Circulation of Different Lineages of Dengue Virus Type 2 in Central America, Their Evolutionary Time-Scale and Selection Pressure Analysis

Dengue is caused by any of the four serotypes of dengue virus (DENV-1 to 4). Each serotype is genetically distant from the others, and each has been subdivided into different genotypes based on phylogenetic analysis. The study of dengue evolution in endemic regions is important since the diagnosis is often made by nucleic acid amplification tests, which depends upon recognition of the viral genome target, and natural occurring mutations can affect the performance of these assays. Here we report for the first time a detailed study of the phylogenetic relationships of DENV-2 from Central America, and report the first fully sequenced DENV-2 strain from Guatemala. Our analysis of the envelope (E) protein and of the open reading frame of strains from Central American countries, between 1999 and 2009, revealed that at least two lineages of the American/Asian genotype of DENV-2 have recently circulated in that region. In occasions the co-circulation of these lineages may have occurred and that has been suggested to play a role in the observed increased severity of clinical cases. Our time-scale analysis indicated that the most recent common ancestor for Central American DENV-2 of the American/Asian genotype existed about 19 years ago. Finally, we report positive selection in DENV-2 from Central America in codons of the genes encoding for C, E, NS2A, NS3, and NS5 proteins. Some of these identified codons are novel findings, described for the first time for any of the DENV-2 genotypes

Adverse effects in wild fish living downstream from pharmaceutical manufacture discharges

International audienceA set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations

GAS1:A New β-Glucan Immunostimulant Candidate to Increase Rainbow Trout (Oncorhynchus mykiss) Resistance to Bacterial Infections With Aeromonas salmonicida achromogenes

β-glucans are prebiotic and/or food additives used by the aquaculture industry to enhance the immune response of fish. Their efficiency may vary according to their origin and structure. In this study, the immunostimulant effects of two β-glucan types extracted from wild-type baker’s yeast (Saccharomyces cerevisiae) and its null-mutant Gas1 were investigated. Gas1 has a beta-1,3-glucanosyltransferase activity necessary for cell wall assembly. Using a positive (commercial product MacroGard(®)) and a negative control (a diet without glucans), we evaluated the immune responses and disease resistance of rainbow trout juveniles (mean weight, ~44 g) fed control, low (0.2%) and high (0.5%) doses of Macrogard(®), Gas1, and Wild type-β-glucan after a short-term (15 days, D15) or mid-term (36 days, D36) feeding periods. We found that β-glucan supplemented diets did not affect growth performance, mortality, splenic index, or leukocyte respiratory burst activity on D15 nor D36. However, each β-glucan triggered different immune effectors, depending of the doses or length of exposure compared to others and/or the negative control. Indeed, high dose of MacroGard(®) significantly increased lysozyme activities at D15 compared with the control and other diets (p<0.05). At D36, MacroGard β-glucan enhanced the production of lymphocytes in comparison with the control diet (p<0.05). Regarding WT β-glucan, at D36, WT-β-glucan, especially the high dose, provided the highest enzymatic activities (lysozyme and ACH50) and Ig level (p<0.01). Furthermore, on D36, Gas1 also increased lysozyme activity, Ig proportion, and some immune genes (mcsfra, hepcidin) compared with MacroGard(®) (p<0.05). Besides, both doses of Gas1-β-glucans increased the resistance of juveniles to bacterial infection highlighted by a higher survival rate at 14 days post-challenge compared with the control and other types and doses of β-glucans (p<0.05). In conclusion, our results suggest that Gas1-β-glucan could represent a promising immunostimulant that would help to prevent diseases in aquaculture even more efficiently than other β-glucans already in use. Mode of action and particular efficiency of this new Gas1 mutant are debated

West Nile Virus in Birds, Argentina

West Nile Virus in Birds, Argentin

Transmission of West Nile Virus by Culex quinquefasciatus Say Infected with Culex Flavivirus Izabal

Unlike most known flaviviruses (Family, Flaviviridae: Genus, Flavivirus), insect-only flaviviruses are a unique group of flaviviruses that only infect invertebrates. The study of insect-only flaviviruses has increased in recent years due to the discovery and characterization of numerous novel flaviviruses from a diversity of mosquito species around the world. The widespread discovery of these viruses has prompted questions regarding flavivirus evolution and the potential impact of these viruses on the transmission of flaviviruses of public health importance such as WNV. Therefore, we tested the effect of Culex flavivirus Izabal (CxFV Izabal), an insect-only flavivirus isolated from Culex quinquefasciatus mosquitoes in Guatemala, on the growth and transmission of a strain of WNV isolated concurrently from the same mosquito species and location. Prior infection of C6/36 (Aedes albopictus mosquito) cells or Cx. quinquefasciatus with CxFV Izabal did not alter the replication kinetics of WNV, nor did it significantly affect WNV infection, dissemination, or transmission rates in two different colonies of mosquitoes that were fed blood meals containing varying concentrations of WNV. These data demonstrate that CxFV probably does not have a significant effect on WNV transmission efficiency in nature

West Nile Virus, Venezuela

Submitted by Sandra Infurna ([email protected]) on 2020-04-01T17:32:07Z No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-04-01T17:51:00Z (GMT) No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5)Made available in DSpace on 2020-04-01T17:51:00Z (GMT). No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5) Previous issue date: 2007University of Massachusetts Medical School. Center for Infectious Disease and Vaccine Research. Worcester, MA, USA.Universidad de Carabobo Biomed. Maracay, Venezuela.Universidad Central de Venezuela. Caracas, Venezuela.Coleccion Ornitologica Phelps. Caracas, Venezuela.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.Universidad Central de Venezuela. Maracay, Venezuela.Instituto Nacional de Investigaciones Agrícolas. Maracay, Venezuela.Universidad Central de Venezuela, Caracas, VenezuelaFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Centers for Disease Control and Prevention. San Juan, Puerto Rico, USA.Universidad del Zulia. Maracaibo, Venezuela.Universidad de Carabobo Biomed. Maracay, Venezuela.Ministerio de Salud Insalud. Carabobo, Venezuela.Universidad Central de Venezuela, Caracas, VenezuelaUniversidad de Carabobo Biomed. Maracay, Venezuela.Centers for Disease Control and Prevention.Fort Collins, Colorado, USA.Harvard School of Public Health. Boston, Massachusetts, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA

Susceptibility and permissivity of zebrafish (Danio rerio) larvae to cypriniviruses

No abstract available