Haemonchus Contortus Larvae Research Articles

Bacillus thuringiensis Cry14A family proteins as novel anthelmintics against gastrointestinal nematode parasites.

Bacillus thuringiensis crystal (Cry) proteins have been expressed in commercial transgenic crops for nearly 30 years, providing safe and effective control of insect pests and significantly reducing the application of hazardous chemical pesticides. B. thuringiensis crystal proteins have also been shown to target parasitic nematodes, including plant parasitic nematodes. Recently, transgenic soybean crops expressing Cry14Ab have been shown to provide control against the soybean cyst nematode Heterodera glycines, marking the first time a crystal protein is being commercialized in transgenic crops for control of a nematode pest. However, apart from H. glycines and the free-living nematode, Caenorhabditis elegans, the breadth of nematode activity of Cry14Ab, e.g., against gastrointestinal parasitic nematodes (GINs), has not been reported. Here we study the efficacy of Cry14Ab against a wide range of gastrointestinal nematode parasites (GINs) in vitro and in vivo. We find that Cry14Ab is effective in vitro against the barber's pole worm Haemonchus contortus larvae, small strongyles cyathostomin larvae, the hookworm Ancylostoma ceylanicum adults, the roundworm Ascaris suum L4 larvae, and the whipworm Trichuris muris adults. In rodents infected with GIN parasites, Cry14Ab is effective as an in vivo anthelmintic against the hookworms A. ceylanicum and N. americanus, against the mouse parasite Heligmosomoides polygyrus bakeri, and against the roundworm A. suum. Cry14Ab also variably reduces the reproduction of the whipworm T. muris in vivo. Using optimized profile Markov Models, we looked for other putative anthelmintic Cry proteins and, within this list, identified a Bt crystal protein, GenBank accession no. MF893203, that we produced and demonstrated intoxicated GINs. This protein, with 90% amino acid identity to Cry14Ab, is active against C. elegans, A. ceylanicum adults, and A. suum L4 larvae in vitro. MF893203 was given the official designation of Cry14Ac. Cry14Ac is also an effective in vivo anthelmintic against A. ceylanicum hookworms in hamsters and intestinal A. suum in mice. Taken together, our results demonstrate that Cry14Ab and Cry14Ac have wide therapeutic utility against GINs.

Effectiveness of benzimidazole treatments against Haemonchus contortus in sheep and goats – Do they produce similar responses?

The primary aim of this study was to compare the in vivo responses to orally administered doses of albendazole (5 mg/kg body weight) between experimentally infected sheep and goats. Fifty-four Improved Valachian lambs and 54 Saanen goat kids were split into six groups of nine animals. The sheep and goats were infected with larvae of the gastrointestinal nematode parasite Haemonchus contortus containing 10, 20, 30, 40, 60, and 80 % of the isotype-1 β-tubulin gene codon 200 alleles previously shown to be associated with benzimidazole (BZ)-resistance. All groups of goats generally had higher mean eggs per gram (EPG) before treatment, which was significant (p<0.05) only for the group with 80 % resistance alleles. An in vivo faecal egg reduction test (FECRT) was used to determine the efficacy of albendazole (ABZ) eight days after treatment. Anthelmintic treatment significantly reduced the EPGs in the groups with 10, 20, and 80 % resistance alleles in sheep and with 10, 20, 30, and 40 % resistance alleles in goats. Differences in efficacy between the sheep and goats after the application of doses of ABZ recommended for sheep mostly ranged from 2 % to 10 %. The largest variation was in the group infected with worms containing 60 % resistance alleles, where the efficacy was 13 % higher in goats. Our secondary aims were to evaluate the data obtained from an in vitro egg hatch test (EHT) in sheep and goats and to compare these data with the results from the isotype-1 β-tubulin gene codon 200 pyrosequencing and the FECRT. The percentages of the BZ-resistance alleles were comparable with the mean hatching obtained in the EHT and were also supported by the FECRT data for all groups. The results of the in vivo tests should be verified in the future using in vivo surveys conducted in mixed breeds and infections in multiple species.

Phytochemicals, antioxidant ability and in vitro anthelmintic activity of crude extracts from Vitexnegundo leaves against Haemonchus contortus.

The aim of this study was to evaluate the in vitro anthelmintic effect of crude aqueous, methanol, ethanol, hydro alcohol and acetone extracts of Vitex negundo leaves against Haemonchus contortus eggs and larvae. Phytochemical analysis to identify the number of compounds in extracts was done by chemical tests and gas chromatography coupled to a mass spectrophotometer detector (GC-MS). First off all the effectiveness of dried plant materials was evaluated on larval development by mixing powdered material (no nano particles) to faecal cultures from donor sheep. Adding powder to the faecal culture resulted into 100% inhibition in larval development at 200 and 300mg/g of faeces. The anthelmintic activity was assessed using the egg hatch assay (EHA) and the larval mortality assay (LMA). Comparison of mean inhibition percentage of egg embryonation, mean inhibition percentage of egg hatching and mean percentage of larval mortality at different concentrations with control was performed by one-way ANOVA. The means were compared for statistical significance using DMRT at P < 0.05. For both the assays, 50% inhibitory concentration (IC50) and lethal concentration (LC50) were calculated by probit analysis. Chemical test revealed presence of high concentration of saponin and flavoinoids and moderate concentration of total phenols in leaves. The antioxidant activity (radical scavenging activity, RSA %) measured was 35.47%. On GC-MS, the methanolic leaves extract revealed 30 phyto-compounds. On EHA, there was marked effect on inhibition of egg hatching by aqueous, hydro alcohol and acetone extracts. On LMA all the five extracts showed excellent larvicidal activity. V. negundo leaves methanol extract mediated silver nanoparticles were found very effective at much lower concentrations as compared to crude methanol extract. The results indicated that the V. negundo leaves crude extracts possessed excellent in vitro ovicidal and larvicidal properties against H. contortus which needs more investigation, especially in vivo trials for the control of parasite.

Crude Extracts of Pleurotus Spp. and the Presence of Their Proteins in the Ovicidal and Larvicidal Activity of Haemonchus contortus.

Mushrooms of the genus Pleurotus have shown nematophagous activity as it produces many chemical compounds and enzymes affecting parasitic nematodes. This study aimed to extract the inhibitory activity of the five strains of the fungus Pleurotus spp. It was evaluated against eggs and larvae of Haemonchus contortus. The extract of P. ostreatus obtained the highest level of inhibition of eggs at 97.6% (1341 μg/mL) followed by P. pulmonarius (EPP) at 81.2% (774 μg/mL). The extract selected for evaluation against larvae was P. pulmonarius, showing no effect for L3 larvae, but for L4 larvae an immobility effect of 56.93% was observed at 900 μg/mL. The protein profile showed the presence of 23 protein bands in the extract. The crude extract of P. pulmonarius showed degradation of tissues both inside the eggs and larvae L1. Metabolites produced by Pleurotus mushrooms can consider using in agriculture sustainable by utilizing in producing of ovicidal and larvicidal against H. contortus instead of chemical compounds.

50 Effects of cottonseed supplementation on the rumen microbiota of parasite-challenged meat goats

Abstract Cotton serves as a vital economic driver within the agricultural sector of Mississippi. The seeds of cotton are rich in fat and protein content, making them a cost-effective alternative to soybean meal and other expensive protein sources. Additionally, cottonseed is the primary source of gossypol, a phenolic compound with significant potential for natural parasite control. The rumen microbiota, a diverse community of microorganisms, has a pivotal role in nutrient digestion and detoxification. However, the impact of cottonseed on rumen microbial ecosystems remains largely unexplored. The aim of this study is to investigate the effects of cottonseed supplementation on the rumen microbiota of meat goats with and without the challenge of parasites. Forty female weaned Boer × Spanish crossed meat goats were assigned to one of the four treatments (n = 10 per treatment) in a 2 × 2 factorial design consisting of control group (CON), parasite challenge group (P), cottonseed supplementation (0.5% body weight) without parasite challenge group (CS-NP), and CS supplementation with parasite challenge group (CS-P). The parasite challenge was performed with a dose of 4,000 infective third-stage larvae of Haemonchus contortus per animal. After 25 d following the first dose, the treatments were applied for 10 wk. The goats were slaughtered at the end of the experiment, and rumen digesta samples were collected for microbiota analysis using high-resolution full-length 16S rRNA gene amplicon sequencing. The results revealed that the parasite challenge significantly reduced the number of bacterial species in the rumen (P = 0.032), regardless of cottonseed supplement. Anaeromassilibacillus senegalensis, which has been isolated from kwashiorkor (severe protein malnutrition) patient, Hungateiclostridium aldrichii, and Mogibacterium diversum were enriched in rumen of P group, while Anaerocella delicata and the rumen lipolytic organism Anaerovibrio lipolyticus were reduced compared with the CON group [linear discriminant analysis (LDA) scores &amp;gt; 3.6]. Cottonseed supplementation did not affect the number of bacterial species in the rumen of parasite-challenged goats, but it did lead to an increase of Anaerovibrio lipolyticus (P = 0.008) and a reduction of Anaeromassilibacillus senegalensis (P = 0.007). Moreover, cottonseed supplementation tended to increase the number of bacterial species in the rumen of meat goats without parasite challenge (P = 0.08) and increased the relative abundance of butyrate-producing bacteria such as Pseudobutyrivibrio xylanivorans and Intestinimonas butyriciproducens, along with the butanol-producing bacteria Clostridium saccharoperbutylacetonicum (LDA scores &amp;gt; 2). Conversely, cottonseed supplementation inhibited cellulolytic bacteria Fibrobacter succinogenes, polysaccharide-degrading bacteria Butyrivibrio proteoclasticus, and several Prevotella species, including P. oris, P. loescheii, P. copri, and P. albensis (LDA score &amp;gt; 2). In conclusion, parasite challenge affects the rumen microbial diversity and certain bacterial species that utilize protein and lipids, and cottonseed supplementation partially restores the altered rumen microbial ecosystem of the parasite-challenged meat goats.

Ovicidal, larvicidal and adulticidal activity of black pepper (Piper nigrumL.) essential oil and tea tree oil (Melaleuca alternifolia) against Haemonchus contortus.

Haemonchosis is a worldwide helminthic disease affecting ruminants. The anthelminthic resistance has become raised. Medicinal plants are safely used as synthetic anthelmintics. Currently, the efficacy of black pepper essential oil (BPO) and tea tree oil (TTO) were in vitro evaluated against Haemonchus contortus adults, eggs and larvae at concentrations of 1.25, 2.5 and 5mg/ml in addition to the commercially used albendazole at a concentration of 10μg/ml. Oils were used in both normal and nanoparticles-loaded forms. Oxidative stress enzymes of worms were estimated. Scanning electron microscopy (SEM) for treated worms was done. Both normal and nanoemulsion forms of both BPO and TTO stopped the adult motility [BPO 2.5h (hrs), NBPO 1.5h, TTO 3h, NTTO 1.5h] and induced a marked decrease in the oviposition. Post treatment, the egg development and hatching were significantly (P ≤ 0.05) reduced. The damage of the egg shell, embryonal cessation and destruction of larvae occurred. Noticeable elevated antioxidant enzymes (catalase CAT, glutathione transferase GST and glutathione GSH) were found, while oxidative enzymes (lipid peroxidation LPO and nitric oxide synthase NOS) decreased. Scanning electron microscopy (SEM) for both oil-treated worms revealed anterior ends damage and several cuts associated with cuticular pores. The use of albendazole induced more or less anthelmintic and enzymatic activities with less morphological alterations of adults revealed by SEM. This study proved the marked anthelmintic potency of the BPO and TTO and their nanoemulsion forms against H. contortus rather than the widely used anthelmintic drugs.

Chlamydospore dormancy and predatory activity of nematophagous fungus Duddingtonia flagrans.

The chlamydospores of Duddingtonia flagrans are an essential survival and reproductive structure and also an effective ingredient for the biocontrol of parasitic nematodes in livestock. In this study, entering and exiting dormancy conditions and predatory activity of the fungal chlamydospores were conducted. During this fungal growth process, the cultivation time is negatively correlated with spore germination rates. After the spores were processed by vacuum drying for 168 h, their germination rate dropped to 0.94%. In contrast, the percentage of living spores remained 54.82%, suggesting that the spores entered structural dormancy in the arid environment. Meanwhile, the efficacies of the spore against Haemonchus contortus larvae were 93.05% (0 h), 92.19% (16 h), 92.77% (96 h), and 86.45% (168 h), respectively. After dormant spores were stored at 4°C, -20°C, and 28°C (RH90 ~ 95%) for 7 days, their germination rate began to increase significantly (p < 0.05). For in vitro predation assay under the condition of 28°C (RH90 ~ 95%), the predation rate was significantly higher on the 7th day after incubation than that on the 3rd day (p < 0.05). During the period when spores were stored at room temperature for 8 months, their germination rate decreased in the first 5 months and then increased slowly to reach a peak in the 7th month. However, the reduction rate of H. contortus L3 in feces captured by spores remained above 71% for the first 7 months. These results will help us increase the end products yield and the quality of biological control of parasitic nematodes in livestock.

Molecular interaction analysis of the lignans from Piper cubeba in complex with Haemonchus contortus phosphomethyltransferase

In vitro larvicidal assays carried out previously by our research group with cubebin, dihydrocubebin and hinokinin, lignans extracted from the fruits of Piper cubeba, against Haemonchus contortus larvae showed strong action larvicidal these compounds. Hinokinin was the most active (EC50 = 0.34 µg/mL) with strong action on the cuticle of the larvae as observed by scanning electron microscopy of the L3 stage. Therefore, to understand the mechanism of action of these compounds in silico studies were carried out using the enzyme phosphomethyltransferase of Haemonchus contortus that contain PMT-1 and PMT-2 di-domains responsible for phosphocholine synthesis, which is one of the main lipids in nematodes. This pathway is not found in mammals, so this enzyme is an important biological target for the development of new anthelmintics. Results of molecular docking, molecular dynamic and a density functional theory calculations studies with the three lignans show few interactions with PMT-1. However, hinokinin has important interactions with PMT-2, that can deactivate the enzyme and interrupt the phosphocholine synthesis, which is an essential compound for the development and maintenance of the nematode cuticle and its survive. Therefore, the previous results of the in vitro assay allied with in silico results, now realized; suggest that hinokinin may be a possible selective target for the development of new anthelmintics against Haemonchus contortus since the PMT-2 domain is present in this nematode.

Genome-Wide Analysis of Sheep Artificially or Naturally Infected with Gastrointestinal Nematodes.

The anthelmintic resistance of gastrointestinal nematodes (GINs) poses a significant threat to sheep worldwide, but genomic selection can serve as an alternative to the use of chemical treatment as a solution for parasitic infection. The objective of this study is to conduct genome-wide association studies (GWASs) to identify single nucleotide polymorphisms (SNPs) in Rambouillet (RA) and Dorper × White Dorper (DWD) lambs associated with the biological response to a GIN infection. All lambs were genotyped with a medium-density genomic panel with 40,598 markers used for analysis. Separate GWASs were conducted using fecal egg counts (FECs) from lambs (<1 year of age) that acquired their artificial infections via an oral inoculation of 10,000 Haemonchus contortus larvae (n = 145) or naturally while grazing on pasture (n = 184). A GWAS was also performed for packed cell volume (PCV) in artificially GIN-challenged lambs. A total of 26 SNPs exceeded significance and 21 SNPs were in or within 20 kb of genes such as SCUBE1, GALNT6, IGF1R, CAPZB and PTK2B. The ontology analysis of candidate genes signifies the importance of immune cell development, mucin production and cellular signaling for coagulation and wound healing following epithelial damage in the abomasal gastric pits via H. contortus during GIN infection in lambs. These results add to a growing body of the literature that promotes the use of genomic selection for increased sheep resistance to GINs.

Effect of Ivermectin on the Expression of P-Glycoprotein in Third-Stage Larvae of Haemonchus contortus Isolated from China.

Haemonchus contortus poses a severe hazard to the healthy development of the sheep industry and threatens the welfare of sheep. Ivermectin is the primary anthelmintic used for the prevention and treatment of H. contortus parasitism. However, the widespread and uncontrolled application of ivermectin has resulted in the development and spread of resistant strains of H. contortus. P-glycoprotein (P-gp) plays important roles in the pharmacology and toxicology of ivermectin, and changes in P-gp expression levels can be used to analyze the resistance of H. contortus to ivermectin. This study aimed to analyze the effects of ivermectin on P-gp expression in H. contortus L3 larvae isolated from China and to evaluate whether changes in P-gp expression levels can be used to analyze resistant H. contortus strains. In the absence of drug treatment, the ivermectin-resistant strains isolated in China showed increased expression of P-gp11 (p < 0.01) compared with sensitive strains from elsewhere, whereas the expressions of P-gp2 and P-gp9.1 were downregulated (p < 0.01). When the same strain was compared before and after drug treatment, obvious differences in expression were observed between the different strains. Ivermectin-induced P-gp expression was found to be very complex among the L3 larvae of different strains. In addition, it was confirmed that using P-gp to determine ivermectin resistance in H. contortus strains from different geographic environments can yield different results.

Using a Bioactive Eremophila-Derived Serrulatane Scaffold to Generate a Unique Carbamate Library for Anti-infective Evaluations.

The known Eremophila microtheca-derived diterpenoid 3,7,8-trihydroxyserrulat-14-en-19-oic acid (1) was targeted for large-scale purification, as this bioactive plant compound has proven to be an attractive scaffold for semisynthetic studies and subsequent library generation. Compound 1 was converted to a selectively protected trimethyl derivative, 3-hydroxy-7,8-dimethoxyserrulat-14-en-19-oic acid methyl ester (2), using simple and rapid methylation conditions. The resulting scaffold 2 was reacted with a diverse series of commercially available isocyanates to generate an 11-membered carbamate-based library. The chemical structures of the 11 new semisynthetic analogues were fully characterized by spectroscopic and spectrometric analysis. All natural products and semisynthetic compounds were evaluated for their anthelmintic, antimalarial, and anti-HIV activities. Compound 3 was shown to elicit the greatest antiplasmodial activity of all compounds tested, with IC50 values of 4.6 and 11.6 μM against Plasmodium falciparum 3D7 and Dd2, respectively. Compound 11 showed the greatest inhibition of development to fourth-stage Haemonchus contortus larvae (L4) and induction of a skinny (Ski) phenotype (67.5% of nematodes) at 50 μM. Compound 7, which inhibited 59.0% of HIV production at 100 μg/mL, was the carbamate analogue that displayed the best antiviral activity.

Effect of Temperature on Egg Hatching and Development of Infective Larvae of Haemonchus contortus at Fixed Relative Humidity

Effect of Temperature on Egg Hatching and Development of Infective Larvae of Haemonchus contortus at Fixed Relative Humidity

Using UHPLC-MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library.

In order to further expand the NatureBank open access compound library, chemical investigations of the Australian marine sponge, Ianthella basta, were undertaken since UHPLC-MS analysis of the extract from this sponge indicated the presence of a new alkaloid. Large-scale extraction and mass-directed isolation studies on the CH2Cl2/MeOH I. basta extract resulted in the purification of a new bromotyrosine-derived alkaloid, 5-debromopurealidin H (1), along with the known marine natural product, ianthesine E (2). The chemical structure of the new compound was determined following detailed spectroscopic and spectrometric data analysis. These two compounds (1 and 2) along with seven previously reported marine bromotyrosine alkaloids from the NatureBank open access library, which included psammaplysins F (3) and H (4), bastadins 4 (5), 8 (6) and 13 (7), aerothionin (8) and hexadellin A (9), were evaluated for their nematocidal activity against exsheathed third-stage larvae of Haemonchus contortus, a highly pathogenic parasite of ruminants. Of the nine compounds, bastadin 8 (6), hexadellin A (9) and bastadin 4 (5) showed inhibition towards larval motility after 72 h of exposure with IC50 values of 1.6 µM, 10.0 µM and 33.3 µM, respectively.

Anthelmintic Activity, Cytotoxicity, and Phytochemical Screening of Plants Used to Treat Digestive Parasitosis of Small Ruminants in Benin (West Africa).

Simple SummaryIn the present study, we explored the anthelmintic activity, cytotoxicity, and chemical composition of the main plants used by small ruminant breeders in Benin to treat digestive parasitosis. The results obtained are relevant in the sense that they will allow a rational use of the plants studied in the control of digestive parasites but also to initiate the process of identification of new anthelmintic molecules in the context of the development of resistance against the most currently used anthelmintic molecules.Medicinal plants continue to be used alone or in combination with veterinary drugs to treat animal ailments, especially in developing countries where livestock farmers often lack access to modern veterinary services and drugs. In addition, digestive parasitosis remain a major constraint for small ruminant livestock. The objective of this study was to screen the anthelmintic activity of the main plants used in the treatment of the digestive parasitosis of small ruminants in Benin. A total of 40 extracts were prepared using the successive maceration of 10 plants in four solvents of increasing polarity. The phytochemical screening of the plants was performed, and the anthelmintic activity of the extracts was evaluated on L3 larvae of Haemonchus contortus. The cytotoxicity of the 40 extracts was determined on WI38 noncancerous fibroblast cells using the MTT assay, and the total phenol content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) were quantified in the most effective extracts using colorimetric methods. The results show that the plants contained tannins, flavonoids, and triterpenoids which may, in part, justify their anthelmintic activities. All plants gave active extracts at the highest concentration tested (1200 µg/mL). Methanol (MeOH) extracts were, in general, more effective than the hexane (HEX), dichloromethane (DCM), and aqueous (H2O) ones in inhibiting larval migration, with the MeOH extracts of Terminalia leiocarpa, Adansonia digitata, and Momordica charantia being the most effective. Nevertheless, the MeOH extract of M. charantia was highly cytotoxic at the concentration of 100 µg/mL. The anthelmintic activity of M. charantia, Vitex doniana, and Caesalpinia bonduc was studied on H. contortus for the first time. These results provide scientific information that can be used for better valorization of the anthelmintic potential of the studied plants and to initiate the process of the identification of new anthelmintic molecules.

Bio-directed Chemical Study of Pleurotus ostreatus Spent Substrate and Its Nematicidal Activity.

In the present study, the nematicidal activity of the chemical fractionation of the spent substrate of the edible mushroom Pleurotus ostreatus against eggs and L3 larvae of Haemonchus contortus was evaluated. The hydroalcoholic extract of the spent substrate was subjected to a bipartition with ethyl acetate giving two fractions: one aqueous (F. Ac) and one organic (F. AcOET). Both fractions were evaluated against eggs and L3 larvae at different concentrations (5, 2.5, 1.25, 0.625 and 0.3125mg/mL) and 2% methanol, PBS and thiabendazole (5mg/mL) as controls. Chemical fractionation of F. AcOET was performed in open column chromatography where 76 fractions were obtained and when analyzed by thin layer chromatography (TLC) were grouped into 11 mixtures (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11). These mixtures were evaluated at 10mg/mL against eggs and L3 larvae. The data obtained were analyzed by ANOVA and a Tukey test in the SAS V9 program. The results showed that, in the evaluation of F. AcOET and F. Ac, for the inhibition of egg hatching, the highest percentages were 78.80 and 76.89% at 5mg/mL, respectively. As for the percentage of larval mortality, F. AcOET obtained 60.91 and F. Ac 29.77% at 5mg/mL. The results of the evaluations of the mixtures showed that mixtures R4, R5 obtained 100 and 95.41% larval mortality and mixtures R6 and R7 presented 100% inhibitory activity of egg hatching, so these were analyzed by gas chromatography mass spectrometry finding compounds such as vanillin, β-sitosterol, ρ-methyl ρ-hydroxycinnamate and ρ-hydroxybenzaldehyde. The results of the present study demonstrate that the spent substrate of P. ostreatus has potential anthelmintic activity against H. contortus. Moreover, by reusing and taking advantage of this substrate, its environmental pollution effects can be reduced.

Hematological, biochemical alterations and methane production in sheep submitted to mixed infection of Haemonchus contortus and Trichostrongylus colubriformis

The main current concern in ruminant production is focused on sustainability. In this sense, the objective was to evaluate ruminal fermentative alterations and methane (CH4) production, as well as hematological and biochemical alterations in sheep submitted to a single mixed infection with 10,000 infective larvae (L3) of Haemonchus contortus and 30,000 L3 of Trichostrongylus colubriformis. Twenty castrated males Santa Inês sheep, seven months old averaging 30.8 ± 6.41 kg of body weight were used. Ten animals were infected, and ten animals were uninfected, in a completely randomized design. During the experimental period, blood and ruminal content samples were collected, as well as the leftovers and diet provided. Enteric methane (CH4) production of the animals was measured at the end of the experiment. Parasitic infection affected dry matter intake, decreased red blood cell count, hemoglobin, and packed cell volume (PCV), and increased eosinophils and platelets numbers (P < 0.05). Ruminal fermentative changes were also observed, with changes in the short-chain fatty acid (SCFA) production profile, increase in propionate and decrease in acetate, and higher CH4 production in infected animals. Thus, it is concluded that H. contortus and T. colubriformis mix infection in sheep reduces forage dry matter consumption, causes hematological changes and ruminal fermentation patterns, impairing nutritional metabolism with greater CH4 production by infected animals.

Eucalyptus oil nanoemulsions against eggs and larvae of Haemonchus contortus

Haemonchus contortus is a highly pathogenic and prevalent helminth that causes many deaths in sheep herds. Anthelmintics are usually employed to overcome this issue; however, they do not guarantee immediate and lasting efficacy because of the occurrence of drug-resistant parasites. Among substances that are used in scientific studies for parasitic control, essential oils are known to have different pharmacological properties. However, they demonstrate instability owing to several factors, and therefore, nanoemulsification is considered an alternative to control the instability and degradability of these compounds. The objective of this study was to evaluate the cytotoxicity of nanoemulsions containing essential oil of Eucalyptus globulus against the blood of healthy sheep and to verify their activity against the parasite H. contortus in sheep. The results presented adequate nanotechnological characteristics (diameter 72 nm, PDI 0.2, zeta −11 mV, and acidic pH) and adequate morphology. Further, the corona effect and cytotoxic profiles of the free oil and nanoemulsion against blood cells from healthy sheep were evaluated. The tests results did not present a toxicity profile. For evaluating efficacy, we observed an important anthelmintic action of the nanoemulsion containing oil in comparison to the free oil; the results demonstrate a potential role of the nanoemulsion in the inhibition of egg hatchability and the development of larvae L1 to L3 (infective stage). Based on these results, we developed an important and potential anthelmintic alternative for the control of the parasite H. contortus.

Comparative study on pathological changes in sheep and goats experimentally infected with Haemonchus Contortus

BackgroundThe parasites causes localized and generalized infections to the host depends on the parasite attachment organs, depth of penetration, site of location and worm burdens.MethodsThe experimental study was done between December, 2019 and April, 2020 in the fly-proof experimental animal facility located in the premise of the College of Veterinary Medicine and Agriculture at Bishoftu, Ethiopia. A total of 14 male goat (G1 and G2) and 14 male sheep (G3 and G4) were allotted in to four equal groups. Single dose of 10,000 of infective larvae of Haemonchus contortus (L3) was orally administered to each animal in G1 and G3. Parameters such as body weight, PCV, haemoglobin, worm count, serum total protein, serum albumin, alkaline phosphatase and aspartate aminotransferase were measured. Moreover, histopathological sections were stained and examined for general changes as well as for changes in specific cells such as tissue eosinophilia and parietal cell population.ResultsThe findings show that 1) All infected sheep and goats developed the infection with higher mean worm burden in goats (5590) than sheep (2887) and the difference was significant (P < 0.05); 2) All infected sheep and goats exhibited a progressive anaemia; the level being more severe in goats than in sheep (P < 0.05) with mean PCVs of 13 and 18.6% respectively; 3) While body weight gain was minimal in sheep, goats have lost significant weight compared to pre-infection levels, to control animals or in relation to infected sheep (P < 0.05); 4) analysis of biochemical changes revealed marked reduction in serum total protein and albumin which was much more significant in goats than in sheep (P < 0.05); 5) the abomasum of infected sheep and goats have shown thickening, nodule development, eosinophilic infiltration and damage to parietal cells. Tissue eosinophilia was more prominent in sheep while parietal cell loss was severe in goats.ConclusionIn conclusion, goats under experimental infection and similar management condition with sheep develop much more severe infection and associated pathology compared to sheep and hence deserve special attention.

IN VITRO STUDY OF Vitex gardneriana SCHAUER TOXICITY ON Artemia salina AND ITS EFFECT ON EGGS AND LARVAE OF Haemonchus contortus

This research aimedto investigate the toxic action of Vitexgardneriana on microcrustacean Artemiasalina by using hydroalcoholic extract fromleaves (EHF) and acute toxicity test (CL50)concentrations of 100, 500, 1.000, 10.000,20.000, and 50.000/mL. Sodium hypochlorite(NaClO) at 1% was used as positive control,and saline and 1% DMSO were used asnegative control. Vitex gardneriana showedlow toxic potential, with 50% mortality inthe microcrustacean metanauplii population(concentration: 34.600 mg/mL). A. salina isa seawater microcrustacean widely used inbioassays for determining the toxic dose ofbioactive substances because of its low costsand its related simple, aseptic procedures. Todetermine the toxic action of the hydroalcoholicextract of V. Gardneriana on eggs and larvaeof Haemonchus contortus, 2,5mL of EHF witha concentration of 34,600 mg/mL were addedinto single-species nematode fecal culturescontaining approximately 12.000 eggs. Only26,6% of the eggs hatched, correspondingto an EHF efÀ ciency of 73,3%, whereas thehatchability was 50% in control, with 6.000larvae recovered. The À ndings show thepotential of this plant as an alternative inparasite control.

The industrial process of solvent extraction of castor oil reduces the toxicity of the meal

Castor (Ricinus communis L.) oil is an important raw material for the chemical industry. The industrial process of castor oil extraction exposes the material to chemical, thermal, and mechanical treatments that influence the properties of the proteins in the meal. This study tested the hypothesis that the regular industrial process of castor oil extraction with solvent changes properties of the meal like the profile of proteins, the nematicide efficiency, and its toxicity. The changes made by the process of oil extraction create opportunities for adding value to this by-product. Samples of castor cake and meal were collected along the process of oil extraction under the regular operation of an industry. The samples were analyzed for chemical composition, hemagglutination activity, nematicide efficiency, and toxicity for feeding broilers and sheep. It was found that the step of solvent evaporation is responsible for the most relevant modifications in the meal, with significant changes in the protein profile, loss of hemagglutination capacity, and reduction of toxicity and nematicide efficiency. The castor meal produced just after the solvent evaporation has the toxicity reduced to a level that was tolerable to be used in the ration of small ruminants without detectable loss of performance or clinical signs of intoxication. The castor meal was toxic for broilers. The nematicide capacity of castor meal against larvae of Haemonchus contortus is reduced after the step of solvent extraction, but it is still significant and detected in doses as low as 5 mg/g. When castor meal was separated in fractions by sieving, the fine fraction (particles smaller than 0.5 mm) had high protein content (60.2%), low fiber content (6.0%), and high water holding capacity (164.2% of its dry weight).