scholarly journals Natural vertical transmission by Stegomyia albopicta as dengue vector in Brazil

2009 ◽  
Vol 69 (1) ◽  
pp. 123-127 ◽  
Author(s):  
AB. Cecílio ◽  
ES. Campanelli ◽  
KPR. Souza ◽  
LB. Figueiredo ◽  
MC. Resende
Keyword(s):  
Dengue Virus ◽  
Vertical Transmission ◽  
Dengue Vector ◽  
Infection Rates ◽  
Dengue Viruses ◽  
Stegomyia Albopicta ◽  
First Time ◽  
Minimum Infection Rate ◽  
Dengue Virus Type 2

The mosquito Stegomyia albopicta is among the most important arbovirus vectors in the world, particularly for Dengue viruses. Their natural history suggests that biologically these viruses are highly adapted to their mosquito hosts and they were most likely mosquito viruses prior to becoming adapted to lower primates and humans. As well as being maintained by transmission among susceptible humans, Dengue viruses may also be maintained by vertical transmission in mosquitoes during inter-epidemic periods. The larvae and mosquitoes of Stegomyia albopicta were used to identify the vertical transmission of the dengue virus in nature and to confirm the vectorial capacity concerning the Dengue virus type 2 infection. The minimum infection rate concerning S. albopicta infection with the Dengue virus was 1:36.45. In Brazil this was the first time that high minimum infection rates of vertical transmission of S. albopicta were detected in this species.

scholarly journals On the Dynamics of Dengue Virus Type 2 with Residence Times and Vertical Transmission

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Derdei Bichara ◽  
Susan Holechek ◽  
Jorge Velazquez-Castro ◽  
Anarina Murillo ◽  
Carlos Castillo-Chavez
Keyword(s):  
Dengue Virus ◽  
Vertical Transmission ◽  
Virus Type ◽  
Residence Times ◽  
Dengue Virus Type 2

scholarly journals On the dynamics of dengue virus type 2 with residence times and vertical transmission

2016 ◽  
Vol 3 (1) ◽  
pp. 140-160 ◽  
Author(s):  
Derdei Bichara ◽  
Susan A. Holechek ◽  
Jorge Velázquez-Castro ◽  
Anarina L. Murillo ◽  
Carlos Castillo-Chavez
Keyword(s):  
Dengue Virus ◽  
Vertical Transmission ◽  
Virus Type ◽  
Residence Times ◽  
Dengue Virus Type 2

scholarly journals trans-Complementation Analysis of the Flavivirus Kunjin ns5 Gene Reveals an Essential Role for Translation of Its N-Terminal Half in RNA Replication

1999 ◽  
Vol 73 (11) ◽  
pp. 9247-9255 ◽  
Author(s):  
Alexander A. Khromykh ◽  
Petra L. Sedlak ◽  
Edwin G. Westaway
Keyword(s):  
Dengue Virus ◽  
Rna Polymerase ◽  
Rna Replication ◽  
Replication Complex ◽  
Bhk Cells ◽  
Large Deletions ◽  
Reported Data ◽  
First Time ◽  
Dengue Virus Type 2

ABSTRACT Recently we described rescue of defective Kunjin virus (KUN) RNAs with small deletions in the methyltransferase and RNA polymerase motifs of the ns5 gene, using BHK cells stably expressing KUN replicon RNA (repBHK cells) as helper (A. A. Khromykh et al., J. Virol. 72:7270–7279, 1998). We have now extended our previous observations and report successful trans-complementation of defective KUN RNAs with most of the ns5 gene deleted or substituted with a heterologous (dengue virus) ns5 sequence. Replication of full-length KUN RNAs with 3′-terminal deletions of 136 (5%), 933 (34%), and 1526 (56%) nucleotides in the ns5 gene was complemented efficiently in transfected repBHK cells. RNA with a larger deletion of 2,042 nucleotides (75%) was complemented less efficiently, and RNA with an even larger deletion of 2,279 nucleotides (84%) was not complemented at all. Chimeric KUN genomic RNA containing 87% of the KUN ns5 gene replaced by the corresponding sequence of the dengue virus type 2 ns5 gene was unable to replicate in normal BHK cells but was complemented in repBHK cells. These results demonstrate for the first time complementation of flavivirus RNAs with large deletions (as much as 75%) in the RNA polymerase gene and establish that translation of most of the N-terminal half of NS5 is essential for complementation intrans. A model of formation of the flavivirus replication complex implicating a possible role in RNA replication of conserved coding sequences in the N-terminal half of NS5 is proposed based on the complementation and earlier results with KUN and on reported data with other flaviviruses.

scholarly journals Reduced sphingosine kinase 1 activity in dengue virus type-2 infected cells can be mediated by the 3′ untranslated region of dengue virus type-2 RNA

2013 ◽  
Vol 94 (11) ◽  
pp. 2437-2448 ◽  
Author(s):  
J. M. Carr ◽  
T. Kua ◽  
J. N. Clarke ◽  
J. K Calvert ◽  
J. R. Zebol ◽  
...  
Keyword(s):  
Cell Death ◽  
Dengue Virus ◽  
Virus Type ◽  
Elongation Factor ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Diarrhea Virus ◽  
Infected Cells ◽  
Dengue Virus Type 2

Sphingosine kinase 1 (SphK1) is a lipid kinase with important roles including regulation of cell survival. We have previously shown reduced SphK1 activity in cells with an established dengue virus type-2 (DENV-2) infection. In this study, we examined the effect of alterations in SphK1 activity on DENV-2 replication and cell death and determined the mechanisms of the reduction in SphK1 activity. Chemical inhibition or overexpression of SphK1 after established DENV-2 infection had no effect on infectious DENV-2 production, although inhibition of SphK1 resulted in enhanced DENV-2-induced cell death. Reduced SphK1 activity was observed in multiple cell types, regardless of the ability of DENV-2 infection to be cytopathic, and was mediated by a post-translational mechanism. Unlike bovine viral diarrhea virus, where SphK1 activity is decreased by the NS3 protein, SphK1 activity was not affected by DENV-2 NS3 but, instead, was reduced by expression of the terminal 396 bases of the 3′ UTR of DENV-2 RNA. We have previously shown that eukaryotic elongation factor 1A (eEF1A) is a direct activator of SphK1 and here DENV-2 RNA co-localized and co-precipitated with eEF1A from infected cells. We propose that the reduction in SphK1 activity late in DENV-2-infected cells is a consequence of DENV-2 out-competing SphK1 for eEF1A binding and hijacking cellular eEF1A for its own replication strategy, rather than a specific host or virus-induced change in SphK1 to modulate viral replication. Nonetheless, reduced SphK1 activity may have important consequences for survival or death of the infected cell.

scholarly journals In VitroEvaluation of Antiprotozoal and Antiviral Activities of Extracts from ArgentineanMikaniaSpecies

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Laura C. Laurella ◽  
Fernanda M. Frank ◽  
Andrea Sarquiz ◽  
María R. Alonso ◽  
Gustavo Giberti ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
Sesquiterpene Lactones ◽  
Infrared Analysis ◽  
Leishmania Braziliensis ◽  
Organic Extract ◽  
Chromatographic Profile ◽  
Antiviral Activities ◽  
Dengue Virus Type 2

The aim of this study was to investigate the antiprotozoal and antiviral activities of four ArgentineanMikaniaspecies. The organic and aqueous extracts ofMikania micrantha, M. parodii, M. periplocifolia,andM. cordifoliawere tested onTrypanosoma cruziepimastigotes,Leishmania braziliensispromastigotes, and dengue virus type 2. The organic extract ofM. micranthawas the most active againstT. cruziandL. braziliensisexhibiting a growth inhibition of77.6±4.5% and84.9±6.1%, respectively, at a concentration of 10 μg/ml. The bioguided fractionation ofM. micranthaorganic extract led to the identification of two active fractions. The chromatographic profile and infrared analysis of these fractions revealed the presence of sesquiterpene lactones. None of the tested extracts were active against dengue virus type 2.

scholarly journals Association between NS3 and NS5 Proteins of Dengue Virus Type 2 in the Putative RNA Replicase Is Linked to Differential Phosphorylation of NS5

1995 ◽  
Vol 270 (32) ◽  
pp. 19100-19106 ◽  
Author(s):  
Mini Kapoor ◽  
Luwen Zhang ◽  
Muralidhara Ramachandra ◽  
Jingo Kusukawa ◽  
Kurt E. Ebner ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
Differential Phosphorylation ◽  
Dengue Virus Type 2
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