Markers of anthelmintic resistance in gastro-intestinal parasites of ruminants
Stipend: £16, 613 pa (baseline at 2014/15 rate), with added enhancement for a veterinary graduate
Start date: 1st October
Supervisors: Prof Eileen Devaney and Dr Roz Laing
Grazing livestock are infected by multiple species of gastrointestinal (GI) worms. These ubiquitous parasites compromise the health and welfare of their hosts and severely constrain productivity. Current control practices are inadequate, relying on a small number of anthelmintics, which are now compromised by anthelmintic resistance (AR). In the sheep industry, AR is widespread and there are well-documented cases of UK farms harbouring multi-drug-resistant worms, which have been forced to abandon sheep rearing. Farmers have few alternatives however, with no commercially available vaccine and only two new classes of anthelmintic developed in the last 30 years. While the consequences of AR are currently most severe in the sheep industry, resistance is of increasing concern in the dairy and beef sectors. Cattle are infected with a number of GI parasites, which are closely-related to those in sheep and are treated with the same few drugs. This situation is potentially a ticking bomb due to the lack of sensitive diagnostic tests that can detect AR at an early stage.
This PhD project will integrate with a larger BBSRC-funded project, which is using novel genomic approaches to understand the mechanisms of AR in GI parasites. A major focus of the PhD is to identify genetic markers of AR in the sheep nematode Teladorsagia circumcincta with a view to developing a sensitive diagnostic test for AR in this species and related parasites of sheep and cattle. Genome-wide sequencing approaches will be used to genotype T. circumcincta populations from UK farms with known resistance problems. Single nucleotide polymorphisms (SNPs) will be identified in the populations, pre- and post-anthelmintic treatment, and used to identify regions of the genome under selection. These loci will be further investigated as part of the larger project to identify the mutations conferring resistance. SNPs that are associated with AR will be validated in a previously generated biobank of UK farm parasites and developed as molecular markers.
The availability of molecular markers for AR will allow better surveillance, diagnosis and intervention at a suitably early stage (before clinical failure). Importantly, it will allow accurate evaluation of methods aimed at restricting the spread of AR and preserving the effectiveness of currently licensed anthelmintics. An understanding of the mechanisms underlying AR may also reveal opportunities to attenuate/reverse resistance and to design more effective formulations or treatment strategies. These findings will be relayed to the farming community in collaboration with EBLEX, via industry-led working groups SCOPS (Sustainable Control of Parasites of Sheep) and COWS (Control of Worms Sustainably).
This PhD project applies state-of-the-art sequencing technologies to address an important problem for animal health and food production. The work is multi-disciplinary and, as such, will provide significant training in a number of important areas including veterinary fieldwork, molecular biology, next generation sequencing, population genomics, bioinformatics and knowledge exchange. Skills acquired during the PhD will be applicable to many other systems and different career pathways. The student will integrate with an experienced, enthusiastic and supportive team of researchers who will provide expertise and training in all areas.
How to apply
The project is funded by a KTN BBSRC CASE Award for a period of 4 years and the student will be required to spend a period greater than 3 months duration working with the industrial supervisor. Candidates should have a 1st or 2:1 in molecular biology, genetics or related subject, or be a veterinary graduate.