Ticks and zoonotic Tick-Borne Pathogens in Scotland

New disease models support pig vaccine and therapeutic developments

Moredun Scientific, the contract research arm of the Moredun Group, conduct studies to enable their clients to evaluate the efficacy of new and improved vaccines and therapeutic drugs for use in livestock. To facilitate such studies validated experimental models of infectious disease are required and a portfolio of models has been developed to meet the needs of the animal health industry.

For pig producers, pathogens of significant importance include Porcine Reproductive and Respiratory Syndrome Virus (PPRSV) and the bacteria Streptococcus suis and Escherichia coli.

For PRRSV studies a natural seeder model has been successfully developed to mimic natural virus transmission on farms. A small number of pigs are infected with the virus and then mixed with uninfected pigs, transmission of the virus to the uninfected animals occurs through direct and indirect contact with infected animals and mimics the natural transmission that would occur in the field. In addition, a direct challenge model is also available. Both models have been successfully used to assess the efficacy of test products in preventing or reducing the spread of infection.

S.suis infections cause sepsis and meningitis in piglets. Across Europe different serotypes of the pathogen are responsible for disease outbreaks. Serotype 2 is widespread and Moredun Scientific’s serotype 2 infection model has been frequently used in both therapeutic and vaccine studies. Models for other bacterial serotypes are currently under development.

E.coli is a pathogen associated with post-weaning diarrhea in young piglets which causes significant losses for pig producers. The Moredun Scientific model uses E.coli F4 as the challenge strain and has enabled potential prophylactic and therapeutic control measures to be evaluated in 4 week old piglets.

For further information please contact David Reddick, Head of Animal Health at Moredun Scientific dreddick@moredunscientific.com

Moredun and Pentlands Science Park showcased at latest Midlothian Science Zone Business Forum

The Midlothian Science Zone (MSZ), where Moredun resides, is a cluster of science parks, research institutes and businesses that each carry out worldleading research in animal health and life science.

Recently MSZ have been running a series of Business Forums to showcase the facilities and expertise in the area. It also provides opportunity for discussion, collaboration and awareness between Zone residents.

On 13th September Moredun and Pentlands Science Park were the focus of the latest forum as one of the founding members of the MSZ. Participants listened to presentations given by Richard Mole (Business Development Manager), Stephen Anderson

Moredun Research Institute, Pentlands Science Park.

(Head of Bioservices), Rhona Macdonald (Head of Marketing, Moredun Scientific), and Jill Gayford (Park Manager, Pentlands Science Park).

Previous locations for the MSZ Business Forum include the Agri-EPI Centre, The University of Edinburgh’s Easter Bush campus, and Edinburgh Technopole.

Ticks and zoonotic Tick-Borne Pathogens in Scotland: evaluating risk for humans and livestock

Sheep tick.

Moredun have recently become involved in a new Scottish Government-funded project to further develop research into ticks, tickborne diseases and their effect on humans, livestock and wildlife.

Ticks are blood sucking ectoparasites that require a suitable host to complete their lifecycle and are the second most important pathogen vector after mosquitoes globally. There are at least twenty species of ticks indigenous to the UK, with the most common being Ixodes ricinus. This tick is more commonly known as the sheep tick and is the vector for several diseases which affect livestock such as louping ill, tickborne fever (TBF), babesiosis (red water fever), and tick pyaemia. However, the same ticks can transmit Lyme disease (Borrelia) as well as louping ill and tickborne fever to humans, dogs, and horses. The sheep tick is distributed widely all over the UK but prefers dense vegetation and warm, wet conditions to support the free-living stages of its life cycle. Vector-borne zoonotic disease transmission requires the interaction of a pathogen, vector, and one or more reservoir hosts, in our case represented by avian, rodent and deer. In disease systems maintained by tick hosts the spatial and temporal patterns of contact between ticks and their wildlife hosts can influence the efficiency and stability of transmission to other species.

There is increasing awareness of ticks and tickborne diseases, amidst reports of ticks spreading geographically and increasing in numbers. Factors which may contribute to this are climate change (particularly during relatively wet summers), sheep farming economics, a reduction in sheep dipping, environmental biodiversity management strategies in relation to habitat, and the marked increase in deer numbers acting as tick maintenance hosts.

Upland grazing is the preferred habitat of the sheep tick. Tick infestations are therefore of significant importance to hill sheep production, with animal welfare concerns resulting from irritation, anaemia and risk of disease transmission, and economic losses resulting from disease outbreaks. Tick infestations are also a public health concern due to the risks and effects of Lyme disease and other zoonotic diseases. However, more and more often, ticks can be found in urban or semi-rural environments, such as gardens and parks, and this can increase the risk of zoonotic transmission.

As well as those diseases mentioned above, tickborne pathogens are responsible for an under-studied subset of emerging infections, such as babesiosis, ehrlichiosis and theileriosis, plus several potential exotic

Ticks are a common occurance in heathland.

diseases which could easily take hold in the UK tick population if introduced. An example of this is the recent discovery in UK ticks (and potentially in one or two individuals) of Tick-Borne Encephalitis Virus (TBEV), which is widespread in continental Europe. Using a multi-disciplinary, multi-centre One Health approach, Moredun have been awarded a new Scottish Government grant to improve our tick research. This will be done in conjunction with SRUC (Scotland’s Rural College) and University of Glasgow aimed at increasing our current research capacity, developing improved risk maps and looking more deeply into how ticks interact and mix between humans, wildlife and the environment, and the associated zoonotic pathogen risk.

This project is part of the current Strategic Research Programme and is a continuation of our previously funded research on ticks and Lyme Disease in collaboration with the University of Glasgow. This work will be supported with the use of molecular tools at Moredun and SRUC (Scotland’s Rural College) to identify ticks and their related pathogens, combined with spatiotemporal modelling expertise at SRUC to understand tick distributions and movement

Tick borne encephalitis virus. opportunities. Molecular tools can identify one or more pathogens in the ticks collected in locations chosen to represent different ecological environments and contact with humans, whereas statistical models will be employed to model tick distribution, overlay livestock, human population and pathogens density in the same area to identify places at higher risk of transmission of zoonotic diseases. Therefore, this project uniquely explores how both humans and livestock interact with, and change, their environment, thereby influencing tick presence and the associated pathogen risk. This aspect will also be investigated by a new PhD student associated to the project. Dr Mara Rocchi, the Head of Moredun’s Virus Surveillance Unit, says: “The overarching aim of this new project is to understand how livestock and humans interact with, and affect, the environmental factors that influence the distribution of ticks and pathogens in the landscape. Changing environments result in a change in the spread and the contact rates of ticks and tickborne zoonotic pathogens with humans and livestock. Another main aim is to develop new, optimised models of tick abundance and produce distribution maps of tickborne pathogens across Scotland.” Moredun members can access our fact sheet “Ticks and Tickborne Diseases” (2018) on our website: https://moredun.org.uk/ resources/factsheets/ticks-and-tickbornediseases