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Haemonchus contortus is known for its high pathogenicity in sheep, and the uncontrolled use of anthelmintics resulted in the emergence of multiple drug-resistant populations. Breeding sheep for gastrointestinal nematode resistance is a sustainable alternative to reduce dependence of anthelmintic drugs, and differences in the degree of resistance between breeds have been reported. Here we compare two sheep breeds (Santa Ines and Ile de France), concerning the differences in innate and adaptive immune response involved in the resistance against H. contortus infection. Immunohistochemical analyses of the abomasum were conducted in naïve Santa Ines (n = 14) and Ile de France (n = 12) lambs randomized into four groups: infected Santa Ines (n = 8), non-infected control Santa Ines (n = 6), infected Ile de France (n = 8), and non-infected control Ile de France (n = 4). The infected lambs were initially infected with H. contortus infective larvae at 14 days of age, and multiple infections were conducted every second day until they reached 66 days of age. There was a significant effect (P < 0.001) of the infection with increase in numbers of CD3 + T; CD79α+ B; GATA3+ Th2/ILC2; POU2F3+ tuft cells; FOXP3+ T reg; and IgE + cells in the fundus of the abomasal mucosa in both Santa Ines and Ile de France lambs. Nevertheless, the infected Santa Ines lambs presented the highest averages for CD79α+ B; GATA3+ Th2/ILC; IgE + cells; and POU2F3+ tuft cells and there was a significant association of the breed and infection status with regards to POU2F3+ tuft cells, with the highest mean in the infected Santa Ines group. The infected Santa Ines group had three lambs with high degree of resistance and five lambs that showed a moderate infection. Our results suggest a mechanism of synergistic coordination between different immune-cell types in promoting resistance of suckling lambs under H. contortus infection., Competing Interests: Declaration of competing interest There are no conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024. Published by Elsevier Ltd.)

RNA interference (RNAi) on parasitic nematodes has been described as a valuable tool for screening putative targets that could be used as novel drug and/or vaccine candidates. This study aimed to set up a pipeline to identify potential targets using RNAi for vaccine/anti-parasite therapy development against Haemonchus contortus, a blood-feeding abomasal nematode parasite. The available H. contortus sequence data was mined for targets, which were tested for essentiality using RNAi electroporation assays. A total of 56 genes were identified and tested for knockdown using electroporation of first-stage larvae (L1) H. contortus with the target double-stranded RNA. Electroporation of L1 proved to be effective overall; 17 targets had a strong phenotype and significant reduction in alive H. contortus, and another 24 had a moderate phenotype with a significant reduction in larvae development. A total of 28 targets showed a significant reduction in the development of H. contortus larvae to the infective stage (L3) following the RNAi assay. Down-regulation of target transcript levels was evaluated in some targets by semi-quantitative PCR. Four out of five genes tested showed complete knockdown of mRNA levels via semi-quantitative PCR, whereas the knockdown was partial for one. In conclusion, the results indicate that the RNAi pathway is confirmed in H. contortus and that several target genes have the potential to be investigated further as possible vaccine candidates., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The gastrointestinal nematode infection poses a covert threat to both humans and domestic animals worldwide, eliciting a type 2 immune response within the small intestine. Intestinal tuft cells detect the nematode and activated group 2 innate lymphoid cells. Tuft cell-derived leukotrienes (one of the metabolites of arachidonic acid) were found to drive rapid anti-helminth immunity, but it is still poorly understood whether the tuft cell-mediated type 2 immune circuit and arachidonic acid metabolism modulate anti-parasitic immunity in the gastric epithelium. This study was designed to evaluate the immunological responses of goats inoculated with or without H. contortus. Results showed that H. contortus infection induced a systemic type 2 immune response, characterised by lymphocyte proliferation and greater eosinophils both in peripheral blood and abomasal mucosa, as well as increased type 2 cytokines IL-4, IL-5, and IL-13. Infection of H. contortus altered the transcriptome of the abomasum epithelium, especially tuft cell-mediated circuit-key genes. The infection also influenced the abomasal microbiota, arachidonic acid metabolism and related lipid metabolites, accompanying with great increases in the secretion of leukotrienes and prostaglandins. These findings demonstrate the role of tuft cells mediated circuit in sensing H. contortus infection and immune activation, reveal the candidate function of arachidonic acid involved in anti-helminth immunity, and suggest novel strategies for the control of parasitic diseases in livestock and humans., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Bitter melon (Momordica charantia) has several biological properties including anthelmintic activity. Presented in vivo study evaluated the anthelmintic activity of the hydroalcoholic extract of M. charantia Presented in vivo study (HEMC) and its effect on animal performance, carcass characteristics and lamb meat quality in animals infected by Haemonchus contortus. The HEMC demonstrated effectiveness against the parasite. Lambs treated with HEMC showed a significant reduction in egg count per gram of faeces and in the number of parasites in the abomasum. However, nutrient intake decreased with increasing doses of HEMC, leading to reductions in final live weight and carcass weight. No significant effects were observed on meat quality. Therefore, it is concluded that HEMC presents anthelmintic action, but it also impairs animal performance, highlighting the need to assess the benefits and impacts of HEMC use for H. contortus control., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Laura reports administrative support and equipment, drugs, or supplies were provided by National Council for Scientific and Technological Development., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The objective was to determine host animal protein/amino acid redistribution and use among the abomasum, duodenum and muscle of sheep infected with Haemonchus contortus. Sixteen male Ujumqin sheep (32.4 ± 3.9 kg) were dewormed and randomly assigned to two groups, infected or not infected with H. contortus (GIN and CON). The GIN group had lower (P < 0.05) dry matter intake, average daily gain, and live body weight than CON, with extensive focal infiltration of lymphocytes in the lamina propria and bottom of the abomasal epithelium. In the abomasum and duodenum, there were 100 and 220 genes, respectively, that were up-regulated, whereas 56 and 149 were down-regulated. In the abomasum, the most enriched KEGG pathways were related to immunity and inflammation reaction, including: viral protein interaction with cytokine and cytokine receptor (P = 0.017), influenza A (P = 0.030), IL-17 signaling pathway (P = 0.030). In the duodenum, KEGG pathways were more enriched in nutrient metabolism, including pancreatic secretion (P < 0.001), protein digestion and absorption (P < 0.001), graft-versus-host disease (P = 0.004). Furthermore, most genes related with the above KEGG pathways were increased in the abomasum but decreased in the duodenum. Amino acid profiles in abomasum and duodenum of CON and GIN groups were clustered in a partial least-squares discriminant analysis model, with significant changes in 36 and 19 metabolites in abomasal and duodenal chyme, respectively. Further confirmed by transcriptome-targeted metabolome association analysis, GIN mainly enhanced metabolism of arginine and sulphur amino acids in abomasum and those metabolic pathways were associated. Meanwhile, GIN mainly decreased pyruvate related amino acid metabolism in duodenum. Moreover, concentrations of Arg (P = 0.036), His (P = 0.027), and Cys (P = 0.046) in longissimus thoracis et lumborum were decreased in GIN, whereas concentrations of Gly (P = 0.012) and Ala (P = 0.046) were increased. In conclusion, H. contortus enhanced metabolism of arginine and sulphur amino acids in the abomasum; decreased pyruvate metabolism in the duodenum; and drove more protein/amino acids for abomasal tissues to resist physical and immune damage, reducing protein and amino acids in duodenum and muscle for support host growth. Specific nutrients (such like arginine, histidine, and cysteine) may play important role in control gastrointestinal nematode infection for ruminant., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Gastrointestinal helminth infection, particularly by Haemonchus contortus, poses significant challenges to sheep farming worldwide. While anthelmintic drugs have been traditional control measures, the emergence of resistance calls for alternative strategies. Understanding the interaction between parasites, host, and their microbiome is crucial for management of helminth infection. This study intricately explores the interactions between microbial communities in Kashmir Merino sheep infected with H. contortus, to understand the complex interplay between host, parasite, and their microbiome. Sheep abomasal contents and H. contortus were collected from infected and control groups, processed for DNA extraction, and subjected to metagenomic sequencing of the 16 S rRNA gene. Downstream analysis unveils distinct microbial patterns, where Proteobacteria were dominant in H. contortus, while Bacteroidota and Firmicutes prevailed in the sheep abomasum. The revelation of unique genera and shifts in diversity indices underscored helminth-induced disruptions in the host. Beta diversity analysis further showed significant variations in bacterial profiles, providing insights into the intricate host, parasite, and microbiome dynamics. Additionally, this study elucidated the presence of pathogenic bacteria within H. contortus, accentuating their potential role in exacerbating sheep health issues. This finding underscores the complexity of the host-parasite-microbiome interaction showing helminth-induced microbiome alterations of the host., Competing Interests: Declaration of Competing Interest The authors have disclosed that there are no potential conflicts of interest related to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This experiment aimed to assess the regulatory effects of treatment with Balanites aegyptiaca fruit ethanol extract (BA-EE) on oxidant/antioxidant status, anti-inflammatory cytokines, and cell apoptosis gene expression in the abomasum of Haemonchus contortus-infected goats. Twenty goat kids were assigned randomly to four equal groups: (G1) infected-untreated, (G2) uninfected-BA-EE-treated, (G3) infected-albendazole-treated, (G4) infected-BA-EE-treated. Each goat in (G1), (G3), and (G4) was orally infected with 10,000 infective third-stage larvae. In the fifth week postinfection, single doses of albendazole (5 mg/kg.BW) and BA-EE (9 g/kg.BW) were given orally. In the ninth week postinfection, the animals were slaughtered to obtain abomasum specimens. The following oxidant/antioxidant markers were determined: malondialdehyde (MDA), glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT). The mRNA gene expression of cytokines (IL-3, IL-6, IL-10, TNF-α) and cell apoptosis markers (Bax, Bcl-2) were estimated. (G1) showed significantly reduced GSH content and GST and SOD activities but a markedly increased MDA level. (G3) and (G4) revealed a markedly lower MDA level with pronouncedly elevated GSH, SOD, and GST levels. The antioxidant properties of BA-EE were superior to those of albendazole. The mRNA gene expressions of IL-3, IL-6, IL-10, TNF-α, and Bax-2 were upregulated in (G1) but downregulated in (G3) and (G4). Bcl-2 and Bcl-2/Bax ratio expression followed a reverse course in the infected and both treated groups. We conclude that BA-EE treatment has a protective role in the abomasum of H. contortus-infected goats. This could be attributed to its antioxidant properties and ability to reduce pro-inflammatory cytokines and cell apoptosis., (© 2024. The Author(s).)

The health of the gastrointestinal tract in cattle is one of the factors influencing adequate nutrient absorption and body weight gain. This study aimed to evaluate the prevalence of lesions found in the abomasum of Polish fattening Holstein-Friesian bulls. A total of 149 abomasa from adult bulls from two voivodeships of central Poland were inspected for pathologicalanatomic position (displacement, volvulus), impaction, mucosal membrane lesions (inflammation, hyperplasia), and signs of parasite infestation(Moroccan leather, worm nodules) in one of the Polish abattoirs just after slaughter. Among all the examined males no lesions were observed in only 8 individuals. The most common findings were erosions (75.8%) and type 1 ulcerations (48.3%) of the body, pylorus, or both locations. Signs of parasite infestations were observed in 78.5% of the inspected animals. Significant differences correlated with age were found in the prevalence of healed ulcers, and between voivodeships in the prevalence of type 2 ulcers. The findings of this study indicate that most fattening bulls in Poland suffer from subclinical forms of abomasa inflammation (both diffuse and focal) and middle-large abomasum parasites invasions, which can influence the economics and profitability, as well as welfare, of livestock production., (© 2024. The Author(s).)

Purpose: The aim of the study was to supplement the data concerning the spreading of nematode Ashworthius sidemi among wild ruminants in Russia., Methods: The samples of A. sidemi were collected from two fallow deer, which were born and raised in the game farm in Smolensk region (55° 16' N-34° 29' E). The affiliation of the detected nematodes as A. sidemi was made using morphological features (shape of the spicules and the dorsal ray of bursa for males, as well as the presence and shape of the neodont in the buccal cavity for males and females)., Results: The intensity of infection in 2 studied fallow deer was 7 and 19 individuals of A. sidemi. All of the specimens of A. sidemi had the features of juvenile forms. The registration of fallow deer as another one host of A. sidemi in Russia indicates a further spreading of this nematode and confirms the necessity of strengthening the control of this parasite., Conclusion: The finding of this nematode in non-native captive animals shows the imperfection of control in this sphere. A. sidemi could have been introduced to the game farm both with imported or with native animals due to insufficient quarantine and isolation. More wide further research would be useful in the light of control this potentially dangerous parasite., (© 2021. Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Background: Due to increased anthelmintic resistance, alternative methods to drugs are necessary to control gastrointestinal nematodes (GINs). Some of the most promising alternatives are based on the immune response of the host, such as the selection of genetically resistant breeds or the use of vaccines against these parasites. Given the limited information available on the immune response against GINs in goats, this study investigated the local immune response of goat kids of an indigenous Canary Islands breed (Majorera breed) experimentally infected with Teladorsagia circumcincta, one of the most pathogenic and prevalent GIN species., Methods: For this purpose, the relationship between different parasitological (number of mature and immature worms, worm length, and number of intrauterine eggs) and immunological parameters at the local level (related to both the humoral and cellular immune response) was analyzed at early (1 week post-infection [wpi]) and late (8 wpi) stages of infection., Results: Primary infection of goat kids with T. circumcincta infective larvae (L3) generated a complex immune response that could be defined as Th2 type, characterized by increased infiltration in abomasal tissues of several effector cells as well as a progressive presence of specific antibodies against parasitic antigens in the gastric mucus. Cellular responses were evidenced from 1 wpi onward, showing an increase in antigen-presenting cells and various lymphocyte subsets in the gastric mucosa., Conclusions: The complexity of the host response was evidenced by statistically significant changes in the number of all these subpopulations (MHCII + , CD4 + , CD8 + , γδ + , CD45R + , IgA + , and IgG + ), as well as in the evolution of the relative cytokine gene expression. From a functional point of view, negative associations were observed between the number of most of the immune cells (CD4, IgA, IgG, and CD45R cells) and parameters that could be related to the fecundity of worms, a phenomenon that was especially evident when the number of IgG and CD45R cells or the specific IgA levels of the gastric mucus were compared with parasitological parameters such as the female worm length or fecal egg counts at 8 wpi., (© 2022. The Author(s).)

The nematophagous fungus Duddingtonia flagrans is used in integrated management of gastrointestinal nematodes in ruminants. The chlamydospores of the fungus, orally administered, pass through the segments of the ruminant digestive tract and, in the feces, capture the nematodes preventing their migration to grasslands. The drastic conditions of the gastrointestinal segments can negatively affect the fungus' biocontrol activity. The aim of this study was to assess the effect of in vitro conditions of the sheep's main gastrointestinal segments on the concentration, viability and nematode predatory ability of D. flagrans chlamydospores. The segments evaluated separately in vitro were the oral cavity, rumen, abomasum, and small intestine. The results showed that chlamydospores concentration was not affected by exposure to the different segments. The viability of the chlamydospores after exposure to the oral cavity (2.53 × 10 6  CFU/mL) and small intestine (1.24 × 10 5  CFU/mL) was significantly lower than its control treatment, with values of 6.67 × 10 6  CFU/mL and 2.31 × 10 5  CFU/mL respectively. Nematode predatory ability after rumen exposure was reduced by 7% compared to the control treatment, by 25% after abomasum exposure and by 17% after small intestine. This study revealed the individual in vitro effect of each segment of ovine gastrointestinal tract on the integrity of this strain of the fungus D. flagrans affecting its viability and nematode predatory ability under the evaluated conditions. Delivery systems could be designed to protect chlamydospores considering the impact of each gastrointestinal segment., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The abomasal parasitic nematode Haemonchus contortus can influence the abomasal microbiome of the host. On the other hand, no information occurs on the influence of the parasite on the hindgut microbiome of the host. We evaluated the impact of Haemonchus contortus on the fecal microbial community of the experimentally infected lambs treated with a mixture of medicinal herbs to ameliorate the haemonchosis. Twenty-four female lambs were divided into four groups: infected animals (Inf), infected animals supplemented with a blend of medicinal herbs (Inf+Herb), uninfected control animals (Control), and uninfected animals supplemented with medicinal herbs (C+Herb). Inf and Inf+Herb lambs were infected orally with approximately 5000 L3 larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Herb blend (Herbmix) consisted of dry medicinal plants of Althaea officinalis, Petasites hybridus, Inula helenium, Malva sylvestris, Chamomilla recutita, Plantago lanceolata, Rosmarinus officinalis, Solidago virgaurea, Fumaria officinalis, Hyssopus officinalis, Melisa officinalis, Foeniculum vulgare, and Artemisia absinthium. Each animal was fed meadow hay and a commercial concentrate (600 + 350 g DM/d). Inf+Herb and C+Herb lambs were fed Herbmix (100 g DM/d and animal). Treatment lasted for 50 days. The fecal microbial fermentation parameters (short-chain fatty acids, ammonia, and pH) were evaluated at intervals of 0, 20, 32, and 50 days. The fecal eubacterial populations were evaluated by denaturing gradient gel electrophoresis (DGGE) at day 32 when H. contortus infection was the highest. No substantial effects of the H. contortus infection and the herbal treatment on fecal microbial fermentation parameters and fecal eubacterial populations were observed. Evaluation of DGGE patterns by Principal component analysis pointed to the tendency to branch the C+Herb group from the other experimental groups on Day 32. The results indicate that hindgut microbial activity was not disturbed by H. contortus infection and herbal treatment., Competing Interests: The authors have declared that no competing interests exist.

Gastrointestinal nematode (GIN) infections are one of the major constraints for grazing sheep and goat production worldwide. Genetic selection for resistant animals is a promising control strategy. Whole-transcriptome analysis via RNA-sequencing (RNA-seq) provides knowledge of the mechanisms responsible for complex traits such as resistance to GIN infections. In this study, we used RNA-seq to monitor the dynamics of the response of the abomasal mucosa of Creole goat kids infected with Haemonchus contortus by comparing resistant and susceptible genotypes. A total of 8 cannulated kids, 4 susceptible and 4 resistant to GIN, were infected twice with 10 000 L3 H. contortus. During the second infection, abomasal mucosal biopsies were collected at 0, 8, 15 and 35 days post-infection (dpi) from all kids for RNA-seq analysis. The resistant animals showed early activation of biological processes related to the immune response. The top 20 canonical pathways of differentially expressed genes for different comparison showed activation of the immune response through many relevant pathways including the Th1 response. Interestingly, our results showed a simultaneous time series activation of Th2 related genes in resistant compared to susceptible kids.

Plant extracts used for the treatment of helminth infections in sheep are an alternative to chemical anthelmintic drugs. Previous studies have reported the anthelmintic activity of acetone leaf extracts of Leucosidea sericea. For this study, we evaluate the ultrastructure changes induced by the acetone leaf extract of L. sericea and the component agrimol G (AG) that was isolated for the first time on adult haemonchus parasites. Adult haemonchus parasites harvested from sheep were incubated with the plant extract and AG for 3 h and evaluated by both scanning and transmission electron microscopy in comparison and in combination with albendazole or ivermectin. In all cases the method of evaluation shows ultrastructural changes, with albendazole inducing mitochondrial damage and ivermectin inducing muscle degeneration, both as previously described. Incubation with the plant extract and AG resulted in the formation of numerous non-membrane bound multi-vesicular like bodies and evenly spread disruptions/erosion in the epicuticle. Combining AG with ivermectin or albendazole resulted in an absence of effect of AG. Based on the structural changes induced by AG, together with the absence of an effect in combination with ivermectin and albendazole would suggest a disrupted microtubular network. The latter does however require biochemical confirmation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

We have validated ITS-2 rDNA nemabiome next-generation amplicon sequencing to determine relative species abundance of gastrointestinal nematode species in ovine fecal samples. In order to determine species representation biases, ITS-2 rDNA amplicon sequencing was applied to mock communities or field populations with known proportions of L3 for eight of the major ovine gastrointestinal nematode species: Teladorsagia circumcincta, Trichostrongylus vitrinus, Haemonchus contortus, Cooperia curticei, Trichostrongylus axei, Trichostrongylus colubriformis, Chabertia ovina and Oesophagostumum venulosum. Correction factors, calculated from this data, were shown to reduce species representation biases when applied to an independent set of field samples of known composition. We compared ITS-2 rDNA amplicon sequencing data that was generated from harvested eggs, freshly hatched L1 or L3 larvae following fecal culture and no statistically significant differences were found for the more abundant parasite species. We then applied the validated ITS-2 rDNA nemabiome amplicon sequencing assay to a set of archived L1 gastrointestinal nematode populations, collected in 2008 from fecal samples from 93 groups of 20 ewes and 61 groups of 20 lambs derived from 99 UK sheep farms. The presence of the major gastrointestinal nematode species had previously been determined on this large sample set by species-specific PCR. We show how the ITS-2rDNA amplicon sequencing data provided much more detailed information on species abundance than the previous species-specific PCR. This new data represents the most comprehensive overview of the relative abundance of the major gastrointestinal nematode species across UK sheep farms to date. Substantial variance in the relative abundance of both T. circumcincta and T. vitrinus between farms was revealed with the former species being of statistically significantly higher abundance in all three regions sampled (England, Scotland and Wales). The data also revealed that the relative abundance of T. circumcinta was statistically significantly higher in ewes than in lambs with the opposite pattern being the case for T. vitrinus. The nemabiome sequencing data also clearly illustrated the sporadic nature and skewed distribution of H. controtus across UK sheep farms as well as a higher relative abundance on farms from England compared to Wales and Scotland. The nemabiome survey also provides the first widescale data on the relative abundance of the two major large intestinal nematodes C. ovina and O. venulosum. This work validates ITS-2 rDNA nemabiome sequencing for use in sheep and illustrates the power of the approach for large scale surveillance of ovine gastrointestinal nematodes., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Haemonchosis is one of the most economically important parasitic diseases affecting small ruminants all over the world. Chemotherapeutic control has several shortcomings (limited anthelmintic arsenal, frequent resistance) and is hardly affordable by many farm economies. A recombinant antigen (rHc23) was shown to induce significant protection in vaccination trials with single dose challenges and different adjuvants., Results: Lambs were vaccinated with 100 μg rHc23/dose + bacterial immunostimulant (BI) (LPS from Escherichia coli + Propionibacterium acnes extract) (days - 2, 0, 7 and 14) and subjected to a trickle infection with two dosages [6x, 1000 infective larvae (L3) or 6x, 2000 L3]. Vaccinated lambs showed a significant antibody response against rHc23 and Haemonchus contortus soluble extract as assessed by ELISA and Western blot (WB). Fecal egg counts (epg) along the experiment of vaccinated and BI treated lambs were significantly reduced. All vaccinated animals showed total egg output and abomasal helminth burdens (median, average) lower than those from unvaccinated or BI-treated animals lambs although differences were not statistically significant., Conclusions: Vaccination with 100 μg rHc23/dose + BI against H.contortus trickle infections apparently induced lower epg values and helminth burdens at the end of the experiment. Intragroup individual variations did not allow to obtain conclusive results and more research is needed including adjuvants and larger groups of animals to validate the potential value of rHc23 as candidate to develop a recombinant vaccine for lambs haemonchosis.

Molecules from natural sources, such as essential oils, have shown activity against parasites in vitro, but have not yet been explored extensively in vivo. Anethole and carvone (10% each), encapsulated with 80% of a solid matrix, referred to as EO (encapsulated oils), were tested in vivo in 2 experiments. In Experiment 1: Lambs were artificially infected with multidrug resistant Haemonchus contortus, or left uninfected, and treated (or not) with 50 mg/kg bw (body weight) of EO in a controlled environment. Thirty-two male lambs were kept in individual cages for a period of 45 days, after which animals were evaluated for parasitological, hematological, toxicological, and nutritional parameters. After 45 days of treatment, EO at 50 mg/kg bw provided a significant (P ≤ 0.05) reduction in fecal egg count (FEC). Although FEC was reduced, animals from both treatments had similar counts of total adult worms. The low FEC was caused probably by a significant reduction (P ≤ 0.05) in both male worm size and female fecundity. Dry matter intake of uninfected controls was significantly (P ≤ 0.05) reduced, although no toxicity was observed in treated animals. Thus, in Experiment 2, conducted for five months we used an EO dose of 20 mg/kg bw. Thirty-four weaned lambs, free of parasites, were divided in two groups and kept in collective pens. One group received EO at 20 mg/kg bw mixed with concentrate for 5 months and the other was kept as a control group (CTL). Parasitological and hematological parameters as well as body weight were evaluated. In the first 2.5 months, CTL and EO groups were confined, and both presented similar clinical parameters. Then, animals were allotted to graze on contaminated pastures to acquire natural infection for the next 2.5 months. The infection was patent after 25 days and both groups had similar decreases in weight gain, increases in FEC, and decreases in blood parameters. Coprocultures from CTL and EO groups established that parasite population was 90% Haemonchus sp. We concluded that the technology of encapsulation is safe and practical to deliver to lambs at the farm level and anethole and carvone at 50 mg/kg bw caused a significant decrease in FEC and, consequently, in pasture contamination by free living stages of H. contortus. However, EO at 20 mg/kg bw was not effective to prevent or treat sheep naturally-infected with gastrointestinal nematodes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Haemonchus contortus constitutes a severe problem for ruminant's production, it is the most frequent nematode parasite both in template and tropical regions, induces economical losses, and shows increasing resistance to currently available anthelmintics. Tannins are secondary metabolites that naturally fulfill defense functions in plants, representing a non-conventional, natural alternative in the treatment of gastrointestinal parasites in sheep. The objective of this work was to explore the in vitro anthelmintic activity of hydrolysable tannins on adult stage of Haemonchus contortus. Adults nematodes were obtained directly from the abomasum of ovines, and a dose response curve was performed with tannins extract at 0, 2, 4, 8, 25 and 50 mg/mL, and a time response curve at 0.5, 1, 2 and 24 h at 37 °C. Hydrolysable tannins decreased motility and induced mortality of H. contortus. We observed cuticle disruption around the mouth and reproductive organs, as well as evisceration. After 24 h of exposition, 8 mg/mL induced 83% of mortality and with 25 mg/kg 100% of mortality was achieved. The LD 50 was 3.54 mg/mL, while LD 90 was 10 mg/mL. We propose hydrolysable tannins as an alternative to contribute in the nematode control in ruminants., (Copyright © 2018. Published by Elsevier B.V.)

A crucial step in the infection process of grazing ruminants by gastro-intestinal nematodes is the exsheathment of the infective third-stage larva following ingestion. Recently, heat shock was shown to play an important role in the carbon dioxide (CO 2 )-dependent exsheathment response in Haemonchus contortus. The current in vitro study set out to evaluate the role of heat shock in other abomasal species. In rumen fluid, all species tested exsheathed rapidly and efficiently in response to heat shock and CO 2. This response was significantly higher compared to slow temperature changes, supporting the hypothesis that heat shock plays an important role in vivo. However, in artificial buffer, the effect of heat shock was species-dependent. For H. contortus and Ostertagia leptospicularis, the response in artificial buffer was similar to rumen fluid. In contrast, Ostertagia ostertagi and Teladorsagia circumcincta exsheathment was significantly lower and/or slower in artificial buffer, and there was no benefit of heat shock. For these two species, it appears that there are co-factors in the rumen fluid, in addition to heat shock and CO 2 , contributing to exsheathment. Overall, the data indicate that there are significant differences between abomasal species in their response to exsheathment triggers.

Haemonchus contortus is one of the most pathogenic gastrointestinal nematodes in small ruminants. To understand molecular mechanisms underlying host resistance to this parasite, we used RNA-sequencing technology to compare the transcriptomic response of the abomasal tissue, the site of the host-parasite interaction, of Merino sheep bred to be either genetically resistant or susceptible to H. contortus infection. Two different selection flocks, the Haemonchus selection flock (HSF) and the Trichostrongylus selection flock (TSF), and each contains a resistant and susceptible line, were studied. The TSF flock was seemingly more responsive to both primary and repeated infections than HSF. A total of 127 and 726 genes displayed a significant difference in abundance between resistant and susceptible animals in response to a primary infection in HSF and TSF, respectively. Among them, 38 genes were significantly affected by infection in both flocks. Gene ontology (GO) enrichment of the differentially expressed genes identified in this study predicted the likely involvement of extracellular exosomes in the immune response to H. contortus infection. While the resistant lines in HSF and TSF relied on different mechanisms for the development of host resistance, adhesion and diapedesis of both agranulocytes and granulocytes, coagulation and complement cascades, and multiple pathways related to tissue repair likely played critical roles in the process. Our results offered a quantitative snapshot of changes in the host transcriptome induced by H. contortus infection and provided novel insights into molecular mechanisms of host resistance.

Nine of 23 (39%) research ewes with severe diarrhea and weight loss had histologic lesions consistent with Eimeria gilruthi infection in their abomasa. Gross anatomic lesions included hundreds of opaque 1-mm nodules in abomasal mucosa that corresponded microscopically to 200-300 µm diameter organisms surrounded by areas of necrosis. Analysis of fecal samples from 4 ewes demonstrated oocysts from typical ovine Eimeria species, none of which were E. gilruthi. Two separate PCR reactions were performed on abomasal tissue from 4 sheep to amplify the 18S ribosomal DNA (rDNA) and internal transcribed spacer (ITS) region of the rDNA, respectively. The resultant 18S rDNA nucleotide sequences shared 99% homology with multiple Eimeria species in GenBank. The ITS region shared 77% homology with E. ellipsoidalis in GenBank. Further studies are needed to understand the life cycle and pathogenicity of E. gilruthi. Our results underscore the inclusion of E. gilruthi in the differential diagnosis of diarrhea and weight loss in sheep.

Reduced worm burden in St. Croix (STC) sheep during Haemonchus contortus (Hc) infection is predicated on rapid interleukin-4 (IL-4) signalling and T helper type 2 immune (Th2) response. The aim of these studies was to further elucidate differences in Th2 responses by STC and Suffolk (SUF) sheep. Ten days after challenge Hc infection, peripheral blood mononuclear cells (PBMC) were collected and cultured with larval (HcLA) and adult worm (HcWA) antigen. STC PBMC produced nearly twice as much IL-4 as SUF (823.57 pg/mL vs 454.28 pg/mL) at 6 hours of HcLA culture despite no difference in IL-4 gene expression and the IL-4 receptor (IL4Rα) was upregulated in STC PBMC but was undetectable in SUF. Expression of other Th2-type genes were increased in STC PBMC including IL13, IL5 and MRC1. IL-4 supplementation to HcLA culture was insufficient to achieve upregulation of Th2 genes in SUF PBMC. Production of IL-4 did not occur in SUF PBMC until 24 hours after culture with HcLA, and expression of IL4 in the abomasum was similarly delayed until 10 days after challenge infection, which was associated with significantly higher larval burden (530 vs 16). These data demonstrate delayed upregulation of Th2 genes in SUF sheep contributes to susceptibility to Hc., (© 2018 John Wiley & Sons Ltd.)

The suitability of a single mid-season targeted selective treatment (TST) for gastrointestinal nematodes control, based on flexible average daily weight gain (ADWG) thresholds, was investigated in 23 groups of first grazing season calves. In each group, animals were weighed three times: before turnout, at mid-season and at housing. Just after the first weighing, each group was divided in two homogenous sub-groups in terms of age, breed and weight, and randomly allocated to one of two sub-groups intented for two different mid-season anthelmintic treatment strategies: (1) a treatment of all calves composing the sub-group (whole-group treatment (WT)) or (2) a targeted selective weight gain-based treatment (TST) of the animals showing an individual pre-treatment ADWG inferior to the mean pre-treatment ADWG of the corresponding WT sub-group. Anthelmintic treatment (levamisole 7.5 mg/kg BW) was performed 3 to 4 months after turnout. At housing, two parasitological parameters (the anti-Ostertagia ostertagi antibody level-Ostertagia optical density ratio (ODR) and the pepsinogen level) and a clinical parameter (the breech soiling score) were assessed at individual level in each group. Then, the high exposed groups to gastrointestinal nematode (GIN) were defined as groups for which untreated animals exhibited a mean Ostertagia ODR ⩾0.7 and among these groups, the ones characterized by high abomasal damage due to Ostertagia for which untreated animals exhibited a mean pepsinogen level ⩾2.5 U Tyr were also identified. Among TST sub-groups, the treatment ADWG thresholds varied from 338 to 941 g/day and the percentage of treated animals from 28% to 75%. Pre- and post-treatment ADWG as well as parasitological and clinical parameters measured at housing were similar between TST and WT sub-groups including the 17 high exposed groups to GIN. Within these 17 groups, the treatment allowed to significantly improve post-treatment ADWG compared with untreated animals. In the six high exposed groups showing mean pepsinogen level ⩾2.5 U Tyr, the average effect of treatment on post-treatment ADWG was the highest and estimated up to 14 kg after a grazing duration of 4 months. In contrast, in six other groups showing mean Ostertagia ODR<0.7 in untreated animals, no effect of treatment was seen suggesting an absence of production losses related to a low level of GIN infection. This study highlighted the suitability of a convenient mid-season TST strategy for first grazing season calves, based on the use of flexible thresholds of ADWG, allowing similar growth compared with a whole-group treatment while keeping a GIN population in refugia.

Haemonchus contortus is the most pathogenic gastrointestinal helminth of small ruminants. Natural or experimental repeated infections and several native antigens confer a partially protective immune response but vaccination with subunit antigens has been elusive. Promising results have been obtained with a recombinant form of a somatic antigen (rHc23). In this paper we present the results obtained in vaccination trials in lambs using two dosages of rHc23 and standard adjuvants. Six-months old Manchego females lambs were vaccinated with rHc23 (50 or 200 μg/dose) adjuvanted with 1mL aluminum hydroxide on days -42, -28 and -14 or with 200 μg/dose rHc23 and 5 mg Quil A on days -49, -28 and -7. Control lambs were kept receiving only the adjuvants the same days or no treatment. Moreover one group did not receive any treatment or infection. On day 0 vaccinated lambs, untreated animals and those receiving the adjuvant were infected per os with a monospecific single infection of 4000 L3 of H. contortus. Infection was kept for 58 days and follow-up included the determination of serum specific antibody response (ELISA, WB), hematological parameters (eosinophil counts, hematocrit) and fecal egg counts (epg). Absence of hematocrit alterations, reduction of helminth's eggs output and abomasal parasite burden at the end of the experiment were the efficacy criteria of vaccination with the recombinant. Immunization with both adjuvants and antigen dosages elicited strong antibody responses particularly with Quil A. Vaccinated groups showed significant reduction of fecal egg excretion and abomasal helminth burdens. Highest protection of lambs against challenge was achieved with aluminum hydroxide and 200 μg/dose rHc23 with a reduction of over 70% of the abomasal burden and over 80% of fecal egg output. Results suggest that rHc23 could be a valuable recombinant candidate for vaccination against haemonchosis. No clear relationship was found between antibody levels and protection this pointing towards involvement of both humoral and cellular components in the protective response elicited by rHc23.

It is a common view that assemblages of parasitic nematodes are influenced by climatic conditions; however, there are only a few articles available regarding those that infect farm animals. We investigated the relationship between climate variables and infection with abomasal trichostrongyles in 335 1-year-old rams grazed on steppe pastures in Eastern Algeria. Abomasa were collected from 12 local slaughterhouses located in four climatic areas (from humid to arid) and the worms extracted, identified and counted. The abundance was low and the fauna composed primarily of Teladorsagia circumcincta, Marshallagia marshalli and Trichostrongylus sp. The high percentage of M. marshalli is typical of steppe areas. Ostertagia ostertagi and Haemonchus contortus were present in low numbers. Rainfall was the most important climatic variable related to the main species. This relationship was not linear for M. marshalli but an optimal rainfall was detected (350-400 mm/year). The more complex climatic indicators used in the study did not demonstrate a more significant correlation than rainfall. The predictive value of rainfall on the abundance or proportion of species in the assemblage was modest but highly significant. The seasonality of assemblages was different between the two main sub-climates (sub-humid and semi-arid).

The interactions between gastric microbiota, ovine host, and Haemonchus contortus portray the ovine gastric environment as a complex ecosystem, where all factors play a pertinent role in fine-tuning each other and in haemeostasis. We delineated the impact of early and late Haemonchus infection on abomasal and ruminal microbial community, as well as the ovine host. Twelve, parasite-naive lambs were divided into four groups, 7 days post-infection (dpi) and time-matched uninfected-control groups; 50 dpi and time-matched uninfected control groups were used for the experiment. Six sheep were inoculated with 5000 H. contortus infective larvae and followed for 7 or 50 days with their corresponding uninfected-control ones. Ovine abomasal tissues were collected for histological analysis and gastric fluids were collected for PH value measurements, microbial community isolation and Illumina MiSeq platform and bioinformatic analysis. Our results showed that Haemonchus infection increased the abomasal gastric pH (P = 0.05) and resulted in necrotizing and inflammatory changes that were more severe during acute infection. Furthermore, infection increased the abomasal bacterial load and decreased the ruminal microbiome. A 7-day infection of sheep with H. contortus significantly altered approximately 98% and 94% of genera in the abomasal and ruminal bacterial profile, respectively (P = 0.04-0.05). However, the approximate altered genera 50 days after infection in the ovine abomasal and ruminal microbiome were about 62% and 69%, correspondingly (P = 0.04-0.05) with increase in some bacteria and decrease in others. Overall, these results indicate that Haemonchus infection plays a crucial role in shaping stomach microbial community composition, and diversity.

We conducted herein transcriptome sequencing of the ovine abomasal tissues using the Illumina HiSeq 4000 platform to segregate early and late H. contortus-infected sheep (7 and 50days post-infected groups, respectively) from the control naive ones. A total of 548, 357 and 7 were substantially induced genes in 7days post-infection versus uninfected-control group, 50days post-infection versus 7days post-infection (7dpi), and 50days post-infection (50dpi) versus uninfected-control group, respectively. However, a total of 301, 355 and 11 were significantly repressed genes between 7dpi versus uninfected-control group, 50dpi versus 7dpi, and 50dpi versus uninfected-control group, correspondingly. This indicates that H. contortus infection induced a more potent activation of abomasal gene expression in the early stage of infection as compared to the late stage. Seven pathways were annotated by Kyoto Encyclopedia of Genes, and Genomes pathway analysis accounted for the significant percentage in early H. contortus infection. This study shows for the first time that both galectin-11 and matricellular protein osteopontin are up-regulated in abomasal tissue after chronic H. contortus infection, while galectin-4 is specifically down-regulated in the early infection. Additionally, our results showed that the induction or repression of these molecules is likely to determine the infection progression., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A 1023 bp full length cDNA encoding Teladorsagia circumcincta GAPDH (TeciGAPDH) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. A phylogenetic tree was constructed using helminth GAPDH sequences. The predicted protein consisted of 341 amino acids and was present as a single band of about 38 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TeciGAPDH with homologues from other helminths showed that the greatest similarity (93%) to the GAPDH of Haemonchus contortus and Dictyocaulus viviparus, 82-86% similarity to the other nematode sequences and 68-71% similarity to cestode and trematode enzymes. Substrate binding sites and conserved regions were identified and were completely conserved in other homologues. At 25 °C, the optimum pH for TeciGAPDH activity was pH 8, the V max was 1052 ± 23 nmol min -1  mg -1 protein and the apparent K m for the substrate glyceraldehyde-3-phosphate was 0.02 ± 0.01 mM (both mean ± SD, n = 2). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant TeciGAPDH in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to native GAPDH indicates similar antigenicity of the two proteins., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We report, herein, the purification to homogeneity and the biochemical and kinetic characterization of HcTrxR3, a new isoform of thioredoxin reductase (TrxR) from Haemonchus contortus. HcTrxR3 was found to have a relative molecular weight of 134,000, while the corresponding value per subunit obtained under denaturing conditions, was of 67,000. By peptide mass spectrophotometric analysis, HcTrxR3 was determined to have 99% identity with the H. contortus HcTrxR1 although, and most importantly, they are different in their amino acid sequence in two amino acid positions: 48 (isoleucine instead of leucine) and 460 (leucine instead of proline). The enzyme catalyzes NADPH-dependent reduction of DTNB and, unexpectedly, it follows the pattern of glutathione reductases (GR) performing the reduction of oxidized glutathione (GSSG) to reduced glutathione using NADPH as the reducing cofactor. Hence, it is important to highlight this enzyme's new and unexpected condition that makes so special and one our main finding. Enzyme K cat values for DTNB, GSSG and NADPH were 12, 3 and 8 s -1 , respectively. HcTrxR3 developed, into specific TrxR substrates: ebselen and sodium selenite, with activity at 0.5 and 0.068 (U/mg), respectively; and 0.044 (U/mg) for S-nitrosoglutathione through its GR activity. The enzyme was inhibited by gold compound auranofin (AU), a selective inhibitor of thiol-dependent flavoreductases. Although HcTrxR3 has both TrxR and GR activity as thioredoxin glutathione reductase (TGR) does, it is a TrxR because it has no glutaredoxin domain and it does not develop any hysteretic behavior as does TGR. The importance of this new enzyme is potential to further clarify the detoxification and haemostasis redox mechanism in H. contortus. Likewise, this enzyme could also be a protein model to recognize more differences between TrxR and GR., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Ostertagiosis remains an economically important parasitic disease in cattle in the temperate regions of the world. Repeated exposures to Ostertagia ostertagi in calves cause significant pathology in the abomasum but elicit little protective immunity. The larvae use the host's gastric glands as a niche for development, where the parasite completes its parasitic stages, while in the gastric glands, the larvae must down-regulate the host inflammatory immune responses. Annexin (ANX) A1, commonly found in most eukaryotes, is heavily involved in controlling anti-inflammatory responses by binding receptors on leukocytes. We hypothesized, therefore, that parasite proteins of the ANX family may be involved in host-parasite interactions during ostertagiosis. BLASTN search with the bovine ANXA1 identified two families of Oos-ANX like proteins (Oos-ANXL), each of which was highly conserved at the genetic level and identical at the amino acid sequence level. Oos-ANXL-1 is encoded by two transcripts and Oos-ANXL-2 by 20 transcripts. The present study characterized one Oos-ANXL, representing the most abundant Oos-ANXL, which was further defined as Oost-ANXL-2.1. Oos-ANXL-2.1 with a coding sequence of 519 bp was PCR-amplified, cloned, and expressed. Oos-ANXL-2.1 was immunolocalized to both L3 and adult, but not L4. The staining appeared to be associated with the gut and hypodermis in L3, but it was specifically localized to the hypodermis in adult worms. Western blots detected three protein bands in parasite lysates using anti-recombinant Oos-ANXL-2.1 antibody. Integrated optical density for each of the 3 Oos-ANXL-2s or the total Oos-ANXL-2s detected by Western blots (P < 0.05) was higher in adult worms than in L3 or L4. The results indicate that the production of Oos-ANXL-2s is developmentally regulated and most abundant in the adult worm. This rather large family of proteins could be a potential vaccine target against O. ostertagi infection and warrants further investigation.

Canaria Hair Breed (CHB) sheep display resistance against the adult stage of the nematode, Haemonchus contortus. Previous studies have suggested significant correlations between γδ + T lymphocytes and fecundity of female adult worms, suggesting a novel role in immune modulation by these cells. The largest proportion of γδ + T lymphocytes in sheep are the subpopulation of γδ + /WC1 + T cells. The aim of this study was to evaluate the effect of γδ + ⁄WC1 + T cell depletion via infusion of anti-γδ/WC1 monoclonal antibody (mAb) on the subsequent immune response of CHB sheep infected with H. contortus. Significantly lower γδ + T cell levels in both peripheral blood and in the basal layers of the abomasal tissue resulted following anti-γδ/WC1 mAb infusion of CHB sheep compared to control animals. Worms recovered from the anti-γδ/WC1 mAb treated CHB sheep had significantly longer female worms with correspondingly more eggs in utero than the saline control group. Significant correlations between eosinophils and worm length and fecundity were no longer apparent in the anti-γδ/WC1 mAb treated CHB sheep. These results support the notion that γδ + T cells in CHB sheep play a critical role in fecundity regulation (length and eggs in utero) of H. contortus adult female worms, and highlights a new mechanism of modulation by this lymphocyte population, possibly involving eosinophil activation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A 1299 bp full length cDNA encoding Teladorsagia circumcincta enolase (TeciENO) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. Helminth enolase sequences were used to construct a phylogenetic tree. The predicted protein consisted of 433 amino acids and was present as a single band of about 50 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TeciENO with homologues from other helminths showed 98% similarity with Haemonchus contortus enolase, 78-95% similarity to other nematode sequences and 72-75% similarity to cestode and trematode enolases. Substrate binding sites and conserved regions were identified and were completely conserved in other homologues. The optimum pH for TeciENO activity at 25 °C was pH 7, the K m for 2-phophoglycerate 0.09 ± 0.04 mM and the V max was 604 ± 6 nmol min -1  mg -1 protein (both mean ± SD, n = 2). TeciENO activity was inhibited by 11.5% by 1 mM citrate (p < 0.001). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant TeciENO in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to native enolase indicates similar antigenicity of the two proteins., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Among gastro-intestinal nematodes, the blood-sucking worms belonging to the subfamily of Haemonchinae are considered to be of pathogenic and economic great importance, particularly in small ruminants. Haemonchus contortus, primary found in domestic ruminants and wild bovines (Mouflon, Chamois), is probably the most studied, but occurrence of Ashworthius sidemi has gradually increased over recent years, especially in Cervids and free roaming wild bovid as the European bison in eastern Europe, and some cases of co-infestation were recently observed on five Roe deer (Capreolus capreolus) and one Red deer (Cervus elaphus) in France. If the diagnosis is possible on the morphological features for adult worms for helminthologists, the identification on some stages (female, subadult, eggs and larvae) is difficult or impossible. Sequencing ND4 domain from the mitochondrial DNA of H. contortus and A. sidemi worms, we observed clearly two distinct clades, with an inter-specific divergence of 28.1%. Basing on this specific domain, a multiplex PCR-based method was developed: new primers were designed and used pooled in one mix PCR, producing amplicons of 454bp for H. contortus and 330bp for A. sidemi, allowing a trivial and an inexpensive taxonomic affiliation after migration. This multiplex PCR-based method was developed here to distinguish H. contortus and A. sidemi regardless their developmental stage, easy to use for highlighting co-infestation cases in both wild and domestic ruminants. It is a non-invasive approach appearing as a good diagnostic tool relevant to coprological cultures., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with Haemonchus contortus or H. placei. Ten male Holstein newborns were subdivided in three groups (GI placebo; GII infected with H. contortus; GIII inoculated with H. placei). Eye mucosa staining was evaluated. Hematological and biochemical tests were performed on animals. The euthanasia of all ten experimental calves was performed on the 42nd day post-inoculation. Fragments were collected from each of all 10 abomasums for histopathological analysis. Discrete submandibular edema was diagnosed in animals from both infected groups (H. contortus or H. placei). However, there were no significant changes (P > 0.05) in the color of the ocular mucosa of calves from all three experimental groups across the entire experimental period. Hematological and biochemical changes diagnosed on animals could not be linked to infections by species of Haemonchus spp. Regarding histopathological exams, it was possible to diagnose hypertrophy, hyperplasia, binucleated cells, inflammatory infiltrate, multifocal hemorrhage and edema in abomasums from calves of both groups infected with H. placei and H. contortus. It can, thus, be concluded that not only are calves susceptible to infections by both Haemonchus species, but they can also present clinical changes and similar anatomic histopathological lesions independent of being infected by Haemonchus placei or Haemonchus contortus. These results reflect a negative effect on helminth control by mixed grazing between sheep and cattle, especially when using calves., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study aims at investigating the occurrence, risk factors and production impacts on beef carcass parameters of three of the most important cattle helminth infections in England and Wales. Abomasa, reticulorumens and livers from healthy cattle were collected and examined post-mortem quarterly over a one year period in an abattoir in South-West England. Specific viscera from 974 cattle were collected, examined and scored for Ostertagia spp., adult rumen fluke and liver fluke lesions/presence. A total of 89%, 25% and 29% of the carcasses had lesions/presence of Ostertagia spp., rumen fluke and liver fluke, respectively, and 39% had presence of helminth co-infection. Animal demographic and carcass parameters associated with helminth infections were investigated using multilevel multinomial and multilevel linear mixed models respectively. After adjusting for other factors, significant differences in the distribution of helminth infections were observed among cattle by type of breed, animal category (cow, heifer, steer and young bull), age, season and concurrent helminth infections. Compared to carcasses free of helminths, carcasses presenting solely Ostertagia Spp. lesions or adult rumen fluke had significantly lower cold carcass weight (coef.: -30.58 [-50.92;-10.24] and -50.34 [-88.50;-12.18]) and fat coverage (coef.: -3.28 [-5.56;-1.00] and -5.49 [-10.28;-0.69]) and carcasses presenting solely liver fluke lesions had significantly lower conformation grade (coef.: -3.65 [-6.98;-0.32]). Presence of helminth poly-infections was negatively associated with cold carcass weight., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Calotropis procera is among the species of medicinal plants that have traditionally been used for the treatment of parasites in small ruminants, stimulating the scientific validation of anthelmintic effects. This study aimed to investigate the chemical composition of ethyl acetate extract of Calotropis procera latex (EAECPL), assess the in vitro effect against Haemonchus contortus and the structural changes caused in the adult worm. The latex was collected, lyophilized and subjected to washing with the ethyl acetate solvent to obtain EAECPL. The constituents of the extract were isolated by column chromatography and identified by (13)C and (1)H nuclear magnetic resonance spectroscopy. The egg hatching test (EHT), larval development test (LDT) and adult worms motility test (WMT) were conducted to evaluate the effectiveness of EAECPL on eggs, larvae and adult of H. contortus, respectively. The worms obtained from the WMT, after 24h exposure to EAECPL or controls were observed on a scanning electron microscope (SEM). The results were analysed by variance analysis and compared with Tukey's test (P<0.05). Three compounds were isolated from EAECPL and identified as urs-19(29)-en-3-yl acetate, (3β)-Urs-19(29)-en-3-ol, and 1-(2',5'-dimethoxyphenyl)-glycerol. In the EHT, EAECPL inhibited larval hatching by 91.8% at dose of 4mg/ml. In the LDT 1mg/ml inhibited 99.8% larval development. In the WMT, EAECPL in the concentration of 100μg/ml inhibited 100% motility of worms, 12h post-exposition. In the SEM, obvious differences were not detected between the negative control worms and the worms treated with EAECPL. In this study, EAECPL showed an effect on inhibition egg hatching, larval development and motility of the adult worms of H. contortus. This should be related both to the identified compounds, as well as the other compounds present in the EAECPL, acting alone or synergistically., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The objective of the present study was to determine the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene of Haemonchus contortus from various sheep flocks in eastern Amazon, and to identify management practices that may favor the emergence of resistance to anthelmintic drugs in the same area. In total, 305 specimens of H. contortus were collected from sheep at 12 farms located in the state of Pará. An allele-specific PCR was performed to detect the F200Y polymorphism, and questionnaires were used to obtain information about the farms and flocks. All genotypes were detected as follows: 31% of the parasites were RR, 37% of the parasites were SR, and 32% were SS. The completed questionnaires revealed that all farms employed semi-intensive farming systems, performed suppressive anthelmintic treatment, and based their choice of drug on cost and availability rather than on any knowledge regarding drugs that remained effective on their property. It can thus be concluded that the SNP in codon 200 of the β-tubulin isotype 1 gene is present in the H. contortus populations from eastern Amazon, and that a series of management practices that favor the emergence of anthelmintic resistance are employed on these farms., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Previously, chemical analysis of gastric fundic mucin showed that infection of sheep with Haemonchus contortus or Teladorsagia circumcincta changed the proportions of monosaccharides and decreased terminal mucin fucosylation and sialylation. To identify the effects of these parasites on the two mucin-secreting cell lineages, fundic and antral tissues were collected for histochemistry from 69 lambs aged from 3-4 to 9-10 months-of-age which had received a single infection of either H. contortus or T. circumcincta and euthanased at Day 21 or 28 post- infection respectively. All fundic tissues were stained separately with: (1) with Periodic Acid Schiff (PAS) for all mucins; (2) Alcian Blue (AB) pH 2.5 for acidic mucins (sialylated and sulphated); (3) AB pH 1 for sulphated mucins and (4) High Iron Diamine (HID) for sulphated mucins. Antral and fundic tissues from 24 lambs were also stained for acidic and neutral mucins or with specific lectins for α-1-linked fucose and for α-2,3- and α-2,6-linked sialic acids. Only mucin sulphation appeared to differ visually in uninfected lambs over this age range: there was weak staining with HID in tissues from lambs 3-6 months-of-age, but was generally more intense in those over 7 months-of-age. Sulphomucins were not apparent in surface mucous cells (SMC) or generally in the upper pits. Sialylomucins were located predominantly in the pits and glands, with small amounts of sialylated mucins in SMC and on the luminal surface, mainly in younger animals up to 6 months-of-age and less in the older animals. Parasitism markedly reduced the predominantly neutral surface mucin5AC of the SMC and pit cells, despite pit elongation in both antrum and fundus, whereas the acidic Muc6 secreted by mucus neck cells (MNC) increased along with MNC hyperplasia. Sulphated mucins were present mainly from the mid-pits downward and heavy staining was more common in older animals. In these sheep, the markedly reduced neutral mucin in the SMC and pit cells in both antrum and fundus contrasts with reported hypersecretion of mucus in the intestine, which is believed to aid in parasite expulsion. It has been proposed that intestinal goblet cell hypersecretion occurs only in resistant animals, therefore reduced mucins in the abomasum may be indicative of susceptibility to abomasal parasites., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Resistance to ivermectin and moxidectin was explored by a faecal egg count reduction test in two sheep flocks with suspected anthelmintic resistance. The FECRT confirmed one suspicion, with a mean percentage of reduction in egg excretion within the treated groups of 0% for ivermectin (CI 95%: -228 to 58) and 13% for moxidectin (CI 95%: -152 to 70). This was further explored by a controlled efficacy test. An experimental infection of 18 naïve lambs was set up using infective larvae isolated from this flock (5000 L3/lamb). Compared to the control group, abomasal worm burdens (Teladorsagia circumcincta) were reduced by 90% [CI 95%: 81.5-94.8] and 85% [CI 95%: 72.4-92.2] after ivermectin (p<0.05) and moxidectin (p<0.05) treatment respectively. Again, compared to the control group, there was a reduction for intestinal strongyles (Trichostrongylus colubriformis) of 100% and 99% [CI 95%: 97.5-99.7] for ivermectin and moxidectin respectively. No difference was found between the efficacy of moxidectin and ivermectin. Pharmacokinetic values indicated that the strongyles were submitted to anthelmintic concentrations usually lethal to them. This trial demonstrated the first multiple resistance of ovine strongyles in France., (Copyright © 2016 Elsevier B.V. All rights reserved.)

:  Because there appeared to be no data available on serum gastrin concentrations in animals infected with Marshallagia marshalli, and considering the high prevalence of this parasite in livestock throughout many countries, we decided to perform research in the field using experimental infection. After surgical implantation of abomasal cannula into 10 male Baluchi sheep, each animal was orally infected with 5,000 M. marshalli larvae. Serum gastrin concentrations and abomasal pH were measured with a human ELISA kit and a PHM LE438 standard pH electrode, respectively. According to the results obtained from the study, serum gastrin increased after 14 and 21 days post-infection (dpi), while abomasal pH increased after 7 dpi and reached a maximal value 16 dpi. The increase in serum gastrin concentration was revealed 6 days after elevation in abomasal pH, which could be the result of reduced acid secretion. Generally, the present study pointed out that a limited number of M. marshalli could increase serum gastrin concentrations.

Early immune events associated with reduced larval burden remain unclear in parasite-resistant breeds of sheep. Therefore, our objective was to determine breed differences in immune-related gene expression following infection with H. contortus. Gene expression in abomasal tissue and mucosa and in abomasal lymph nodes (ALN) was measured in 24 St. Croix (hair) lambs and 24 Dorset x (Finn-Rambouillet) (wool) lambs at 0 (uninfected), 3, 5 and 7 days after infection with 10 000 L3 H. contortus larvae. Expression of IL-4 in abomasal mucosa was detected on day 3 and increased to day 7 in hair lambs, but was not detectable in wool lambs. Genes that recruit neutrophils (CXCL1) and macrophages (MCP1) were upregulated in abomasal mucosa of hair lambs. Genes associated with alternative macrophage activation (ARG-1) and eosinophil activation (Gal-14) were also upregulated in the abomasal mucosa of hair lambs. Tissue remodeling genes (MMP13, PDGF) and tumour necrosis factor alpha (TNF-α) and MCP1 were upregulated in abomasal tissue of wool lambs; these lambs also had greater expression of forkhead box P3 in ALN. These data indicate a role for early IL-4 expression locally and demonstrate potential downregulation of immunity in wool sheep that could facilitate establishment of H. contortus., (© 2016 John Wiley & Sons Ltd.)

Multiple drug resistance of nematodes against anthelmintics has become one of the most important economic problems in sheep production worldwide. The aim of this experiment was to evaluate the efficacy of monepantel (2.5mg/kg) against gastrointestinal nematodes in fecal egg count reduction test (FECRT) and controlled efficacy test (CT) in naturally infected sheep. We used 30 sheep for the FECRT and 20 sheep for the CT, equally divided into control and treated groups. In the FECRT, the reduction was 98%. Larval identification of pre-treatment coprocultures revealed 100% Haemonchus spp. for both control and treated groups. Post-treatment culture of treated sheep was 100% Oesophagostomum spp., but only few larvae were recovered. In the control group, they were 99% Haemonchus spp and 1% Oesophagostomum spp. larvae. Based on the FECRT, Haemonchus spp. was considered susceptible to monepantel. The efficacy of monepantel in the CT against Haemonchus contortus and Trichostrongylus axei was 100% and against Cooperia curticei was 99.7%. For Trichostrongylus colubriformis, the efficacy was -21.5%. In both treated and untreated animals, Oesophagostomum columbianum was recovered from the large intestines. Based on FECRT and CT and in accordance with WAAVP standards, monepantel was ineffective against T. colubriformis and O. columbianum, but effective against H. contortus, T. axei and C. curticei in the studied flock., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The hypothesis tested in this experiment was that Trichostrongylus colubriformis infection would reduce growth rates of grazing meat-breed lambs; however production loss would be reduced by suppression of the host immune response. The experiment had a 3×2 factorial design using 6-7 month old meat-breed lambs which remained uninfected or infected (IFY) with 2000 or 4000 T. colubriformis L3/week for 12 weeks and were immunosuppressed (SUPY) using methylprednisolone acetate once weekly or remained non-immunosuppressed (SUPN). Immunosuppression increased worm egg counts (WEC) of infected lambs (SUPY 2421 eggs per gram (epg), SUPN 1154 epg on day 84, p<0.05) and T. colubriformis burdens (p<0.05-0.10) and reduced circulating eosinophils (p<0.05 on days 11, 42, 56 and 84) and intestinal total antibody titres (p<0.02). There was a significant (p<0.05) interaction between the main effects of infection and immunosuppression with infection having a larger negative effect on the liveweight of non-immunosuppressed lambs. The immunological response of the host to T. colubriformis infection accounted for 75% of the overall cost of infection (3.1kg) with the majority of this cost occurring during the first 35 days of infection. In contrast, most of the cost associated with the direct effect of infection occurred after day 35. These results confirm in grazing meat-breed lambs that the host's immunological response to T. colubriformis infection is the major component of production loss., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Arrested development of abomasal trichostrongylid nematodes was studied in 30 permanent grazing lambs on a large farm in the North-East of Algeria. The steppe climate has cold winters and hot and dry summers. The lambs were monitored monthly for gastrointestinal nematodes using nematode faecal egg counts, from February 2008 to February 2009. Every 2 months, two of the original 30 permanent lambs were necropsied after being held in pens for three weeks so that recently ingested infective larvae could develop into adults. The highest percentage of fourth stage larvae (L4), reaching 48% of the total worm burden, was recorded in abomasal contents in June. Teladorsagia and other Ostertagiinae constituted the highest percentage of L4 larvae (71%), whereas the percentage of Trichostrongylus (17.4%) or Haemonchus (11.6%) remained low. The dynamics of infection observed here (highest faecal egg count in August) and the stage composition of worm burden (highest percentage of L4 in June) provide strong evidence that arrested development had occurred., (© S. Meradi et al., published by EDP Sciences, 2016.)

A simple polymerase chain reaction (PCR) test was used to identify Ashworthius sidemi, a blood-sucking gastrointestinal nematode that commonly infects bison, red and roe deer, and moose in Poland. The present study uses this technique to confirm the possibility of transmission of A. sidemi infection from wildlife to domestic animals, such as cattle and sheep, grazing on the same natural pastures. A 406 bp fragment of genomic A. sidemi DNA was actually detected in DNA isolated from larval cultures derived from feces from cattle. A. sidemi DNA has been detected in cattle which represent a new host for this parasite. This is the first evidence of A. sidemi in cattle. The results reveal that a PCR test based on DNA from L3 larvae can be used for in vivo detection of A. sidemi invasions in breeding animals. In conclusion, the transfer of A. sidemi infection from wildlife to the farm animals sharing the same pastures appears possible., (Copyright © 2015. Published by Elsevier B.V.)

Gene encoding a somatic protein of Haemonchus contortus (Hc23) known to confer significant protection against experimental haemonchosis has been cloned and expressed in a prokaryotic system. A cDNA library of H. contortus using the vector λ ZAP II was obtained. Full-length gene was amplified, cloned and expressed in Escherichia coli BL21. The recombinant protein was purified in Ni-NTA column. Recombinant protein (rHc23) had 203 aminoacids and a molecular mass of 24.15 kDa. Recombinant protein (100 μg/dose) with aluminum hydroxide as adjuvant was administered to 5-6 months age female Assaf lambs on days -42, -28 and -14. On day 0 animals were infected with 15,000 L3 of H. contortus. Vaccination with rHc23 elicited a significant protection against challenge, with >80% reductions in both fecal egg counts and average abomasal parasite burdens at the end of the experiment (45 days post challenge) besides lack of variations in packed cell volume. Results support the feasibility of vaccination against lamb haemonchosis with a recombinant product from an exposed antigen., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Management of gastrointestinal parasites is a critical issue for sheep producers worldwide. Increases in the prevalence of drug-resistant worms have complicated parasite control and increased economic losses. Therefore, other methods of parasite control need to be assessed, including the use of genetically resistant animals in breeding programs. Hair sheep breeds such as the St. Croix have greater parasite resistance than conventional wool breeds. However, the immune mechanisms that control parasite resistance in hair or wool breeds have not yet been fully determined, and information on cytokine expression profiles for both wool sheep selected for increased resistance and hair sheep is limited. Our objective was to investigate gene expression differences in 24 parasite-resistant hair and 24 susceptible wool sheep to identify immune effectors associated with resistance to . One-half of the lambs were infected and sacrificed at 3 or 27 d after infection. Remaining lambs were not infected. Breed differences in expression of genes associated with Th1 and Th2 immune responses in lymph nodes and abomasal tissue were determined. Th2-associated genes included IL-4, IL-13, IL-5, IgE, the α chain of the IL-4 receptor, and the α chain of the high-affinity IgE receptor (FcεRI). Th1-associated genes included interferon gamma (IFN-γ), the p35 subunit of IL-12 (IL-12 p35), and the β1 and β2 chains of the IL-12 receptor (IL-12 Rβ1 and IL-12 Rβ2, respectively). In both hair and wool sheep, infection with resulted in greater expression of IgE, IL-13, IL-5, and IL-12 p35 and somewhat reduced expression of IFNγ in lymph nodes. In abomasal tissue, parasite infection resulted in greater IgE, IL-13, FcεRI, and IL-12 p35 expression in infected lambs compared with control lambs. Between breeds, hair sheep had a stronger Th2 response after infection than wool sheep, with increased expression of IgE and IL-13 and decreased expression of IFNγ in lymph nodes and increased expression of IL-13 and decreased expression of IL-12 p35 in abomasal tissue. Expression of IL-4 in lymph nodes did not differ between hair and wool lambs, and IL-4, IL-5, IL-12 Rβ1, and IL-12 Rβ2 expression was too low to measure at the times sampled in abomasal tissue.

Full length cDNAs encoding phosphofructokinase (PFK) were cloned from Teladorsagia circumcincta (TcPFK) and Haemonchus contortus (HcPFK). TcPFK (2361 bp) and HcPFK (2367 bp) cDNA encoded 787 and 789 amino acid proteins respectively. The predicted amino acid sequences showed 98% similarity with each other and 70% with a Caenorhabditis elegans PFK. Substrate binding sites were completely conserved in both proteins. Soluble N-terminal His-tagged PFK proteins were expressed in Escherichia coli strain BL21, purified and characterised. The recombinant TcPFK and HcPFK had very similar kinetic properties: the pH optima were pH 7.0, Km for fructose 6-phosphate was 0.50 ± 0.01 and 0.55 ± 0.01 mM respectively when higher (inhibiting concentration, 0.3 mM) ATP concentration was used and the curve was sigmoidal. The Vmax for TcPFK and HcPFK were 1110 ± 16 and 910 ± 10 nM min(-1 )mg(-1) protein respectively. Lower ATP concentration (non-inhibiting, 0.01 mM) did not change the Vmax for TcPFK and HcPFK (890 ± 10 and 860 ± 12 nM min(-1 )mg(-1) protein) but the substrate affinity doubled and Km for fructose 6-phosphate were 0.20 ± 0.05 and 0.25 ± 0.01 mM respectively. Recognition of TcPFK and HcPFK by mucosal and serum antibodies in nematode exposed animals demonstrates antigenicity and suggests involvement in the host response to nematode infection., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Haemonchus longistipes is a gastrointestinal abomasal nematode which is one of the most prevalent and pathogenic parasites infesting the stomach of ruminants. On the basis of light and ultrastructural data, the objective of the present study was to introduce a first identification of the cameline haemonchosis caused by H. longistipes. Abomasa of 42 Egyptian camels Camelus dromedarius (Artiodactyla: Camelidae) were collected monthly from September 2013 to April 2014 from the main slaughter house of Cairo, Egypt. Adult male and female nematode worms were recovered from 26 (62%) specimens of the examined abomasa. The parasites were of yellow color; the body was filiform (slender) tapered towards the anterior end in male and towards both ends in female. Buccal capsules absent, the buccal cavity was small with a conspicuous dorsal lancet extended from dorsal wall. The cervical papillae were prominent and spine-like. The body length of the female worm was 16.6-20.5 (18.5 ± 0.3) mm. The anterior end to the cervical papillae was 3.19-4.30 (4.12 ± 0.5) mm. The vulva of the female had a linguiform process or flap, the tail is without a spine, and the anal pore at the posterior end of the body had a simple dorsal rim. The body of male was 10.4-14.7 (13.9 ± 2.0) mm in length. The male bursa had elongated lobes supported by long, slender rays. The small dorsal lobe was asymmetrical with Y-shaped dorsal rays. The spicules were long with a length of 0.52-0.54 (0.53 ± 0.05) mm, each provided with a small barb and pore near its extremity. Synlophe was bilaterally and dorsoventrally symmetrical; it extended from cephalic expansion over anterior 50% of prebursal or prevulvar body and consisted of a maximum of 42 ridges. The described species herein was compared with the three morphologically similar species Haemonchus mitchelli, Haemonchus okapiae, and H. longistipes with their synlophes consist of 42 ridges distributed over the anterior half of the body. These species can be separated by unique structural characteristics of their synlophes, spicules, and copulatory bursa. The most morphologically similar species to the recovered worm was H. longistipes. Also, some of the parameters with regard to morphology and morphometry of this parasite were described for the first time.

Physocephalus dromedarii stat. nov. was found in the abomasum of two adult female dromedaries originating from a farm in Dubai. Previously, this nematode has been misidentified as a subspecies of Ph. sexalatus but morphological differences are striking enough for it to be upgraded to a species. Physocephalus dromedarii is larger than Ph. sexalatus and has longer spicules. There are 20-22 oblique crests at the ventral surface between the caudal alae of the male compared to 7-8 in the case of Ph. sexalatus. The most significant differences are the presence of two pairs of papillae between cloaca and postcloacal plate of the male and the existence of a swelling in the second half of the female body formed by loops of both uterine horns.