Project Details
Projekt
Vector competence for TBEV replication limiting viral spread (VECTORS)
Subject Area
Virology
Microbial Ecology and Applied Microbiology
Microbial Ecology and Applied Microbiology
Term
from 2016 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 288394902
Tick-borne encephalitis virus (TBEV) is an emerging pathogen in humans and animals, ranging over a wide geographical range spanning from Japan, throughout Asia into Europe. The incidence of zoonotic TBEV infections has risen dramatically in many endemic countries during the past decades, having for example increased almost six-fold in Germany, although the overall level of increase varies considerably across German regions: TBEV is present in eastern and southern Germany, but there is no evidence for its circulation in the most western part of the country. Likewise, no TBEV circulation has been found in The Netherlands in humans and animals. The reasons behind this interrupted TBEV prevalence remain largely unknown. A major component of the TBEV life cycle is its replication in I. ricinus, its major tick vector. We hypothesize, in line with the overall aim of the Priority Program Ecology and species barriers in Emerging Viral Diseases SPP1596, that biological traits of I. ricinus, such as intrinsic susceptibility to TBEV infection, co-feeding behaviour, ability for trans-stadial TBEV transmission, microbiome, and dynamics of these, are determinants of TBEV endemicity. VECTORS aims at linking basic and state-of-the-art molecular virology and microbiology to invertebrate vector biology and ecology. The specific objectives are to: 1) Determine the ability of I.ricinus ticks originating from different locations east and west of a postulated demarcation line separating eastern endemic from western non-endemic areas in Germany to be infected with, and capable to transmit TBEV via co-feeding and/or via trans-stadial infection. 2) Assess the influence of the microbiome of I.ricinus subpopulations on their TBEV replication competence. To this end ticks will be collected from endemic and non-endemic areas in Germany and along the German-Dutch border to determine the spatio-temporal distribution of infected and non-infected populations of the respective three tick stages, and their possible overlaps. TBEV circulating strains will be isolated and used for the generation of molecular clones, which will be used for experimental infection and TBEV tick co-feeding and trans-stadial transmission experiments. Collected ticks will also be used to determine their microbiomes, and experimental TBEV infections in naïve and antibiotics treated ticks, will assess their potential impact on TBEV replication competence. The collected data will form the basis for a science-based risk assessment concerning the future increase in intensity and spread of TBEV infections in currently endemic and virgin areas in Germany and Europe.
DFG Programme
Priority Programmes
