rachel; Riley, Kasandra; Samji, Tasleem

    2011-03-01

    Like their host cells, many viruses produce noncoding (nc)RNAs. These show diversity with respect to time of expression during viral infection, length and structure, protein-binding partners and relative abundance compared with their host-cell counterparts. Viruses, with their limited genomic capacity, presumably evolve or acquire ncRNAs only if they selectively enhance the viral life cycle or assist the virus in combating the host's response to infection. Despite much effort, identifying the functions of viral ncRNAs has been extremely challenging. Recent technical advances and enhanced understanding of host-cell ncRNAs promise accelerated insights into the RNA warfare mounted by this fascinating class of RNPs. PMID:20719877

  6. Sendai virus intra-host population dynamics and host immunocompetence influence viral virulence during in vivo passage

    PubMed Central

    Peña, José; Chen-Harris, Haiyin; Allen, Jonathan E.; Hwang, Mona; Elsheikh, Maher; Mabery, Shalini; Bielefeldt-Ohmann, Helle; Zemla, Adam T.; Bowen, Richard A.; Borucki, Monica K.

    2016-01-01

    In vivo serial passage of non-pathogenic viruses has been shown to lead to increased viral virulence, and although the precise mechanism(s) are not clear, it is known that both host and viral factors are associated with increased pathogenicity. Under- or overnutrition leads to a decreased or dysregulated immune response and can increase viral mutant spectrum diversity and virulence. The objective of this study was to identify the role of viral mutant spectra dynamics and host immunocompetence in the development of pathogenicity during in vivo passage. Because the nutritional status of the host has been shown to affect the development of viral virulence, the diet of animal model reflected two extremes of diets which exist in the global population, malnutrition and obesity. Sendai virus was serially passaged in groups of mice with differing nutritional status followed by transmission of the passaged virus to a second host species, guinea pigs. Viral population dynamics were characterized using deep sequence analysis and computational modeling. Histopathology, viral titer and cytokine assays were used to characterize viral virulence. Viral virulence increased with passage and the virulent phenotype persisted upon passage to a second host species. Additionally, nutritional status of mice during passage influenced the phenotype. Sequencing revealed the presence of several non-synonymous changes in the consensus sequence associated with passage, a majority of which occurred in the hemagglutinin-neuraminidase and polymerase genes, as well as the presence of persistent high frequency variants in the viral population. In particular, an N1124D change in the consensus sequences of the polymerase gene was detected by passage 10 in a majority of the animals. In vivo comparison of an 1124D plaque isolate to a clone with 1124N genotype indicated that 1124D was associated with increased virulence. PMID:27774301

  7. Dissecting innate immune signaling in viral evasion of cytokine production.

    PubMed

    Zhang, Junjie; Zhu, Lining; Feng, Pinghui

    2014-03-02

    In response to a viral infection, the host innate immune response is activated to up-regulate gene expression and production of antiviral cytokines. Conversely, viruses have evolved intricate strategies to evade and exploit host immune signaling for survival and propagation. Viral immune evasion, entailing host defense and viral evasion, provides one of the most fascinating and dynamic interfaces to discern the host-virus interaction. These studies advance our understanding in innate immune regulation and pave our way to develop novel antiviral therapies. Murine γHV68 is a natural pathogen of murine rodents. γHV68 infection of mice provides a tractable small animal model to examine the antiviral response to human KSHV and EBV of which perturbation of in vivo virus-host interactions is not applicable. Here we describe a protocol to determine the antiviral cytokine production. This protocol can be adapted to other viruses and signaling pathways. Recently, we have discovered that γHV68 hijacks MAVS and IKKβ, key innate immune signaling components downstream of the cytosolic RIG-I and MDA5, to abrogate NFΚB activation and antiviral cytokine production. Specifically, γHV68 infection activates IKKβ and that activated IKKβ phosphorylates RelA to accelerate RelA degradation. As such, γHV68 efficiently uncouples NFΚB activation from its upstream activated IKKβ, negating antiviral cytokine gene expression. This study elucidates an intricate strategy whereby the upstream innate immune activation is intercepted by a viral pathogen to nullify the immediate downstream transcriptional activation and evade antiviral cytokine production.

  8. [Emerging viral diseases in Europe].

    PubMed

    Löbermann, M; Gürtler, L G; Eichler-Löbermann, B; Reisinger, E C

    2012-04-01

    Emergence of viral agents in Europe is influenced by various factors. Climatic changes influencing possible vectors, insufficient vaccination, and travel of man and goods are among the most important reasons to explain these changes. Fever and arthralgia are the leading symptoms in infection with Dengue, Sindbis, or Chikungunya virus. In contrast, tick-born encephalitis (TBE), Toscana, or West Nile virus infections mainly lead to meningo-encephalitis. In Europe, hemorrhagic fever is caused by Crimean Congo and Hanta virus. Protective vaccines are available for emerging viral agents like TBE, influenza and measles.

  9. Viral IAPs, then and now.

    PubMed

    Clem, Rollie J

    2015-03-01

    The identification, now more than 20 years ago, of the first iap genes in baculoviruses subsequently led to many important discoveries concerning the regulation of apoptosis and other important biological processes in insects and mammals. Currently there are more than 200 known viral IAP homologs in baculoviruses and other families of invertebrate DNA viruses. This review begins with a personal account of the events leading up to the discovery of the first iap genes, followed by a summary of what is currently known about the different types of viral IAPs and their functions in regulating apoptosis, and possibly other cellular processes.

  10. Viruses of Fish: An Overview of Significant Pathogens

    PubMed Central

    Crane, Mark; Hyatt, Alex

    2011-01-01

    The growing global demand for seafood together with the limited capacity of the wild-capture sector to meet this demand has seen the aquaculture industry continue to grow around the world. A vast array of aquatic animal species is farmed in high density in freshwater, brackish and marine systems where they are exposed to new environments and potentially new diseases. On-farm stresses may compromise their ability to combat infection, and farming practices facilitate rapid transmission of disease. Viral pathogens, whether they have been established for decades or whether they are newly emerging as disease threats, are particularly challenging since there are few, if any, efficacious treatments, and the development of effective viral vaccines for delivery in aquatic systems remains elusive. Here, we review a few of the more significant viral pathogens of finfish, including aquabirnaviruses and infectious hematopoietic necrosis virus which have been known since the first half of the 20th century, and more recent viral pathogens, for example betanodaviruses, that have emerged as aquaculture has undergone a dramatic expansion in the past few decades. PMID:22163333

  11. Epidemiology of the spread of viral diseases under aquaculture.

    PubMed

    Murray, Alexander G

    2013-02-01

    Aquaculture production is increasing rapidly worldwide. However, production has been associated with the emergence of several novel diseases, including viral diseases, that have caused serious problems for producers. Using examples largely from salmon farming in Scotland I review briefly the factors that allow transmission to occur in aquaculture. These include transmission through the water, which is relatively local to the infected farm, and anthropogenic transports (such as transport of fish between sites) that may occur over very long distances. A Disease Management Area (DMA) approach, as developed in Scotland to fight infectious salmon anaemia, can be effective at reducing pathogen transmission and hence disease emergence.

  12. Molecular basis of host specificity in human pathogenic bacteria

    PubMed Central

    Pan, Xiaolei; Yang, Yang; Zhang, Jing-Ren

    2014-01-01

    Pathogenic bacteria display various levels of host specificity or tropism. While many bacteria can infect a wide range of hosts, certain bacteria have strict host selectivity for humans as obligate human pathogens. Understanding the genetic and molecular basis of host specificity in pathogenic bacteria is important for understanding pathogenic mechanisms, developing better animal models and designing new strategies and therapeutics for the control of microbial diseases. The molecular mechanisms of bacterial host specificity are much less understood than those of viral pathogens, in part due to the complexity of the molecular composition and cellular structure of bacterial cells. However, important progress has been made in identifying and characterizing molecular determinants of bacterial host specificity in the last two decades. It is now clear that the host specificity of bacterial pathogens is determined by multiple molecular interactions between the pathogens and their hosts. Furthermore, certain basic principles regarding the host specificity of bacterial pathogens have emerged from the existing literature. This review focuses on selected human pathogenic bacteria and our current understanding of their host specificity. PMID:26038515

  13. Translating HIV sequences into quantitative fitness landscapes predicts viral vulnerabilities for rational immunogen design.

    PubMed

    Ferguson, Andrew L; Mann, Jaclyn K; Omarjee, Saleha; Ndung'u, Thumbi; Walker, Bruce D; Chakraborty, Arup K

    2013-03-21

    A prophylactic or therapeutic vaccine offers the best hope to curb the HIV-AIDS epidemic gripping sub-Saharan Africa, but it remains elusive. A major challenge is the extreme viral sequence variability among strains. Systematic means to guide immunogen design for highly variable pathogens like HIV are not available. Using computational models, we have developed an approach to translate available viral sequence data into quantitative landscapes of viral fitness as a function of the amino acid sequences of its constituent proteins. Predictions emerging from our computationally defined landscapes for the proteins of HIV-1 clade B Gag were positively tested against new in vitro fitness measurements and were consistent with previously defined in vitro measurements and clinical observations. These landscapes chart the peaks and valleys of viral fitness as protein sequences change and inform the design of immunogens and therapies that can target regions of the virus most vulnerable to selection pressure.

  14. Viral Membrane Channels: Role and Function in the Virus Life Cycle

    PubMed Central

    Sze, Ching Wooen; Tan, Yee-Joo

    2015-01-01

    Viroporins are small, hydrophobic trans-membrane viral proteins that oligomerize to form hydrophilic pores in the host cell membranes. These proteins are crucial for the pathogenicity and replication of viruses as they aid in various stages of the viral life cycle, from genome uncoating to viral release. In addition, the ion channel activity of viroporin causes disruption in the cellular ion homeostasis, in particular the calcium ion. Fluctuation in the calcium level triggers the activation of the host defensive programmed cell death pathways as well as the inflammasome, which in turn are being subverted for the viruses’ replication benefits. This review article summarizes recent developments in the functional investigation of viroporins from various viruses and their contributions to viral replication and virulence. PMID:26110585

  15. Viral (hepatitis C virus, hepatitis B virus, HIV) persistence and immune homeostasis

    PubMed Central

    Zhou, Yun; Zhang, Ying; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhan S

    2014-01-01

    Immune homeostasis is a host characteristic that maintains biological balance within a host. Humans have evolved many host defence mechanisms that ensure the survival of individuals upon encountering a pathogenic infection, with recovery or persistence from a viral infection being determined by both viral factors and host immunity. Chronic viral infections, such as hepatitis B virus, hepatitis C virus and HIV, often result in chronic fluctuating viraemia in the face of host cellular and humoral immune responses, which are dysregulated by multi-faceted mechanisms that are incompletely understood. This review attempts to illuminate the mechanisms involved in this process, focusing on immune homeostasis in the setting of persistent viral infection from the aspects of host defence mechanism, including interferon-stimulated genes, apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3), autophagy and interactions of various immune cells, cytokines and regulatory molecules. PMID:24965611

  16. Viral Membrane Channels: Role and Function in the Virus Life Cycle.

    PubMed

    Sze, Ching Wooen; Tan, Yee-Joo

    2015-06-01

    Viroporins are small, hydrophobic trans-membrane viral proteins that olig