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Background: Nippostrongylus brasiliensis—a nematode of rodents—is commonly used as a model to study the immunobiology of parasitic nematodes. It is a member of the Strongylida—a large order of socioeconomically important parasitic nematodes of animals. Lipids are known to play essential roles in nematode biology, influencing cellular membranes, energy storage and/or signalling. Methods: The present investigation provides a comprehensive, untargeted lipidomic analysis of four developmental stages/sexes (i.e. egg, L3, adult female and adult male stages) of N. brasiliensis utilising liquid chromatography coupled to mass spectrometry. Results: We identified 464 lipid species representing 18 lipid classes and revealed distinct stage-specific changes in lipid composition throughout nematode development. Triacylglycerols (TGs) dominated the lipid profile in the egg stage, suggesting a key role for them in energy storage at this early developmental stage. As N. brasiliensis develops, there was a conspicuous transition toward membrane-associated lipids, including glycerophospholipids (e.g. PE and PC) and ether-linked lipids, particularly in adult stages, indicating a shift toward host adaptation and membrane stabilisation. Conclusions: We provide a comprehensive insight into the lipid composition and abundance of key free-living and parasitic stages of N. brasiliensis. This study provides lipidomic resources to underpin the detailed exploration of lipid biology in this model parasitic nematode. [ABSTRACT FROM AUTHOR]

Maternal bacterial and viral infections that induce neuroinflammation in the developing brain are associated with impaired cognitive function and increased anxiety in the offspring. In contrast, maternal infection with the immunoregulatory murine gastrointestinal (GI) nematode, Heligmosomoides bakeri, appears to benefit neurodevelopment as juvenile 2- and 3-week-old male and female offspring had enhanced spatial memory, which may be due to a Th2/Treg biased neuroimmune environment. Here, the impact of maternal H. bakeri infection during pregnancy and lactation on the spatial and anxiety-like behaviours of adult, 3-month-old uninfected male and female offspring was explored for the first time. It was observed that adult female offspring of H. bakeri-infected dams had enhanced spatial reference memory and reduced anxiety-like behaviour compared to females of uninfected dams. These effects were not observed in adult male offspring. Thus, the positive influence of a maternal GI nematode infection on spatial memory of juvenile offspring persists in adult female offspring.

Infections with gastrointestinal nematodes (GINs) reduce the economic efficiency of sheep operations and compromise animal welfare. Understanding the host's response to GIN infection can help producers identify animals that are naturally resistant to infection. The objective of this study was to characterize the hepatic transcriptome of sheep that had been naturally exposed to GIN parasites. The hepatic transcriptome was studied using RNA-Sequencing technology in animals characterized as high (n = 5) or medium (n = 6) based on their innate immune acute-phase (AP) response phenotype compared with uninfected controls (n = 4), and with biased antibody-mediated (AbMR, n = 5) or cell-mediated (CMR, n = 5) adaptive immune responsiveness compared to uninfected controls (n = 3). Following the assessment of sheep selected for innate responses, 0, 136, and 167 genes were differentially expressed (DE) between high- and medium-responding animals, high-responding and uninfected control animals, and medium-responding and uninfected control animals, respectively (false discovery rate (FDR) < 0.05, and fold change |FC| > 2). When adaptive immune responses were assessed, 0, 53, and 57 genes were DE between antibody- and cell-biased animals, antibody-biased and uninfected control animals, and cell-biased and uninfected control animals, respectively (FDR < 0.05, |FC| > 2). Functional analyses identified enriched gene ontology (GO) terms and metabolic pathways related to the innate immune response and energy metabolism. Six functional candidate genes were identified for further functional and validation studies to better understand the underlying biological mechanisms of host responses to GINs. These, in turn, can potentially help improve decision making and management practices to increase the overall host immune response to GIN infection. [ABSTRACT FROM AUTHOR]

Disease cross-transmission between wild and domestic ungulates can negatively impact livelihoods and wildlife conservation. In Pin valley, migratory sheep and goats share pastures seasonally with the resident Asiatic ibex (Capra sibirica), leading to potential disease cross-transmission. Focussing on gastro-intestinal nematodes (GINs) as determinants of health in ungulates, we hypothesized that infection on pastures would increase over summer from contamination by migrating livestock. Consequently, interventions in livestock that are well-timed should reduce infection pressure for ibex. Using a parasite life-cycle model, that predicts infective larval availability, we investigated GIN transmission dynamics and evaluated potential interventions. Migratory livestock were predicted to contribute most infective larvae onto shared pastures due to higher density and parasite levels, driving infections in both livestock and ibex. The model predicted a c.30-day anti-parasitic intervention towards the end of the livestock’s time in Pin would be most effective at reducing GINs in both hosts. Albeit with the caveats of not being able to provide evidence of interspecific parasite transmission due to the inability to identify parasite species, this case demonstrates the usefulness of our predictive model for investigating parasite transmission in landscapes where domestic and wild ungulates share pastures. Additionally, it suggests management options for further investigation. [ABSTRACT FROM AUTHOR]

Maternal bacterial and viral infections that induce neuroinflammation in the developing brain are associated with impaired cognitive function and increased anxiety in the offspring. In contrast, maternal infection with the immunoregulatory murine gastrointestinal (GI) nematode, Heligmosomoides bakeri , appears to benefit neurodevelopment as juvenile 2- and 3-week-old male and female offspring had enhanced spatial memory, which may be due to a Th2/Treg biased neuroimmune environment. Here, the impact of maternal H. bakeri infection during pregnancy and lactation on the spatial and anxiety-like behaviours of adult, 3-month-old uninfected male and female offspring was explored for the first time. It was observed that adult female offspring of H. bakeri -infected dams had enhanced spatial reference memory and reduced anxiety-like behaviour compared to females of uninfected dams. These effects were not observed in adult male offspring. Thus, the positive influence of a maternal GI nematode infection on spatial memory of juvenile offspring persists in adult female offspring. [ABSTRACT FROM AUTHOR]

Background and Aim: Gastrointestinal (GI) nematode infection remains an important problem in livestock, particularly cattle. The infection may lead to serious health complications and affect animal products. The objective of this study was to investigate GI nematode infection and its associated risk factors in dairy and beef cattle farmed in Pak Chong District of Nakhon Ratchasima Province, northeast Thailand. Materials and Methods: Fecal specimens were collected from 101 dairy cattle and 100 beef cattle. Formalin-ethyl acetate concentration techniques were used to process the samples and the samples were observed under a light microscope. Samples were subjected to molecular identification of specific genera using conventional polymerase chain reaction and DNA sequencing. Results: The overall prevalence of GI nematode infection was 33.3%. The strongyle nematode was the most significant GI nematode in this area with a prevalence of 28.4%. The prevalence of strongyle nematodes was 58.0% in beef cattle and only 7.9% in dairy cattle. Trichuris spp. was another nematode found in both types of cattle with an overall prevalence of 5.0% with 9.0% in beef cattle and 1.0% in dairy cattle. The results of the epidemiological study indicate that the age of cattle, food, water sources, farming system, and housing floor are the most important risk factors. Among the strongyle nematodes, Ostertagia spp. was the most prevalent (82.0%), followed by Haemonchus spp. (62.3%) and Trichostrongylus spp. (8.2%), respectively. Conclusion: Infection with GI nematodes still exists in this area, particularly in beef cattle. Our reported data may benefit local parasitic control policies in the future.

The objective of the essay was to determine the influence of protein–energy supplementation on the gastrointestinal nematode population during spring rise in ewes and their offspring as a non–chemical alternative in Integrated Parasite Control. One hundred twenty six Corriedale ewes were divided into two groups, one supplemented with protein–energy blocks from one month before lambing until weaning and the other without supplementation. Every 17 days, faecal matter was randomly collected from 20 ewes and 20 lambs from both groups. Modified McMaster and coproculture were performed, estimating the pathogenicity index for each gender. Lambs´ weight at birth, marking and weaning were recorded and the daily weight gains from birth to marking and from marking to weaning were calculated. Eggs count per gram of faeces were higher (P

Background: This study aimed to investigate gastrointestinal nematode infections of Indonesian deer and sheep in an agritourism farm. Method: A total of 54 fecal samples were collected from spotted deer (Axis axis; n=6), Timor deer ( Rusa timorensis; n=3) and sheep (n=45) from an agritourism farm in Bogor Regency, West Java, Indonesia. In addition, five fecal samples were collected from five Timor deer enclosures in Bogor city. All samples were subjected to fecal egg and larval identification. Collected larvae were identified by polymerase chain reaction and sequencing. Results: Gastrointestinal nematode infection was higher in sheep than deer. Most infections were caused by strongyle infection in both animals. In this study, Haemonchus contortus was successfully sequenced from sheep and Indonesian deer. Our results showed that H. contortus isolates from Indonesian deer were placed in a clade with H. contortus from other infected hosts like sheep and goats. Conclusions: This is the first report of H. contortus isolated from Indonesian deer. The parasite control program is necessary to be conducted in both animals, especially considering the high number of sheep infected with nematode in the studied farm. [ABSTRACT FROM AUTHOR]

Widespread and improper use of various anthelmintics, genetic, and epidemiological factors has resulted in anthelmintic-resistant (AR) helminth populations in livestock. This is currently quite common globally in different livestock animals including sheep, goats, and cattle to gastrointestinal nematode (GIN) infections. Therefore, the mechanisms underlying AR in parasitic worm species have been the subject of ample research to tackle this challenge. Current and emerging technologies in the disciplines of genomics, transcriptomics, metabolomics, and proteomics in livestock species have advanced the understanding of the intricate molecular AR mechanisms in many major parasites. The technologies have improved the identification of possible biomarkers of resistant parasites, the ability to find actual causative genes, regulatory networks, and pathways of parasites governing the AR development including the dynamics of helminth infection and host-parasite infections. In this review, various "omics"-driven technologies including genome scan, candidate gene, quantitative trait loci, transcriptomic, proteomic, and metabolomic approaches have been described to understand AR of parasites of veterinary importance. Also, challenges and future prospects of these "omics" approaches are also discussed. [ABSTRACT FROM AUTHOR]

The in vitro anthelmintic effect of the extracts on Haemonchus contortus (H. contortus) of three forage species in the tropical dry forest is known; however, there is no information about the effects of the extract partitions, nor their chemical composition. The objectives of this study were to evaluate the in vitro ovicidal activity of H. contortus in extract partitions of the species Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce, and to identify the compounds present in the extract partitions with the highest activity by employing ultra HPLC Quadrupole orbitrap mass spectrometry. Four extract partitions, hexane, dichloromethane, ethyl acetate, and hydroethanolic from the three forage species were assessed in an inhibition of egg hatching (IEH) assay. The extract partitions with the highest anthelmintic activity (AA) were subjected to analysis, from which the tentative identification of the compounds was established. The extract partitions, including dichloromethane from Gliricidia sepium, ethyl acetate from Leucaena leucocephala, and hydroethanolic from Pithecellobium dulce showed a greater anthelmintic effect, with IC50 values of 0.39, 0.86, and 0.27 mg/mL for the IEH, respectively. Metabolites with in vitro AA potential included flavonoids, fatty acid esters, hydroxycinnamic acids, organic oxygenated compounds of the benzene class and substituted derivatives, phenolic glycosides, and phenols. [ABSTRACT FROM AUTHOR]

Simple Summary: Ovine gastrointestinal nematodes (GIN) have flexible life history strategies, meaning they can alter the relative energy invested into each life trait in order to optimize their fitness under different environmental contexts. Some of the most prevalent ovine GIN species, such as Haemonchus contortus, have pervasive global distributions, and it is not known whether distinct isolates respond to the same environmental challenge with uniform alterations to their life history strategies or if different strategies affect different fitness outcomes. To investigate this further, this study compared the life history traits (i.e., establishment, fertility, egg-larvae development) and experimental fitness of three H. contortus isolates, following challenge in the parasitic (resistant vs. susceptible sheep) and free-living (summer, spring and winter climates) phases. The findings show H. contortus exhibit isolate-specific life history strategies to effectively maintain their fitness in spite of the environmental challenges. Partial exploration of the isolates' transcriptomes further supports disparate expression profiles between them. These results bring new insights into the mechanisms by which GIN sustain their fitness across fluctuating environments, the results of which carry important implications for the sustainability of control interventions and in the potential comparability of experimental research. Gastrointestinal nematodes (GIN) use flexible life history strategies to maintain their fitness under environmental challenges. Costs incurred by a challenge to one life trait can be recouped by increasing the expression of subsequent life traits throughout their life cycle. Anticipating how parasites respond to the challenge of control interventions is critical for the long-term sustainability of the practice and to further ensure that the parasites withstand favourable adaptive responses. There is currently limited information on whether distinct populations of a GIN species respond to the same environmental challenge in a consistent manner, with similar alterations to their life history strategies or comparable fitness outcomes. This study compared the life history traits and experimental fitness of three distinct Haemonchus contortus isolates exposed to environmental challenges at both the parasitic (i.e., passage through resistant or susceptible sheep) and free-living (i.e., exposure to diverse climatic conditions) life stages. The key findings show that H. contortus maintain their fitness under challenge with isolate-specific alterations to their life history strategies. Further, partial exploration of the H. contortus isolates transcriptomes using cDNA-AFLP methods confirmed disparate expression profiles between them. These results bring fresh insights into our understanding of the non-genetic adaptive processes of GIN that may hinder the efficacy of parasite control strategies. [ABSTRACT FROM AUTHOR]

Abstract Background Gastrointestinal nematode (GIN) control is traditionally achieved with the use of anthelmintic drugs, however due to regulations in organic farming and the rise in anthelmintic resistance, alternatives are sought after. A promising alternative is the use of bioactive plant feeding due to the presence of plant secondary metabolites (PSMs) such as proanthocyanidins (PAs). This study focussed on the perennial shrub heather (Ericaceae family), a plant rich in PAs, highly abundant across Europe and with previously demonstrated anthelmintic potential. Methods In vitro assays were used to investigate heather’s anthelmintic efficacy against egg hatching and larval motility. Heather samples were collected from five European countries across two seasons, and extracts were tested against two GIN species: Teladorsagia circumcincta and Trichostrongylus colubriformis. Polyphenol group-specific ultraperformance liquid chromatography-tandem mass spectrometry analysis was performed to identify relevant polyphenol subgroups present, including the PA concentration and size and ratio of the subunits. Partial least squares analysis was performed to associate efficacy with variation in PSM composition. Results Heather extracts reduced egg hatching of both GIN species in a dose-dependent manner by up to 100%, while three extracts at the highest concentration (10 mg/ml) reduced larval motility to levels that were not significantly different from dead larvae controls. PAs, particularly the procyanidin type, and flavonol derivatives were associated with anthelmintic activity, and the particular subgroup of polyphenols associated with the efficacy was dependent on the GIN species and life stage. Conclusions Our results provide in vitro evidence that heather, a widely available plant often managed as a weed in grazing systems, has anthelmintic properties attributed to various groups of PSMs and could contribute to sustainable GIN control in ruminant production systems across Europe. Graphical Abstract

A study was conducted with Red Maasai and Dorper lambs to evaluate the effects of infection with the gastrointestinal nematode (GIN) Haemonchus contortus on feed intake, liveweight gain (LWG), feed energy and nitrogen partitioning, and enteric methane (CH4) emissions. Six- to seven-month-old Red Maasai (n=12) and Dorper (n=12) lambs were randomly allocated to three treatments (n=8, four lambs per breed) in a 2×3 factorial cross-over study over two periods (P1 and P2) of 36 days each. The treatments consisted of three combinations of GIN infection and feeding level: Infected + ad libitum feeding (I-adlib), uninfected + ad libitum feeding (Un-adlib), and uninfected + restricted feeding (Un-restd), across the two breeds. Lambs in the I-adlib group were trickle-infected daily with 1,000 L3 stage larvae of H. contortus for four consecutive days (Days 1–4), whereas lambs in the other experimental treatments were kept GIN free. The feed intake was measured daily. Liveweight (LW), faecal egg counts (FEC), and packed cell volume (PCV) were measured on Day 1 and weekly thereafter. On Days 29–33 total faecal and urine outputs were determined in metabolic crates. The lambs were then housed in respiration chambers for three consecutive days (Days 34–36). There was a washout period of 21 days before P2 started. Uninfected lambs (Un-adlib and Un-restd) had undetectable FEC throughout the study. On Day 36, FEC did not differ between the breeds (P>0.05). Infected lambs (I-adlib) had lower PCV than uninfected (Un-adlib and Un-restd) lambs on day 36. Neither breed nor infection influenced feed and nutrient intake, but as expected, restricted-fed lambs had a lower intake (P0.05). Neither breed nor infection affected feed digestibility, nitrogen retention or energy metabolisability (P>0.05). However, feed restriction decreased feed intake, LWG and N retention, whereas feed digestibility and energy metabolisability were unaffected. Neither daily CH4 emissions nor yield (per unit of feed intake) were affected by experimental infection, but Un-restd lambs had lower CH4 emissions per day. Red Maasai lambs had consistently lower daily CH4 emissions and yields than Dorper (P

Abstract Rangelands are multi‐use landscapes which are socially and ecologically important in different ways. Among other interactions, shared use of rangelands by wildlife and livestock can lead to disease transmission. Understanding wildlife and livestock health and managing disease transmission in rangelands requires an integration of social and ecological knowledge. Using the example of Western Kazakhstan, home to two types of ungulate hosts, the critically endangered saiga antelopes, Saiga tatarica, and livestock, we conducted a cross‐scale analysis of social‐economic, ecological and climatic factors that contribute to transmission of diseases We focused on gastrointestinal nematodes (GINs) because they are transmitted between hosts that share pasture and they affect ungulate fitness. We used an interdisciplinary social–ecological methods approach which included conducting faecal egg counts of GINs in saigas and livestock, semi‐structured interviews and focus group discussions with livestock owners and herders in the region, and triangulation of information through secondary sources. Livestock rearing was done in two ways: (a) village‐based livestock and (b) outlying farms. The latter overlapped more with saigas. Village‐based livestock had significantly higher worm burdens than those on outlying farms, which had comparable burdens to saigas. Various factors exacerbate GIN prevalence and transmission: Veterinary services are minimal; both saiga and livestock numbers are increasing; and changing climate is increasing farmers' dependence on shared pastures for hay production. It will be crucial for saiga conservationists to engage in multi‐pronged conservation interventions, which are evaluated and adapted through the lens of rural livelihoods and the livestock health on which they depend. Our work provides researchers and practitioners with an avenue to better understand complex inter‐relationships and plan interventions within rangelands, while viewing host health from an interdisciplinary perspective—ultimately working towards wildlife conservation while safeguarding livelihoods across the world's rangelands. A free Plain Language Summary can be found within the Supporting Information of this article.

Gastrointestinal nematodes (GINs) are key parasites of grazing sheep worldwide. To understand the factors influencing GIN infections, we examined the relationships among infection and nutrition, foraging behavior, and animal performance. Further, the parasitism and nutrition of sheep between improved and semi-natural pastures in Japan were compared. Sheep were grazed for 1 month each, first on an improved and then on a semi-natural pasture. Afterward, vegetation surveys, forage analyses, and (plant) nematode larval counts were conducted in both pastures, and fecal egg counts, biochemical analyses, and bite counts were completed for each sheep. The semi-natural pasture had diverse plant species, though it contained less crude protein, and nematode larvae were rarely observed on bamboo. Consequently, fecal egg per gram decreased after grazing on the semi-natural pasture. White blood counts, hematocrit, and glucose also decreased and body weight increased after grazing on this pasture. Principal component and correlation analyses revealed a significant relationship between GIN infection and behavior, but not between nutrition and either behavior or infection. As parasitized animals may become more aggressive feeders to compensate for their reduced nutritional uptake, grazing sheep on semi-natural pastures may facilitate more stable performance due to the lower risk of nematode infection from wild plants.

Background: Gastrointestinal nematode (GIN) control is traditionally achieved with the use of anthelmintic drugs, however due to regulations in organic farming and the rise in anthelmintic resistance, alternatives are sought after. A promising alternative is the use of bioactive plant feeding due to the presence of plant secondary metabolites (PSMs) such as proanthocyanidins (PAs). This study focussed on the perennial shrub heather (Ericaceae family), a plant rich in PAs, highly abundant across Europe and with previously demonstrated anthelmintic potential. Methods: In vitro assays were used to investigate heather's anthelmintic efficacy against egg hatching and larval motility. Heather samples were collected from five European countries across two seasons, and extracts were tested against two GIN species: Teladorsagia circumcincta and Trichostrongylus colubriformis. Polyphenol group-specific ultraperformance liquid chromatography-tandem mass spectrometry analysis was performed to identify relevant polyphenol subgroups present, including the PA concentration and size and ratio of the subunits. Partial least squares analysis was performed to associate efficacy with variation in PSM composition. Results: Heather extracts reduced egg hatching of both GIN species in a dose-dependent manner by up to 100%, while three extracts at the highest concentration (10 mg/ml) reduced larval motility to levels that were not significantly different from dead larvae controls. PAs, particularly the procyanidin type, and flavonol derivatives were associated with anthelmintic activity, and the particular subgroup of polyphenols associated with the efficacy was dependent on the GIN species and life stage. Conclusions: Our results provide in vitro evidence that heather, a widely available plant often managed as a weed in grazing systems, has anthelmintic properties attributed to various groups of PSMs and could contribute to sustainable GIN control in ruminant production systems across Europe. [ABSTRACT FROM AUTHOR]

Background and Aim: Promotions of goat farming by both public and private sectors encouraged considerable goat raising in central Thailand. Gastrointestinal nematodes (GIN) infection is a major health and economic problem; however, evidence of resistance to broad-spectrum anthelmintics is frequently reported. Investigation of anthelmintic resistance (AR) status and identification of factors related to the development of AR is important components for sustainable GIN control. However, no information is available on this topic in the study area. The present study aimed to gather information on GIN control practices and to evaluate the effectiveness of albendazole, ivermectin, and levamisole for treating GIN infestation in goat herds in Sing Buri Province. Materials and Methods: Twenty-nine herds were randomly selected. Information on management practices was collected by face-to-face interview using a structured questionnaire. Three field experiments for routinely used anthelmintics, including albendazole, ivermectin, and levamisole were conducted from June 2019 to November 2019. Fecal samples were collected pre- and post-treatment and examined for fecal egg count reduction to determine the status of anthelmintic resistance of goat GIN. Results: Several improper practices were identified that lead to AR, especially chronic use of albendazole and ivermectin. All herds were considered resistant to albendazole and ivermectin, and levamisole resistant nematodes were detected in two herds. AR was strongly linked with the continuous use of anthelmintics. Conclusion: Levamisole, which was still effective in the province, should be used with caution to minimize the selection of resistant strains. Farmers should be provided with updated information for sustainable parasite control. Further, the efficacy of anthelmintics should be routinely monitored.

Haemonchus contortus is a gastrointestinal nematode that negatively affects the meat and milk production of husbandry animals. The purpose of the study was to determine the anthelmintic activity of Chenopodium album plant extract in controlling H. contortus parasites. The antioxidant, cytotoxic, and antibacterial activities of the C. album plants were also investigated. In an anthelmintic activity test, 100% of H. contortus parasite mortality was observed after 3 h exposure at a dose of 150 μg/mL. The antioxidant properties of C. album showed an IC50 value of 90.98 μg/mL, indicating moderate antioxidant activity when compared to the BHT standard. The cytotoxic effect showed LC50 values of 4.52, 3.11, 2.3, 1.52, and 1.167 μg/mL after 12, 18, 24, 30, and 36 h against Artemia salina, respectively. However, the C. album extract did not demonstrate any antibacterial properties against Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Shigella dysentriae, Shigella boydii, or E. coli at a concentration of 150 μg/mL. A molecular docking study showed that isolariciresinol 4'-O-beta-D-glucoside, (1S,2S,4R)-1,8-epoxy-p-menthan-2-ol glucoside and linalool (CID-74407576, CID-73815050, and CID-6549) had binding energies of −7.8, −7.5, and −7.1 kcal/mol, respectively, with the Nu-class GST protein. Moreover, the ADMET properties of hit compounds also similarly showed ideal behavior to known drug molecules. Hence, C. album could be a promising candidate for developing an effective drug against H. contortus.

The current research aimed to study the morphological aspects of eggs of nematodes that parasitic on Awasi sheep and make a comparison with the existing data in specialized references. The eggs were isolated and collected from the nematodes female from the gastrointestinal mass of the sheep. The morphological appearance and measurements of eggs were made with microscope. The results showed the eggs from the following species: Haemonchus contortus, Marshallagia marshalli, Oesophagostomum columbianum and Trichostrongylus colubriformis were similar to the characters that depending on identification keys specialized literates.

[Display omitted] • A genome-wide scan detected signatures of benzimidazole (BZ) selection in Haemonchus contortus field populations. • A ddRADseq panel of >49 k genomic markers was generated for population genomic studies in H. contortus. • Iso-1 β-tubulin is quantitatively the most important BZ resistance locus in the H. contortus genome. • There is evidence for two additional BZ resistance loci of secondary importance. • We provide a framework for detection of genomic signatures in parasitic nematode field populations. Genome-wide methods offer a powerful approach to detect signatures of drug selection. However, limited availability of suitable reference genomes and the difficulty of obtaining field populations with well-defined, distinct drug treatment histories mean there is little information on the signatures of selection in parasitic nematodes and on how best to detect them. This study addresses these knowledge gaps by using field populations of Haemonchus contortus with well-defined benzimidazole treatment histories, leveraging a recently completed chromosomal-scale reference genome assembly. We generated a panel of 49,393 genomic markers to genotype 20 individual adult worms from each of four H. contortus populations: two from closed sheep flocks with an approximate 20 year history of frequent benzimidazole treatment, and two populations with a history of little or no treatment. Sampling occurred in the same geographical region to limit genetic differentiation and maximise the detection sensitivity. A clear signature of selection was detected on chromosome I, centred on the isotype-1 β-tubulin gene. Two additional, but weaker, signatures of selection were detected; one near the middle of chromosome I spanning 3.75 Mbp and 259 annotated genes, and one on chromosome II spanning a region of 3.3 Mbp and 206 annotated genes, including the isotype-2 β-tubulin locus. We also assessed how sensitivity was impacted by sequencing depth, worm number, and pooled versus individual worm sequence data. This study provides the first known direct genome-wide evidence for any parasitic nematode, that the isotype-1 β-tubulin gene is quantitatively the single most important benzimidazole resistance locus. It also identified two additional genomic regions that likely contain benzimidazole resistance loci of secondary importance. This study provides an experimental framework to maximise the power of genome-wide approaches to detect signatures of selection driven by anthelmintic drug treatments in field populations of parasitic nematodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The GLOWORM-FL model framework was extended to incorporate rotational grazing. • Gastrointestinal nematode populations were predicted on multiple, group-specific cattle grazing fields. • Predicted L3 contamination varied relative to grazing management and showed agreement with pasture larval counts. • The model simulated varying seasonal pasture infectivity at localities with different temperature and rainfall profiles. • Contamination mapping could help to plan grazing to manage nematode infections and anthelmintic resistance. Gastrointestinal nematode (GIN) parasites in grazing cattle are a major cause of production loss and their control is increasingly difficult due to anthelmintic resistance and climate change. Rotational grazing can support control and decrease reliance on chemical intervention, but is often complex due to the need to track grazing periods and infection levels, and the effect of weather on larval availability. In this paper, a simulation model was developed to predict the availability of infective larvae of the bovine GIN, Ostertagia ostertagi , at the level of individual pastures. The model was applied within a complex rotational grazing system and successfully reproduced observed variation in larval density between fields and over time. Four groups of cattle in their second grazing season (n = 44) were followed throughout the temperate grazing season with regular assessment of GIN faecal egg counts, which were dominated by O. ostertagi , animal weight and recording of field rotations. Each group of cattle was rotationally grazed on six group-specific fields throughout the 2019 grazing season. Maps and calendars were produced to illustrate the change in pasture infectivity (density of L3 on herbage) across the 24 separate grazing fields. Simulations predicted differences in pasture contamination levels in relation to the timing of grazing and the return period. A proportion of L3 was predicted to persist on herbage over winter, declining to similar intensities across fields before the start of the following grazing season, irrespective of contamination levels in the previous year. Model predictions showed good agreement with pasture larval counts. The model also simulated differences in seasonal pasture infectivity under rotational grazing in systems that differed in temperature and rainfall profiles. Further application could support individual farm decisions on evasive grazing and refugia management, and improved regional evaluation of optimal grazing strategies for parasite control. The integration of weather and livestock movement is inherent to the model, and facilitates consideration of climate change adaptation through improved disease control. [ABSTRACT FROM AUTHOR]

Abstract Background The diagnosis of gastrointestinal nematode (GIN) infections in ruminants is routinely based on morphological/morphometric analysis of parasite specimens recovered by coprological methods, followed by larval culture (LC) techniques. Such an approach is laborious, time-consuming, requires a skilled expert, and moreover suffers from certain limitations. Molecular tools are able to overcome the majority of these issues, providing accurate identification of nematode species and, therefore, may be valuable in sustainable parasite control strategies. Methods Two multiplex real-time polymerase chain reaction (PCR) assays for specific detection of five main and one invasive GIN species, including an internal amplification control to avoid false-negative results, were designed targeting SSU rRNA and COI genetic markers, as well as established ITS1/2 sequences. The assays were optimized for analysis of DNA extracted directly from sheep faeces and verified for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis, Nematodirus battus, Chabertia ovina, and Ashworthius sidemi. Semi-quantitative evaluation of infection intensity was enabled using a plasmid construct and a dilution series of sheep faeces with a known number of nematode eggs. Assays were tested on 44 individually collected faecal samples from three farms, and results were compared to those from faecal egg counts (FEC) using the concentration McMaster technique and LC. Results Multiplex real-time PCR assays showed great specificity to target nematodes. During the analysis of faecal samples, the assays proved to have higher sensitivity in strongylid-type egg detection over FEC by revealing three false-negative samples, while showing moderate agreement in evaluation of infection intensity. The multiplex assays further clarified GIN species identification compared to LC, which had confused determination of Teladorsagia spp. for Trichostrongylus spp. Conclusions Our multiplex assays proved to be a rapid and accurate approach enabling simultaneous and reliable GIN species identification from faeces and semi-quantitative estimation of the number of eggs present. This approach increases diagnostic value and may add a high degree of precision to evaluation of anthelmintic efficacy, where it is important to identify species surviving after treatment. Graphical Abstract

The in vitro anthelmintic effect of the extracts on Haemonchus contortus (H. contortus) of three forage species in the tropical dry forest is known; however, there is no information about the effects of the extract partitions, nor their chemical composition. The objectives of this study were to evaluate the in vitro ovicidal activity of H. contortus in extract partitions of the species Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce, and to identify the compounds present in the extract partitions with the highest activity by employing ultra HPLC Quadrupole orbitrap mass spectrometry. Four extract partitions, hexane, dichloromethane, ethyl acetate, and hydroethanolic from the three forage species were assessed in an inhibition of egg hatching (IEH) assay. The extract partitions with the highest anthelmintic activity (AA) were subjected to analysis, from which the tentative identification of the compounds was established. The extract partitions, including dichloromethane from Gliricidia sepium, ethyl acetate from Leucaena leucocephala, and hydroethanolic from Pithecellobium dulce showed a greater anthelmintic effect, with IC50 values of 0.39, 0.86, and 0.27 mg/mL for the IEH, respectively. Metabolites with in vitro AA potential included flavonoids, fatty acid esters, hydroxycinnamic acids, organic oxygenated compounds of the benzene class and substituted derivatives, phenolic glycosides, and phenols.

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. • H. contortus changed the spatial distribution of amino acids in host sheep. • H. contortus increased host protein for repairing physical and immune barriers. • H. contortus decreased the protein digestion, absorption and deposition of host. • This study provides theoretical basis for improving ruminant gut health. [ABSTRACT FROM AUTHOR]

ABSTRACT The gut microbiota is closely associated with the health and production performance of livestock. Partial studies on ruminant microbiota are already in progress in the Qinghai-Tibetan Plateau Area (QTPA) in China, but large-scale and representative profiles for the QTPA are still lacking. Here, 16S rRNA sequencing was used to analyze 340 samples from yak, cattle, yak-cattle hybrids, and Tibetan sheep, which lived in a shared environment from 4 eco-regions of the QTPA during the same season, and aimed to investigate the fecal microbiota community composition, diversity, and potential function. All samples were clustered into 2 enterotypes, which were derived from the genera Ruminococcaceae UCG-005 and Acinetobacter, respectively. Environment, human activity, species, and parasitization all affected the fecal microbiota. By assessing the relationship between the fecal microbiota and the above variables, we identified a scattered pattern of fecal microbiota dissimilarity based more significantly on diet over other factors. Additionally, gastrointestinal nematode infection could reduce the capacity of the bacterial community for biosynthesis of other secondary metabolites, carbohydrate metabolism, and nucleotide metabolism. Ultimately, this study provided a fecal microbiota profile for ruminants living in 4 eco-regions of the QTPA and its potential future applications in developing animal husbandry regimes. IMPORTANCE Cattle, yak, and sheep reside as the main ruminants distributed throughout most regions of Qinghai-Tibetan Plateau Area (QTPA) in China. However, there is a lack of large-scale research in the QTPA on their fecal microbiota, which can regulate and reflect host health as an internalized “microbial organ.” Our study depicted the fecal microbiota community composition and diversity of yak, cattle, yak-cattle hybrids, and Tibetan sheep from 4 eco-regions of the QTPA. Additionally, our results demonstrated here that the ruminant samples could be clustered into 2 enterotypes and that diet outweighed other factors in shaping fecal microbiota in the QTPA. This study provided a basis for understanding the microbiota characteristic of ruminants and its possible applications for livestock production in the QTPA.

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.

Background: This study was conducted to determine the prevalence and intensity of nematode infections in sheep located in northeastern Iran from Apr 2018 to Mar 2019. Methods: Gastrointestinal nematodes of 300 sheep were inspected. The season of slaughter, anatomic location where the parasite was located, the animal’s sex, infection prevalence and intensity were recorded. Seasonal differences in arrested larvae numbers also were assessed using Cochran's Q test. Results: Overall, 4,331 adult nematode specimens were collected. Among the examined sheep, 53% (159/300) were infected with one or more nematode species. Among infected sheep, 42.8% were infected with a single species of nematode, 26.4% were infected with two species of nematodes, and 30.8% were infected with three or more species of nematodes. Marshallagia marshalli (13.3%) was the most common nematode recovered from the abomasums of infected sheep, while Trichostrongylus vitrinus (4.6%) was commonly recovered from the small intestines, and Trichuris ovis (25.6%) was commonly recovered from the large intestines. In total, 463 arrested larvae were found in the abomasums of 7.5% of infected sheep and 104 arrested larvae were found in the small intestines of 8.8% of infected sheep. A significantly higher numbers of arrested larvae were found in summer compared to autumn (P<0.001). Conclusion: Intestinal parasites continue to be a problem for sheep in northeastern Iran and additional control measures need to be explored. [ABSTRACT FROM AUTHOR]

Keywords: disease; gastrointestinal nematode; goat; pasture; saiga; sheep; social-ecological system; ungulate EN disease gastrointestinal nematode goat pasture saiga sheep social-ecological system ungulate 382 399 18 04/06/22 20220401 NES 220401 INTRODUCTION Background Rangelands, comprising grasslands, shrub-lands, savannas and marshes grazed by livestock and wildlife (Allen et al., 2011), cover I c i . 40% of all land, and provide habitats for multiple species (Reid et al., 2008). Saigas are most likely to share pasture with outlying livestock (Khanyari, Robinson, Morgan, Brown, et al., 2021) which have significantly lower worm burdens than village-based livestock, and comparable burdens to saigas. Overall, it is evident that various factors are exacerbating GIN prevalence and transmission: both saigas and livestock host GINs and both are increasing in number; veterinary services are minimal; livestock movements are now limited; and a changing climate is increasing farmers' dependence on hay pastures, which are shared with saigas. The aim was to understand livestock rangeland use, livestock composition and distribution and livestock health and its management (Table 1). Recently, the Kazakh government has introduced large subsidy programmes supporting livestock production (Petrick et al., 2018), but these tend to benefit large-scale livestock owners, while households (livestock owners not registered as farms) are ineligible (Kerven et al., 2021). [Extracted from the article]

Copyright of Informacion Tecnica Economica Agraria is the property of Asociacion Interprofesional para el Desarrollo Agrario (AIDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: This study was conducted to determine the prevalence and intensity of nematode infections in sheep located in northeastern Iran from Apr 2018 to Mar 2019. Methods: Gastrointestinal nematodes of 300 sheep were inspected. The season of slaughter, anatomic location where the parasite was located, the animal’s sex, infection prevalence and intensity were recorded. Seasonal differences in arrested larvae numbers also were assessed using Cochran's Q test. Results: Overall, 4,331 adult nematode specimens were collected. Among the examined sheep, 53% (159/300) were infected with one or more nematode species. Among infected sheep, 42.8% were infected with a single species of nematode, 26.4% were infected with two species of nematodes, and 30.8% were infected with three or more species of nematodes. Marshallagia marshalli (13.3%) was the most common nematode recovered from the abomasums of infected sheep, while Trichostrongylus vitrinus (4.6%) was commonly recovered from the small intestines, and Trichuris ovis (25.6%) was commonly recovered from the large intestines. In total, 463 arrested larvae were found in the abomasums of 7.5% of infected sheep and 104 arrested larvae were found in the small intestines of 8.8% of infected sheep. A significantly higher numbers of arrested larvae were found in summer compared to autumn (P

Goat production in Nigeria has faced a major constraint resulting from parasitic infections, notably the parasitic gastrointestinal (GI) nematode which has resulted in high morbidity, mortality, high cost of treatment and high economic losses. Another problem encountered in the treatment of gastrointestinal nematode infection is anthelmintic resistance, hence, the need to investigate the anthelmintic resistance status of GI nematodes of West African Dwarf (WAD) goats in Ikwuano area of Abia State, Nigeria. A faecal egg count reduction test (FECRT) was carried out in naturally infected WAD goats. A total of 60 WAD goats were randomly assigned into 3 groups of 20 WAD goats in each group and screened for GI nematode eggs. Group A treated with ivermectin, group B was treated with levamisole and group C was treated with fenbendazole. The percentage reductions in FEC in male and female WAD goats in ivermectin treated group were 72.42% and 67.98%, Levamisole treated group were 61.67% and 65.22% in male and female WAD goats respectively and 59.50% and 52.63% for male and female in fenbendazole treated group. The percentage reduction of FEC in young and Adult WAD goats treated with ivermectin were 63.05% and 70.52%, and 58.08% and 67.04% for levamisole treated group respectively, while fenbendazole treated group had 60.03 and 54.08% reduction respectively. Resistance was observed in all the anthelmintic drugs used, which poses a huge threat to livestock production in the study area. [ABSTRACT FROM AUTHOR]

Haemonchus contortus is an infectious gastrointestinal nematode parasite of small ruminants. This study addresses the in vitro/in vivo anti-haemonchiasis potential, toxicological effects, and mechanism of action of nanoparticles. Online databases were used to search and retrieve the published literature (2000 to 2021). A total of 18 articles were selected and reviewed, out of which, 13 (72.2%) studies reported in vitro, 9 (50.0%) in vivo, and 4 (22.2%) both in vitro/in vivo efficacy of different nanoparticles. Mostly, organic nanoparticles (77.7%) were used including polymeric (85.7%) and lipid nanoparticles (14.3%). The highest efficacy, in vitro, of 100% resulted from using encapsulated bromelain against eggs, larvae, and adult worm mortality at 4, 2, and 1 mg/ml, respectively. While in vivo, encapsulated Eucalyptus staigeriana oil reduced worm burden by 83.75% and encapsulated Cymbopogon citratus nano-emulsion by 83.1%. Encapsulated bromelain, encapsulated Eucalyptus staigeriana oil, and encapsulated Cymbopogon citratus nano-emulsion were safe and non-toxic in vivo. Encapsulated bromelain damaged the cuticle, caused paralysis, and death. Nanoparticles could be a potential source for developing novel anthelmintic drugs to overcome the emerging issue of anthelmintic resistance in H. contortus. Studies on molecular effects, toxicological consequences, and different pharmacological targets of nanoparticles are required in future research.

Background: A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods: A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results: Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions: Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected. [ABSTRACT FROM AUTHOR]

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Infection by gastrointestinal nematodes (GIN), particularly Haemonchus contortus , can be detrimental to sheep health and performance. Genetic susceptibility to GIN varies between breeds, with those lacking high levels of natural resistance often requiring frequent anthelmintic treatment when facing parasitic challenge. Genetic technology can serve as a tool to decrease GIN susceptibility via selection for sheep with reduced fecal egg count (FEC) estimated breeding values (EBVs). However, the physiological changes that result from implementation of this strategy are not well described. Additionally, there is a need for comparison of animals from recent selective breeding against breeds with inherent GIN resistance. In this study we administered a challenge of H. contortus to Dorper x White Dorper (DWD; n = 92) lambs that have been genetically selected for either low (DWD-) or high (DWD+) FEC EBVs and Barbados Blackbelly x Mouflon (BBM; n = 19) lambs from a genetically resistant breed backgrounds. Lamb FEC, packed-cell volume (PCV) and serum IgG were measured at intermittent levels over 5 weeks. At day 21 and day 35, the selectively bred DWD- had a lower mean FEC compared to DWD+, but were higher than BBM. Reductions in both PCV and serum IgG from initial day 0 levels were observed in DWD lambs, but not in BBM. Furthermore, from a subset of lambs (n = 24) harvested at day 21, DWD- only tended (p = 0.056) to have lower mean worm counts than DWD+, with BBM having the lowest mean worm count. Differentially expressed genes (DEGs) identified via RNA-sequencing of abomasal tissue at day 21 indicate a more pronounced Th2 immune response and more rapid worm expulsion occurred in iBBM than iDWD- and iDWD+ lambs. However, gene expression in DWD- suggests an association between reduced FEC EBV and gastric acid secretion and the ability to limit worm fecundity. Ultimately, selection of Dorper sheep for low FEC EBV can reduce susceptibility to GIN, but it will likely require multiple generations with this trait as a breeding priority before presenting a similar resistance level to Caribbean breeds. • Reducing FEC EBV results in lower FECs following a Haemonchus contortus challenge. • Barbados Blackbelly lambs prevented the establishment of Haemonchus contortus larvae. • Dorper lambs with a lower FEC EBV upregulate genes involved in immunity. [ABSTRACT FROM AUTHOR]

Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments. Protection is associated with reduced cumulative faecal egg counts across the duration of the trials, relative to control animals. To better understand the diversity of antigens in O. ostertagi ES-thiol we used high-resolution shotgun proteomics to identify 490 unique proteins in the vaccine preparation. The most numerous ES-thiol proteins, with 91 proteins identified, belong to the sperm-coating protein/Tpx/antigen 5/pathogenesis-related protein 1 (SCP/TAPS) family. This family includes previously identified O. ostertagi vaccine antigens O. ostertagi ASP-1 and ASP-2. The ES-thiol fraction also has numerous proteinases, representing three distinct classes, including: metallo-; aspartyl- and cysteine proteinases. In terms of number of family members, the M12 astacin-like metalloproteinases, with 33 proteins, are the most abundant proteinase family in O. ostertagi ES-thiol. The O. ostertagi ES-thiol proteome provides a comprehensive database of proteins present in this vaccine preparation and will guide future vaccine antigen discovery projects. [Display omitted] • Antigens purified from Ostertagia ostertagi excretory-secretory products protect cattle against homologous challenge. • The ES-thiol vaccine reduces O. ostertagi cumulative faecal egg counts in vaccinated cattle. • Shotgun proteomics was used to identify 490 proteins in the protective ES-thiol protein fraction. • Activation associated proteins (ASPs) and astacin metalloproteinases are abundant in O. ostertagi ES-thiol. [ABSTRACT FROM AUTHOR]

Background: The diagnosis of gastrointestinal nematode (GIN) infections in ruminants is routinely based on morphological/morphometric analysis of parasite specimens recovered by coprological methods, followed by larval culture (LC) techniques. Such an approach is laborious, time-consuming, requires a skilled expert, and moreover suffers from certain limitations. Molecular tools are able to overcome the majority of these issues, providing accurate identification of nematode species and, therefore, may be valuable in sustainable parasite control strategies. Methods: Two multiplex real-time polymerase chain reaction (PCR) assays for specific detection of five main and one invasive GIN species, including an internal amplification control to avoid false-negative results, were designed targeting SSU rRNA and COI genetic markers, as well as established ITS1/2 sequences. The assays were optimized for analysis of DNA extracted directly from sheep faeces and verified for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis, Nematodirus battus, Chabertia ovina, and Ashworthius sidemi. Semi-quantitative evaluation of infection intensity was enabled using a plasmid construct and a dilution series of sheep faeces with a known number of nematode eggs. Assays were tested on 44 individually collected faecal samples from three farms, and results were compared to those from faecal egg counts (FEC) using the concentration McMaster technique and LC. Results: Multiplex real-time PCR assays showed great specificity to target nematodes. During the analysis of faecal samples, the assays proved to have higher sensitivity in strongylid-type egg detection over FEC by revealing three false-negative samples, while showing moderate agreement in evaluation of infection intensity. The multiplex assays further clarified GIN species identification compared to LC, which had confused determination of Teladorsagia spp. for Trichostrongylus spp. Conclusions: Our multiplex assays proved to be a rapid and accurate approach enabling simultaneous and reliable GIN species identification from faeces and semi-quantitative estimation of the number of eggs present. This approach increases diagnostic value and may add a high degree of precision to evaluation of anthelmintic efficacy, where it is important to identify species surviving after treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metabarcoded sequencing was used to determined species composition (nemabiome) of gastrointestinal nematode (GIN) larvae. • Deep amplicon sequencing determined proportions of benzimidazole (BZ)-resistant SNPs in Teladorsagia circumcincta. • Nemabiomes varied with time and between ewes and lambs, possibly associated with weather. • The F200Y BZ resistance mutation was close to genetic fixation in T. circumcincta. • There was no genetic evidence of reversion to BZ anthelmintic susceptibility. Anthelmintic resistance threatens the sustainability of sheep production globally. Advice regarding strategies to reduce the development of anthelmintic resistance incorporates the outcomes of modelling exercises. Further understanding of gastrointestinal nematode species diversity, and population dynamics and genetics (which may vary between species) is required to refine these models; and field studies combining faecal egg outputs, species composition and resistance genetics are needed to calibrate them. In this study, faecal samples were taken from ewes and lambs on a commercial farm in south-eastern Scotland at approximately 3 t-4 week intervals between spring and autumn over a period of 4 years. Faecal egg counts were performed on these samples, and L 3 were collected from pooled coprocultures. Deep amplicon sequencing was used to determine both the species composition of these L 3 and the proportions of benzimidazole-resistant single nucleotide polymorphisms in the isotype-1 β-tubulin locus of the predominant species, Teladorsagia circumcincta L 3. Despite consistent management throughout the study, the results show variation in gastrointestinal nematode species composition with time and between age groups, that was potentially associated with weather conditions. The F200Y benzimidazole resistance mutation is close to genetic fixation in the T. circumcincta population on this farm. There was no evidence of variation in isotype-1 β-tubulin single nucleotide polymorphisms frequency between age groups, and no genetic evidence of reversion to benzimidazole susceptibility, despite targeted benzimidazole usage. This study highlights the need to include speciation when investigating gastrointestinal nematode epidemiology and anthelmintic resistance, and serves as an example of how genetic data may be analysed alongside species diversity and faecal egg counts, when markers for other anthelmintic classes are identified. [ABSTRACT FROM AUTHOR]

Abstract Background The gastrointestinal parasitic nematode Haemonchus contortus is a pathogenic organism resistant to several anthelmintics. This study assessed the efficacy of a medicinal herbal mixture (Herbmix) and organic zinc, as an essential trace element for the proper functioning of both unspecific and specific immune defensive mechanisms, against experimental infections with H. contortus in lambs. All lambs were infected orally with approximately 5000 third-stage larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Twenty-four female lambs 3–4 months of age were divided into four groups: unsupplemented animals (control), animals supplemented with Herbmix (Hmix), animals supplemented with organic zinc (Zn) and animals supplemented with Herbmix and organic zinc (Hmix+Zn). Eggs per gram (EPG) of faeces were quantified 20, 28, 35, 42, 49, 56, 62 and 70 d post-infection and mean abomasal worm counts were assessed 70 d post-infection. Samples of blood were collected from each animal 7, 35, 49 and 70 d post-infection. Results Quantitative analyses of the bioactive compounds in Herbmix identified three main groups: flavonoids (9964.7 μg/g), diterpenes (4886.1 μg/g) and phenolic acids (3549.2 μg/g). Egg counts in the lambs treated with Hmix, Zn and Hmix+Zn decreased after 49 d. The EPGs in the Zn and Hmix+Zn groups were significantly lower on day 56 (P

Sheep are a species exploited in different areas of production. They are prone to different pathogens, highlighting parasites such as Haemonchus contortus. The prevailing climate and husbandry management practices are considered the main factors driving the spatial and temporal distribution of the nematode. Its distribution is worldwide, causing economic losses due to morbidity and mortality, and prevalence studies have been reported in different countries such as India, Spain, Nigeria, and Mexico; therefore, the aim of this study was to determine the edaphoclimatic factors of different zones from Culiacan municipality and the production system that influence the prevalence of Haemonchus spp. in lambs. The research was carried out in Culiacan municipality, Sinaloa, Mexico, over a period of one year. It was an observational study, which included 23 sheep production units distributed in 10 districts of the municipality, with a total of 1520 samples of feces from animals under 3 months of age. Feces were processed individually by flotation technique. The overall prevalence was 13.42 %, and the autumn season (OR 2.38 (1.69-3.34) P<0.001), valley zone (OR 2.70 (1.21-6.02); P<0.016) and extensive system (OR 4.81 (3.38-6.85); P<0.0001) were risk factors associated with the presence of the nematode in lambs, so they should be considered for the establishment of preventive measures and control of parasitosis. [ABSTRACT FROM AUTHOR]

A total of 617 faecal samples (including 235, 188 and 194 samples from native cows, crossbred cows and buffaloes, respectively) were examined from January 2017 to December 2017, with an overall prevalence rate of 56.73% (native: 60.85%, crossbred: 57.45% and buffaloes: 51.03%) for gastrointestinal nematode infections and mixed infection in 11.35% with no statistical difference (p>0.05). Throughout the whole study period strongyles were found to be the most dominant (47.49%) followed by Strongyloides sp. (16.86%). A highly significant statistical variation (p<0.05) were reported in season wise as well as district wise analysis with maximum infection in rainy season (64.90%) and in Jodhpur district (62.54%), respectively. Quantitative analysis revealed EPG (eggs per gram of faeces) for stongyles ranging from 100- 2500 (1291±237.56) and Strongyloides sp. from 100-800 (416.67±75.71). Multivariate binary logistic regression model revealed positive association of rainy (B=0.407) and negative association of summer season (B=-.221) when compared to winter season whereas, association was reported negative in Barmer district (B=0.517) when compared to Jodhpur district. Similarly, comparing to native animals, a negative association in crossbred (B=-0.197) and buffaloes (B=-0.462)was also reported in the study period. Coproculture analysis revealed the presence of nematodes of genera Haemonchus sp. (40.58%), Oesophagostomum sp. (26.09%), Strongyloides sp. (18.84%), Trichostrongylus sp. (8.695%) and Cooperia sp. (5.797%) in decreasing order of prevalence. Considering the impact of the infections on animal production and public health, the current investigation may be used to design rational, economic, selectively effective strategic and locally sustainable control programs against gastrointestinal nematode infections in the dairy animals of arid western plains of Rajasthan. [ABSTRACT FROM AUTHOR]

Parasitic cysteine proteases are involved in parasite stage transition, invasion of host tissues, nutrient uptake, and immune evasion. The cysteine protease cathepsin F is the most abundant protein produced by fourth-stage larvae (L4) of the nematode Teladorsagia circumcincta, while its transcript is only detectable in L4 and adults. T. circumcincta cathepsin F is a recently evolved cysteine protease that does not fall clearly into either of the cathepsin L or F subfamilies. This protein exhibits characteristics of both cathepsins F and L, and its phylogenetic relationship to its closest homologs is distant, including proteins of closely related nematodes of the same subfamily. [ABSTRACT FROM AUTHOR]