| effect of selenium and vitamin e on oxidative stress in lambs experimentally infected with haemonchus contortus. | the objective of this study was to evaluate oxidative stress in lambs experimentally infected with haemonchus contortus and supplemented with selenium and vitamin e. twenty male corriedale lambs were divided into four experimental groups with five animals each: g1 consisted of animals infected and supplemented with 0.2 mg/kg of live weight (lw) sodium selenite by intramuscular injection (im); g2 consisted of animals infected with larvae and supplemented with 0.2 mg/kg lw sodium selenite im and 2 ... | 2010 | 20607397 |
| anthelmintic effect of eucalyptus staigeriana essential oil against goat gastrointestinal nematodes. | the aim of this study was to evaluate the anthelmintic efficacy of eucalyptus staigeriana essential oil (eseo). the in vitro effects of eseo were determined through the egg hatching test and the inhibition of larval development of haemonchus contortus. the oil was subjected to acute and subacute toxicity rodents. the in vivo effects were determined through fecal egg count reduction test in goats. 1.35 and 5.4 mgml(-1) eseo inhibited 99.27 and 99.20% h. contortus egg hatching and larval developme ... | 2010 | 20609526 |
| immunization against lamb haemonchosis with a recombinant somatic antigen of haemonchus contortus (rhcp26/23). | haemonchosis, caused by the abomasal nematode haemonchus contortus, is a common parasitic disease of sheep. our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. recombinant dna technology was applied to obtain a synthetic protein (rhcp26/23). immunological assays (elisa, western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein an ... | 2010 | 20631899 |
| comparative analysis of destruction of the infective forms of trichuris trichiura and haemonchus contortus by nematophagous fungi pochonia chlamydosporia; duddingtonia flagrans and monacrosporium thaumasium by scanning electron microscopy. | the present study aimed to demonstrate by scanning electron microscopy (sem) the in vitro predatory activity of nematophagous fungi pochonia chlamydosporia (vc1 and vc4 isolates) duddingtonia flagrans (ac001 isolate) and monacrosporium thaumasium (nf34a isolate) on eggs of trichuristrichiura and infective larvae (l3) of haemonchus contortus. the work was divided into two experimental tests (a and b). in tests a and b, the predatory activity of nematophagous fungi p. chlamydosporia, d. flagrans a ... | 2011 | 20638203 |
| in vitro effects of cassava (manihot esculenta) leaf extracts on four development stages of haemonchus contortus. | three extracts (aqueous, methanolic and dichloromethane) of manihot esculenta (cassava) leaf were tested in vitro on four development stages of haemonchus contortus using egg hatch assay (eha), larval development assay (lda), l3 migration inhibition assay (lmi) and adult worm motility assay (awm). compared to the negative control, significant effects (p<0.0001) were observed for the methanolic extract of leaf against larval development (57.6% +/-7.6), with a dose dependent effect. these results ... | 2010 | 20638799 |
| activity in vitro of fungal conidia of duddingtonia flagrans and monacrosporium thaumasium on haemonchus contortus infective larvae. | the objective of this work was to evaluate the predatory activity of the fungi duddingtonia flagrans (ac001) and monacrosporium thaumasium (nf34a) on haemonchus contortus infective larvae (l3) in two experimental assays (a and b). in assay a, two treatments and one control were formed and kept for 7 days in petri dishes with 2% water-agar. each treatment consisted of 1000 h. contortus l3 and 1000 conidia of only one fungal isolate, and the control group consisted of 1000 l3, without fungus, with ... | 2010 | 20663244 |
| monepantel allosterically activates deg-3/des-2 channels of the gastrointestinal nematode haemonchus contortus. | monepantel is the first drug of a new family of anthelmintics, the amino acetonitrile derivatives (aad), presently used to treat ruminants infected with gastrointestinal nematodes such as haemonchus contortus. monepantel shows an excellent tolerability in mammals and is active against multidrug-resistant parasites, indicating that its molecular target is absent or inaccessible in the host and is different from those of the classic anthelmintics. genetic approaches with mutant nematodes have sugg ... | 2010 | 20679419 |
| phenotypic and genotypic characterisation of benzimidazole susceptible and resistant isolates of haemonchus contortus. | the study was designed to compare the in vitro egg hatch test (eht) and molecular allele-specific polymerase chain reaction pcr (as-pcr) methods as tools for detection of benzimidazole resistance in haemonchus contortus, a nematode parasite of small ruminants. comparisons were made during the course of an experimental infection and changes in eht and as-pcr were monitored to measure the correlation between in vitro and molecular tests. both methods were carried out according to world association ... | 2010 | 20684865 |
| curtisia dentata (cornaceae) leaf extracts and isolated compounds inhibit motility of parasitic and free-living nematodes. | haemonchus contortus and trichostrongylus colubriformis are among the most important parasitic nematodes of small ruminants. caenorhabditis elegans, a free-living nematode, is used as a model for evaluating anthelmintic activity of a variety of test substances. extracts of several medicinal plants are useful in vitro and in vivo against nematode development. extracts of curtisia dentata, a south african medicinal plant, and compounds isolated from leaves of this plant were investigated for anthe ... | 2009 | 20698444 |
| factors affecting susceptibility to rna interference in haemonchus contortus and in vivo silencing of an h11 aminopeptidase gene. | gene silencing by rna interference (rnai) has been applied very successfully to caenorhabditis elegans to study gene function but has proven less effective in parasitic nematodes. in the sheep gastrointestinal nematode haemonchus contortus, previous studies demonstrated reproducible silencing of β-tubulin but not of other genes targeted. here we aimed to examine whether the level of target transcript or site of gene expression influence susceptibility to rnai by soaking. target genes represented ... | 2011 | 20699100 |
| the astacin metalloprotease moulting enzyme nas-36 is required for normal cuticle ecdysis in free-living and parasitic nematodes. | nematodes represent one of the most abundant and species-rich groups of animals on the planet, with parasitic species causing chronic, debilitating infections in both livestock and humans worldwide. the prevalence and success of the nematodes is a direct consequence of the exceptionally protective properties of their cuticle. the synthesis of this cuticle is a complex multi-step process, which is repeated 4 times from hatchling to adult and has been investigated in detail in the free-living nema ... | 2011 | 20800010 |
| comparison of parasitological and productive traits of criollo lambs native to the central mexican plateau and suffolk lambs experimentally infected with haemonchus contortus. | the study compares the parasitological and productive traits of criollo lambs native to the central mexican plateau (cncmp) and suffolk (su) lambs experimentally infected with haemonchus contortus. cncmp lambs (n=20) and su lambs (n=15) were infected with l3 of h. contortus while five lambs of each genotype were kept as controls. fecal egg count (fec), packed cell volume (pcv), blood eosinophil number (ben), ocular mucous membrane color (as measured by the famacha index), changes in body conditi ... | 2010 | 20801736 |
| intra-species variability in its-1 sequences of haemonchus contortus isolated from goats in west bengal, india. | this study evaluated the existence of different genotypes of haemonchus contortus prevailing among goats in west bengal, india. these parasites were isolated from the abomasum of goat intestine and the molecular characterization was performed by comparing variation of nucleotide sequences of the internal transcribed spacer 1 (its-1) gene region. single-strand conformation polymorphism (sscp) analysis of its-1 amplified product showed the presence of three distinct conformations both in male and ... | 2010 | 20804642 |
| effects of age and immune suppression of sheep on fecundity, hatching and larval feeding of different strains of haemonchus contortus. | the effects of host age and immune suppression on abomasal parasitic infection in sheep were investigated following single experimental oral infections with mhco3 (ise), mhco4 (wrs) and mhco10 (cavr) strains of haemonchus contortus in naïve 5-month-old crossbred lambs (n=1 per group) and 15-month-old greyface sheep treated with methyl prednisolone acetate (n=2 per group) or without corticosteroid treatment (n=2 per group). adult female h. contortus in 5-month-old lambs (n=1 per group) shed on av ... | 2010 | 20822936 |
| phylogenomics of ligand-gated ion channels predicts monepantel effect. | the recently launched veterinary anthelmintic drench for sheep (novartis animal health inc., switzerland) containing the nematocide monepantel represents a new class of anthelmintics: the amino-acetonitrile derivatives (aads), much needed in view of widespread resistance to the classical drugs. recently, it was shown that the acr-23 protein in caenorhabditis elegans and a homologous protein, mptl-1 in haemonchus contortus, are potential targets for aad action. both proteins belong to the deg-3 s ... | 2010 | 20838602 |
| a suite of genes expressed during transition to parasitic lifestyle in the trichostrongylid nematode haemonchus contortus encode potentially secreted proteins conserved in teladorsagia circumcincta. | the control of gastro-intestinal nematodes remains largely based on anthelminthic treatments, however spreading of anthelmintic resistance has reduced their efficacy. the genes involved in the transition to parasitic lifestyle could constitute targets of interest to develop alternative control strategies. in the trichostrongylid nematode haemonchus contortus, we have used a ssh (suppressive subtractive hybridization) based approach to generate two distinct subtracted cdna libraries specifically ... | 2010 | 20843605 |
| standardization of the larval migration inhibition test for the detection of resistance to ivermectin in gastro intestinal nematodes of ruminants. | resistance to anthelmintics is an increasing problem in sheep, goat and cattle industries worldwide. for parasite management on farms reliable methods for the detection of resistance are required and it is important that tests give comparable, reproducible and reliable results in different laboratories. the ability of the larval migration inhibition test (lmit), to detect ivermectin resistance in cattle and sheep nematodes has been evaluated through ring testing in up to six different laboratori ... | 2010 | 20850930 |
| localisation of serotonin and dopamine in haemonchus contortus. | serotonin and dopamine play important roles in the biology of nematodes where they exert their effect on feeding, locomotion and reproductive behavior. haemonchus contortus, a parasitic nematode which infects small ruminants, is responsible for considerable economic losses in agriculture. in the current study we have mapped the localisation of these two neurotransmitters in this parasite using immuno-staining. serotonin localised in amphidial and pharyngeal neurons in both adult female and male ... | 2010 | 20887725 |
| multiple resistance to anthelmintics by haemonchus contortus and trichostrongylus colubriformis in sheep in brazil. | the objective of this study was to determine the level of resistance of haemonchus contortus and trichostrongylus colubriformis in sheep to levamisole, albendazole, ivermectin, moxidectin, closantel and trichlorfon. the parasites were isolated from sheep naturally infected by gastrointestinal nematodes and were then kept in monospecifically-infected lambs for production of infective larvae (l3) of both species. forty-two lambs, at three months of age, were simultaneously artificially infected wi ... | 2010 | 20887800 |
| seasonal prevalence of gastrointestinal nematode parasites of sheep in northern region of nile delta, egypt. | over 1 year, from january to december 1999, a total of 173 slaughtered sheep at al-mahala abattoir were examined for presence of nematode parasites. eighteen sheep (10.4%) were infected with eight different species of nematodes. the prevalence rates of detected nematode parasites were; haemonchus contortus (3.5%), haemonchus placei (1.7%), trichuris ovis (5.8%), parabronema skrjabini (2.9%), ostertagia trifurcata (1.2%), chabertia ovina (0.6%) and strongyloides papillosus (0.6%), and graphidiops ... | 2010 | 20922430 |
| effects of artemisinin and artemisia extracts on haemonchus contortus in gerbils (meriones unguiculatus). | haemonchus contortus is a blood-sucking abomasal parasite of small ruminants that is responsible for major losses to producers worldwide. resistance of this nematode to commercial anthelmintics has produced a demand for alternative control methods. plants in the genus artemisia have traditionally been used as anthelmintics and whole plants and plant extracts have demonstrated activity against gastrointestinal nematodes in several studies. in addition, artemisia annua is the sole commercial sourc ... | 2010 | 20943323 |
| efficacy of anthelmintic properties of medicinal plant extracts against haemonchus contortus. | the development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. among these alternatives are several medicinal plants traditionally used as anthelmintics. this present work evaluated the efficacy of ethyl acetate, acetone, and methanol dried leaf and seed extracts of five medicinal plants were tested in vitro ovicidal and larvicidal activities on haemonchus contortus. the in vitro assay was based on egg hatch as ... | 2010 | 20980034 |
| observation on the incidence of the common stomach worm, haemonchus contortus, in young cattle in a montreal abattoir. | | 1945 | 21008175 |
| antibodies from sheep immunized against haemonchus contortus with h-gal-gp inhibit the haemoglobinase activity of this protease complex. | highly protective intestinal cell membrane antigens have been prepared from haemonchus contortus, an important blood feeding nematode which parasitizes sheep and goats. one such antigen, h-gal-gp, is a glycoprotein complex containing predominantly digestive proteases. this study showed that h-gal-gp readily digested ovine haemoglobin and albumin, the two most abundant proteins in the parasite's blood meal. it was found that adding protective antibodies from h-gal-gp immunized sheep to the h-gal- ... | 2010 | 21039613 |
| arginine metabolism in the sheep abomasal nematode parasites haemonchus contortus and teladorsagia circumcincta. | the ornithine urea cycle, polyamine synthesis, nitric oxide synthesis and metabolism of arginine to putrescine have been investigated in l3 and adult haemonchus contortus and teladorsagia circumcincta. neither parasite had a detectable arginine deiminase/dihydrolase pathway nor a functional ornithine urea cycle. nitric oxide synthase was present in central and peripheral nerves, but was not detected in whole parasite homogenates. both arginase (e.c. 3.5.3.1) and agmatinase (e.c. 3.5.3.11) activi ... | 2010 | 21055403 |
| systems biology of ovine intestinal parasite resistance: disease gene modules and biomarkers. | this study reports on the molecular systems biology of gastrointestinal nematode (gin) infection and potential biomarkers for gin resistance in sheep. microarray gene expression data were obtained for 3 different tissues at 4 time points from sheep artificially challenged with two types of nematodes, haemonchus contortus (hc) and trichostrongylus colubriformis (tc). we employed an integrated systems biology approach, integrating 3 main methods: standard differential gene expression analyses, wei ... | 2010 | 21072409 |
| the activity and hydrogen peroxide sensitivity of the peroxiredoxins from the parasitic nematode haemonchus contortus. | the requirement of aerobic organisms to control damage caused by reactive oxygen species has led to the evolution of the antioxidant systems. peroxiredoxins are a large family of peroxidases which detoxify hydrogen peroxide at the expense of thiols. the parasitic nematode haemonchus contortus contains two peroxiredoxins, hcprx1 a mitochondrial protein and hcprx2 a cytoplasmic protein. although both peroxiredoxins contain the conserved eukaryotic motifs 'gglg' and 'yf', identified as critical for ... | 2010 | 21075149 |
| anthelminthic activity of acetone extract and fractions of vernonia amygdalina against haemonchus contortus eggs and larvae. | the current control of parasitic nematodes in small ruminants relies on the use of chemical anthelminthics, but the development of resistance and the problem of drug residues require research into alternatives. acetone extract and solvent-solvent fractions of vernonia amygdalina del. (compositae) were evaluated in vitro for potential anti-parasitic effects against the eggs and larvae of haemonchus contortus. significant effects were obtained with the extract and fractions but differences were ob ... | 2010 | 21088894 |
| a novel high throughput assay for anthelmintic drug screening and resistance diagnosis by real-time monitoring of parasite motility. | helminth parasites cause untold morbidity and mortality to billions of people and livestock. anthelmintic drugs are available but resistance is a problem in livestock parasites, and is a looming threat for human helminths. testing the efficacy of available anthelmintic drugs and development of new drugs is hindered by the lack of objective high-throughput screening methods. currently, drug effect is assessed by observing motility or development of parasites using laborious, subjective, low-throu ... | 2010 | 21103363 |
| a modified in vitro larvae migration inhibition assay using rumen fluid to evaluate haemonchus contortus viability. | anthelmintic effects of plant secondary compounds may be occurring in the rumen, but in vitro larvae migration inhibition (lmi) methods using rumen fluid and forage material have not been widely used. forage material added to an in vitro system can affect rumen ph, ammonia n, and volatile fatty acids, which may affect larvae viability (lv). validating a lmi assay using rumen fluid and a known anthelmintic drug (ivermectin) and a known anthelmintic plant extract (quebracho tannins; qt) is importa ... | 2010 | 21109354 |
| in vivo anthelmintic activity of an aqueous extract from sisal waste (agave sisalana perr.) against gastrointestinal nematodes in goats. | the resistance of gastrointestinal nematodes (gins) of small ruminants to anthelmintics has required the investigation of new alternatives. the aim of the present study was to evaluate the in vivo anthelmintic activity of an aqueous extract from sisal waste (agave sisalana) (aesw) against gins in goats and to observe the animals for toxic effects. thirty animals that were naturally infected with gins were distributed into three groups: group i, was treated with daily doses of aesw (1.7 g/kg) for ... | 2010 | 21156340 |
| albendazole failure to control resistant nematodes in lambs: lack of effect of fasting-induced improvement on drug absorption. | enhanced plasma availability of albendazole sulphoxide (abzso), the active metabolite of albendazole (abz), has been described in feed-restricted sheep. the aim of the present work was to determine if the absorption-related pharmacokinetic changes derived from fasting animals prior to drug treatment would modify the clinical efficacy of abz against resistant gastrointestinal nematodes in lambs. forty corriedale lambs, naturally infected with resistant gastrointestinal nematodes, were divided int ... | 2010 | 21158637 |
| anthelmintic activity of botanical extracts against sheep gastrointestinal nematodes, haemonchus contortus. | the source of chemical anthelmintics (levamisole, flubendazole, and thiabendazole) had limited the success of gastrointestinal nematodiasis control in sheep and goats and thus awakened interest in the study of medicinal plant extracts as alternative sources of anthelmintics. the egg hatching and larvicidal effect of indigenous plant extracts were investigated against the sheep parasite, haemonchus contortus. the purpose of the present study was to assess the efficacy of leaf, bark, and seed ethy ... | 2010 | 21161270 |
| differences in efficacy of monepantel, derquantel and abamectin against multi-resistant nematodes of sheep. | drug resistance has become a global phenomenon in gastrointestinal nematodes of sheep, particularly resistance to macrocyclic lactones. new anthelmintics are urgently needed for both the control of infections with multi-resistant nematodes in areas where classical anthelmintics are no longer effective, and the prevention of the spread of resistance in areas where the problem is not as severe. recently, two new active ingredients became commercially available for the treatment of nematode infecti ... | 2010 | 21161271 |
| persistence of the efficacy of copper oxide wire particles against haemonchus contortus in sheep. | the aim was to determine the persistent efficacy of copper oxide wire particles (cowp) against haemonchus contortus in sheep, using the harmonization guidelines protocol. thirty-six male lambs (2 months old) reared free of gastrointestinal nematodes were used (average body weight of 10.8±3.8kg). before and for the duration of the study, lambs were kept in raised cages with slatted floors and were offered ad libitum a complete mixed diet. animals were divided into six groups (n=6): one non-treate ... | 2010 | 21163579 |
| covariate selection in multivariate spatial analysis of ovine parasitic infection. | gastrointestinal (gi) strongyle and fluke infections remain one of the main constraints on health and productivity in sheep dairy production. a cross-sectional survey was conducted in 2004-2005 on ovine farms in the campania region of southern italy in order to evaluate the prevalence of haemonchus contortus, fasciola hepatica, dicrocoelium dendriticum and calicophoron daubneyi from among other parasitic infections. in the present work, we focused on the role of the ecological characteristics of ... | 2010 | 21167615 |
| the kinetics of local cytokine and galectin expression after challenge infection with the gastrointestinal nematode, haemonchus contortus. | gastrointestinal nematode parasites undergo several developmental stages within their mammalian host, each presenting different antigenic challenges to the immune system. to examine the expression of different immune mediators over time, biopsy samples were collected from the cannulated abomasum (true stomach) of immune sheep at several times after a challenge infection with haemonchus contortus l3s. il-5 and il-13 mrna expression levels were significantly increased above saline-challenged contr ... | 2010 | 21172352 |
| cloning, expression and characterization of nad+-dependent glyceraldehyde-3-phosphate dehydrogenase of adult haemonchus contortus† | glyceraldehyde-3-phosphate dehydrogenase (gapdh) regulates a wide range of biological processes, including pathogen evasion. in the present research, the gapdh gene of haemonchus contortus (hcgapdh) was cloned and characterized. specific primers for the rapid amplification of cdna ends (race) were designed based on the expressed sequence tag (est, aw670737) to amplify the 3â² and 5â² ends of hcgapdh. the full length of cdna from this gene was obtained by overlapping the sequences of 3â² and 5 ... | 2010 | 21205411 |
| using lectins to identify hidden antigens in fasciola hepatica. | fasciola hepatica is the causative agent of fascioliasis, one of the most economically important helminth diseases of livestock worldwide. traditionally, fascioliasis has been controlled by the strategic use of fasciolicidal drugs, but the emergence of resistant parasites has spurred an interest in developing vaccines as an alternative means of control. most vaccine studies to date have evaluated conventional antigens, which are exposed to the host's immune system during the course of a natural ... | 2011 | 21208513 |
| association between major histocompatibility complex microsatellites, fecal egg count, blood packed cell volume and blood eosinophilia in pelibuey sheep infected with haemonchus contortus. | the objective of this study was to assess the correlation among traits associated with resistance or susceptibility to haemonchus contortus infestation and to evaluate the participation of the ovine major histocompatibility complex (mhc) in pelibuey sheep, a prevalent breed in tropical and sub-tropical regions in mexico and elsewhere. association among the fecal egg count (fec), blood packed cell volume (pcv), antibody (ab) levels, serum proteins (sp) and blood eosinophil count (eos) was assesse ... | 2010 | 21208746 |
| development of graphidium strigosum (nematoda, haemonchidae) in its natural host, the rabbit (oryctolagus cuniculus) and comparison with several haemonchidae parasites of ruminants. | the morphogenesis (studied for the first time) and the chronology of the life cycle of graphidium strigosum (dujardin, 1845) were studied in detail in its natural host, oryctolagus cuniculus. naive rabbits were each infected per os with g. strigosum infective larvae (l3). animals were euthanized each day for the first 10 days after infection (dai), then every 2 days from 12 to 40 dai. the free living period lasted 5-8 days at 24°c. by 1 dai, all the larvae were exsheathed in the stomach. the thi ... | 2011 | 21210152 |
| decrease in establishment of haemonchus contortus caused by inoculation of a taenia hydatigena larvae vesicular concentrate. | the effect of taenia hydatigena larvae vesicular concentrate (thlvc) on the establishment of an experimental infection by haemonchus contortus was evaluated. the lambs that received thlvc showed a greater (p<0.05) average of blood eosinophils (be) than the lambs that did not receive thlvc. lambs that were only infected with h. contortus larvae showed a fecal egg count (fec) and an adult phase (ap) number greater (p<0.05) than lambs that received thlvc prior to infection. no effect was observed i ... | 2010 | 21216105 |
| the use of parasites as bioindicators of pesticide exposure. | organisms used in risk assessment of pesticides must be the most sensitive ones to pesticides exposure. the aim of this study was to observe the effect of two commercial pesticide products (containing glyphosate and tolylfluanid) to larval stages of parasites cooperia curticei, ostertagia circumcincta, haemonchus contortus and trichostrongylus axei. there were two concentrations tested for each product vs. control group. larvae (500 individuals/petri dish) were incubated at 27 °c and observed da ... | 2009 | 21217852 |
| effect of feeding sericea lespedeza leaf meal in goats experimentally infected with haemonchus contortus. | effect of sericea lespedeza [sl; lespedeza cuneata (dum-cours.) g. don.] leaf meal feeding was evaluated in two experiments in indoor reared goats with experimental infection of haemonchus contortus larvae. in the first experiment, ten 8-10 month old male spanish and alpine cross kids pair matched for body weight and age were fed sl or bermudagrass [bg; cynodon dactylon (l.) pers.] hay one week before infection and were infected with 5000 h. contortus l(3). the animals were maintained on the sam ... | 2010 | 21232867 |
| evaluation and application of a molecular method to assess the composition of strongylid nematode populations in sheep with naturally acquired infections. | we evaluated the performance of a pcr method for the diagnosis of naturally acquired strongylid nematode infections in sheep (n = 470; in a temperate climatic zone of south-eastern australia), using a panel of 100 'negative control' samples from sheep known not to harbour parasitic helminths. we compared the diagnostic sensitivity (98%) and specificity (100%) of this assay against a conventional faecal flotation method and also established a system to rank the contribution of particular strongyl ... | 2011 | 21256979 |
| atypical (rio) protein kinases from haemonchus contortus--promise as new targets for nematocidal drugs. | almost nothing is known about atypical kinases in multicellular organisms, including parasites. supported by information and data available for the free-living nematode, caenorhabditis elegans, and other eukaryotes, the present article describes three rio kinase genes, riok-1, riok-2 and riok-3, from haemonchus contortus, one of the most important parasitic nematodes of small ruminants. analyses of these genes and their products predict that they each play critical roles in the developmental pat ... | 2011 | 21262337 |
| fecundity in adult haemonchus contortus parasites is correlated with abomasal tissue eosinophils and ?d t cells in resistant canaria hair breed sheep. | canaria hair breed (chb) sheep are more resistant than canaria sheep (cs) to experimental haemonchus contortus infection. protective responses appear effective against the adult stage of the parasite, not as commonly reported in other breeds against the larval stages. in this study we have quantified several abomasal immune cells and correlated these with parasitological variables for each breed. a significant negative correlation between cd4+ t cell numbers and worm burden or length at 28 dpi w ... | 2011 | 21277683 |
| the unique resistance and resilience of the nigerian west african dwarf goat to gastrointestinal nematode infections. | west african dwarf (wad) goats serve an important role in the rural village economy of west africa, especially among small-holder livestock owners. they have been shown to be trypanotolerant and to resist infections with haemonchus contortus more effectively than any other known breed of goat. | 2011 | 21291550 |
| the kinetic properties of the glutamate dehydrogenase of teladorsagia circumcincta and their significance for the lifestyle of the parasite. | like other nematodes, both l(3) and adult teladosagia circumcincta secrete or excrete nh(3)/nh(4)(+), but the reactions involved in the production are unclear. glutamate dehydrogenase is a significant source nh(3)/nh(4)(+) in some species, but previous reports indicate that the enzyme is absent from l(3)haemonchus contortus. we show that glutamate dehydrogenase was active in both l(3) and adult t. circumcincta. the apparent k(m)s of the l(3) enzyme differed from those of the adult enzyme, the mo ... | 2011 | 21296180 |
| voluntary feed intake and diet selection of merino sheep divergently selected for genetic difference in resistance to haemonchus contortus. | this research was designed to determine if divergent selection for resistance to haemonchus contortus had produced correlated changes in voluntary feed intake and diet selection. voluntary feed intake, diet selection and production were determined in 54 merino weaner rams from the csiro haemonchus selection flock, increased resistance to haemonchus (irh), decreased resistance to haemonchus (drh) and random bred control (c) selection lines. weaner rams were fed ad libitum either a high (9.2 mj me ... | 2011 | 21330058 |
| vaccination of goats with dna vaccines encoding h11 and il-2 induces partial protection against haemonchus contortus infection. | dna vaccines expressing haemonchus contortus h11 antigen with or without interleukin (il)-2 were tested for protection against h. contortus infection in goats. sixteen goats (8-10months of age) were allocated into four trial groups. on days 0 and 14, group 1 was immunised with a dna vaccine expressing h11 and il-2 and group 2 was immunised with a dna vaccine expressing h11 only. group 3 was an unvaccinated positive control group challenged with h. contortus third stage larvae (l3). group 4 was a ... | 2011 | 21330170 |
| a comparison of two integrated approaches of controlling nematode parasites in small ruminants. | control of gastrointestinal nematodes (gin) in small ruminants in regions of the world where anthelmintic resistance is prevalent must rely on more than just chemical deworming strategies. the objective of this experiment was to compare two integrated treatment protocols for control of gin (primarily haemonchus contortus in this region) using anthelmintics, copper oxide wire particles (cowp) and famacha(©), compared to traditional anthelmintic use only. three separate trials were conducted on ma ... | 2011 | 21333450 |
| direct immunization of the abomasum or rectum of goats induces local lymph node responses against haemonchus contortus mucosal antigens. | we investigated several methods to immunize the abomasum (fourth and gastric stomach) of kid goats by direct (abomasal) or distal (rectal or nasal) routes utilizing mucosal antigens isolated from the abomasal parasite, haemonchus contortus. direct (ultrasound guided), immunization of the abomasal mucosa together with rectal immunization established lymphocyte proliferation responses in abomasal lymph nodes (alns), while distal methods, alone, produced equivocal results. the differential response ... | 2011 | 21333770 |
| a stochastic model accommodating the famacha© system for estimating worm burdens and associated risk factors in sheep naturally infected with haemonchus contortus. | a previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with haemonchus contortus over five consecutive haemonchus seasons (november to january/february) on a farm in the summer rainfall region in south africa, although only one season is discussed. the algorithm associates haemoglobin levels with worm counts in individual animals. variables were represented by distributions based on famacha(©) scores a ... | 2011 | 21334812 |
| effect of dietary supplementation on resistance to experimental infection with haemonchus contortus in creole kids. | the aim of the present study was to test the effect of dietary supplementation on resistance to experimental infection with haemonchus contortus in creole kids. one trial with three replicates involved a total of 154 female kids that were chosen from three successive cohorts of the creole flock of inra-gardel in 2007. the kids were placed into four treatments according to the amount of concentrate they received: g0 (no concentrate and a quality dichantium spp. hay ad libitum, hay), g1 (hay+100g ... | 2011 | 21349645 |
| influence of gastrointestinal trichostrongylidosis on ram fertility. | a study on the influence of gastrointestinal trichostrongyles on ram fertility was performed. two groups of semen donor rams (sarda breed) were utilized; one was experimentally infected with haemonchus contortus, trichostrongylus colubriformis and teladorsagia circumcincta and the other was used as a control group. in all animals, coprological, haematological and reproductive parameters were studied. the results suggest that the parasites had a limited effect with some changes in phosphorus, cho ... | 2010 | 21370756 |
| rumen function and digestion of merino sheep divergently selected for genetic difference in resistance to haemonchus contortus. | the aim of this experiment was to investigate the effect of haemonchus contortus infection on rumen function and digestion of merino sheep from lines divergently selected for genetic resistance to h. contortus. rumen function and whole-tract digestibility were determined in 29 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. wethers were fed a restricted ... | 2011 | 21376471 |
| efficacy of an energy block containing duddingtonia flagrans in the control of gastrointestinal nematodes of sheep. | the efficacy of the nematode-trapping fungus duddingtonia flagrans incorporated into an energy block was evaluated for the control of gastrointestinal nematodes in sheep. four naturally parasitised sheep with average nematode egg counts of 2,470 eggs per gram grazed by pairs on two similar parasite-free paddocks for 30-ádays. during that period, one pair of sheep (treated animals, t1) received an energy block containing chlamydospores of d. flagrans at a dose of 200,000 chlamydopores/kg bw/day, ... | 2011 | 21380576 |
| t-cell receptor and immunoglobulin gene polymorphisms and resistance to haemonchus contortus in sheep. | summary: dna extracted from animals originating from three large half-sib sheep families derived from a single, highly resistant ram were probed with ovine t-cell receptor α and β chain and immunoglobulin lambda light chain variable and constant region cdna probes. when genomic dna was digested with taqi, 19 polymorphic bands were detected with the lambda light chain immunoglobulin variable region probe and 6,4 and 5 polymorphic bands were detected with the t-cell receptor α and β probes and the ... | 1994 | 21395753 |
| oral dosing with papaya latex is an effective anthelmintic treatment for sheep infected with haemonchus contortus. | the cysteine proteinases in papaya latex have been shown to have potent anthelmintic properties in monogastric hosts such as rodents, pigs and humans, but this has not been demonstrated in ruminants. | 2011 | 21406090 |
| structural and functional characterisation of the ovine interferon gamma (ifng) gene: its role in nematode resistance in rasa aragonesa ewes. | the ovine interferon gamma (ifng) gene was structurally and functionally characterised, and the association between its variants and the response to haemonchus contortus infection was examined in resistant and susceptible rasa aragonesa ewes in different physiological conditions. sequential faecal egg counts (fecs) were performed on a naturally infected flock of 400 rasa aragonesa ewes and two groups of ewes selected for high (n=38) or low (n=33) fec, which were subsequently challenged with h. c ... | 2011 | 21419496 |
| neutrophil and eosinophil chemotactic factors in the excretory/secretory products of sheep abomasal nematode parasites : ncf and ecf in abomasal nematodes. | both eosinophil chemotactic factor (ecf) and neutrophil chemotactic factor (ncf) activities were demonstrated in excretory/secretory (es) products and homogenates of haemonchus contortus and teladorsagia circumcincta larvae and adult worms in a modified checkerboard assay using a micro-chemotaxis chamber. neutrophil chemotaxis was seen in 28 of 35 experiments and eosinophil chemotaxis in 20 of 38 experiments. chemokinetic activity for neutrophils and eosinophils (accounting for 40-50% of total c ... | 2011 | 21424403 |
| ovicidal and larvicidal activity of the crude extracts from phytolacca icosandra against haemonchus contortus. | the development of anthelmintic resistance has impacted on the success of conventional anthelmintics (ah) for the control of gastrointestinal nematodes in grazing/browsing sheep and goats. medicinal plants from the traditional herbolary in mexico may provide new candidates that can be explored as alternative sources of ahs for ruminants. this study evaluated the leaf extracts derived from phytolacca icosandra against infective l(3) larvae and eggs from haemonchus contortus collected from sheep. ... | 2011 | 21439732 |
| anthelmintic activity of trianthema portulacastrum l. and musa paradisiaca l. against gastrointestinal nematodes of sheep. | evaluation of anthelmintic effects of trianthema (t.) portulacastrum l. (aizoaceae) whole plant and musa (m.) paradisiaca l. (musaceae) leaves against prevalent gastrointestinal worms of sheep was done that may justify their traditional use in veterinary clinical medicine. in vitro anthelmintic activity of the crude aqueous methanolic extract (came) of both the plants was determined using mature female haemonchus (h.) contortus and their eggs in adult motility assay (ama) and egg hatch test (eht ... | 2011 | 21440370 |
| molecular cloning, expression and characterization of enolase from adult haemonchus contortus. | enolase represents a multifunctional protein involved in basic energy metabolism. in the present research, the enolase gene of haemonchus contortus (hceno) was cloned and characterized. specific primers for the rapid amplification of cdna ends (race) were designed based on the expression sequence tag (est, genbank accession no. bf422728) to amplify the 3'- and 5'-ends of hceno. the full length of cdna from this gene was obtained by overlapping the sequences of 3'- and 5'-extremities and amplific ... | 2011 | 21444098 |
| dual oxidase 2 and glutathione peroxidase gene expression are elevated in hyperimmunized sheep challenged with haemonchus contortus. | a sequential biopsy sampling method was used to investigate oxidant and antioxidant gene responses in resistant sheep challenged with haemonchus contortus larvae or a sham saline challenge. the expression of key sheep oxidant and antioxidant producing genes were measured in sequential samples removed from the abomasums at days 0, 1, 2, 3, 5, 7 and 28 post challenge. gene expression levels at each time point were compared to expression at day 0, and levels of the various genes were also correlate ... | 2011 | 21444154 |
| effects of myracrodruon urundeuva extracts on egg hatching and larval exsheathment of haemonchus contortus. | the anthelmintic resistance has limited the control of gastrointestinal nematodes of small ruminants and thus has awakened interest in the study of tanniferous plants as a source of anthelmintics. these experiments were carried out to evaluate the in vitro efficacy of myracrodruon urundeuva leaf extract (le) and stem extract (se) against haemonchus contortus. an inhibitor of tannins, polyvinyl polypyrrolidone (pvpp), was used to verify if these metabolites are involved in the anthelmintic activi ... | 2011 | 21465262 |
| in vitro analysis of the anthelmintic activity of forage chicory (cichorium intybus l.) sesquiterpene lactones against a predominantly haemonchus contortus egg population. | the anthelmintic activity of chicory (cichorium intybus l.) herbage has been attributed to sesquiterpene lactones. chicory leaves contain significant amounts of lactucin (lac), 8-deoxylactucin (dol), and lactucopicrin (lpic), but the proportions of these three sesquiterpene lactones vary among forage chicory cultivars. to determine whether the individual compounds differ in anthelmintic activity, we prepared sesquiterpene lactone-enriched extracts from leaves of two forage chicory cultivars, 'gr ... | 2011 | 21477927 |
| functional reconstitution of haemonchus contortus acetylcholine receptors in xenopus oocytes provides mechanistic insights into levamisole resistance. | background and purpose the cholinergic agonist levamisole is widely used to treat parasitic nematode infestations. this anthelmintic drug paralyses worms by activating a class of levamisole-sensitive acetylcholine receptors (l-achrs) expressed in nematode muscle cells. however, levamisole efficacy has been compromised by the emergence of drug resistant parasites, especially in gastrointestinal nematodes such as haemonchus contortus. we report here the first functional reconstitution and pharmaco ... | 2011 | 21486278 |
| slo-1-channels of parasitic nematodes reconstitute locomotor behaviour and emodepside sensitivity in caenorhabditis elegans slo-1 loss of function mutants. | the calcium-gated potassium channel slo-1 in caenorhabditis elegans was recently identified as key component for action of emodepside, a new anthelmintic drug with broad spectrum activity. in this study we identified orthologues of slo-1 in ancylostoma caninum, cooperia oncophora, and haemonchus contortus, all important parasitic nematodes in veterinary medicine. furthermore, functional analyses of these slo-1 orthologues were performed using heterologous expression in c. elegans. we expressed a ... | 2011 | 21490955 |
| minimising the development of anthelmintic resistance, and optimising the use of the novel anthelmintic monepantel, for the sustainable control of nematode parasites in australian sheep grazing systems. | to compare the risk of different treatment scenarios on selecting for anthelmintic resistance on australian sheep farms. | 2011 | 21495986 |
| involvement of tannins and flavonoids in the in vitro effects of newbouldia laevis and zanthoxylum zanthoxyloïdes extracts on the exsheathment of third-stage infective larvae of gastrointestinal nematodes. | the present study aimed at examining the possible role of tannins and flavonoids on the in vitro anthelmintic properties of the extracts of two plants from the southern area of western africa, i.e. newbouldia laevis and zanthoxylum zanthoxyloïdes. extracts of the two plants were prepared by use of acetone/water (70/30) and their anthelmintic activity was measured by use of the larval exsheathment inhibition assay (leia) applied on the abomasal species, haemonchus contortus and the intestinal spe ... | 2011 | 21497021 |
| direct anthelmintic effects of cereus jamacaru (cactaceae) on trichostrongylid nematodes of sheep: in vivo studies. | following claims of anthelmintic activity of cereus jamacaru dc (cactaceae) by a commercial farmer, in vivo studies were conducted to determine the possible direct anthelmintic effects of the plant on ovine gastrointestinal nematodes. eighteen sheep were infected with 4000 haemonchus contortus and 6000 trichostrongylus colubriformis larvae given in three divided doses over a period of three days. once the infections were patent, the sheep were allocated to three groups and were drenched once a w ... | 2011 | 21498000 |
| ovicidal and larvicidal activity of cassia alata leaf acetone extract and fractions on haemonchus contortus: in vitro studies. | the failure of modern anthelmintics to control nematode parasites of sheep and goats is a reality on many farms in the tropical/subtropical regions of the world. this necessitates chemotherapeutic control alternatives and plant secondary metabolite with activity is one of those potential solutions. | 2011 | 21501100 |
| the haemonchus contortus unc-49b subunit possesses the residues required for gaba sensitivity in homomeric and heteromeric channels. | hco-unc-49 is a gaba receptor from the parasitic nematode haemonchus contortus that has a relatively low overall sequence similarity to vertebrate gaba receptors but is very similar to the unc-49 receptor found in the free living nematode caenorhabditis elegans. while the nematode receptors do share >80% sequence similarity they exhibit different sensitivities to gaba. in addition, the unc-49c subunit appears to be a positive modulator of gaba sensitivity in the h. contortus heteromeric channel, ... | 2011 | 21524670 |
| comparing the sensitivity of two in vitro assays to evaluate the anthelmintic activity of tropical tannin rich plant extracts against haemonchus contortus. | the present trial aimed at comparing the sensitivity of two in vitro methods, i.e. the larval migration inhibition assay (lmia) and the larval exsheathment inhibition assay (leia), to evaluate the anthelmintic (ah) properties of tannin-rich plant extracts against haemonchus contortus infective larvae. the two assays were applied on the same batch of h. contortus infective larvae exposed to water/acetonic extracts obtained from four tropical plants with different tannin contents: acacia gaumeri, ... | 2011 | 21530082 |
| protection of calves against haemonchus placei and haemonchus contortus after immunization with gut membrane proteins from h. contortus. | a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in 4 groups of 9 worm free calves challenged with either 8,000 h. contortus or haemonchus placei infective larvae. vaccinates received 50 μg of the antigen and 1mg quila adjuvant three times 21 days apart, while the controls got adjuvant alone. the calves were challenged 7 days after the last immunization and killed for worm counts 43 days later. immunization resulted in high titre antib ... | 2011 | 21535018 |
| norcantharidin analogues with nematocidal activity in haemonchus contortus. | with the major problems with resistance in parasitic nematodes of livestock to anthelmintic drugs, there is an urgent need to develop new nematocides. in the present study, we employed a targeted approach for the design of a series of norcantharidin analogues (n=54) for activity testing against the barber's pole worm (haemonchus contortus) of small ruminants in a larval development assay (lda) and also for toxicity testing on nine distinct human cell lines. although none of the 54 analogues synt ... | 2011 | 21536433 |
| evaluation of immune response to artificial infections of haemonchus contortus in gulf coast native compared with suffolk lambs. | the gulf coast native (native) breed of sheep among many others is identified as being relatively resistant to haemonchus contortus, an abomasal nematode parasite of small ruminants. understanding the mode of immune response that helps these breeds of sheep control infection could help design and implement appropriate control programs. in this experiment, the components of the immune response during the early infection period in resistant native lambs were evaluated and compared with susceptible ... | 2011 | 21570191 |
| a multi-species model to assess the effect of refugia on worm control and anthelmintic resistance in sheep grazing systems. | objective develop a computer simulation model that uses daily meteorological data and farm management practices to predict populations of trichostrongylus colubriformis, haemonchus contortus and teladorsagia (ostertagia) circumcincta and the evolution of anthelmintic resistance within a sheep flock. use the model to explore if increased refugia, provided by leaving some adult sheep untreated, would delay development of anthelmintic resistance without compromising nematode control. procedures c ... | 2011 | 21595639 |
| in vitro anthelmintic activity of crude extracts of five medicinal plants against egg-hatching and larval development of haemonchus contortus. | ethnopharmacological relevance: senna occidentalis, leonotis ocymifolia, leucas martinicensis, rumex abyssinicus, and albizia schimperiana are traditionally used for treatment of various ailments including helminth infection in ethiopia. materials and methods: in vitro egg hatch assay and larval development tests were conducted to determine the possible anthelmintic effects of crude aqueous and hydro-alcoholic extracts of the leaves of senna occidentalis, aerial parts of leonotis ocymifolia, leu ... | 2011 | 21605649 |
| dose titration of sericea lespedeza leaf meal on haemonchus contortus infection in lambs and kids. | the objective of three experiments was to determine the impact of supplementing sericea lespedeza (lespedeza cuneata; sl) in three concentrations in a loose or pelleted diet on gastrointestinal nematodes (gin) in small ruminants. experiments on lambs were conducted at the usda, agricultural research service in booneville, ar (exp. 1) and at louisiana state university in baton rouge, la (exp. 2); an experiment on goat kids occurred at university of maryland-eastern shore (exp. 3). exp. 1 used cro ... | 2011 | 21621921 |
| targeted treatment strategies for sustainable worm control in small ruminants. | sustainable worm control strategies are based largely on ensuring that a source of worms not exposed to anthelmintics ("in refugia") remains after treatments are given, so that resistant worms do not become a dominant part of the total population. in environments with seasonally poor survival of worm larvae on pasture, this may require withholding treatments from a proportion of animals when the whole group would normally be treated. the "targeted treatment" approach involves using anthelmintics ... | 2008 | 18414373 |
| anthelmintic screening of fractions of elephantorrhiza elephantina root extract against haemonchus contortus. | in the previous work conducted, it was found that the root extract of elephantorrhiza elephantina (bruch.) skeels. exhibited good anthelmintic efficacy against eggs and larvae of haemonchus contortus. this study was therefore undertaken to screen fractions of the extracts of e. elephantina for their anthelmintic activity against adult h. contortus using a bioactivity-guided assay. the adult worm bioassay was conducted using aqueous, hexane and ethyl acetate fractions of the plant extracts at con ... | 2011 | 21643660 |
| proteases in blood-feeding nematodes and their potential as vaccine candidates. | parasitic nematodes express and secrete a variety of proteases which they use for many purposes including the penetration of host tissues, digestion of host protein for nutrients, evasion of host immune responses and for internal processes such as tissue catabolism and apoptosis. for these broad reasons they have been examined as possible parasite control targets. blood-feeding nematodes such as the barber-pole worm haemonchus contortus that infect sheep and goats and the hookworms, ancylostoma ... | 2011 | 21660664 |
| rnai effector diversity in nematodes. | while rna interference (rnai) has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. to test if this is due to inter-species differences in rnai effector complements, we performed a primary sequence similarity survey for orthologs of 77 caenorhabditis elegans rnai pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were available, with all outputs subjected to domain-structure verification. our ... | 2011 | 21666793 |
| enzymes of the ornithine-glutamate-proline pathway in the sheep abomasal nematode parasites haemonchus contortus and teladorsagia circumcincta. | a fully functional ornithine-glutamate-proline pathway was detected in l3 and adult haemonchus contortus and teladorsagia circumcincta, making the parasites capable of interconversion of these amino acids. ornithine aminotransferase (oat) (e.c. 2.6.1.13) was a reversible pyridoxal-5-phosphate (plp)-dependent enzyme with an optimum ph 8.5. hydroxylamine completely inhibited oat activity in both parasites. for all five enzymes, substrate affinity was similar for each species and life cycle stage, ... | 2011 | 21781965 |
| in vitro activities of acetonic extracts from leaves of three forage legumes (calliandra calotyrsus, gliricidia sepium and leucaena diversifolia) on haemonchus contortus. | to assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, calliandra calotyrsus (c. calotyrsus), gliricidia sepium (g. sepium) and leucaena diversifolia (l. diversifolia) in vitro on haemonchus contortus (h. contortus). | 2011 | 21771435 |
| haemonchus contortus protease inhibition by n-alkyl ferulates from maprounea guianensis. | this report describes the inhibition of the proteolytic activity of haemonchus contortus lysate by a mixture of n-alkyl ferulates isolated from maprounea guianensis. these compounds were evaluated in vitro for the ability to inhibit the h. contortus proteases using sds-page copolymerized with gelatine (zymography) and by assaying the hemoglobinolytic activity of these enzymes in solution. the ferulates abrogated the proteolysis compared to e-64, suggesting the activity is the result of a cystein ... | 2011 | 21757211 |
| the efficacy of trichlorphon and naphthalophos against multiple anthelmintic-resistant nematodes of naturally infected sheep in argentina. | an anthelmintic efficacy trial was conducted in sheep harbouring anthelmintic-resistant worms in argentina. seventy lambs were selected from a flock that had been grazed on pastures infected with trichostrongyles previously shown to be resistant to the main anthelmintic groups. lambs were allocated to comparable groups of ten animals each and treated with trichlorphon (50 mg/kg body weight (b.w.) orally); naphthalophos (50 mg/kg b.w. orally); ivermectin (0.2 mg/kg b.w. subcutaneously); fenbendaz ... | 2011 | 21739383 |
| comparison of molecular and mcmaster microscopy techniques to confirm the presence of naturally acquired strongylid nematode infections in sheep. | patent strongylid nematode infections were identified using mcmaster worm egg counts (wec) and pcr assays (its-2 nuclear ribosomal dna) to screen genomic dna extracted directly from lamb faecal samples. lambs from four different farms in southern western australia were sampled rectally on two separate occasions, with mcmaster wecs and pcrs conducted on a total of 858 samples. negative controls (n=96) (wec<50eggs per gram [epg]) and positive controls (n=96) (faecal samples spiked with a 100++l su ... | 2011 | 21827796 |
| glutamate-gated chloride channels of haemonchus contortus restore drug sensitivity to ivermectin resistant caenorhabditis elegans. | anthelmintic resistance is a major problem in livestock farming, especially of small ruminants, but our understanding of it has been limited by the difficulty in carrying out functional genetic studies on parasitic nematodes. an important nematode infecting sheep and goats is haemonchus contortus; in many parts of the world this species is resistant to almost all the currently available drugs, including ivermectin. it is extremely polymorphic and to date it has proved impossible to relate any se ... | 2011 | 21818319 |
| use of fluorescent lectin binding to distinguish teladorsagia circumcincta and haemonchus contortus eggs, third-stage larvae and adult worms. | lectin binding to carbohydrates on parasite surfaces has been investigated as a method of distinguishing adult worms, eggs and sheathed and exsheathed l3 of teladorsagia circumcincta and haemonchus contortus, economically important abomasal parasites in temperate climates. both species were maintained as pure laboratory cultures of field isolates from new zealand. each of the four life cycle stages could be distinguished by the binding of at least one lectin: adult worms by sambucus nigra agglut ... | 2011 | 21732182 |
| efficacy of a combined oral formulation of derquantel-abamectin against the adult and larval stages of nematodes in sheep, including anthelmintic-resistant strains. | derquantel (dql), a semi-synthetic member of a novel anthelmintic class, the spiroindoles, in combination with abamectin (aba) [as the combination product startect(-«)] is a new entry for the treatment and control of parasites in sheep. the 19 studies reported herein were conducted in australia, new zealand, south africa and the united kingdom to demonstrate the efficacy of derquantel-abamectin (dql-aba) against a broad spectrum of gastrointestinal and respiratory nematodes of sheep, and to supp ... | 2011 | 21684691 |
| influence of protein supplementation during late pregnancy and lactation on the resistance of santa ines and ile de france ewes to haemonchus contortus. | this experiment aimed to evaluate the effect of periparturient metabolizable protein (mp) nutrition on resistance to haemonchus contortus in single rearing ile de france and santa ines ewes. the restriction-fed iso-energetic diet was calculated to provide either 0.8 (low mp diet) or 1.3 (high mp diet) times mp, from three weeks before parturition until eight weeks into lactation. the ewes were experimentally infected with 1000 h. contortus infective larvae (l3) three times a week (mondays, wedne ... | 2011 | 21726941 |
| vaccination of goats with a glutathione peroxidase dna vaccine induced partial protection against haemonchus contortus infection. | due to their critical functions in worm physiology, glutathione peroxidases in haemonchus contortus are potential candidates for vaccine to control haemonchosis. however, information on the protection potential of these molecules is lacking. in this study, recombinant hc29 antigen was tested for protection against experimental h. contortus infections in goats. fifteen animals were allocated into three trial groups. the animals of hc29 group was vaccinated with a recombinant hc29 dna vaccine twic ... | 2011 | 21680097 |
| anthelmintic activity of cymbopogon martinii, cymbopogon schoenanthus and mentha piperita essential oils evaluated in four different in vitro tests. | anthelmintic resistance is a worldwide concern in small ruminant industry and new plant-derived compounds are being studied for their potential use against gastrointestinal nematodes. mentha piperita, cymbopogon martinii and cymbopogon schoenanthus essential oils were evaluated against developmental stages of trichostrongylids from sheep naturally infected (95% haemonchus contortus and 5% trichostrogylus spp.) through the egg hatch assay (eha), larval development assay (lda), larval feeding inhi ... | 2011 | 21820807 |
| dose-dependent systemic exposure of albendazole metabolites in lambs. | alvarez, l., su+írez, g., ceballos, l., moreno, l., lanusse, c. dose-dependent systemic exposure of albendazole metabolites in lambs. j. vet. pharmacol. therap. doi: 10.1111/j.1365-2885.2011.01326.x. the gastrointestinal absorption of most drugs follows a first-order kinetics, whereby a constant fraction of the total drug is absorbed in each equal time interval. although this related absorption principle is applicable to the most of the therapeutically used drugs, it remains unclear for poorly w ... | 2011 | 21819410 |
| small ruminant resistance against gastrointestinal nematodes: a case of haemonchus contortus. | gastrointestinal nematode (gin) infections are a common constraint to small ruminant industry throughout the world, and among those, haemonchosis has its own significance. control of gin primarily relies on the use of anthelmintics, but this approach has become less reliable due to the development of resistance in gins against commonly used anthelmintics and an increased consumer demand for environmentally friendly animal products. these issues have stimulated investigations to find alternative ... | 2011 | 21842390 |
| anthelmintic resistance in a dairy cattle farm in the state of minas gerais. | eighty-four half-blood gir +ù holstein (f1) calves aged six months who were naturally infected by gastrointestinal helminths and maintained in rotational grazing received different anthelmintic treatments. group a received anthelmintics according to the usual management in the property (eight treatments, seven including a macrocyclic lactone agent). group b received strategic treatment (ivermectin 3.15%) at the beginning and at the end of the rainy period. eggs per gram of feces (epg) counts and ... | 2011 | 21722485 |