Short title: New technologies for tick vector ecology
Summary
This 4-year PhD project will combine chemical physics, proteomics and disease
ecology to uncover linkages between vector ecology and human disease risk,
focussing on the tick vector Ixodes ricinus. In harnessing the power of novel
technologies, including spectroscopy and proteomics, and applying them to a
significant disease problem, the project will be breaking new ground at the interface
of molecular, environmental, and health sciences.
Background and Aims
Vector-borne diseases account for much of the world’s health problems. In the
northern hemisphere, ticks in the genus Ixodes are the principal vectors for emerging
diseases including Lyme borreliosis (LB) and tick-borne encephalitis.
A striking knowledge gap with respect to tick-borne diseases is the lack of
quantitative information about how ticks interact with their biotic and abiotic
environment. Ixodes ticks require a blood meal to develop into their next life stage
(from larva to nymph and from nymph to adult). While they can feed on a range of
different vertebrate hosts, only some host species are competent LB reservoirs. Thus,
tick host choice has a profound effect on pathogen transmission. However, there are
currently no established methods for determining which host species a tick has fed
on, nor for determining how much time ticks are spending in one life stage before
developing into the next. These technology gaps limit our understanding of how local
environmental conditions (e.g. vertebrate host communities, climate) influence the
ability of ticks to spread disease to people.
The candidate will be supervised by a multi-disciplinary team of researchers at
Glasgow (Biek, Wynne, Burchmore, Ferguson). By combining their expertise in
chemical physics, proteomics and disease ecology, this PhD project will generate
much needed insights into the biology of feeding and transmission for Europe’s most
important disease vector, Ixodes ricinus.
Our project has three major aims:
1) To establish the use of infrared (IR) spectroscopy to age-grade free-living
ticks
We will adapt an approach using near-IR spectroscopy that can age-grade
mosquitoes through detection of changes in cuticular composition (Mayagaya et al.
2009). By applying mid-IR spectroscopy, which we found to be more sensitive, we
will predict the age of lab-reared ticks of known age kept for several months under
semi-field conditions.
2) To apply tandem mass spectral libraries to discriminate the sources of tick
blood meals in European ticks
A recent proteomic approach has been shown to accurately identify tick blood meals
under laboratory conditions (Önder et al. 2013). We will test the applicability of this
technique under field conditions and on European tick vectors.
3) To test whether tick age structure and host choice can predict LB risk
Replicate sites of low and high LB prevalence will be selected for sampling questing
ticks. By applying the methodologies developed for Aims 1 & 2 to these samples, we
will test whether local variation in the amount of time ticks spend in different life
stages and the type of host species they feed on can predict the prevalence of LB
pathogens and thus human disease risk.
While these objectives provide a general framework, the candidate will be expected
to develop own research ideas and experimental approaches as part of this PhD
project.
Mayagaya, V. S., Michel, K., Benedict, M. Q., Killeen, G. F., Wirtz, R. A., Ferguson, H. M., & Dowell, F.
E. 2009. Non-destructive determination of age and species of Anopheles gambiae sl using near-infrared
spectroscopy. The American journal of tropical medicine and hygiene, 81(4), 622-630.
Özlem Önder, Wenguang Shao, Brian D Kemps, Henry Lam, and D. Brisson. 2013. Identifying sources
of tick blood meals using unidentified tandem mass spectral libraries. Nature Communications, 4, 1746–
10.
Training and Environment
The project will provide exceptional opportunities for training in state-of-the-art
technologies in infectious disease research. At the same time, these technologies
have much broader applicability, giving the scholar useful transferable skills for a
variety of career choices in biomedical sciences.
The Wynne lab will provide training in spectroscopic techniques. Experiments will be
based around a new (2014) state-of-the-art Fourier-transform infrared (FTIR)
spectrometer from Bruker with detection capabilities from far- to near-IR. New
statistical analysis methods will be implemented such as neural network analysis of
the age-dependent spectra.
The Burchmore lab will offer in-depth training in the use of mass spectrometry for
host blood meal identification based on proteomic signatures. This will include the
potential to develop novel approaches such as the use of MALDI – TOF/TOF mass
spectrometers for high throughput acquisition of spectral libraries.
Biek and Ferguson will provide guidance and training in field and lab-based
ecological techniques as well as epidemiological concepts and models and their
applications in the context of disease dynamics. Due to the nature of the project the
scholar will also be developing important general skills in experimental design as well
as statistical and computational analyses.
The scholar will be joining a vibrant community of students and postdocs working on
interdisciplinary approaches in infectious disease and life sciences, providing
opportunities to develop broader scientific perspectives. E.g. see
http://www.gla.ac.uk/research/az/boydorr/
http://www.gla.ac.uk/colleges/mvls/researchinstitutes/gpf/
http://www.gla.ac.uk/researchinstitutes/bahcm/research/sigs/vectorbiologydisease/
http://www.gla.ac.uk/researchinstitutes/bahcm/
http://www.chem.gla.ac.uk/staff/wynne/
Requirements
Applicants should have a first or upper second class degree in a relevant science
discipline (e.g. molecular biology, zoology, biochemistry, bioinformatics), be highly
motivated and have excellent English communication skills. The successful
candidate will need to be enthusiastic about acquiring new skills in an
interdisciplinary setting and have a strong interest in biological processes as well as
new technologies such as mass spec and infrared spectroscopy. Research
experience, laboratory skills, knowledge about ecological fieldwork, and
demonstrated ability to work independently will be considered an advantage.
There are no restrictions with respect to nationality or citizenship.
Candidates are asked to make informal contact prior to applying by contacting
roman.biek@glasgow.ac.uk.