Search Results (160)

Parasitic infections constitute a common concern for livestock breeders, since they induce animals with various physiological, behavioral, and neurological alterations. Consequently, they negatively affect their health, productivity, and welfare, leading to reduced productivity and increased mortality, and causing severe economic losses to livestock breeders. In the context of recent interest in the development of functional animal feeds and/or feed supplements with potent antiparasitic activity, we exploited the chemical contents and bioactivities of 21 wild and cultivated Fabaceae plant species against Haemonchus contortus and Trichostrongylus colubriformis, two widely prevalent gastrointestinal nematode parasites of small ruminants. The respective results revealed that four wildly grown plants exhibit potent antiparasitic activity, with Lathyrus laxiflorus exerting the most significant protective effect against both parasites tested. This plant was also found to display the highest antioxidant potency and the richest phenolic and tannin contents, with rutin molecules being the most abundant. Moreover, the extracts of 11 cultivated species were found to display potent antiparasitic activity, while Trifolium repens, Medicago sativa, and Lathyrus sativus species were determined to provide higher extraction yields and display the most potent antiparasitic activities. Results herein are indicative of Fabaceae plants’ potential to act against parasitic infections, either as grazing plants in pasture-based systems, or as bioactive dietary supplements in intensive farming systems, eventually contributing to reductions in antiparasitic drug utilization. Full article

Background/Objectives/Methods: A bioassay-informed investigation of the Australian pasture soil-derived Streptomyces sp. S4S-00193A39 yielded the anthelmintic principals as three new spiroketal polyketide alkaloids, goondoxazoles A–C (1–3), with structures assigned by detailed spectroscopic analysis. Results: A structure–activity relationship based on the ability to inhibit the motility of Dirofilaria immitis microfilariae (mf) revealed a positive correlation for the benzoxazole moiety present in 2 and 3 (EC₅₀ 55–85 nM) versus the ring-opened aminobenzoic acid moiety evident in 1 (EC₅₀ 1.38 µM). This hypothesis was strengthened by extension of the SAR assessment to the known benzoxazole natural products A-33583 (12), UK-1 (13) and nataxazole (14), and the new analogue 5-hydroxynataxazole (15), which were isolated in our lab from three additional Australian pasture soil-derived Streptomyces spp. Of note, while the benzoxazole methyl esters 13–15 exhibited approximately 9- to 65-fold lower potency against D. immitis mf compared with 2 and 3, the carboxylic acid substituted benzoxazole 12 displayed comparable activity (EC₅₀ 72 nM) against D. immitis mf, and >5-fold improved potency against D. immitis L4 larvae (EC₅₀ 0.43 µM). Conclusions: These observations reveal the promising anthelmintic potential (against D. immitis) for the new structurally complex and chiral goondoxazoles (e.g., 2 and 3), and demonstrate that this effect can be replicated, even improved, by simpler, achiral benzoxazole microbial natural products (e.g., 12). Full article

The frequent and indiscriminate use of all classes of synthetic anthelmintics to deworm small ruminants has decreased their effectiveness in a worldwide problem of anthelmintic resistance. Using active plant metabolites with anthelmintic properties has become a suggested alternative to control parasitic helminths. The present study investigated the ovicidal and larvicidal activity of a fraction (CnF4) containing protocatechuic acid (3,4-dihydroxybenzoic acid) from Chamaecrista nictitans (Fabaceae) and a commercial standard of protocatechuic acid against strains of the parasitic nematode Haemonchus contortus susceptible (HcIVM-S) and resistant (HcIVM-R) to ivermectin, using egg hatch inhibition (EHI) and L3 larval mortality assays. The CnF4 fraction showed an EHI greater than 90% at 0.8 mg/mL against HcIVM-S and an EHI = 88.39% at 1.6 mg/mL against HcIVM-R. The commercial standard of protocatechuic acid displayed an EHI of 97.49% at 0.25 mg/mL against HcIVM-S and an EHI greater than 98% at 0.5 mg/mL. In the larval mortality assays, protocatechuic acid caused 72.4% larval mortality of HcIVM-S at 8 mg/mL and 53.2% mortality of HcIVM-R at 16 mg/mL. These results indicate that protocatechuic acid was more effective in inhibiting egg hatching and causing larval mortality against HcIVM-S compared to HcIVM-R. Full article

Gastrointestinal nematodes, particularly Haemonchus contortus, represent a major threat to ruminant health and productivity worldwide, largely due to the widespread emergence of anthelmintic resistance. In Bosnia and Herzegovina, benzimidazole resistance has previously been confirmed in domestic ruminants; however, data on wildlife remain lacking. Given the frequent spatial and temporal overlap between domestic and wild ruminants on shared pastures, this study aimed to investigate the occurrence of benzimidazole-resistant H. contortus genotypes within a multi-host system. During the 2024/2025 season, a total of 111 abomasal samples were collected from sheep (n = 20), lambs (n = 12), goats (n = 17), roe deer (n = 40) and chamois (n = 22) across four localities in Bosnia and Herzegovina (Laktaši, Banja Luka, Modriča and Višegrad). Adult H. contortus specimens were morphologically identified and confirmed using real-time quantitative PCR (rt-qPCR). Benzimidazole resistance was assessed by allele-specific rt-qPCR targeting the F200Y mutation in the β-tubulin isotype 1 gene. Statistically significant interspecies differences in β-tubulin genotype distribution were observed (p < 0.05), primarily driven by variation in the homozygous resistant (RR) genotype. High RR prevalence was detected in sheep (60%), lambs (50%) and roe deer (52.5%), whereas lower proportions were observed in chamois (27.3%) and goats (23.5%). Overall, 44.1% of all analyzed H. contortus isolates carried homozygous resistant alleles, indicating an advanced stage of benzimidazole resistance within this multi-host system. These findings demonstrate that benzimidazole resistance in H. contortus is not confined to domestic livestock but is also present in wild ruminants sharing the same grazing areas, consistent with circulation of resistant parasites within shared grazing systems. Full article

Background: Haemonchus contortus is a gastrointestinal nematode that affects small ruminants and exhibits widespread resistance to commercial anthelmintics. This has driven interest in natural compounds such as fatty acids and sterols; however, their biological relevance against resistant parasite strains remains insufficiently understood. Methods: The nematicidal potential of four fatty acids (palmitic, linoleic, pentadecanoic, and stearic acids) and two sterols (β-sitosterol and ergosterol), all of them commercially available in Mexico, was evaluated against infective L3 larvae of a benzimidazole-resistant H. contortus strain. In vitro larval mortality and migration inhibition assays were performed, and molecular docking analyses were conducted to explore interactions with the glutamate-gated chloride channel (GluCl) using AutoDock4. Statistical analyses were performed using ANOVA followed by Tukey’s post hoc test (p < 0.05). Results: Molecular docking indicated strong binding affinities of ergosterol and β-sitosterol to GluCl, comparable to that of ivermectin. In vitro assays showed that fatty acids, particularly linoleic acid, produced more pronounced effects on larval motility, suggesting predominantly nematostatic activity. No clear dose–response relationship was observed in migration assays, and in vitro mortality remained limited across treatments. Conclusions: The results highlight a disconnect between in silico binding affinity and in vitro biological activity, particularly in a drug-resistant H. contortus strain. Integrating in vitro bioassays with computational approaches provides valuable mechanistic insight but also underscores the limitations of affinity-based predictions for assessing anthelmintic efficacy. Full article

Although best known as a major parasite of sheep and goats, the blood-feeding abomasal nematode Haemonchus contortus can also infect cattle and buffaloes under the mixed-grazing Mediterranean conditions prevalent in Greece. The objectives of this study were as follows: (i) to determine the prevalence of H. contortus infections in dairy and beef cattle and buffaloes in Greece through an abattoir survey, (ii) to evaluate potential host- and farm-related risk factors including age, sex, management system, cattle productive orientation, and the co-existence of cattle and buffaloes on the occurrence of haemonchosis, and (iii) to assess the likelihood of detecting homozygous benzimidazole (BZ)-resistant H. contortus in large ruminant populations in relation to these determinants. A total of 213 abomasa (115, 55, and 43 from dairy, beef cattle, and buffaloes, respectively) were examined. A structured questionnaire provided additional animal- and farm-level information. Haemonchus-like helminths were collected and molecularly identified at the species level by amplifying a 321 bp fragment of the internal transcribed spacer 2 region of nuclear DNA. An allele-specific multiplex PCR, targeting codon 200 of the β-tubulin gene, was applied to detect BZ-resistant alleles. The prevalence of H. contortus infection was 21.2% in cattle and 69.8% in buffaloes. In cattle, multivariable analysis revealed that mixed-species farming (i.e., farms where cattle were the primary species and buffaloes were kept in smaller numbers), productive orientation, and slaughter age were significant predictors of increased H. contortus infection. Controversially, none of these factors were significantly associated with infection in buffaloes. Finally, multivariable modelling suggested that resistance patterns varied by host species, being more prevalent in intensively managed, older cattle, yet less common among older buffaloes and in herds where both species coexisted. Full article

Parasitic infection is a major cause of infertility in small ruminants. This study aimed to assess the association between bioelectrical impedance analysis (BIA) measurements, testicular morphometrics, and sperm quality in parasitized goats. Thirty-eight intact mature Spanish bucks were allowed to graze on a naturally parasitically infected pasture for 3 months. Nineteen bucks were dewormed regularly (healthy group), while the other 19 bucks did not receive any anthelmintics (parasitized group). Fecal and blood samples were collected weekly to assess fecal egg count (FEC) and packed cell volume (PCV), respectively. Based on the size and morphology of the parasite eggs, they were presumptively identified as Haemonchus contortus. At the end of the grazing period, bucks were slaughtered, and testicles and epididymis were collected for analysis. In addition, BIA was applied to each testicle to measure series resistance (Rs) and reactance (Xc). Epididymal spermatozoa were retrieved and evaluated for motility, viability, morphology, and membrane and acrosome integrities. Data was analyzed using the Mann–Whitney U and Pearson Correlation Coefficient tests. The results showed that Rs (169.41 ± 1.76 Ω vs. 235.21 ± 20.21 Ω), Xc (37.55 ± 0.48 Ω vs. 52.08 ± 4.68 Ω), testicular and epididymis weights and lengths, sperm motility, viability, and membrane and acrosome integrities were lower (p < 0.0001) in parasitized than in healthy goats. Strong correlations (p < 0.001) were observed between Rs, sperm viability (r = 0.20), membrane integrity (r = 0.15), and acrosome integrity (r = 0.14), as well as between Xc and the same sperm parameters (r = 0.21, 0.18, and 0.16, respectively). In conclusion, our findings demonstrate that parasitic infection is associated with testicular health and subsequent epididymal sperm quality of goats. BIA can be utilized as an efficient tool to predict the impact of parasitic infection on testicular function in goats. Full article

Haemonchus contortus is a blood-feeding gastrointestinal nematode that significantly impacts the health and productivity of small ruminants. The burden of parasitism and the escalating incidence of anthelmintic resistance necessitate alternative control methods. Here, we characterize the enzymatic activities of five mammalian cell-expressed recombinant H. contortus cysteine proteases (HcCPs), which include two cathepsin B-like proteins (HcCBP1 and HcCBP2) and three cysteine protease 1 proteins (HcCP1a, HcCP1b, and HcCP1c). We hypothesize that these enzymes degrade host blood proteins, thereby facilitating the parasite’s nutrient acquisition and survival. Using synthetic cathepsin (cat) substrates, we show that HcCBP2 was the only protein that exhibited high catB/L but low catB or catK activity, which was inhibited by the cysteine protease inhibitor E-64. All mHcCPs degraded fibrinogen (Fg), which led to delayed plasma clotting, reduced clot density, and lysed plasma clots. All HcCPs partially degraded hemoglobin (Hb), except for mHcCBP2, which degraded Hb and bovine serum albumin completely and bovine IgG partially in the presence of a reducing agent. In conclusion, by sustaining blood feeding and facilitating immune evasion and nutrient acquisition, the HcCPs may play an essential role in the parasite’s survival. Thus, vaccines or cysteine protease inhibitors targeting these parasitic enzymes may mitigate or prevent infections. Full article

Parasitic infections, particularly those caused by Haemonchus contortus (H. contortus), severely impact livestock production, with growing resistance to commercial anthelmintics posing a major challenge. Green-synthesized metallic nanoparticles using Artemisia cina (A. cina), a plant with known anthelmintic and antioxidant properties, represent a promising sustainable alternative for parasite control. In this study, silver nanoparticles (AgNPs) were synthesized using an aqueous extract of A. cina to evaluate their anthelmintic activity against infective larvae (L3) of H. contortus and their effect on the expression of oxidative stress-related genes. The larval mortality bioassay was conducted in 96-well microtiter plates by incubating L3 larvae with increasing AgNP concentrations for 24 h. To investigate oxidative stress responses, larvae were exposed to sublethal concentrations of AgNPs, A. cina aqueous extract, AgNO₃, and H₂O₂. Expression levels of SOD, GPx, and CAT genes were then quantified by RT-qPCR at multiple post-exposure time intervals. The synthesis was optimized by varying parameters such as pH, temperature, and extract volume. The nanoparticles were characterized using UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and Electrophoretic Light Scattering (ELS). Overall, synthesis at pH 8 yielded small, spherical, stable, and abundant AgNPs. In vitro assays on L3 larvae showed a mortality rate of 91.33% at the highest AgNP concentration (500 μg/mL), with lethal concentration (LC50 and LC90) values of 4.128 ppm (μg/mL) and 17.993 μg/mL, respectively. Relative expression analyses revealed that AgNPs induced the overexpression of the SOD gene, highlighting its role in the oxidative stress response. In contrast, the expression levels of GPx and CAT genes were markedly downregulated. These results suggest that SOD could serve as a potential biomarker of oxidative stress induced by AgNPs in combination with A. cina metabolites, influencing the infective stages of H. contortus. Full article

Synthetic anthelmintic drugs not only contribute to the development of pathogen resistance and environmental pollution but also to the development of pathogen resistance. Therefore, identifying the anthelmintic properties of widely used medicinal plants could be of great practical interest to veterinary and human medicine. In our experiment, we evaluated the in vitro survivability of the noninvasive and invasive (L_1–2 and L_3, respectively) larvae of Strongyloides papillosus and Haemonchus contortus subject to aqueous solutions of ethanolic tinctures of traditional medicinal plants (46 species). Most of the plant species we studied belonged to the families Asteraceae (Achillea millefolium, Arctium lappa, Artemisia absinthium, Bidens tripartita, Calendula officinalis, Cynara cardunculus var. scolymus, Echinacea purpurea, Helichrysum arenarium, Inula helenium, Matricaria chamomilla, Silybum marianum, Tanacetum vulgare, Taraxacum officinale, Tragopogon porrifolius), Rosaceae (Agrimonia eupatoria, Fragaria vesca, Sanguisorba officinalis), and Lamiaceae (Leonurus cardiaca, Mentha × piperita, Origanum vulgare, Salvia officinalis, Thymus vulgaris). Other plant families were represented by 1–3 species: Fabaceae (Glycyrrhiza glabra, Hedysarum alpinum, Trifolium pratense), Salicaceae (Populus nigra, P. tremula, Salix alba), Fagaceae (Quercus robur), Betulaceae (Betula pendula), Juglandaceae (Juglans regia), Rhamnaceae (Frangula alnus), Acoraceae (Acorus calamus), Apiaceae (Foeniculum vulgare), Caprifoliaceae (Valeriana officinalis), Cucurbitaceae (Cucurbita pepo), Equisetaceae (Equisetum arvense), Ericaceae (Vaccinium vitis-idaea), Gentianaceae (Centaurium erythraea), Hypericaceae (Hypericum perforatum), Malvaceae (Althaea officinalis), Plantaginaceae (Linaria vulgaris, Plantago major), Poaceae (Zea mays), Polygonaceae (Polygonum aviculare), and Ranunculaceae (Nigella sativa). We determined Artemisia absinthium, Inula helenium, Matricaria chamomilla, Salvia officinalis, and Populus nigra, whose aqueous solutions of alcohol tinctures demonstrated nematocidal properties. The other plants we studied did not affect the viability of parasitic nematode larvae. Full article

Background/Objectives: Animal health remains a critical issue that directly impacts economic sustainability through animal welfare and production. In small ruminants, the gastrointestinal parasite Haemonchus contortus can lead to anemia and possibly mortality, since parasite burden can be considerable and is challenging to control. Small ruminant health can be affected by poor diet and environmental conditions that lead to changes in the metabolic balance. The link between animal health and metabolic profiles has been investigated in the past. These studies have shed important light on physiological changes by identifying dietary and disease biomarkers. This study aimed to correlate the metabolite signature of feces from goats, having two levels of Haemonchus contortus infection, grazing on two different forages (Bermudagrass and Sunn Hemp). Methods: Fecal samples were taken from goats grazing either Sunn Hemp or Bermudagrass pastures, with naturally variable Haemonchus contortus loads. Samples were evaluated using ¹H-NMR and LC/MS methods to describe and compare metabolic patterns under varied forage conditions between low and high Fecal Egg Count (FEC). Results: Our findings indicated no significant difference using univariate analyses but identified 10 discriminatory features using multivariate analyses for Bermudagrass and Sunn Hemp using ¹H-NMR. With LC-MS, we found 14 significantly different features (p < 0.05, FC > 2), 115 discriminatory features for Bermudagrass and 113 in Sunn Hemp from multivariate analyses. Combining the findings of the two approaches suggested that Haemonchus contortus influenced several pathways associated with the metabolism of amino acids and energy conversion. Conclusions: The analysis of metabolome changes across both forages may help in revealing novel knowledge and accurate identification of possible biomarkers for gastrointestinal parasites. Further study is needed to validate the potential biomarker before deploying diagnostic tools based on the metabolomics indicators for early parasite diagnosis. Full article

Australian plants of the family Haemodoraceae have been a reliable source of new secondary metabolites, particularly those of the ‘phenylphenalenone’ class, and related chromenes and xanthones. Some of these compounds demonstrate anti-microbial properties against both Gram-negative and Gram-positive bacteria. Chemical profiling of thirty individual ethanolic extracts from six separate species of Australian plants belonging to the family Haemodoraceae was conducted using an HPLC-MS approach reinforced by HRLC(ESI)-MS. Six of the extracts were further explored by employing HRLC(ESI)-MS and the compounds present were characterised and confirmed based on a comparison to the original data. All thirty extracts were assessed for biological activity against the parasitic nematode Haemonchus contortus in vitro. The chemical profiling methodology adopted resulted in the identification of thirty-four previously reported compounds, identifying on average 64% of the previously reported secondary metabolites across the species Haemodorum simulans, Haemodorum spicatum, Haemodorum brevisepalum and Macropidia fuliginosa. Furthermore, compounds from the phenylbenzoisoquinolindone class were detected in the bulbs of Haemodorum simulans and Haemodorum coccineum, representing the first report of the structure class in extracts of the genus Haemodorum. Extracts of the H. simulans stems, M. fuliginosa bulbs and H. distichophyllum roots and bulbs exhibited anthelmintic activity in vitro. The chemical profiling HPLC-MS methodology adopted was successful in the rapid identification of most of the previously reported secondary metabolites across the Haemodoracae species, indicating that the analytical approach was robust. This study demonstrates the effectiveness of dereplication via HPLC-MS-based chemical profiling across six Australian Haemodoraceae species, identifying numerous known and putatively novel secondary metabolites. It also reports, for the first time, anthelmintic activity in selected species and marks the first detailed phytochemical investigation of H. distichophyllum since its initial pigment analysis over 50 years ago. Full article

Gastro-intestinal nematodes (GINs) are still of great concern in grazing ruminants, such as camelids, ovines and caprines, affecting animal health and productivity. This is mainly due to the development of anthelmintic resistance (AR) to the compounds used long term, without much evaluation on their efficacy, including ivermectin (IVM), the most used anthelmintic drug in livestock. The aims of this study were to determine the efficacy of IVM and identify which GIN species are affecting different ruminant farms in Quebec (QC), Canada. Firstly, we collected fecal samples from six farms with different ruminant species (camelids, goats and sheep) before and after IVM treatment when applicable, analyzing them by Fecal Egg Count (FEC) and further assessments on IVM efficacy through the Fecal Egg Count Reduction Test (FECRT). In addition, molecular analyses were conducted using PCR, targeting the ITS-2 and COX-1 genes to identify GIN species. FECRT was applied only for three farms, showing that variable results with optimal efficacy (ranging from 95.5–100%) were obtained in only one farm, whereas on the other two farms, FECRT exhibited reduced efficacy, suggesting the development of IVM resistance. Among the GIN species found, Haemonchus contortus and Trichostrongylus vitrinus were identified in most of the farms, being present in sheep, goat, llama and alpaca farms, whereas Teladorsagia circumcincta was identified only in sheep and llama samples from four farms but not in alpaca samples. Trichostrongylus axei and Chabertia ovina were present in two farms (sheep and sheep and llamas). Oesophagostomum venulosum was detected in one sheep and one alpaca farm. Only one sheep farm was positive for Trichostrongylus colubriformis and Cooperia curticei. Also, Nematodirus spp. and Trichuris spp. were found in four farms, including sheep and camelids. In addition, three other species were found in camelids, including Camelostrongylus mentulatus (only in the llama samples), whereas Lamanema chavezi and Marshallagia marshalli were identified in one alpaca farm. Therefore, our work reports evidence of an uneven efficacy of IVM against GINs from ruminant farms, including the most likely emergence of IVM resistance. The diversity of GIN species found in ruminant farms in QC along with the inconsistent IVM efficacy are helpful information for veterinarians and animal producers in setting an optimal parasite management programs, including the proper use of IVM and alternative anthelmintic drugs to control these pathogens in grazing livestock. Full article

Haemonchus contortus and Haemonchus placei infect different species of ruminants, but when small ruminants and cattle share the same pasture, cross-infections can occur. Weather conditions and the herbage microenvironment influence the development and survival of larvae during the free-living stage. Development of free-living stages (eggs, L1, L2, and L3) for both nematode species in sheep faeces deposited on short grass (4 cm) and tall grass (60 cm) ground was evaluated during nine days at the beginning of the rainy season. Rainfall occurred during five of the nine days assessed, and the tall and short grass environments demonstrated different temperatures, with a maximum of 34.0 °C to 42.0 °C and 31.0 °C to 38.0 °C and a minimum of 12.0 °C to 17.0 °C and 10.0 °C to 24.5 °C for the short and tall grass, respectively. Due to the development of eggs into infective larvae (L3), decreased egg counts were observed over time in faecal samples from both species and environments. However, some eggs were still present in samples until eight days post-deposition among tall grass. In both environments, the development times for all larval stages were similar. Small numbers of H. contortus larvae were found in the soil and grass, whereas no H. placei larvae were found. In conclusion, the trend of development in different environments was similar for both nematode species; however, the tall grass environment provided better conditions for the development of larval stages of both Haemonchus species. Full article