Field testing of recombinant subunit vaccines against in lambing ewes demonstrates a lack of efficacy in the face of a multi-species parasite challenge.

Introduction: We previously demonstrated efficacy of an 8-antigen recombinant subunit vaccine against a single species homologous challenge in lambs and in lambing ewes in pen trials. We subsequently demonstrated efficacy of a simplified, 2-antigen, version of this vaccine in lambs in pen trials. Here, we test both vaccines in lambing ewes in a field setting.

Enhancing the understanding of coinfection outcomes: Impact of natural atypical porcine pestivirus infection on porcine reproductive and respiratory syndrome in pigs.

Atypical porcine pestivirus (APPV) is a novel member of the Pestivirus genus detected in association with congenital tremor (CT) type A-II outbreaks and from apparently healthy pigs, both as singular infection and as part of multi-pathogen infections. 'Classical' pestiviruses are known to cause immunosuppression of their host, which can increase susceptibility to secondary infections, severely impacting health, welfare, and production. To investigate APPV's effect on the host's immune system and characterise disease outcomes, 12 piglets from a natural APPV CT type A-II outbreak were experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV), a significant porcine pathogen.

Linking active rectal mucosa-attached microbiota to host immunity reveals its role in host-pathogenic STEC O157 interactions.

The rectal-anal junction (RAJ) is the major colonization site of Shiga toxin-producing Escherichia coli (STEC) O157 in beef cattle, leading to transmission of this foodborne pathogen from farms to food chains. To date, there is limited understanding regarding whether the mucosa-attached microbiome has a profound impact on host-STEC interactions. In this study, the active RAJ mucosa-attached microbiota and its potential role in host immunity-STEC commensal interactions were investigated using RAJ mucosal biopsies collected from calves orally challenged with two STEC O157 strains with or without functional stx2a (stx2a+ or stx2a-).

Host resources and parasite traits interact to determine the optimal combination of host parasite-mitigation strategies.

Organisms have evolved diverse strategies to manage parasite infections. Broadly, hosts may avoid infection by altering behaviour, resist infection by targeting parasites or tolerate infection by repairing associated damage. The effectiveness of a strategy depends on interactions between, for example, resource availability, parasite traits (virulence, life-history) and the host itself (nutritional status, immunopathology).

Tuft cell acetylcholine is released into the gut lumen to promote anti-helminth immunity.

Upon parasitic helminth infection, activated intestinal tuft cells secrete interleukin-25 (IL-25), which initiates a type 2 immune response during which lamina propria type 2 innate lymphoid cells (ILC2s) produce IL-13. This causes epithelial remodeling, including tuft cell hyperplasia, the function of which is unknown. We identified a cholinergic effector function of tuft cells, which are the only epithelial cells that expressed choline acetyltransferase (ChAT).

Characterisation of protective vaccine antigens from the thiol-containing components of excretory/secretory material of Ostertagia ostertagi.

Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments.

Tuft Cells: Detectors, Amplifiers, Effectors and Targets in Parasite Infection.

Tuft cells have recently emerged as the focus of intense interest following the discovery of their chemosensory role in the intestinal tract, and their ability to activate Type 2 immune responses to helminth parasites. Moreover, they populate a wide range of mucosal tissues and are intimately connected to immune and neuronal cells, either directly or through the release of pharmacologically active mediators. They are now recognised to fulfil both homeostatic roles, in metabolism and tissue integrity, as well as acting as the first sensors of parasite infection, immunity to which is lost in their absence.

A curated multivariate approach to study efficacy and optimisation of a prototype vaccine against teladorsagiasis in sheep.

This work discusses and demonstrates the novel use of multivariate analysis and data dimensionality reduction techniques to handle the variety and complexity of data generated in efficacy trials for the development of a prototype vaccine to protect sheep against the Teladorsagia circumcincta nematode. A curated collection of data dimension reduction and visualisation techniques, in conjunction with sensible statistical modelling and testing which explicitly model key features of the data, offers a synthetic view of the relationships between the multiple biological parameters measured. New biological insight is gained into the patterns and associations involving antigen-specific antibody levels, antibody avidity and parasitological parameters of efficacy that is not achievable by standard statistical practice in the field.

Exploring the transcriptomic changes underlying recombinant vaccine efficacy against Teladorsagia circumcincta in 3-month-old lambs.

Teladorsagia circumcincta is an abomasal parasitic nematode that can cause serious issues in small ruminant production, which are aggravated by drug resistance. Vaccines have been suggested as a feasible, long-lasting alternative for control since adaptation to the host's immune mechanisms by helminths develops at a much slower pace than anthelmintic resistance. Recently, a T.

Efficacy of Phase I and Phase II Bacterin Vaccines in a Pregnant Ewe Challenge Model.

The bacterium can cause the disease Q-fever in a wide range of animal hosts. Ruminants, including sheep, are thought to play a pivotal role in the transmission of to humans; however, the only existing livestock vaccine, namely, Coxevac (Ceva Animal Health Ltd., Libourne, France), a killed bacterin vaccine based on phase I strain Nine-Mile, is only approved for use in goats and cattle.

Variability in the Response against in Lambs of Two Canarian Sheep Breeds.

The increasing resistance to anthelmintics has necessitated the exploration of alternative control strategies of gastrointestinal nematode (GIN) infections. A sustainable option is genetic selection based on differences in susceptibility to GIN infection between and within breeds of sheep. Here, three-month-old Canaria Hair breed (GIN-resistant) and Canaria Sheep breed (GIN-susceptible) showed no significant between-breed differences after trickle infection with , whereas considerable individual variability was found in both breeds.

The cost of host genetic resistance on body condition: Evidence from divergently selected sheep.

Trade-offs between host resistance to parasites and host growth or reproduction can occur due to allocation of limited available resources between competing demands. To predict potential trade-offs arising from genetic selection for host resistance, a better understanding of the associated nutritional costs is required. Here, we studied resistance costs by using sheep from lines divergently selected on their resistance to a common blood-feeding gastro-intestinal parasite ().

The microbial condition of Scottish wild deer carcasses collected for human consumption and the hygiene risk factors associated with Escherichia coli and total coliforms contamination.

Wild deer hunting is necessary in Scotland to control deer population density, with most carcasses being processed for human consumption. As limited information is available on the microbial condition of Scottish venison, we studied the variation of total coliforms and Escherichia coli (E. coli) on 214 wild deer carcasses collected from six approved establishments.

Vaccine-induced time- and age-dependent mucosal immunity to gastrointestinal parasite infection.

Individuals vary broadly in their response to vaccination and subsequent challenge infection, with poor vaccine responders causing persistence of both infection and transmission in populations. Yet despite having substantial economic and societal impact, the immune mechanisms that underlie such variability, especially in infected tissues, remain poorly understood. Here, to characterise how antihelminthic immunity at the mucosal site of infection developed in vaccinated lambs, we inserted gastric cannulae into the abomasa of three-month- and six-month-old lambs and longitudinally analysed their local immune response during subsequent challenge infection.

Differences in the protection elicited by a recombinant Teladorsagia circumcincta vaccine in weaned lambs of two Canarian sheep breeds.

Gastrointestinal nematode (GIN) infections are a serious drawback on small ruminant production. Since anthelmintic resistance has extended, optimisation of alternative non-chemical control strategies has attracted interest. Recently, a prototype recombinant vaccine protected immunologically mature sheep from Texel-cross and Canaria Sheep breeds against Teladorsagia circumcincta.