Markers of anthelmintic resistance in gastro-intestinal parasites of ruminants
Lead Research Organisation:
University of Glasgow
Department Name: College of Medical, Veterinary, Life Sci
Abstract
Studentship strategic priority area: Food Security (Animal Health)
Keywords: Parasitic nematodes, ivermectin, resistance genotyping
Abstract:
Grazing livestock (sheep and cattle) 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 the use of a small number of anthelmintics, which are now compromised by widespread anthelmintic resistance (AR). Teladorsagia circumcincta, the brown stomach worm, is the most important GI parasite infecting sheep in the UK and is the cause of significant productions losses. T. circumcincta is present on 100% of UK sheep farms and causes a spectrum of disease ranging from ill-thrift to death. Resistance to the three most common anthelmintic classes is widespread and there are well-documented cases of UK farms harbouring 'triple-resistant' T. circumcincta. These multi-drug-resistant parasites can no longer be controlled by treatment with any of these anthelmintics and have resulted in a number of farms being forced to abandon sheep rearing. Although previous studies have sought to identify the mechanisms of AR in T. circumcincta, most studies have used laboratory isolates of worms rather than field populations and have been restricted in the approaches available. Here, we will compare the genotype of populations of T. circumcincta worms pre- and post-treatment from UK farms with known resistance problems. The approach is novel, based on newly developed methods that allow the whole genome to be sampled, rather than investigating a single candidate gene/s. Eggs will be collected from sheep pre-treatment (representing mixed populations of sensitive and resistant worms) and then again post-treatment (survivors will be resistant). DNA will be extracted for genotyping and the identification of markers of resistance from L3 stage parasites. Single nucleotide polymorphisms (SNPs) will be identified in the pre- and post-treatment populations and used to identify regions of the genome under selection. SNPs that are associated with resistance in these parasite populations will be tested in UK field samples with known drug treatment and management strategies and will be developed as molecular markers for closely related GI nematodes of sheep and cattle. The project is multi-disciplinary and will provide significant training in a number of important areas including veterinary fieldwork (to collect pre and post-treatment samples), laboratory work (molecular biology and genetics), computing (population genomics and bioinformatics) and knowledge exchange (industrial placement). It addresses an important area in food security and animal health and welfare with the eventual aim of developing management strategies to mitigate the spread of AR on UK farms.
Keywords: Parasitic nematodes, ivermectin, resistance genotyping
Abstract:
Grazing livestock (sheep and cattle) 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 the use of a small number of anthelmintics, which are now compromised by widespread anthelmintic resistance (AR). Teladorsagia circumcincta, the brown stomach worm, is the most important GI parasite infecting sheep in the UK and is the cause of significant productions losses. T. circumcincta is present on 100% of UK sheep farms and causes a spectrum of disease ranging from ill-thrift to death. Resistance to the three most common anthelmintic classes is widespread and there are well-documented cases of UK farms harbouring 'triple-resistant' T. circumcincta. These multi-drug-resistant parasites can no longer be controlled by treatment with any of these anthelmintics and have resulted in a number of farms being forced to abandon sheep rearing. Although previous studies have sought to identify the mechanisms of AR in T. circumcincta, most studies have used laboratory isolates of worms rather than field populations and have been restricted in the approaches available. Here, we will compare the genotype of populations of T. circumcincta worms pre- and post-treatment from UK farms with known resistance problems. The approach is novel, based on newly developed methods that allow the whole genome to be sampled, rather than investigating a single candidate gene/s. Eggs will be collected from sheep pre-treatment (representing mixed populations of sensitive and resistant worms) and then again post-treatment (survivors will be resistant). DNA will be extracted for genotyping and the identification of markers of resistance from L3 stage parasites. Single nucleotide polymorphisms (SNPs) will be identified in the pre- and post-treatment populations and used to identify regions of the genome under selection. SNPs that are associated with resistance in these parasite populations will be tested in UK field samples with known drug treatment and management strategies and will be developed as molecular markers for closely related GI nematodes of sheep and cattle. The project is multi-disciplinary and will provide significant training in a number of important areas including veterinary fieldwork (to collect pre and post-treatment samples), laboratory work (molecular biology and genetics), computing (population genomics and bioinformatics) and knowledge exchange (industrial placement). It addresses an important area in food security and animal health and welfare with the eventual aim of developing management strategies to mitigate the spread of AR on UK farms.
People |
ORCID iD |
| Eileen Devaney (Primary Supervisor) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/N50385X/1 | 01/10/2015 | 30/09/2019 | |||
| 1644062 | Studentship | BB/N50385X/1 | 01/10/2015 | 30/09/2019 |
| Title | Game about anthelmintic resistance and parasitic gastroenteritis |
| Description | A card game produced for use in outreach events (was used, for example, at the Royal Highland Show with farmers and the public, and with prison learners). Flexible in the learning outcomes. Consists of cards with strongyle eggs on the back, and worm species on the front, with additional information as to their anthelmintic susceptiblity. Can be used with all ages. |
| Type Of Art | Artefact (including digital) |
| Year Produced | 2018 |
| Impact | Used in multiple outreach events already. |
| Description | Novel sequencing datasets of UK field populations of Teladorsagia circumcincta have been produced. This worm species is the primary pathogen causing a disease called parasitic gastroenteritis in UK lambs. Eggs were collected pre- and post- treatment of sheep with ivermectin, a commonly used anthelmintic product used to treat this species. Pre- and post-treatment larval populations (progeny of treated adults) were sequenced and the data has been archived in the public domain (ENA database). Data was aligned to two reference genomes and analysed and results are described in the PhD thesis. However, both reference genomes were only partially assembled and it was realised that aspects of each were limiting interpretation of results. For this reason the BUG project is seeking to improve the reference genome further. Once this has been achieved, the data will be re-analysed to identify genetic markers of ivermectin resistance which could be used to test for and detect resistant individuals in the field. |
| Exploitation Route | The sequencing data is a rich resource which has not been previously available. This will be used by ourselves in the future when the genome is improved to re-analyse the data using the bioinformatics protocol developed as part of this PhD. In addition, the data is available in the public archives for use in other studies. |
| Sectors | Agriculture, Food and Drink,Pharmaceuticals and Medical Biotechnology |
| Description | Following presentation of a poster concerning the species variability within a strongyle faecal egg count, at a PhD AHDB seminar in December 2016, Signet Manager, Samuel Boon, decided to ask sheep breeders to submit faecal samples speciation of strongyles. This was because Signet breeding services were working with farmers to develop breeding values based on strongyle egg counts and IgA saliva. However, it was felt that the IgA saliva was primarily related to levels of T. circumcincta infection (using homogenised T. circumcincta L3 antigen) and perhaps not to all strongyle species. This was initially for only a handful of farmers, however, following a presentation and discussion at a breeders meeting in October 2017 it was decided to enlarge the group contributing samples. At the October meeting, data relating to species variation within a faecal egg count reduction test assessing resistance on farm to benzimidazoles and ivermectin anthelmintics, was also shown to the farmers to highlight the importance of accurately determining anthelmintic efficacy in practice. |
| First Year Of Impact | 2016 |
| Sector | Agriculture, Food and Drink |
| Impact Types | Societal,Economic |
| Description | BBSRC KTN CASE Award |
| Amount | £150,000 (GBP) |
| Funding ID | BB/N50385X/1 |
| Organisation | Biotechnology and Biological Sciences Research Council (BBSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 10/2015 |
| End | 09/2019 |
| Description | BSAS Steve Bishop Early Career Award |
| Amount | £5,000 (GBP) |
| Organisation | Knowledge Transfer Network |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 09/2020 |
| End | 09/2021 |
| Description | Student bursary for Anthelmintics III |
| Amount | $150 (USD) |
| Organisation | MSD Animal Health |
| Sector | Private |
| Country | United Kingdom |
| Start | 01/2018 |
| End | 01/2018 |
| Description | WAAVP 2019 Conference Students Travel Award |
| Amount | $500 (USD) |
| Organisation | WAAVP |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 07/2019 |
| End | 07/2019 |
| Title | Field samples of Telgadorsagia circumcincta - genomic sequencing data |
| Description | Genomic Illumina sequencing reads of a field population of Teladorsagia circumcincta generated following double digestion restriction-site associated DNA sequencing (ddRAD-Seq). |
| Type Of Material | Database/Collection of data |
| Year Produced | 2019 |
| Provided To Others? | Yes |
| Impact | Novel dataset of genomic sequencing data of T. circumcincta UK field population, which has not been available before. Collected pre- and post-ivermectin treatment of sheep. Generated from individual L3 larvae. Data accession numbers: ERS1770619 ERS1770620 |
| URL | http://www.ebi.ac.uk/ena/ |
| Title | Field samples of Telgadorsagia circumcincta - genomic sequencing data - Pool-Seq |
| Description | Genomic sequencing data from a UK field population of Teladorsagia circumcincta. Samples collected from two separate farms (England, Scotland), with two samples collected from each farm: pre- and post-ivermectin treatment of sheep. Eggs were cultured to L3, speciated and sequenced in pools of 91 larvae by sample. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2019 |
| Provided To Others? | Yes |
| Impact | Novel dataset of UK field T. circumcincta genomic data. Collected pre- and post-ivermectin treatment. There is no other dataset available at the current time, as known of by ourselves. Accession numbers: ERS2487257 ERS2487258 ERS2487259 ERS2487260 ERS2487261 ERS2487262 |
| URL | http://www.ebi.ac.uk/ena/ |
| Description | WORMSS (BSAS Steve Bishop Early Career Award) |
| Organisation | Flock Health Limited |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We have formulated the project concept, obtained ethical permission, and are doing the research. |
| Collaborator Contribution | The collaborator provides expert advice, guidance and has assisted in planning the project. They will also assist in dissemination of results. |
| Impact | Now understand GDPR/ethics - this is going to be very useful for a future project for which we have obtained funding. Learnt better how to write questionnaires for farmers and reach them - this will be useful for impact of current and future projects. The project is ongoing - research outcomes/impact is in the future. |
| Start Year | 2020 |
| Description | A talk or presentation - Short talk at BSP 2017 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | A short presentation was given at the Spring BSP meeting in Dundee, 2017. Several questions and some discussion followed. |
| Year(s) Of Engagement Activity | 2017 |
| URL | http://bsp.uk.net/2017/04/30/bsp-spring-meeting-2017/ |
| Description | A talk or presentation - Short talk at CORE meeting |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | A short presentation on research carried out (relating primarily to a faecal egg count reduction test and species diversity on a UK farm) was presented at a small meeting in Liverpool. Those present were gathered to discuss 'Co-infections and Resistance'. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Blog on BUG consortium grant |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | We curate a blog on the BUG project (https://bugconsortium.wordpress.com) |
| Year(s) Of Engagement Activity | 2015,2016,2017 |
| Description | CARS talk |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Presentation at an international conference on anthelmintic resistance (CARS) in America. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Final year talk at sponsor AHDB Beef and Lamb's PhD conference |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | A 'final year' presentation was given about the research to a large group made up of industry workers of a sponsor, AHDB Beef and Lamb, with their dairy and pig partners and others working within the industry. In addition other PhD students of the sponsor and their supervisors were also present, representing many universities and organisations across the UK. Questions and discussions related to the research contined ad hoc over the two day conference, with the chance to also hear about other research in the farming industry and impacts/requirements for further research needed. |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://ahdb.org.uk/phd-studentships |
| Description | Game playing at the Royal Highland Show |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | We made a game "Fishing for worms" to help educate the public about the issue of anthelmintic resistance |
| Year(s) Of Engagement Activity | 2016 |
| Description | Invited poster - Sheep Breeders Round table |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | The Sheep Breeders Roundtable is organised by one of the funding sponsors of the project, AHDB Beef and Lamb, and I was requested to take part. I provided two posters. One on species differences between strongyle populations at different sampling time points/groups of animals and a further poster, building on the first, but looking specifically at the determination of anthelmintic efficacy by faecal egg count reduction tests. I was able to attend the meeting and discuss the content of the posters and the wider project with those who attended. At the same time we were able to make an announcement about the wider BUG project, requesting material. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.nationalsheep.org.uk/sbrt/ |
| Description | Invited presentation at Sheep Vet Society meeting, May 2018 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | I was asked to provide a 20 minute presentation on faecal egg counts, and the range of complicating factors affecting interpretation in practice. I provided an overview of various methods, discussing sensitivities of these and considered strongyle species population composition impact. In addition I looked at some of the more basic steps from collection to culture, which could impact on the number of eggs counted, and the species identified. There were between 50 and 100 vets present, with professionals involved in various other sheep enterprises (eg. breeding), industry etc present also. The talk stimulated discussion, and, at the autumn SVS meeting, further conversations surrounding the topic of faecal egg counting and anthelmintic resistance were had. |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://www.sheepvetsoc.org.uk/event/spring-meeting-may-2018 |
| Description | Poster presentation at meeting |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | A poster was present by a PhD student associated with the BUG project at the annual AHDB research meeting. The audience here is varied both academic, policy makers and commercial. |
| Year(s) Of Engagement Activity | 2016 |
| Description | Pre-viva talk |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Study participants or study members |
| Results and Impact | Pre-viva talk given to those interested from the institute. Sparked excellent discussion afterwards. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Presentation at COMBAR meeting |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Gave a talk at a meeting specifically gathering those across Europe interested in combating anthelmintic resistance in ruminants (COMBAR). Within the conference were those who were further interested in using the methods presented, and discussing the results. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Presentation at EAAP meeting |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Presented talk at European meeting (EAAP) within a smaller focus group on veterinary parasites and anthelmintic resistance. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Presentation at Graduate Women Scotland meeting by PhD student associated with BUG |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | PhD student presented a talk to Graduate Women Scotland meeting describing aims of project |
| Year(s) Of Engagement Activity | 2016 |
| Description | Presentation of poster at international conference |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Presentation of a poster at an international conference of veterinary parasitology (WAAVP) in America. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Short presentation by request, with discussion |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Roughly 30-40 farmers and others related to the industry attended a breeders meeting. One of the main articles for discussion was the use of faecal egg counts and IgA saliva as part of a rams estimated breeding value score. I was asked to give a short 20-30 minute presentation on strongyle egg counts and the use of IgA saliva to score for phenotypic resistance to parasitic nematodes, in particular T. circumcincta. The presentation stimulated a lively discussion and prompted further questions and debate afterwards. Following the meeting several farmers (in addition to those already doing so) submitted faecal samples for speciation of strongyles to Signet, who are responsible for generating these estimated breeding values. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Short talk - institute and lab talks. Also additional talks/presentations at small meetings relating to the BUG project. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Professional Practitioners |
| Results and Impact | Short presentations are given each year to other members of the institute and/or lab group. These include at least one yearly presentation to the institute on the research carried out as part of the PhD. These talks generally stimulate questions from the audience, and are useful in generating feedback and ideas for continuing analyses and research tasks within the PhD. |
| Year(s) Of Engagement Activity | 2016,2017,2018 |
| Description | Short talk at conference Anthelmintic Resistance III |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | A short talk was given at the international conference 'Anthelmintic Reisistance III' in Florida. Those present included researchers, postgraduate students and industry professionals. The talk described preliminary results from recent work using genome wide sequencing to identify genomic regions of selection following ivermectin treatment in a UK field population of T. circumcincta. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Short talk given to parasitologists within the University of Glasgow |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Other audiences |
| Results and Impact | Gave a 25 minute talk about the research methods and current findings from the project to other parasitologists within the institute at a 'Research Update Meeting'. These meetings are very well attended by parasitologists from a wide range of disciplines. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Three minute thesis talk |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Postgraduate students |
| Results and Impact | I gave a talk as part of the three minute thesis (3MT) competition at the University of Glasgow. There were about 25 people in the room. The talk was filmed, tweeted about by the 3MT group and others and will be loaded onto the University of Glasgow website in the future. The talk covered the reason behind the PhD and briefly mentioned the methods, and future outcomes. |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://www.gla.ac.uk/research/ourresearchenvironment/prs/pgrcoursesandevents/threeminutethesiscompe... |
| Description | Twitter account 'SheepwormPhD' |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | Twitter account set up primarily to reach farmers and vets for knowledge transfer and knowledge exchange. Currently the account has 96 followers, most of whom are within the UK and 13 of whom are new from the last 30 days. The most common word in their profiles is 'sheep'. Most tweets are either re-tweets of industry relevant information, or tweets about sheep/parasite talks or other activities related to work carried out as part of the PhD or wider BUG consortium project. Tweets in the last month ranged from 77 impressions to almost 4000. Actual engagement with the tweet ranged from 1 to 41. |
| Year(s) Of Engagement Activity | 2018,2019 |
| URL | https://twitter.com/sheepwormPhD |
| Description | Two prison visits to provide a teaching session to prison learners. |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | On two separate occasions I went with Cell Block Science (https://news.st-andrews.ac.uk/archive/cell-block-science/) into HMP Shotts and HMP Low Moss to provide a session about sheep parasites and anthelmintic resistance to the prison learners. At each prison two sessions were run, reaching between about 6-10 learners at each session. A combination of powerpoint, discussion, and in-depth activities were used to stimulate learning and problem solving. Learners were taken from the concept of the disease understudy in this PhD, through the complexities of the nature of the disease, to actively planning with farm maps, anthelmintic efficacy data, species data and farm management data how they would manage the disease on their farm. Some learners were from a farming, or animal health background which meant that the information was directly applicable to them and should make a lasting impression for when they leave prison. All learners were actively engaged in the sessions and from the activities performed it was clear that the impact had been achieved. |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://twitter.com/sheepwormPhD/status/1060914897440120841 |