scholarly journals Effects of Virus Dose and Extrinsic Incubation Temperature on Vector Competence of Culex nigripalpus (Diptera: Culicidae) for St. Louis Encephalitis Virus

2012 ◽  
Vol 49 (6) ◽  
pp. 1502-1506 ◽  
Author(s):  
Stephanie L. Richards ◽  
Sheri L. Anderson ◽  
Cynthia C. Lord ◽  
Walter J. Tabachnick
Keyword(s):  
Incubation Temperature ◽  
Vector Competence ◽  
Encephalitis Virus ◽  
Culex Nigripalpus ◽  
Virus Dose

scholarly journals Resuscitating Mutations in a Furin Cleavage-Deficient Mutant of the Flavivirus Tick-Borne Encephalitis Virus

2005 ◽  
Vol 79 (18) ◽  
pp. 11813-11823 ◽  
Author(s):  
Sigrid Elshuber ◽  
Christian W. Mandl
Keyword(s):  
Structural Integrity ◽  
Incubation Temperature ◽  
Surface Protein ◽  
Normal Growth ◽  
Growth Conditions ◽  
Encephalitis Virus ◽  
Furin Cleavage ◽  
Tick Borne Encephalitis ◽  
Substitution Mutations ◽  
Tick Borne Encephalitis Virus

ABSTRACT Cleavage of the viral surface protein prM by the proprotein convertase furin is a key step in the maturation process of flavivirus particles. A mutant of tick-borne encephalitis virus (TBEV) carrying a deletion mutation within the furin recognition motif of protein prM (changing R-T-R-R to R-T-R) was previously shown to be noninfectious in BHK-21 cells. We now demonstrate how natural selection can overcome this lethal defect in two different growth systems by distinct resuscitating mutations. In BHK-21 cells, a spontaneous codon duplication created a minimal furin cleavage motif (R-R-T-R). This mutation restored infectivity by enabling intracellular prM cleavage. A completely different mutation pattern was observed when the mutant virus was passaged in mouse brains. The “pr” part of protein prM, which is removed by cleavage, contains six conserved Cys residues. The mutations selected in mice changed the number of Cys residues to five or seven by substitution mutations near the original cleavage site, probably causing a major perturbation of the structural integrity of protein prM. Although viable in mice, such Cys mutants could not be passaged in BHK-21 cells under normal growth conditions (37°C), but one of the mutants exhibited a low level of infectivity at a reduced incubation temperature (28°C). No evidence for the cleavage of protein prM in BHK-21 cells was obtained. This suggests that under certain growth conditions, the structural perturbation of protein prM can restore the infectivity of TBEV by circumventing the need for intracellular furin-mediated cleavage. This is the first example of a flavivirus using such a molecular mechanism.

scholarly journals Vector Competence of Australian Mosquitoes (Diptera: Culicidae) for Japanese Encephalitis Virus

2003 ◽  
Vol 40 (1) ◽  
pp. 82-90 ◽  
Author(s):  
A. F. Van Den Hurk ◽  
D. J. Nisbet ◽  
R. A. Hall ◽  
B. H. Kay ◽  
J. S. Mackenzie ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Vector Competence ◽  
Encephalitis Virus

Aedes japonicus japonicus (Diptera: Culicidae) from Germany have vector competence for Japan encephalitis virus but are refractory to infection with West Nile virus

2014 ◽  
Vol 113 (9) ◽  
pp. 3195-3199 ◽  
Author(s):  
Katrin Huber ◽  
Stephanie Jansen ◽  
Mayke Leggewie ◽  
Marlis Badusche ◽  
Jonas Schmidt-Chanasit ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Vector Competence ◽  
Encephalitis Virus ◽  
West Nile ◽  
Aedes Japonicus ◽  
Aedes Japonicus Japonicus

scholarly journals Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 10- survey of adult behaviour of Culex nigripalpus and other species of Culex (Culex) in South-Eastern Brazil

1995 ◽  
Vol 29 (4) ◽  
pp. 271-278 ◽  
Author(s):  
Oswaldo Paulo Forattini ◽  
Iná Kakitani ◽  
Eduardo Massad ◽  
Daniel Marucci
Keyword(s):  
Encephalitis Virus ◽  
Potential Vector ◽  
South Eastern ◽  
Culex Nigripalpus ◽  
Eastern Brazil ◽  
High Level

A survey of adult behaviour of Culex (Culex) species was carried out from August 1992 through December 1993 in a human modified (anthropic) environment in the Ribeira Valley, S.Paulo State, Brazil. Culex nigripalpus dominated the catches at several sites and it's tendency to increase in the anthropic environment became quite clear. Nevertheless no high level of synanthropy was demonstrated. So it seems that the mosquito may have a restricted role in natural arbovirus cycles. Nonetheless, Cx. nigripalpus must be considered a potential vector of arboviruses, especially St. Louis encephalitis virus outside dwellings.

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