| synthesis of photoreactive ivermectin b1a derivatives and their actions on haemonchus and bombyx glutamate-gated chloride channels. | glutamate-gated chloride channels (glucls) are inhibitory neurotransmitter receptors that are present only in invertebrates such as nematodes and insects. these channels are important targets of insecticidal, acaricidal, and anthelmintic macrolides such as avermectins, ivermectin (ivm), and milbemycins. to identify the amino acid residues that interact with ivm in glucls, three ivm b1a derivatives with different photoreactive substitutions at c-13 were synthesized in the present study. these der ... | 2015 | 25987225 |
| effects of third generation p-glycoprotein inhibitors on the sensitivity of drug-resistant and -susceptible isolates of haemonchus contortus to anthelmintics in vitro. | p-glycoproteins (p-gps) play an important role in the sensitivity of nematodes to anthelmintic drugs. they have been implicated in a number of anthelmintic resistances, particularly for macrocyclic lactone drugs. hence, inhibition of nematode p-gps has been suggested as a means of reversing some types of anthelmintic resistance. the present study aimed to investigate the ability of the most-recently developed group of p-gp inhibitors (the so-called 'third generation' of inhibitors) including tar ... | 2015 | 25986327 |
| serum interleukin-4 (il-4) production is associated with lower fecal egg count in parasite-resistant sheep. | the objective of this experiment was to determine serum interleukin-4 (il-4) concentration in response to haemonchus contortus infection in parasite-resistant and -susceptible lambs. st. croix (stc) (resistant) and suffolk/hampshire crossbred (sx) (susceptible) lambs were either not infected (n=5/breed), given a primary inoculation (n=5/breed) or challenged infected with h. contortus (n=5/breed). each inoculum given consisted of 10,000 l3 larvae. blood was collected daily for 14 days and then we ... | 2015 | 25986324 |
| in vitro levamisole selection pressure on larval stages of haemonchus contortus over nine generations gives rise to drug resistance and target site gene expression changes specific to the early larval stages only. | there is some evidence that resistance to levamisole and pyrantel in trichostrongylid nematodes is due to changes in the composition of nicotinic acetylcholine receptors (nachrs) which represent the drug target site. altered expression patterns of genes coding for nachr subunits, as well as the presence of truncated versions of several subunits, have been implicated in observed resistances. the studies have mostly compared target sites in worm isolates of very different genetic background, and h ... | 2015 | 25983232 |
| partial protection and abomasal cytokine expression in sheep experimentally infected with haemonchus contortus and pre-treated with taenia hydatigena vesicular concentrate. | the abomasal expression of il-2, il-4, il-6, il-10 and ifnγ in lambs experimentally infected with haemonchus contortus and its relationship to protection induced by a taenia hydatigena larvae vesicular concentrate (thlvc) were evaluated. the lambs that were only infected with h. contortus larvae showed a worm burden greater (p<0.05) than the lambs that received thlvc prior to infection. moreover, the lambs that received thlvc showed a greater (p<0.05) number of blood eosinophils than the lambs t ... | 2015 | 25959643 |
| ivermectin binds to haemonchus contortus tubulins and promotes stability of microtubules. | haemonchus contortus is a nematode of livestock that can cause severe disease and mortality. ivermectin, an anti-parasitic drug that targets glutamate-gated chloride channels, is widely used in humans, livestock, companion animals and agriculture. although an association between genetic changes to β-tubulin and exposure to ivermectin has been previously reported, direct binding between ivermectin and tubulin has not been demonstrated to date. tubulin/microtubules are key targets for many anti-mi ... | 2015 | 25957159 |
| heterologous expression in remodeled c. elegans: a platform for monoaminergic agonist identification and anthelmintic screening. | monoamines, such as 5-ht and tyramine (ta), paralyze both free-living and parasitic nematodes when applied exogenously and serotonergic agonists have been used to clear haemonchus contortus infections in vivo. since nematode cell lines are not available and animal screening options are limited, we have developed a screening platform to identify monoamine receptor agonists. key receptors were expressed heterologously in chimeric, genetically-engineered caenorhabditis elegans, at sites likely to y ... | 2015 | 25928899 |
| comparison of biotransformation and efficacy of aminoacetonitrile anthelmintics in vitro. | the present in vitro study was designed to test and compare anthelmintic activity, hepatotoxicity, and biotransformation of four selected aminoacetonitrile derivatives (aads): monepantel (mop, anthelmintic approved for the treatment), aad-970, aad-1154, and aad-1336. micro-agar larval development test, mtt test of cytotoxicity, and biotransformation study coupled with ultra high performance liquid chromatography-tandem mass spectrometry (uhplc-ms/ms) technique were used for this purpose. larvae ... | 2016 | 25922167 |
| screening and analysis of hc-ubq and hc-gst related to desiccation survival of infective haemonchus contortus larvae. | infective haemonchus contortus larvae (l3s) are able to protect themselves from desiccation. to explore the molecular mechanisms of desiccation survival, mrna differential display rt-pcr was used to screen differentially expressed genes in l3s upon desiccation, followed by rnai experiments to define gene functions. in this, 58 differentially expressed transcripts were obtained. among these, the bf-u01a and ch-u02a fragments represent genes with the highest identity percentage in bioinformatic an ... | 2015 | 25913452 |
| comparative immunoprophylactic efficacy of haemonchus contortus recombinant enolase (rhceno) and con a purified native glycoproteins in sheep. | haemonchus contortus is the most economically important blood feeding nematode parasite of sheep and goats all over the world. enolase in helminth parasites is a multi-functional enzyme which involves in glycolysis and host tissue invasion. in this study, the recombinant h. contortus enolase (rhceno) was evaluated for its immunoprophylactic efficacy in sheep along with con a purified native glycoproteins in a vaccine challenge trial. group i and group ii experimental sheep were immunized thrice ... | 2015 | 25913090 |
| vaccination of sheep and cattle against haemonchosis. | vaccines against gastrointestinal nematodes are one potential option for the control of parasitic gastroenteritis in ruminants. excretory/secretory (e/s) and hidden antigens are being studied as candidates for vaccines against haemonchus spp., which is a major parasite in cattle and small ruminants that are raised in warm climates. protection has been observed after vaccination with some e/s proteases, particularly cysteine proteases and with some glycans that are abundant on the surfaces and in ... | 2015 | 25891536 |
| seasonal patterns of gastrointestinal nematode infection in goats on two lithuanian farms. | this study investigated seasonal changes in naturally acquired gastrointestinal nematode (gin) infections on two lithuanian goat farms with different parasite control practices. | 2015 | 25881323 |
| transmembrane protein 63a is a partner protein of haemonchus contortus galectin in the regulation of goat peripheral blood mononuclear cells. | hco-gal-m and -f were two isoforms of galectin cloned from male and female haemonchus contortus, respectively, and it was demonstrated that recombinant hco-gal-m and -f could act as immune suppressors. however, little is known about the receptors or binding partners of these galectins in the host. the research of the molecular mechanisms that govern the interactions between these galectins and host molecules will fill a gap in our understanding how parasite galectins interact with host cells. | 2015 | 25879191 |
| relative resistance of menz and washera sheep breeds to artificial infection with haemonchus contortus in the highlands of ethiopia. | the aim of this study was to evaluate the relative resistance of menz and washera sheep breeds to artificial infection with haemonchus contortus. the challenge trial was conducted at the debre berhan agricultural research center in ethiopia. a total of 39 (menz = 21, washera = 18) lambs of about 6 months old were used for the trial. all lambs were initially treated against internal parasite using albendazole and fasinex to free them from internal parasites and kept indoors. h. contortus third-st ... | 2015 | 25868601 |
| in-vitro anthelmintic activity of three bangladeshi plants against paramphistomum cervi and haemonchus contortus. | conventional plant-based therapies act as an important therapeutic tool for the treatment of worm infections all over the world and continuous evaluation of medicinal plants to find new potential lead compounds should be carried out. | 2015 | 25868001 |
| a molecular characterization of the agonist binding site of a nematode cys-loop gaba receptor. | cys-loop gaba receptors represent important targets for human chemotherapeutics and insecticides and are potential targets for novel anthelmintics (nematicides). however, compared with insect and mammalian receptors, little is known regarding the pharmacological characteristics of nematode cys-loop gaba receptors. here we have investigated the agonist binding site of the cys-loop gaba receptor unc-49 (hco-unc-49) from the parasitic nematode haemonchus contortus. | 2015 | 25850584 |
| macrocyclic lactones differ in interaction with recombinant p-glycoprotein 9 of the parasitic nematode cylicocylus elongatus and ketoconazole in a yeast growth assay. | macrocyclic lactones (mls) are widely used parasiticides against nematodes and arthropods, but resistance is frequently observed in parasitic nematodes of horses and livestock. reports claiming resistance or decreased susceptibility in human nematodes are increasing. since no target site directed ml resistance mechanisms have been identified, non-specific mechanisms were frequently implicated in ml resistance, including p-glycoproteins (pgps, designated abcb1 in vertebrates). nematode genomes en ... | 2015 | 25849454 |
| integrated assessment of ivermectin pharmacokinetics, efficacy against resistant haemonchus contortus and p-glycoprotein expression in lambs treated at three different dosage levels. | the main goals of the current work were: (a) to assess the ivermectin (ivm) systemic exposure and plasma disposition kinetics after its administration at the recommended dose, x5 and x10 doses to lambs, (b) to compare the clinical efficacy of the same ivm dosages in lambs infected with an ivm-resistant isolate of haemonchus contortus, and (c) to assess the expression of the transporter protein p-glycoprotein (p-gp) in h. contortus recovered at 14 days after administration of the ivm dose regimen ... | 2015 | 25841863 |
| the basic reproduction quotient (q0) as a potential spatial predictor of the seasonality of ovine haemonchosis. | haemonchus contortus is a gastrointestinal nematode parasite of small ruminants, which feeds on blood and causes significant disease and production loss in sheep and goats, especially in warmer parts of the world. the life cycle includes free-living immature stages, which are subject to climatic influences on development, survival and availability, and this species therefore exhibits spatio-temporal heterogeneity in its infection pressure based on the prevailing climate. models that better expla ... | 2015 | 25826315 |
| haemonchus contortus: spatial risk distribution for infection in sheep in europe. | haemonchus contortus is a species of gastrointestinal strongyles of primary concern for sheep. this highly pathogenic, blood-feeding helminth negatively influences animal health, welfare and productivity. in order to elucidate the current scenario in terms of prevalence and intensity of h. contortus infection in sheep farms across europe, a standardized crosssectional survey was conducted in three pilot areas in ireland, switzerland and italy, all part of the eu funded gloworm project. two conse ... | 2015 | 25826314 |
| development of novel valerolactam-benzimidazole hybrids anthelmintic derivatives: diffusion and biotransformation studies in helminth parasites. | in the search for new anthelmintics able to overcome the resistance problem against all available drugs in livestock, the synthesis of novel valerolactam-benzimidazole hybrid compounds was reported. this allowed us to obtain these in vitro and in vivo bioactive compounds using nippostrongylus brasiliensis rat model by integrating physiology-based assays and ex vivo diffusion studies. in order to further study those novel hybrid molecules, haemonchus contortus (a sheep gastrointestinal nematode o ... | 2015 | 25816976 |
| haemonchus contortus resistance to monepantel in sheep. | in a sheep farm in the netherlands with a suspected haemonchus contortus resistance to monepantel (zolvix®, novartis animal health), a fecal egg count reduction test was carried out in two groups of lambs, according to the method of the world association for the advancement of veterinary parasitology. group 1 was the untreated control group, and group 2 was treated with monepantel at the manufacturer's recommended dose rate. efficacy of treatment with monepantel was 0%. larval identification of ... | 2015 | 25770852 |
| decline in faecal worm egg counts in lambs suckling ewes treated with lipophilic anthelmintics: implications for hastening development of anthelmintic resistance. | the aim for this experiment was to look for evidence of milk transfer of anthelmintic actives from ewes to their suckling lambs by reference to lambs' faecal worm egg count (wec). the hypothesis was that wec will decline in lambs suckling ewes treated with anthelmintics known to be lipophilic. one group of lactating border leicester×merino ewes were treated (tx) with a combination of short (2.5mg/kg monepantel) and long-acting (1mg/kg moxidectin long-acting injection and a sustained release of 4 ... | 2015 | 25754351 |
| effects of dietary supplementation with green tea polyphenols on digestion and meat quality in lambs infected with haemonchus contortus. | ujumqin sheep are susceptible to infection by the gastrointestinal nematode haemonchus contortus, which reduces productivity and total meat yield in sheep. thus, the effects of green tea polyphenol (gtp) supplements (0, 2, 4, or 6g of gtp/kg feed) on dietary nutrient digestibility and meat quality in lambs infected with h. contortus were examined; control lambs were not infected. h. contortus infections did not affect digestion but the apparent digestibilities of nutrients were decreased by diet ... | 2015 | 25746574 |
| low cost whole-organism screening of compounds for anthelmintic activity. | due to major problems with drug resistance in parasitic nematodes of animals, there is a substantial need and excellent opportunities to develop new anthelmintics via genomic-guided and/or repurposing approaches. in the present study, we established a practical and cost-effective whole-organism assay for the in vitro-screening of compounds for activity against parasitic stages of the nematode haemonchus contortus (barber's pole worm). the assay is based on the use of exsheathed l3 (xl3) and l4 s ... | 2015 | 25746136 |
| haemonchotolerance in west african dwarf goats: contribution to sustainable, anthelmintics-free helminth control in traditionally managed nigerian dwarf goats. | west african dwarf (wad) goats are extremely important in the rural village economy of west africa, but still little is known about their biology, ecology and capacity to cope with gastrointestinal nematode (gin) infections. here, we summarise the history of this breed and explain its economic importance in rural west africa. we review recent work showing that nigerian wad goats are highly trypanotolerant and resist infections with haemonchus contortus more effectively than other breeds of domes ... | 2015 | 25744655 |
| kinetics and anthelmintic efficacy of topical eprinomectin when given orally to goats. | preliminary data suggest that topical eprinomectin in goat shows an individual variation in anthelmintic efficacy when used off-license at a dose rate of 0.5 or 1.0mg/kg bw. as a result, the use of oral administration of topical formulation of eprinomectin tends to develop in dairy goat farms in france. the plasma levels and milk excretion as well as the anthelmintic efficacy of eprinomectin were determined in goats following oral administration of a topical formulation of the drug at dose rates ... | 2015 | 25744609 |
| two types of galactosylated fucose motifs are present on n-glycans of haemonchus contortus. | n-glycans from the nematode haemonchus contortus (barber pole worm), a parasite of sheep and cattle, were the first to be described to possess up to three fucose residues associated with the n,n'-diacetylchitobiosyl core, two being on the reducing-terminal proximal glcnac and one on the distal core glcnac residue. the assumption was that truncated glycans from this organism with three hexose residues have the composition man3glcnac2fuc1-3. in this study, we have performed hplc and maldi-tof ms/m ... | 2015 | 25740940 |
| a highly conserved, inhibitable astacin metalloprotease from teladorsagia circumcincta is required for cuticle formation and nematode development. | parasitic nematodes cause chronic, debilitating infections in both livestock and humans worldwide, and many have developed multiple resistance to the currently available anthelmintics. the protective collagenous cuticle of these parasites is required for nematode survival and its synthesis has been studied extensively in the free-living nematode, caenorhabditis elegans. the collagen synthesis pathway is a complex, multi-step process involving numerous key enzymes, including the astacin metallopr ... | 2015 | 25736599 |
| persistent challenge with trichostrongylus colubriformis and haemonchus contortus larvae does not affect growth of meat-breed lambs suppressively treated with anthelmintics when grazing. | this experiment tested the hypothesis that persistent challenge with anthelmintic susceptible trichostrongylus colubriformis and haemonchus contortus larvae would not affect growth of grazing, meat-breed lambs when suppressively treated with anthelmintics. the experiment was a 2×2 factorial design using 6-7 months old white suffolk x border leicester/merino (meat-breed) lambs which were either infected with 2000 t. colubriformis and 300 h. contortus l3/week (if) or remained uninfected (uif) for ... | 2015 | 25725548 |
| variability of resistance in black bengal goats naturally infected with haemonchus contortus. | a total 290 black bengal goats (6 buck, 109 doe and 175 kids born from 11 sires) were studied to evaluate the variability of resistance in black bengal goats naturally infected with haemonchus contortus. the variability of resistance in black bengal goat was studied for both genetic and non-genetic factors like village, sex, age dam, sire, dam resistance group and offspring resistance group. male kids have slightly higher resistance than female kids although it was not significant. resistance of ... | 2015 | 25698865 |
| haematobiochemical parameters of goats fed tannin rich psidium guajava and carissa spinarum against haemonchus contortus infection in india. | the antihelminthic properties of tannin-rich plants are being explored as an alternative to chemical drugs to minimise the effects of gastro intestinal nematodes (gin). the present study was, therefore, conducted to investigate the effect of condensed tannins (ct), obtained from regional tanniferous tree leaves, in the haemonchus contortus infected goats on the heamatobiochemical parameters to assess the goat health. twelve adult male goats were randomly divided into three equal groups, namely n ... | 2015 | 25698858 |
| st. croix sheep produce a rapid and greater cellular immune response contributing to reduced establishment of haemonchus contortus. | the objective of this study was to determine breed differences in immune response shortly following haemonchus contortus infection. peripheral and local cellular and humoral immune responses were evaluated in 24 st. croix hair lambs and 24 dorset×(finn-rambouillet) wool lambs at 0, 3, 5 and 7 days after infection with 10,000 l3 h. contortus larvae. blood samples taken immediately before harvest revealed no differences in circulating effector cell populations, yet there were significant differenc ... | 2015 | 25698414 |
| comparative pharmacokinetic and pharmacodynamic response of single and double intraruminal doses of ivermectin and moxidectin in nematode-infected lambs. | to compare the pharmacokinetics, distribution and efficacy (pharmacodynamic response) of intraruminal ivermectin (ivm) and moxidectin (mxd) administered at 0.2 and 0.4 mg/kg to naturally nematode-infected lambs, and to determine the ex vivo accumulation of these anthelmintics by haemonchus contortus. | 2015 | 25689407 |
| prevalence of ovine haemonchosis in wukro, ethiopia. | background. haemonchosis caused by haemonchus contortus is a predominant, highly pathogenic, and economically important disease of sheep and goats. objective. assessing the prevalence of haemonchus parasite and its associated risk factors in sheep slaughtered at different restaurants of wukro. methods. cross-sectional study using random sampling from november 2013 to april 2014 in a total of 384 sheep was conducted and spss version 20 software using descriptive statistics was used for data analy ... | 2015 | 25688297 |
| status of benzimidazole resistance in haemonchus contortus of goats from different geographic regions of uttar pradesh, india. | present study was designed to survey the status of benzimidazole (bz) resistance in goat flocks of different agro climatic regions of uttar pradesh (u.p.), india by faecal egg count reduction test (fecrt) and allele specific pcr (as-pcr). faecal egg counts and larval culture were made from representative samples of all regions. the results of the faecal culture and pcr-rflp on beta tubulin isotype-1 gene showed haemonchus contortus was predominant species. fecrt results showed bz resistance prev ... | 2015 | 25680901 |
| comparison of internal transcribed spacers and intergenic spacer regions of five common iranian sheep bursate nematodes. | accurate identification of sheep nematodes is a critical point in epidemiological studies and monitoring of drug resistance in flocks. however, due to a close morphological similarity between the eggs and larval stages of many of these nematodes, such identification is not a trivial task. there are a number of studies showing that molecular targets in ribosomal dna (internal transcribed spacer 1, 2 and intergenic spacer) are suitable for accurate identification of sheep bursate nematodes. the ob ... | 2014 | 25678919 |
| removal of tapeworm (moniezia spp.) did not increase growth rates of meat-breed lambs in the northern tablelands of nsw. | this experiment tested the hypothesis that growth rates of meat-breed lambs would not be affected by infection with tapeworm (monieza spp.). two experiments, conducted in successive years (2012 and 2013) on a commercial sheep farm on the northern tablelands of nsw, assessed growth rates of meat-breed lambs, between 4 and 6 months of age, following the removal of the cestode, monieza spp. (or commonly referred to as tapeworm). in 2012 and 2013, 93 and 85 lambs respectively were randomly allocated ... | 2015 | 25677979 |
| the emergence of resistance to the benzimidazole anthlemintics in parasitic nematodes of livestock is characterised by multiple independent hard and soft selective sweeps. | anthelmintic resistance is a major problem for the control of parasitic nematodes of livestock and of growing concern for human parasite control. however, there is little understanding of how resistance arises and spreads or of the "genetic signature" of selection for this group of important pathogens. we have investigated these questions in the system for which anthelmintic resistance is most advanced; benzimidazole resistance in the sheep parasites haemonchus contortus and teladorsagia circumc ... | 2015 | 25658086 |
| effect of zinc supplementation on ecto-adenosine deaminase activity in lambs infected by haemonchus contortus: highlights on acute phase of disease. | haemonchus contortus (order strongylida) is a common parasitic nematode infecting small ruminants and causing significant economic losses worldwide. it induces innate and adaptive immune responses, which are essential for the clearance of this nematode from the host. ecto-adenosine deaminase (e-ada) is an enzyme that plays an important role in the immune system, while zinc (zn) has been found playing a critical role in e-ada catalysis. therefore, the aim of this study was to assess the effect of ... | 2015 | 25639494 |
| clinicopathological studies of gastrointestinal tract disorders in sheep with parasitic infection. | this study was envisaged to elucidate the parasitological aspects of gastrointestinal tract (git) disorders of sheep. | 2015 | 27046991 |
| a new enabling proteomics methodology to investigate membrane associated proteins from parasitic nematodes: case study using ivermectin resistant and ivermectin susceptible isolates of caenorhabditis elegans and haemonchus contortus. | the mechanisms involved in anthelmintic resistance (ar) are complex but a greater understanding of ar management is essential for effective and sustainable control of parasitic helminth worms in livestock. current tests to measure ar are time consuming and can be technically problematic, gold standard diagnostics are therefore urgently required to assist in combatting the threat from drug resistant parasites. for anthelmintics such as ivermectin (ivm), target proteins may be present in the cellu ... | 2015 | 25537855 |
| anthelmintic effect of carob pods and sainfoin hay when fed to lambs after experimental trickle infections with haemonchus contortus and trichostrongylus colubriformis. | the aim of the study was to compare the in vivo anthelmintic activity of sainfoin hay (onobrychis viciifolia) and carob pod meal (ceratonia siliqua) against gastrointestinal nematodes. seven days before infection, 64 naive lambs were assigned to four different groups: group s received sainfoin hay and group car was fed with carob pods. the remaining lambs received lucerne hay (medicago sativa) and were assigned to positive (non-treated, nt) and negative (treated, t) control groups (treatment wit ... | 2014 | 25526546 |
| differentiation of haemonchus placei from haemonchus contortus by pcr and by morphometrics of adult parasites and third stage larvae. | molecular and morphological methods were evaluated to distinguish between haemonchus contortus and haemonchus placei species. a total of 141 h. contortus and 89 h. placei male adult specimens collected from artificially infected lambs were identified individually by pcr analysis, using a species-specific primer pair. these pcr results were used as gold standard for haemonchus spp. identification. haemonchus placei presented higher mean spicule and barb lengths than h. contortus (p<0.05). however ... | 2017 | 25517528 |
| comparative pharmacology of flatworm and roundworm glutamate-gated chloride channels: implications for potential anthelmintics. | pharmacological targeting of glutamate-gated chloride channels (glucls) is a potent anthelmintic strategy, evidenced by macrocyclic lactones that eliminate numerous roundworm infections by activating roundworm glucls. given the recent identification of flatworm glucls and the urgent need for drugs against schistosomiasis, flatworm glucls should be evaluated as potential anthelmintic targets. this study sought to identify agonists or modulators of one such glucl, smglucl-2 from the parasitic flat ... | 2014 | 25516835 |
| first report of monepantel haemonchus contortus resistance on sheep farms in uruguay. | on two farms it was noted that after routine treatment with monepantel, fecal egg counts failed to drop. this was accompanied by lambs mortality due to haemonchus contortus infection. the aim of this work was to evaluate the efficacy of monepantel to control gastrointestinal nematodes (gin) in two sheep farms, in uruguay. | 2014 | 25515711 |
| haemonchus contortus p-glycoprotein-2: in situ localisation and characterisation of macrocyclic lactone transport. | haemonchus contortus is a veterinary nematode that infects small ruminants, causing serious decreases in animal production worldwide. effective control through anthelmintic treatment has been compromised by the development of resistance to these drugs, including the macrocyclic lactones. the mechanisms of resistance in h. contortus have yet to be established but may involve efflux of the macrocyclic lactones by nematode atp-binding-cassette transporters such as p-glycoproteins. here we report th ... | 2015 | 25486495 |
| impact of the post-weaning parasitism history on an experimental haemonchus contortus infection in creole goat kids. | gastrointestinal nematode (gin) infections have an important negative impact on small ruminant production. the selection of genotypes resistant to these parasitic infections is a promising alternative control strategy. thus, resistance against gin is an important component of small ruminant breeding schemes, based on phenotypic measurements of resistance in immune mature infected animals. in this study we evaluated both the impact of the post-weaning parasitism history on the response to an expe ... | 2015 | 25468672 |
| storage of gastrointestinal nematode infective larvae for species preservation and experimental infections. | techniques to preserve the infective third-stage larvae (l3) of gastrointestinal nematodes are of considerable interest to preserve rare species and to maintain a stable source for routine experimental infections. this study compares the relative pros and cons of the two most common techniques, cryopreservation and refrigeration by comparing how they influence consequent infection outcome parameters in terms of life-history traits and fitness as a function of time using the gastrointestinal nema ... | 2015 | 25468381 |
| anthelmintic activity of acetone-water extracts against haemonchus contortus eggs: interactions between tannins and other plant secondary compounds. | this study aimed at (i) describing the effects of acetone-water extracts obtained from a range of different plant materials, on the hatching process of haemonchus contortus eggs under in vitro conditions and (ii) identifying the role of tannins and other plant secondary compounds (psc), on these ah effects by using polyvinylpolypyrrolidone (pvpp), an inhibitor of tannins and other polyphenols. an egg hatch assay (eha) was used to determine the ah effect. acetone-water (70:30) extracts from diffe ... | 2014 | 25468031 |
| development of a loop-mediated isothermal amplification (lamp) assay for the sensitive detection of haemonchus contortus eggs in ovine faecal samples. | a major constraint on the effective control and management of helminth parasites in livestock is the lack of rapid and reliable diagnostic tests to identify the parasite species responsible for disease and to allow informed treatment decisions to be made. in the present study, we have developed a novel dna-based assay for the detection of haemonchus contortus eggs in ovine faecal samples, using loop-mediated isothermal amplification (or lamp). lamp allows for rapid detection of h. contortus dna ... | 2014 | 25468028 |
| field efficacy of four anthelmintics and confirmation of drug-resistant nematodes by controlled efficacy test and pyrosequencing on a sheep and goat farm in denmark. | we describe a case of anthelmintic resistance on one of the largest organic small ruminant farms in denmark. the flock was established in 2007 by purchase of animals from other danish farms and had history of clinical parasitism, high mortality of young stock and anthelmintic treatment failure. in october 2011, 40 lambs and 40 kids were selected for a faecal egg count reduction test (fecrt) with fenbendazole (fbz), ivermectin (ivm), moxidectin (mox) and levamisole (lev). lambs were treated with ... | 2014 | 25468020 |
| exploring the limitations of pathophysiological indicators used for targeted selective treatment in sheep experimentally infected with haemonchus contortus. | identifying which sheep to treat as part of a targeted selective treatment approach to gastro-intestinal nematode control relies entirely on the efficacy of the indicators. indicators such as famacha© (anaemia), disco (diarrhea) and reductions in weight gains were designed specifically to reflect those sheep experiencing symptomatic consequences of infection. using the gastro-intestinal nematode haemonchus contortus as a model species, this study explored the utility and sensitivity of these ind ... | 2015 | 25466619 |
| effect of sericea lespedeza leaf meal pellets on adult female haemonchus contortus in goats. | sericea lespedeza (sl; lespedeza cuneata) is a perennial warm-season forage rich in condensed tannins (ct) that has been reported to have anthelmintic activity against small ruminant gastrointestinal nematodes (gin), particularly haemonchus contortus, a highly pathogenic blood-feeder, but the mechanism of action of ct against h. contortus is not clearly understood. an experiment with young goats was designed to study the effect of sl leaf meal pellets on (1) a mature h. contortus infection, and ... | 2015 | 25465738 |
| genetic evidence for hybridisation between haemonchus contortus and haemonchus placei in natural field populations and its implications for interspecies transmission of anthelmintic resistance. | genetic hybridisation between parasitic nematode species has potentially important consequences. it could lead to the introgression of genes between species including those involved in pathogenicity, host specificity, transmission and drug resistance. it could also complicate diagnosis and control. however, there are few compelling examples of its occurrence in parasites in the field. haemonchus contortus and haemonchus placei are two closely related parasitic nematode species that predominantly ... | 2015 | 25449043 |
| relationship between oxidative stress and pathological findings in abomasum of infected lambs by haemonchus contortus. | the aim of this study was to evaluate the nitric oxide (no) levels, and oxidative and antioxidant markers of lambs experimentally and naturally infected by haemonchus contortus, and its relation to lesions in the abomasum. for experimental study, a total of 14 healthy lambs were divided into two groups with seven animals each. group a represented the uninfected animals (control), and group b was formed by infected animals with 15,000 larvae of h. contortus. blood was collected on days 15, 45, an ... | 2014 | 25446248 |
| exploring the role of two interacting phosphoinositide 3-kinases of haemonchus contortus. | phosphoinositide 3-kinases (pi3ks) are relatively conserved and important intracellular lipid kinases involved in signalling and other biological pathways. in the free-living nematode caenorhabditis elegans, the heterodimeric form of pi3k consists of catalytic (age-1) and regulatory (aap-1) subunits. these subunits are key components of the insulin-like signalling pathway and play roles in the regulation of the entry into and exit from dauer. although, in parasitic nematodes, similar components ... | 2014 | 25388625 |
| monepantel irreversibly binds to and opens haemonchus contortus mptl-1 and caenorhabditis elegans acr-20 receptors. | monepantel is a recently developed anthelmintic with a novel mode of action. parasitic nematodes with reduced sensitivity to monepantel have led to the identification of mptl-1, a ligand-gated ion-channel subunit of the parasitic nematode haemonchus contortus, as a potential drug target. homomeric mptl-1 channels reconstituted in xenopus oocytes are gated by µm concentrations of betaine and mm concentrations of choline. measurement of reversal potentials indicated that the channel has a similar ... | 2015 | 25352042 |
| anthelmintic resistance in ovine gastrointestinal nematodes in inland southern queensland. | to establish the prevalence of anthelmintic resistance in ovine gastrointestinal nematodes in southern queensland. | 2014 | 25348144 |
| phenobarbital induction and chemical synergism demonstrate the role of udp-glucuronosyltransferases in detoxification of naphthalophos by haemonchus contortus larvae. | we used an enzyme induction approach to study the role of detoxification enzymes in the interaction of the anthelmintic compound naphthalophos with haemonchus contortus larvae. larvae were treated with the barbiturate phenobarbital, which is known to induce the activity of a number of detoxification enzymes in mammals and insects, including cytochromes p450 (cyps), udp-glucuronosyltransferases (udpgts), and glutathione (gsh) s-transferases (gsts). cotreatment of larvae with phenobarbital and nap ... | 2014 | 25288079 |
| supplementation of moist and dehydrated citrus pulp in the diets of sheep artificially and naturally infected with gastrointestinal nematodes on the parasitological parameters and performance. | the inclusion of industrial byproducts such as citrus pulp in the composition of animal diets has been widely recommended due to sustainability aspects and their high level of carbohydrates. limonene is found in citrus pulp and has been described elsewhere as a major compound of citrus essential oils with excellent anthelmintic activity. the objective of this study was to evaluate the parasitological parameters of lambs artificially infected (experiment 1) with haemonchus contortus and naturally ... | 2014 | 25282048 |
| effect of selenium yeast supplementation on naturally acquired parasitic infection in ewes. | gastrointestinal parasites cause substantial economic losses in pasture-based sheep production systems. supranutritional organic selenium (se) supplementation may be beneficial because it improves immune responses to pathogens. to evaluate the effect of se-yeast supplementation on gastrointestinal parasite load, 30 ewes per treatment group were drenched weekly with no se, 4.9 mg se/week as se yeast (maximum fda-allowed concentration), or supranutritional concentrations of se yeast (14.7 and 24.5 ... | 2014 | 25256922 |
| cysteine proteinase genes in indian strain of haemonchus contortus. | the genes of microvillar cysteine proteinases such as hmcp1, hmcp6 and gcp7 of phenotypically distinct morphotypes of female h. contortus having knobbed and linguiform vulvar flaps were cloned and characterized. complementary dna (cdna) was synthesized from total rna of both the morphotypes. the hmcp1, hmcp6 and gcp7 genes were amplified from cdna. the amplicons were cloned in pdrive t/a cloning vector and sequenced by sanger's dideoxy method. the nucleotide and deduced amino acid sequences were ... | 2014 | 25239651 |
| dna vaccine encoding haemonchus contortus actin induces partial protection in goats. | actin is a globular multi-functional protein that forms microfilaments, and participates in many important cellular processes. previous study found that haemonchus contortus actin could be recognized by the serum of goats infected with the homology parasite. this indicated that h. contortus actin could be a potential candidate for vaccine. in this study, dna vaccine encoding h. contortus actin was tested for protection against experimental h. contortus infections in goats. fifteen goats were all ... | 2014 | 25236283 |
| reduction of benzimidazole resistance in established haemonchus contortus populations in goats using a single infection with a benzimidazole-susceptible isolate. | an in vivo study in goats evaluated the effect of superimposing a single artificial infection with a benzimidazole (bz)-susceptible haemonchus contortus isolate upon established h. contortus populations of known bz resistance by measuring the phenotypic bz resistance of eggs collected from faeces before and after re-infection. two h. contortus isolates, one benzimidazole resistant (bzr) and the other susceptible (bzs), were used to infect worm-free goats. eight goats were initially infected with ... | 2015 | 25226395 |
| long-term effects of drenches with condensed tannins from acacia mearnsii on goats naturally infected with gastrointestinal nematodes. | in this study, the long-term effects of exposure to a drench containing condensed tannins (cts) from acacia mearnsii on gastrointestinal nematodes in goats were investigated. male cross-bred anglo-nubian goat kids between 3 and 5 months of age were dewormed at the beginning of the experiment. the goat kids were divided into one group that received weekly 24 g oral doses of a. mearnsii bark extract dissolved in water containing 16.7% cts (gct group, n = 8) and a second group that did not receive ... | 2014 | 25224791 |
| a dyf-7 haplotype causes sensory neuron defects and is associated with macrocyclic lactone resistance worldwide in the nematode parasite haemonchus contortus. | heavy reliance on macrocyclic lactones to treat parasitic nematodes has resulted in the evolution of widespread drug resistance that threatens human and animal health. management strategies have been proposed that would slow the rise of resistance, however testing these strategies has been hampered by the lack of identified strong-effect resistance markers in parasites. we show that the caenorhabditis elegans gene cel_dyf-7, necessary for amphid sensory neuron development, also confers macrocycl ... | 2014 | 25224687 |
| a one shot blood phenotype can identify sheep that resist haemonchus contortus challenge. | gastrointestinal nematodes remain a major limitation to the productivity of livestock systems. selective breeding to produce populations that have an enhanced ability to resist infection is a viable and ongoing option to reduce this impact. the development of new phenotypes that facilitate this process is therefore of great interest. for this reason we explored relationships between haematological parameters and the ability of sheep to resist nematode infection. a multivariate analytical approac ... | 2014 | 25200384 |
| attempts to vaccinate ewes and their lambs against natural infection with haemonchus contortus in a tropical environment. | a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in three groups of grazing sheep each containing 13 ewes and their 16 lambs naturally infected with gastrointestinal nematodes. two groups were vaccinated with either 5 or 50μg of the antigen per immunisation, while the third, the control group, received adjuvant alone. the sheep were immunised six times at 3week intervals, partly because the vaccine antigens are hidden and thus no immun ... | 2014 | 25148946 |
| expression of caenorhabditis elegans-expressed trans-hps, partial aminopeptidase h11 from haemonchus contortus. | aminopeptidase h11 present in the surface of intestine microvilli in haemonchus contortus was identified as the most effective antigen candidate. however, its recombinant forms produced in escherichiacoli, insect cells and yeast could not provide promising protection against h. contortus challenge, probably due to the inappropriate glycosylation and/or conformational folding. herein, partial h11 containing the potential zinc-binding domain and two predicted glycosylation sites (nt 1 bp-1710 bp, ... | 2014 | 25128369 |
| development of an in vitro screen for compound bioaccumulation in haemonchus contortus. | the objective of the current study was to establish an in vitro screen and a highly sensitive analytical assay to delineate key physicochemical properties that favor compound bioaccumulation in the l3 life stage of a haemonchus contortus isolate. time-dependent studies revealed that absorption and elimination kinetics during the first 6 hr of exposure were sufficient to achieve maximum bioaccumulation for the majority of compounds tested. in subsequent studies, the larvae were incubated for 6 hr ... | 2014 | 25116000 |
| protein profile of lambs experimentally infected with haemonchus contortus and supplemented with selenium and copper. | gastrointestinal nematodes cause significant economic losses in the sheep industry, with frequent reports of anthelmintic resistance. therefore, alternative methods to control these parasites are necessary. thus, the aim of the present study was to assess the effect of treatment with selenium and copper on the protein profile of sheep that were experimentally infected with haemonchus contortus. | 2014 | 25096962 |
| the effect of vitamin e supplementation on an experimental haemonchus contortus infection in lambs. | the objective of this study was to investigate the effect of vitamin e supplementation on an experimental haemonchus contortus infection in lambs. twenty lambs were stratified into two treatment groups based on fecal egg count. worm-free lambs, 28-32 weeks of age, were supplemented with vitamin e (d-α-tocopherol) for 12 weeks following the recommendations of the national research council for the minimum daily requirement (control; 5.3 iu/kg body weight (bw)/day (d), n=10) or the requirement for ... | 2014 | 25085770 |
| pilot project to investigate over-wintering of free-living gastrointestinal nematode larvae of sheep in ontario, canada. | this study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (gin) stages on pasture. the presence of gin larvae was assessed on 3 sheep farms in ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. the infectivity of gin larvae on spring pastures was evaluated using 16 tracer lambs. air and soil temperature and moisture were recorded hourly. free-living stages of tricho ... | 2014 | 25082990 |
| gastrointestinal nematodes and anthelmintic resistance in danish goat herds. | the prevalence of gastrointestinal parasites in danish goats and the presence of anthelmintic resistance (ar) in 10 selected herds were investigated during april-september 2012. all danish herds (n = 137) with 10 or more adult goats were invited to participate, and of these 27 herds met the inclusion criterion of more than 10 young kids never treated with anthelmintics. questionnaire data on management were collected, and faecal samples from 252 kids were analysed by the mcmaster technique. from ... | 2014 | 25076056 |
| hc-fau, a novel gene regulating diapause in the nematode parasite haemonchus contortus. | diapause induced in the early fourth stage of haemonchus contortus is a strategy to adapt this nematode to hostile environmental conditions. in this study, we identified a new gene, hc-fau, a homologue of human fau and caenorhabditis elegans ce-rps30. hc-fau encodes two proteins through alternative rna splicing, hc-faua and hc-faub, consisting of 130 and 107 amino acids, respectively. hc-fau possesses a diverged ubiquitin-like (ubil) protein domain and a conserved ribosome protein s30 domain. th ... | 2014 | 25058511 |
| drug-efflux and target-site gene expression patterns in haemonchus contortus larvae able to survive increasing concentrations of levamisole in vitro. | while there is some evidence that changes in nicotinic acetylcholine receptor (nachr) subunits confer resistance to levamisole in gastrointestinal helminth parasites, the exact nature of the resistance mechanism(s) is unclear. we utilised the presence of a resistant fraction within the wallangra 2003 isolate of haemonchus contortus larvae in order to subdivide the population into three subpopulations of larvae able to survive increasing concentrations of the drug. we then measured gene expressio ... | 2014 | 25057457 |
| galectin hco-gal-m from haemonchus contortus modulates goat monocytes and t cell function in different patterns. | monocytes and t cells are two major subpopulations of peripheral blood mononuclear cells (pbmc) and play an essential role in the innate and adaptive immune systems. different members of the galectin family show multiple and distinct regulatory effects on different cell types. previous studies have demonstrated that the galectin from haemonchus contortus (hco-gal-m) performed immunomodulatory effects on goat pbmc, however, which subpopulation of pbmc is the primary target of hco-gal-m and whethe ... | 2014 | 25056558 |
| lectin, hemolysin and protease inhibitors in seed fractions with ovicidal activity against haemonchus contortus. | bioactive molecules of plant species are promising alternatives for the chemical control of gastrointestinal nematodes in ruminants. extracts of native and exotic seed species from brazil's semi-arid region were tested in vitro in an egg hatch assay and the bioactivity of their proteins was investigated. each seed species was subjected to three extractions with three types of solvents. all the seeds showed ovicidal activity, which varied according to the solvents. higher ovicidal activity was fo ... | 2014 | 25054490 |
| influence of dietary supplementation of condensed tannins through leaf meal mixture on intake, nutrient utilization and performance of haemonchus contortus infected sheep. | the study assessed the effect of dietary supplementation of leaf meal mixture (lmm) containing condensed tannins (ct) on feed intake, nutrient utilization and performance of sheep infected with haemonchus contortus. eighteen adult sheep of similar age and body weight (25.03±1.52) were included in this study and out of these, 12 sheep were infected with single dose of infective third stage larvae of h. contortus at 2,000 larvae per sheep. the experimental sheep were allocated in three different g ... | 2013 | 25049728 |
| effects of supplementation with dietary green tea polyphenols on parasite resistance and acute phase protein response to haemonchus contortus infection in lambs. | the objective of this study was to determine the effects of supplementation with dietary green tea polyphenols (gtps) on parasite resistance and acute phase protein (app) response to haemonchus contortus infection in lambs. thirty male ujumqin lambs were randomly assigned to five treatment groups for an 8-week feeding period. treatments included: (1) uninfected as control, (2) infected but not given gtp (infgtp0) and (3)-(5) infected and fed 2, 4, or 6g gtp/kg feed (dry matter basis; infgtp2, in ... | 2014 | 25042046 |
| evaluation of two iranian domestic ovine breeds for their pathological findings to gastrointestinal infection of haemonchus contortus. | the generally warm, moist environmental conditions in the northwestern iran are ideal for survival and growth of the egg and larval stages of haemonchus contortus and other gastrointestinal nematodes (gin) of sheep and goats.a total of 2,421 animals were slaughtered and examined from july 2010 to july 2011 in urmia abattoir. in case of sheep, 225 out of 2,421 were positive and prevalence of h. contortus infestation was 9.3 %. sex wise prevalence of h. contortus in sheep was 33.08 % (76/229) in m ... | 2014 | 25035592 |
| in vitro evidence that the pastoral artemisia campestris species exerts an anthelmintic effect on haemonchus contortus from sheep. | occurrence of anthelmintic resistant strains of helminths is increasing. the aim of this study was to evaluate the in vitro anthelmintic activity of artemisia campestris in comparison to albendazole against haemonchus contortus of sheep. in this respect, in vitro anthelmintic activities of crude aqueous and crude ethanolic extracts of aerial parts of a. campestris were investigated on eggs and adults of haemonchus contortus. chemical analyses revealed that overall profile of both extracts sample ... | 2014 | 25027867 |
| nutrient partitioning of merino sheep divergently selected for genetic difference in resistance to haemonchus contortus. | this research was designed to determine if divergent genetic selection for resistance to haemonchus contortus had produced correlated changes in the metabolism of amino-nitrogen in the absence or presence of h. contortus infection. partitioning of amino acid-nitrogen between tissues was determined in 42 merino weaner wethers from the csiro haemonchus selection flock, increased resistance to haemonchus (irh), decreased resistance to haemonchus (drh) and random bred control (c) selection lines. we ... | 2014 | 25027755 |
| effect of fall-grazed sericea lespedeza (lespedeza cuneata) on gastrointestinal nematode infections of growing goats. | high prevalence of anthelmintic-resistant gastrointestinal nematodes (gin) in goats has increased pressure to find effective, alternative non-synthetic control methods, one of which is adding forage of the high condensed tannin (ct) legume sericea lespedeza (sl; lespedeza cuneata) to the animal's diet. previous work has demonstrated good efficacy of dried sl (hay, pellets) against small ruminant gin, but information is lacking on consumption of fresh sl, particularly during the late summer-autum ... | 2014 | 24996964 |
| acquired resistance to monepantel in c. elegans: what about parasitic nematodes? | in 2008, novartis animal health developed a new class of anthelmintics, the amino-acetonitrile derivatives (aad) of which monepantel is the most prominent compound. monepantel was designed for the treatment of sheep against the parasitic nematode haemonchus contortus. because monepantel acts through a different mechanism, it is effective against nematodes that have acquired resistance to long-standing anthelmintics. in order to benefit from a maximum lifespan and efficacy of this new compound, t ... | 2017 | 26430545 |
| vaccination of grazing calves with antigens from the intestinal membranes of haemonchus contortus: effects against natural challenge with haemonchus placei and haemonchus similis. | a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in three groups of eight 5 months old grazing calves, naturally infected by haemonchus similis, haemonchus placei and other gastrointestinal nematodes. vaccinated calves received 5 or 50μg of the antigen and 1mg of saponin adjuvant, while the controls received adjuvant alone, initially three times, 3 weeks apart and then four more times at 6 weeks intervals. three weeks after the last im ... | 2014 | 24960373 |
| reduced neophobia: a potential mechanism explaining the emergence of self-medicative behavior in sheep. | gastrointestinal helminths challenge ruminants in ways that reduce their fitness. in turn, ruminants have evolved physiological and behavioral adaptations that counteract this challenge. for instance, emerging behavioral evidence suggests that ruminants self-select medicinal compounds and foods that reduce parasitic burdens. however, the mechanism/s leading to self-medicative behaviors in sick animals is still unknown. we hypothesized that when homeostasis is disturbed by a parasitic infection, ... | 2014 | 24955494 |
| copper and selenium: auxiliary measure to control infection by haemonchus contortus in lambs. | the aim of this study was to evaluate the effects of selenium and copper on oxidative stress and its performance in lambs experimentally infected with haemonchus contortus. twenty-eight five-months old lambs were experimentally infected by the oral route with 5000 third-stage infective larvae and allocated into four groups, i.e., untreated animals, animals treated intramuscularly with sodium selenite (0.2 mg kg(-1)), animals treated subcutaneously with copper (3.5 mg kg(-1)), and animals treated ... | 2014 | 24950380 |
| functional investigation of a qtl affecting resistance to haemonchus contortus in sheep. | this study reports a functional characterization of a limited segment (qtl) of sheep chromosome 12 associated with resistance to the abomasal nematode haemonchus contortus. the first objective was to validate the identified qtl through the comparison of genetically susceptible (n) and resistant (r) sheep produced from martinik × romane back-cross sheep. the r and n genotype groups were then experimentally infected with 10 000 h. contortus larvae and measured for fec (every three days from 18 to ... | 2014 | 24939584 |
| efficacy of free and nanoencapsulated eucalyptus citriodora essential oils on sheep gastrointestinal nematodes and toxicity for mice. | herbal medicines with anthelmintic effects are alternatives for the sustainable control and prevention of disease caused by gastrointestinal parasites. the nanoencapsulation of essential oils has been proposed to enhance the absorption of their constituents and improve their efficacy. the present study aimed to evaluate the efficacy of free and nanoencapsulated eucalyptus citriodora essential oil (eceo) on the control of gastrointestinal nematodes of small ruminants in vitro and in vivo. chitosa ... | 2014 | 24929446 |
| the presence of benzimidazole resistance mutations in haemonchus placei from us cattle. | haemonchus populations were collected from cattle from mid-western and eastern southern us (four and six populations, respectively) to determine the relative prevalence of haemonchus contortus and haemonchus placei and the frequency of the three isotype-1 β-tubulin polymorphisms associated with benzimidazole resistance. a minimum of 32 individual adult worms were genotyped at position 24 of the rdna its-2 for each population to determine species identity (296 worms in total). one population from ... | 2014 | 24916341 |
| proteomic analysis of mecistocirrus digitatus and haemonchus contortus intestinal protein extracts and subsequent efficacy testing in a vaccine trial. | gastrointestinal nematode infections, such as haemonchus contortus and mecistocirrus digitatus, are ranked in the top twenty diseases affecting small-holder farmers' livestock, yet research into m. digitatus, which infects cattle and buffalo in asia is limited. intestine-derived native protein vaccines are effective against haemonchus, yet the protective efficacy of intestine-derived m. digitatus proteins has yet to be determined. | 2014 | 24901227 |
| moisture requirements for the migration of haemonchus contortus third stage larvae out of faeces. | the abomasal nematode haemonchus contortus causes severe disease and production loss in small ruminants in warmer regions and is also an emerging threat in many temperate climates. specific knowledge of the effects of climate on the epidemiology of h. contortus is needed to effectively apply sustainable control strategies, which rely on prediction of infection risk. although the effects of temperature and rainfall on larval development in this species have been characterised, much less is known ... | 2014 | 24893698 |
| desiccation tolerance of gastrointestinal nematode third-stage larvae: exploring the effects on survival and fitness. | the free-living third-stage larvae (l3) of gastrointestinal nematodes are able to tolerate extreme weather conditions such as desiccation, but little is known about the consequent effects this has on their fitness. this study explored how the desiccation of haemonchus contortus l3 larvae affected their absolute fitness by examining their success at consequent life cycle stages for a complete generation, and comparing them against a control. the stages examined include establishment, fecundity, l ... | 2014 | 24828346 |
| relative potency of macrocyclic lactones in in vitro assays with larvae of susceptible and drug-resistant australian isolates of haemonchus contortus and h. placei. | the present study used in vitro assays to determine the relative potency of commercial macrocyclic lactone (ml) anthelmintics against larvae of drug-susceptible and drug-resistant australian isolates of important parasites of sheep and cattle, haemonchus contortus and haemonchus placei, respectively. cattle pour-on products containing abamectin, ivermectin, eprinomectin, doramectin or moxidectin were diluted in dmso and used in larval development assays. abamectin was the most potent chemical (l ... | 2014 | 24813746 |
| anthelmintic activity of artemisia annua l. extracts in vitro and the effect of an aqueous extract and artemisinin in sheep naturally infected with gastrointestinal nematodes. | there is no effective natural alternative control for gastrointestinal nematodes (gin) of small ruminants, with haemonchus contortus being the most economically important gin. despite frequent reports of multidrug-resistant gin, there is no new commercial anthelmintic to substitute failing ones. although trematocidal activity of artemisinin analogs has been reported in sheep, neither artemisinin nor its plant source (artemisia annua) has been evaluated for anthelmintic activity in ruminants. thi ... | 2014 | 24802864 |
| immune response to haemonchus contortus and haemonchus placei in sheep and its role on parasite specificity. | two trials were conducted to determine the prepatent and the patent period of haemonchus contortus and haemonchus placei in santa ines crossbred sheep and to determine whether serial infections with both species confer protection against homologous or heterologous challenge. to evaluate the prepatent and patent periods of infection, five lambs received a single infection with 4000 h. contortus-infective larvae (l3), and another five received a single infection with 4000 h. placei l3. h. contortu ... | 2014 | 24670867 |
| metabolic pathways of anthelmintic drug monepantel in sheep and in its parasite (haemonchus contortus). | monepantel (mop) is a new anthelmintic drug intended for the treatment and control of gastrointestinal roundworms (nematodes) infection and associated disease in sheep. the aim of our study was to find out metabolic pathways of mop in sheep in vivo and in its parasite haemonchus contortus ex vivo. mop biotransformation in two h. contortus strains with different sensitivity to anthelmintics was also compared. ultra high-performance liquid chromatography with tandem mass spectrometry (uhplc-ms/ms) ... | 2014 | 24616229 |
| host-specificity and morphometrics of female haemonchus contortus, h. placei and h. similis (nematoda: trichostrongylidae) in cattle and sheep from shared pastures in são paulo state, brazil. | to better evaluate the usefulness of female haemonchus specimens for specific identification, we undertook a detailed analysis of the morphology of a collection of worms obtained from cattle and sheep in shared pastures. based on the results, we also more precisely evaluated the host-specificity of haemonchus contortus, h. placei and h. similis occurring sympatrically in a farm located in the western region of são paulo state, brazil. a synlophe analysis was employed to identify the three specie ... | 2015 | 24589375 |