Publications by authors named "Piedrafita D"

Pituitary pars intermedia dysfunction (PPID) is the most common endocrine disorder of older horses. Immune dysfunction in horses with PPID could increase susceptibility to infectious diseases, including strongyle infections; however, few data are available. The aim of this study was to determine if horses with PPID had increased strongyle faecal egg counts (FEC) compared with control horses, over a fourteen-week period in Victoria, Australia.

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Fasciola hepatica causes liver fluke disease in production animals and humans worldwide. Faecal egg counts (FEC) are the most common diagnostic tool for the diagnosis of liver fluke disease. However, FEC has low sensitivity and is often unreliable for the detection of patent infection.

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Nematode infection is a major threat to the health of humans, domestic animals and wildlife. Nematodes vary in their effect on the host and in the mechanisms underlying immunity but the general features are becoming clear. There is considerable variation among individuals in resistance to infection and much of this variation is due to genetic variation in the immune response.

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Galectin-11 (LGALS-11) and galectin-14 (LGALS-14) are ruminant specific galectins, first reported in sheep. Although their roles in parasite immunity are still being elucidated, it appears that they influence protection against parasites. In gastrointestinal infections with the nematode Haemonchus contortus, both galectin-11 and galectin-14 appear to be protective.

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Although Nematodirus battus is a serious threat to the health and survival of young lambs, there are few options to control this parasite. Bayesian Monte Carlo Markov Chain modelling with a zero-inflated Poisson distribution was used to estimate the heritability of egg counts in both June and July for each of five consecutive cohorts of 200 Scottish Blackface lambs. In one of the 10 analyses, the results failed the diagnostic tests.

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This study was conducted to investigate whether co-administration of Barbervax® (Bvax) with Haemonchus contortus surface larval antigen (HcsL3) would increase the protective efficacy and duration of protection against H. contortus infection in weaner Merino sheep. A total of 132 10-month-old weaned Merino ewe lambs were randomly allocated into six treatment groups (n = 22).

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Eosinophils play a key role in defence against gastrointestinal nematodes. There is considerable variation among animals in the intensity of eosinophilia following nematode infection. However, the statistical distribution of eosinophils among animals has still to be determined.

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Article Synopsis
  • The study aimed to create a reliable DNA extraction protocol for individual Teladorsagia circumcincta nematodes to enhance genome sequencing and phylogenetic analysis.
  • Eleven different DNA extraction kits were tested, measuring DNA quality, yield, and processing time, with notable variations in concentration and purity across methods.
  • The Schistosoma sp. extraction method was found to be the most effective for individual T. circumcincta specimens, providing superior DNA quality and faster processing times compared to other protocols.
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Background: One of the greatest impediments to global small ruminant production is infection with the gastrointestinal parasite, Haemonchus contortus. In recent years there has been considerable interest in the gut microbiota and its impact on health. Relatively little is known about interactions between the gut microbiota and gastrointestinal tract pathogens in sheep.

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Article Synopsis
  • Galectins are glycan-binding proteins essential for various cellular functions, especially in immune and inflammatory responses.
  • Galectin-11 (LGALS-11) is specifically linked to combatting gastrointestinal nematodes in animals and has shown to hinder the growth of these parasites.
  • The study identifies two genetic variants of LGALS-11 in sheep, highlighting differences in their anti-parasitic abilities related to dimerization, which could inform selective breeding for parasite resistance.
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As COVID-19 spreads through the world, most cases to date are in middle- and high-income nations. The impact on resource-poor nations remains unknown. Amongst many factors likely to affect the impact of COVID-19 in these areas, co-infections need to be considered.

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Eosinophils are prominent effector cells in immune responses against gastrointestinal nematode infections in ruminants, but their in vivo role has been hard to establish in large animals. Interleukin-5 is a key cytokine in the induction and stimulation of anti-parasitic eosinophil responses. This study attempted to modulate the eosinophil response in sheep through vaccination with recombinant interleukin-5 (rIL-5) and determine the effect on subsequent Haemonchus contortus infection.

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Aims: To determine the composition and temporal stability of the gut (faecal) microbiota of sheep (Ovis aries).

Methods And Results: Microbial population dynamics was conducted using ARISA (28 sheep) and 16S rRNA sequencing (11 sheep). Firmicutes and Bacteroidetes were the predominant bacterial phyla, constituting ~80% of the total population.

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  • Fasciola hepatica is a parasitic trematode that impacts livestock and humans, causing disease and economic loss, with increasing resistance to current treatments.
  • The study focuses on the interaction of two glycan-binding proteins, LGALS-11 and LGALS-14, with F. hepatica proteins, revealing novel insights into potential vaccine candidates.
  • LGALS-14 identified a larger number of interacting proteins than LGALS-11, including previously tested vaccine candidates, indicating its significance in understanding host-parasite dynamics.
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  • Widespread anthelmintic resistance in small ruminants is significantly impacting the profitability of the meat and wool industry, particularly in Australia.
  • The study focuses on a region in Victoria, where resistance to anthelmintics is notably high at 71%, with varying drug effectiveness among farms.
  • Older drugs show more resistance compared to newer treatments, highlighting the need for more regional studies to assess and address this growing threat to worm control.
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The immunogenicity and efficacy of Fasciola DNA vaccines have not yet been comprehensively summarised in the form of a systematic review and meta-analysis. Though multiple vaccine studies with respect to Fasciola vaccines exist, the variance in the experimental parameters has made comparison difficult. We conducted a bibliographic database search in Scopus, PubMed, Science Direct, Cochrane Library, EMBASE and Web of Science databases, limited to publications from 1998 to 2017.

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is the most pathogenic nematode of small ruminants. Infection in sheep and goats results in anaemia that decreases animal productivity and can ultimately cause death. The involvement of ruminant-specific galectin-11 (LGALS-11) and galectin-14 (LGALS-14) has been postulated to play important roles in protective immune responses against parasitic infection; however, their ligands are unknown.

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A more thorough understanding of the immunological interactions between Fasciola spp. and their hosts is required if we are to develop new immunotherapies to control fasciolosis. Deeper knowledge of the antigens that are the target of the acquired immune responses of definitive hosts against both Fasciola hepatica and Fasciola gigantica will potentially identify candidate vaccine antigens.

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  • Canaria Hair Breed (CHB) sheep show resistance to the nematode Haemonchus contortus, linked to γδ T lymphocytes.
  • Previous research indicates that γδ T cells may influence the reproductive success of adult worms.
  • Depleting these T cells reduced their levels in CHB sheep, leading to longer female worms and increased egg production, suggesting γδ T cells are crucial for controlling worm fecundity and providing a new understanding of immune modulation in these sheep.
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Background: Intravenous zanamivir has been used to treat patients with severe influenza. Because the majority of cases (including immunocompromised patients) require the drug for an extended period of treatment, there is a higher risk that the virus will develop resistance. Therefore, knowing the possible amino acid substitutions that may arise in recently circulating influenza strains under prolonged zanamivir exposure and their impact on antiviral susceptibility is important.

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Article Synopsis
  • Sheep can develop immunity to the parasite Haemonchus contortus through repeated exposure, affected by factors such as age, gender, and nutrition.
  • There are different immune responses based on the parasite's developmental stage, and understanding these mechanisms has improved significantly in the 2000s.
  • Current vaccines are effective due to high levels of antibodies against gut antigens of H. contortus, leading to a successful vaccine launch in Australia, but more work is needed on recombinant subunit vaccines targeting these gut antigens.
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  • Haemonchus contortus is a blood-feeding parasite that causes significant economic losses in sheep.
  • Two sheep breeds on Gran Canaria have different levels of susceptibility to this parasite: the resistant Canaria Hair Breed (CHB) and the susceptible Canaria Sheep (CS).
  • This study finds that mucosal IgA (mIgA) is linked to resistance mechanisms in CHB sheep, negatively affecting the parasite's adult stage, while in the CS breed, mIgA correlates mainly with the larval stage.
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The development of effective diagnostic tools will be essential in the continuing fight to reduce schistosome infection; however, the diagnostic tests available to date are generally laborious and difficult to implement in current parasite control strategies. We generated a series of single-chain antibody Fv domain (scFv) phage display libraries from the portal lymph node of field exposed water buffaloes, Bubalus bubalis, 11-12 days post challenge with Schistosoma japonicum cercariae. The selected scFv-phages showed clear enrichment towards adult schistosomes and excretory-secretory (ES) proteins by immunofluorescence, ELISA and western blot analysis.

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Background: IL-4 and IL-13 play a critical yet poorly understood role in orchestrating the recruitment and activation of effector cells of the asthmatic response and driving the pathophysiology of allergic asthma. The house dust mite (HDM) sheep asthma model displays many features of the human condition and is an ideal model to further elucidate the involvement of these critical Th2 cytokines. We hypothesized that airway exposure to HDM allergen would induce or elevate the expression profile of IL-4 and IL-13 during the allergic airway response in this large animal model of asthma.

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Article Synopsis
  • Galectins are proteins that help cells respond to sugar molecules, with galectin-11 being a specific type found only in ruminants like sheep, goats, and cattle.
  • Galectin-11 is vital for critical biological functions such as reproduction and immune responses against parasites, which are essential for sustainable livestock production.
  • This study details the process of expressing, purifying, and crystallizing galectin-11 from domestic sheep, achieving high-resolution X-ray data to better understand its structure and function.
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