BioMed Central
London
BioMed Central
13071
1756-3305
Parasites & Vectors
Parasites Vectors
Biomedicine
Parasitology
Entomology
Tropical Medicine
Infectious Diseases
Veterinary Medicine
Virology
SC3
9
9
1
1
1
0
2016
12
2016
The Author(s)
2016
1677
10.1186/s13071-016-1677-0
393
393
Vector competence of northern European Culex pipiens biotypes and hybrids for West Nile virus is differentially affected by temperature
Research
1
7
2016
6
30
2016
5
10
2016
6
30
2016
7
7
FP7 Vectorie
261466
The Author(s).
2016
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (
http://creativecommons.org/licenses/by/4.0/
), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (
http://creativecommons.org/publicdomain/zero/1.0/
) applies to the data made available in this article, unless otherwise stated.
Chantal
B.
F.
Vogels
chantal.vogels@wur.nl
Jelke
J.
Fros
jelke.fros@ndm.ox.ac.uk
Giel
P.
Göertz
giel.goertz@wur.nl
Gorben
P.
Pijlman
gorben.pijlman@wur.nl
Constantianus
J.
M.
Koenraadt
sander.koenraadt@wur.nl
Laboratory of Entomology
Wageningen University
P.O. Box 16
6700 AA
Wageningen
The Netherlands
Laboratory of Virology
Wageningen University
P.O. Box 16
6700 AA
Wageningen
The Netherlands
Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research
University of Oxford
Oxford
OX1 3SY
England
UK
Abstract
Background
Outbreaks of West Nile virus (WNV) have not occurred in northern Europe despite nearby circulation of WNV in the southern part of the continent. The main vector for WNV, the mosquito Culex (Cx.) pipiens, consists of two behaviorally distinct biotypes, pipiens and molestus, which can form hybrids. Although temperature has been shown to influence vector competence of Cx. pipiens for WNV and biotypes are differentially susceptible towards infection, the interaction between the two has not been elucidated.
Methods
We determined vector competence of the Cx. pipiens biotypes and hybrids, after 14 days of incubation at 18, 23 and 28 °C. Mosquitoes were orally infected by providing an infectious blood meal or by injecting WNV directly in the thorax. Infection and transmission rates were determined by testing the bodies and saliva for WNV presence. In addition, titers of mosquitoes with WNV-positive bodies and saliva samples were determined.
Results
Orally infected biotype pipiens and hybrids showed significantly increased transmission rates with higher temperatures, up to 32 and 14 %, respectively. In contrast, the molestus biotype had an overall transmission rate of 10 %, which did not increase with temperature. All mosquitoes that were infected via WNV injections had (close to) 100 % infection and transmission rates, suggesting an important role of the mosquito midgut barrier. We found no effect of increasing temperature on viral titers.
Conclusions
Temperature differentially affected vector competence of the Cx. pipiens biotypes. This shows the importance of accounting for biotype-by-temperature interactions, which influence the outcomes of vector competence studies. Vector competence studies with Cx. pipiens mosquitoes differentiated to the biotype level are essential for proper WNV risk assessments.
Keywords
Arbovirus
Culex
Vector competence
West Nile virus
Infection
Temperature
Electronic supplementary material
The online version of this article (doi:
10.1186/s13071-016-1677-0
) contains supplementary material, which is available to authorized users.