| recombinant galectins of male and female haemonchus contortus do not hemagglutinate erythrocytes of their natural host. | recombinant galectins of female and male adult worms of haemonchus contortus were expressed in escherichia coli and their hemagglutinating activities to human and different animal erythrocytes were analyzed. the results showed that female and male galectins could be highly expressed in e. coli using a temperature-sensitive plasmid, with the recombinant protein being mainly appeared in inclusion bodies. hemagglutinating activity assays showed that both of the galectins hemagglutinated human a, b, ... | 2007 | 17125929 |
| avermectin-resistance in gastrointestinal nematodes of boer goats and dorper sheep in switzerland. | anthelmintic resistance in gastrointestinal nematodes among small ruminants is widespread in south africa and dorper sheep and boer goats have been imported into switzerland from this country on a number of occasions. therefore, this study aimed to investigate the occurrence of avermectin (avm) resistant gastrointestinal nematodes (gin) in these breeds in switzerland. a total of 24 boer goat farms and 12 dorper sheep farms participated in the study. according to the faecal egg count reduction te ... | 2007 | 17088023 |
| phenotyping and genotyping of haemonchus contortus isolates reveals a new putative candidate mutation for benzimidazole resistance in nematodes. | in order to monitor and eventually control the spread of drug-resistant haemonchus contortus, knowledge of the molecular mechanisms underlying resistance is essential. here we phenotypically and genotypically characterize three multidrug-resistant h. contortus field isolates from australia and south africa. all were significantly less susceptible to thiabendazole than a sensitive reference strain in an in vitro egg-hatch assay. the sensitivity was further reduced in a surviving population after ... | 2007 | 17101226 |
| discovery of (z)-2-phenyl-3-(1h-pyrrol-2-yl)acrylonitrile derivatives active against haemonchus contortus and ctenocephalides felis (cat flea). | a series of 2-phenyl-3-(1h-pyrrol-2-yl)acrylonitrile derivatives were synthesized and evaluated for in vitro activity against the endoparasite haemonchus contortus and the ectoparasite ctenocephalides felis. some compounds had significant in vitro activity against these parasites. | 2007 | 17150358 |
| selective and on-demand drenching of lambs: impact on parasite populations and performance of lambs. | to determine whether drenching regimes for lambs by which a proportion (10%) of the heaviest animals was selectively left untreated, or animals are only drenched 'on demand' when faecal nematode egg counts (fec) exceeded a threshold level, would result in measurable increases in parasite larval challenge in the autumn and/or decreases in the performance of lambs. | 2006 | 17151729 |
| abomasal nematode community in an alpine chamois (rupicapra r. rupicapra) population before and after a die-off. | abomasa of 185 chamois shot during 5 consecutive hunting seasons were collected as part of a health monitoring program in an alpine area of italy and examined for nematodes. the data were obtained during both the preceding period and that following a severe die-off caused by a pneumonia outbreak. prevalence, mean abundance, mean intensity, and thul importance index were consistently high, in particular for haemonchus contortus, having a low host specificity and high pathogenic potential. species ... | 2006 | 17152929 |
| anhydrobiosis increases survival of trichostrongyle nematodes. | this study demonstrates that infective-stage larvae of 2 trichostrongyle ruminant gastrointestinal nematodes, haemonchus contortus and trichostrongylus colubriformis, can enter into anhydrobiotic states when completely desiccated. larvae of control trichostrongyle species, heligmosomoides polygyrus and nippostrongylus brasiliensis, that infect mice were unable to survive desiccation or to enter into anhydrobiosis. ruminant larvae were able to survive up to 7 desiccation/rehydration cycles, and, ... | 2006 | 17152941 |
| real-time pcr for quantifying haemonchus contortus eggs and potential limiting factors. | the purpose of this study was to evaluate the practicality of using real-time pcr for quantifying feces-derived trichostrongyle eggs. haemonchus contortus eggs were used to evaluate fecal contaminants, time after egg embryonation, and the presence of competing and non-competing dnas as factors that might interfere with generating reproducible results during simplex and multiplex quantitative real-time pcr (qpcr). real-time pcr results showed linear quantifiable amplification with dna from five t ... | 2007 | 17206500 |
| co-delivery of plasmid-encoded cytokines modulates the immune response to a dna vaccine delivered by in vivo electroporation. | in this study, in vivo electroporation of a dna vaccine adjuvanted with plasmids encoding different cytokines was investigated in large animals. sheep were injected intramuscularly with a dna vaccine encoding an antigen of haemonchus contortus (pnpa) and plasmids encoding different cytokines followed by in vivo electroporation. plasmids (pci) carrying the genes of different cytokines including ovine il-4(pci-il4), il-10(pci-il10), gm-csf(pci-gmcsf), and mcp-1alpha(pci-mcp1alpha), and pci-il4+pci ... | 2007 | 17224210 |
| extending from pars in caenorhabditis elegans to homologues in haemonchus contortus and other parasitic nematodes. | signal transduction molecules play key roles in the regulation of developmental processes, such as morphogenesis, organogenesis and cell differentiation in all organisms. they are organized into 'pathways' that represent a coordinated network of cell-surface receptors and intracellular molecules, being involved in sensing environmental stimuli and transducing signals to regulate or modulate cellular processes, such as gene expression and cytoskeletal dynamics. a particularly important group of m ... | 2007 | 17107637 |
| duration of anthelmintic effect of three formulations of ivermectin (oral, injectable and pour-on) against multiple anthelmintic-resistant haemonchus contortus in sheep. | we report the results of investigations that were conducted in a sheep flock in uttaranchal, india where repeated failure of anthelmintic medication was noted. the study revealed that haemonchus contortus in sheep had developed resistance to benzimidazoles (fenbendazole, mebendazole and albendazole), imidazothiazole (levamisole) and salicylanide (rafoxanide), while it was fully susceptible to avermectins (ivermectin). further, the suppression of nematode egg output in faeces of sheep naturally i ... | 2007 | 17237985 |
| haemonchus contortus intestine: a prominent source of mucosal antigens. | we sought to identify antigens from haemonchus contortus, an abomasal nematode of small ruminants, that stimulate local (abomasal lymph node, aln) cd4+ t lymphocyte responses during a primary infection. results led to a focus on antigens from the parasite intestine. the h. contortus intestine proved to be a major source of antigens that stimulated aln cd4+, cd25+ t lymphocyte responses during infections in lambs. when stimulated by intestinal antigens, aln lymphocytes from these lambs expressed ... | 2007 | 17266741 |
| detection and measurement of benzimidazole resistance alleles in haemonchus contortus using real-time pcr with locked nucleic acid taqman probes. | benzimidazole resistance is a common problem in parasitic nematodes of ruminants and early detection is vital if its spread is to be monitored and controlled. real time pcr offers a fast and reliable method for rapid detection and measurement of resistance allele frequencies. in haemonchus contortus a single nucleotide polymorphism at codon 200 of the beta-tubulin gene (ttc to tac), causing a phenylalanine to tyrosine amino acid substitution, has been shown to be involved in many cases of resist ... | 2007 | 17129676 |
| helminth parasites of gemsbok (oryx gazella) in the klein karoo. | the number and species of helminth parasites from three gemsbok (oryx gazella) were recorded, and their faecal nematode egg counts and the level of pasture contamination determined. six nematode genera were recovered and four species identified, of which trichostrongylus rugatus was the most prevalent. other nematode species recovered were cooperia sp., agriostomum sp., haemonchus contortus, nematodirus spathiger and ostertagia ostertagi. none of the worms were present in all animals studied, an ... | 2006 | 17283732 |
| comparison of three different preservatives for morphological and real-time pcr analyses of haemonchus contortus eggs. | despite the development of several recent pcr assays for the egg stages of various trichostrongyles, there have been no protocols described for preserving field samples for pcr without refrigeration. in this study, lugol's iodine (li), sodium azide (sa), and neutral buffered formalin (nbf) were evaluated using haemonchus contortus eggs to determine their potential as a preservative for trichostrongyle egg samples to be processed with real-time pcr. when egg recovery, embryo development, and egg ... | 2007 | 17289268 |
| relationships between sterol/phospholipid composition and xenobiotic transport in nematodes. | therapeutic failure limits prophylaxis of nematode diseases and has been mainly attributed to mutations in cellular targets of anthelmintics. besides these specific mechanisms, alterations of drug transport also occur in parasites resistant to anthelmintics and depend on both the presence of membrane pumps such as p-glycoprotein (pgp) and on the lipid composition of membranes. we recently showed in the nematode haemonchus contortus, using eggs as a model, that the total cholesterol (tc) concentr ... | 2007 | 17294217 |
| a novel approach for combining the use of in vitro and in vivo data to measure and detect emerging moxidectin resistance in gastrointestinal nematodes of goats. | ivermectin and moxidectin are closely related avermectin/milbemycin anthelmintics and available data suggest that side resistance occurs with these two drugs. however, moxidectin remains effective against many species of ivermectin-resistant worms due to its higher potency. the larval development assay (lda) is routinely used to diagnose ivermectin resistance in haemonchus contortus but laboratory diagnosis of moxidectin resistance is hampered by the lack of any validated in vitro tests. the obj ... | 2007 | 17307184 |
| anthelmintic activity of aporphine alkaloids from cissampelos capensis. | two known aporphine alkaloids, (s)-dicentrine (1) and (s)-neolitsine (2), have been isolated from the meoh extract of the aerial parts of cissampelos capensis (menispermaceae). the structures of these compounds were elucidated by nmr and ms analysis and comparison to literature data. these compounds were isolated by bioassay-guided fractionation using the haemonchus contortus larval development assay. compounds 1 and 2 exhibited ec90 values (concentration at which 90% loss of larval motility is ... | 2007 | 17309014 |
| individual administration of three tanniferous forage plants to lambs artificially infected with haemonchus contortus and cooperia curticei. | we investigated direct anthelmintic effects associated with the feeding of fresh tanniferous forages against established populations of haemonchus contortus and cooperia curticei in lambs. twenty-four parasite naive lambs were inoculated with a single dose of infective larvae of these two parasites 27 days prior to the start of the feeding experiment. lambs were individually fed with either chicory (cichorium intybus), birdsfoot trefoil (lotus corniculatus), sainfoin (onobrychis viciifolia) or a ... | 2007 | 17336459 |
| the kinetics of exsheathment of infective nematode larvae is disturbed in the presence of a tannin-rich plant extract (sainfoin) both in vitro and in vivo. | the mode of action of bioactive plants on gastrointestinal nematodes remains obscure. previous in vitro studies showed that exsheathment was significantly disturbed after contact with tannin-rich extracts. however, the role of important factors (extract concentration, parasite species) has not been assessed and no information is available on the occurrence in vivo. these questions represent the objectives of this study. the model incorporated the parasites haemonchus contortus and trichostrongyl ... | 2007 | 17346358 |
| use of bacillus thuringiensis toxin as an alternative method of control against haemonchus contortus. | the biocide activity of bacillus thuringiensis (b. thuringiensis) ib-16 strain was evaluated against the blood-feeding nematode haemonchus contortus (h. contortus) in vitro and in vivo assays. twenty experimental jirds (meriones unguiculatus) and 32 sheep were infected with h. contortus by oral route. fourteen days post infection 10 jirds were treated with 0.2 mg per ml of ib-16 soluble toxin by intraperitoneal (i.p.) route and 8 sheep were treated with 0.5 mg of toxin per kg of body weight by i ... | 2006 | 17135537 |
| vaccines against blood-feeding nematodes of humans and livestock. | this paper summarises the progress towards vaccine development against the major blood-feeding nematodes of man and livestock, the hookworms and haemonchus contortus, respectively. the impact of the diseases and the drivers for vaccine development are summarized as well as the anticipated impact of the host immune response on vaccine design. the performance requirements are discussed and progress towards these objectives using defined larval and adult antigens, many of these being shared between ... | 2006 | 17274849 |
| assessment of caenorhabditis elegans as a model in haemonchus contortus vaccine research. | | 2007 | 17234278 |
| three surface antigens dominate the mucosal antibody response to gastrointestinal l3-stage strongylid nematodes in field immune sheep. | although gastrointestinal nematode parasites are a major human and veterinary health problem, little is known about how the host is sometimes able to mount an effective immune rejection response. in previous work, we identified a carbohydrate larval surface antigen (carla) as the target of mucosal antibodies that can elicit rejection of trichostrongylus colubriformis l3s in sheep. here we characterise the natural mucosal antibody responses to l3s from three major strongylid gastrointestinal para ... | 2007 | 17383657 |
| effect of pelleting on efficacy of sericea lespedeza hay as a natural dewormer in goats. | resistance of gastrointestinal nematodes (gin) to anthelmintic treatment has increased pressure to find alternative, non-chemical control methods. feeding hay of the high condensed tannin (ct) forage sericea lespedeza [sl; lespedeza cuneata (dum-cours.) g. don.] to sheep and goats has reduced gin fecal egg count (fec) and worm numbers in the abomasum and small intestines. this effect has been reported with both unground (long) and ground hay. pelleting of ground hay increases ease of storage, tr ... | 2007 | 17383822 |
| in vitro and in vivo characterization of p-amino-phenethyl-m-trifluoromethylphenyl piperazine (papp), a novel serotonergic agonist with anthelmintic activity against haemonchus contortus, teladorsagia circumcincta and trichostrongylus colubriformis. | the neurotransmitter serotonin (5-hydroxy tryptamine or 5ht) regulates key physiological processes in nematodes such as locomotion and feeding. papp (p-amino-phenethyl-m-trifluoromethylphenyl piperazine) is a known agonist of the 5-ht(1hc) receptor of the barber pole worm, haemonchus contortus. in this study, papp was highly active against l3-stage larvae of h. contortus and trichostrongylus colubriformis in an in vitro larval migration assay, with ec50 values of 9.36 and 11.8 microm, respective ... | 2007 | 17383823 |
| the effects of amount, timing and distribution of simulated rainfall on the development of haemonchus contortus to the infective larval stage. | three studies were undertaken to determine the effects of amount, timing and distribution of simulated rainfall on the developmental success of haemonchus contortus. faeces containing h. contortus eggs were deposited onto pasture plots under a rainfall-activated retractable roof which eliminated incident rainfall. in october (spring) 2004 and january (summer) 2005, the effects of amount (6, 12, 18 or 24 mm) and timing (1, 4, 8 or 15 days post-faecal deposition) of a single simulated rainfall eve ... | 2007 | 17398009 |
| haemonchus contortus: in vitro and in vivo anthelmintic activity of aqueous and hydro-alcoholic extracts of hedera helix. | in vitro anthelmintic activity of crude extracts of the ripe fruits of hedera helix was investigated on eggs and adult nematode parasites haemonchus contortus. aqueous extract of h. helix was also evaluated for in vivo anthelmintic activity at dose of 1.13 and 2.25 g/kg in sheep artificially infected with h. contortus. ed(50) for egg hatch inhibition was 0.12 and 0.17 mg/ml for aqueous and hydro-alcoholic extracts, respectively. there was no statistically significant difference in the activity o ... | 2007 | 17382320 |
| trapping efficacy of duddingtonia flagrans against haemonchus contortus at temperatures existing at lambing in australia. | the aim of this study was to determine the trapping efficacy of duddingtonia flagrans against haemonchus contortus at the temperature ranges experienced around lambing in the major sheep producing regions of australia. faeces were collected from merino wethers, maintained in an animal house and which had received either d. flagrans chlamydospores for a 6-day period (df) or not (nil). faeces were incubated at one of four daily temperature regimens which were composed of hourly steps to provide 6- ... | 2007 | 17349746 |
| scutiaquinones a and b, perylenequinones from the roots of scutia myrtina with anthelmintic activity. | haemonchus contortus is a worm that causes serious infections in livestock. two new perylenequinones, scutiaquinone a (1) and scutiaquinone b (2), have been isolated from a methanol extract of the roots of scutia myrtina by bioassay-guided fractionation, using an assay that kills this parasite in vitro. the structures of compounds 1 and 2 were elucidated by analysis of their 1d- and 2d-nmr and ms spectra. the isolation, structure, and anthelmintic activities of compounds 1 and 2 are reported. | 2007 | 17378532 |
| control of gastrointestinal nematodes with copper oxide wire particles in a flock of lactating polypay ewes and offspring in iowa, usa. | copper oxide wire particles (cowp) have been used to reduce infection of haemonchus contortus in hair breed lambs in southeastern usa without signs of copper toxicity. however, copper sensitivity among breeds and regions varies. the objective was to determine the effectiveness and safety of cowp in lactating polypay ewes and their offspring grazing alfalfa/bluegrass pasture in a rotational grazing system. mature polypay ewes were administered 0, 0.5, 1, or 2 g (n=8 or 9/dose) cowp approximately ... | 2007 | 17433548 |
| expression and purification of an active cysteine protease of haemonchus contortus using caenorhabditis elegans. | many proteolytic enzymes of parasitic nematodes have been identified as possible targets of control. testing these as vaccine or drug targets is often difficult due to the problems of expressing proteases in a correctly folded, active form in standard expression systems. in an effort to overcome these difficulties we have tested caenorhabditis elegans as an expression system for a haemonchus contortus cathepsin l cysteine protease, hc-cpl-1. recombinant hc-cpl-1 with a polyhistidine tag added to ... | 2007 | 17451718 |
| synthesis and anthelmintic activity of cyclohexadepsipeptides with cyclohexylmethyl side chains. | cyclohexadepsipeptides (chdps) with cyclohexylmethyl side chains represent novel enniatins with in vivo activity against the parasitic nematode haemonchus contortus rudolphi in sheep. it was found that the replacement of benzylic by cyclohexylmethyl side chains on the enniatin skeleton can increase anthelmintic efficacy. here we report on a simple total synthesis of the precursors for this type of chdps and an efficient chemical transformation of the benzylic into the corresponding cyclohexylmet ... | 2007 | 17475487 |
| an attempt to eliminate haemonchus contortus from a sheep flock in ontario. | | 1964 | 17421681 |
| trends and challenges in the effective and sustainable control of haemonchus contortus infection in sheep. review. | haemonchosis, with its very wide distribution, has become a very important production constraint in sheep farms in tropical, subtropical and temperate regions worldwide. various intrinsic and extrinsic factors determine the survival of haemonchus contortus and hence the development of the disease in the animal. in general, control of gastrointestinal nematode infestation in sheep relies heavily on anthelmintic treatments. however, the indiscriminate use of these drugs has led to the widespread e ... | 2007 | 17432053 |
| combining the effects of supplementary feeding and copper oxide needles for the control of gastrointestinal nematodes in browsing goats. | the aim was to assess the benefits obtained from combining supplementary feeding and copper needles (cowp), compared to the use of both approaches independently, for the control of gastrointestinal nematode (gin) infections in browsing kids. forty-four nematode free criollo kids were exposed to natural parasite infection. the kids were divided into six experimental groups: not treated, supplemented (nt-s), not treated, not supplemented (nt-ns), moxidectin treated, supplemented (m-s), moxidectin ... | 2007 | 17400391 |
| vaccination of goats with recombinant galectin antigen induces partial protection against haemonchus contortus infection. | the efficacy of vaccination against haemonchus contortus infection with two recombinant proteins, rhco-gal-m and rhco-gal-f, was studied in 9-10-month-old goats. vaccination with 100 microg protein reduced faecal egg output and worm burdens by 37.25% and 41.1%, respectively. corresponding reductions with 200 microg protein were 48.03% and 46.19%. vaccinated groups had significantly higher igg levels than the negative and positive controls. significant negative correlations were detected between ... | 2007 | 17518950 |
| haemonchus contortus: characterization of the baculovirus expressed form of aminopeptidase h11. | recombinant form of haemonchus contortus aminopeptidase h11, an intestinal membrane glycoprotein considered to be in its native form the most promising vaccine candidate, was produced in insect cells, characterised and tested in pilot vaccination-challenge trial on sheep. the sequence of the cloned gene, obtained by rt pcr isolated from adult worms, showed 97% identity to the highly immunogenic h11 clone, described by graham et al., (database accession number aj249941.1). a 1305 bp fragment of h ... | 2007 | 17482594 |
| accuracy of the famacha system for on-farm use by sheep and goat producers in the southeastern united states. | famacha is a practical on-farm system designed to provide small ruminant producers a tool for improving their management of haemonchus contortus infections. although this system has become very popular and widely accepted by small ruminant producers in many regions of the southern united states, there is very limited data reported on the effectiveness of the famacha system when performed by farmers. the objective of this study was to evaluate the accuracy of the famacha system for on-farm use by ... | 2007 | 17482368 |
| morphological characterization of haemonchus contortus in goats (capra hircus) and sheep (ovis aries) in penang, malaysia. | the large stomach worm, haemonchus contortus is an important pathogen of goats (capra hircus) and sheep (ovis aries). this paper describes characteristics of surface cuticular ridges (synlophe) of h. contortus adults from the two hosts. there were more ridges in h. contortus from goats compared to that from sheep. total body length, vulvar morphology, spicule length and cervical papillae had been considered as markers of physical adaptation and were studied and described. | 2007 | 17568374 |
| a rapid colorimetric assay for the quantitation of the viability of free-living larvae of nematodes in vitro. | with increasing drug resistance in gastrointestinal parasites, identification of new anthelmintics is essential. the non-parasitic nematode caenorhabditis elegans is used extensively as a model to identify drug targets and potential novel anthelmintics because it can be readily cultured in vitro. traditionally, the assessment of worm viability has relied on labour-intensive developmental and behavioral assays. the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide-formazan (mtt-formaz ... | 2007 | 17492469 |
| identification of levamisole resistance markers in the parasitic nematode haemonchus contortus using a cdna-aflp approach. | cdna-aflp (cdna-amplified fragment length polymorphism)-based strategy has been used to identify levamisole (lev) resistance markers in the nematode haemonchus contortus. transcript profiles of adult nematodes from two lev-resistant and two susceptible isolates were compared. among the 17 280 transcript-derived fragments (tdfs) amplified, 26 presented a polymorphic pattern between resistant and susceptible nematodes: 11 tdfs were present in both resistant isolates and absent from both susceptibl ... | 2007 | 17608970 |
| nematode ligand-gated chloride channels: an appraisal of their involvement in macrocyclic lactone resistance and prospects for developing molecular markers. | summaryligand-gated chloride channels, including the glutamate-(glucl) and gaba-gated channels, are the targets of the macrocyclic lactone (ml) family of anthelmintics. changes in the sequence and expression of these channels can cause resistance to the ml in laboratory models, such as caenorhabditis elegans and drosophila melanogaster. mutations in multiple glucl subunit genes are required for high-level ml resistance in c. elegans, and this can be influenced by additional mutations in gap junc ... | 2007 | 17608971 |
| abc transporters and beta-tubulin in macrocyclic lactone resistance: prospects for marker development. | macrocyclic lactones (mls) are highly lipophilic anthelmintics which are known to bind to and open ligand-gated ion channels. however, these anthelmintics, and particularly the avermectin members of the ml class of endectocides, are potent substrates for abc transporters and these transporters may regulate drug concentration in both the host and the parasite. there is accumulating evidence that ivermectin (ivm), and to a lesser extent moxidectin (mox), selects for certain alleles of p-glycoprote ... | 2007 | 17608972 |
| anthelmintic activity of croton zehntneri and lippia sidoides essential oils. | because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. the aim of this study was to evaluate the anthelmintic activity of croton zehntneri and lippia sidoides essential oils and their major constituents, anethole and thymol. the effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode haemonchus contortus. the two ... | 2007 | 17629623 |
| use of copper oxide wire particles to control gastrointestinal nematodes in goats. | the objectives of these experiments were to determine the optimal dose of copper oxide wire particles (cowp) necessary to reduce gastrointestinal nematode (gin) infection in young and mature goats naturally infected with haemonchus contortus or a mixed infection and to determine whether the effectiveness could be enhanced through feeding management. two experiments were conducted during cooler months in georgia, and 4 experiments were conducted during warmer spring or summer months in arkansas. ... | 2007 | 17565056 |
| the second glutamic acid in the c-terminal crd affects the carbohydrate-binding properties of recombinant galectins of haemonchus contortus. | the effects of the second glutamic acid (e) in the c-terminal crds on the hemagglutination and lactose-binding characteristics of the recombinant galectins of nematode haemonchus contortus were observed using two isoforms of recombinant galectins as models, and the sugar-binding abilities of the n-terminal and c-terminal crds of the galectins were also compared. the second e in the crd, wgneer, of hco-gal-m was mutated to glycine acid (g) and resulted in a recombinant galectin (mg mutate) with a ... | 2007 | 17643820 |
| attempts to detect synergy between vaccination and anthelmintic against a drug resistant isolate of haemonchus contortus. | an experiment was conducted to determine whether any synergistic activity could be detected between an experimental vaccine and anthelmintic treatment against a drug resistant strain of haemonchus contortus, i.e. would the combined effect of both interventions be greater than the sum of either alone. two groups of 14 worm-free sheep were immunised twice, either with haemonchus galactose containing glycoprotein complex (h-gal-gp) in quila as adjuvant or with adjuvant alone. all were challenged wi ... | 2007 | 17643823 |
| immune response to haemonchus contortus infection in susceptible (inra 401) and resistant (barbados black belly) breeds of lambs. | the immune responses to haemonchus contortus were compared in studies in resistant barbados black belly (bbb) and susceptible inra 401 (inra) breeds of lambs. the cytokine patterns indicated a th2-biased response in both breeds. a more persistent and elevated th2 cytokine mrna transcription and blood eosinophilia were noted in the bbb lambs. however, at days 4 and 30 post-infection, abomasal recruitment of eosinophils and mast cells were similar between the two breeds. following primary infectio ... | 2007 | 17650183 |
| in vitro pre-exposure of haemonchus contortus l3 to blood eosinophils reduces their establishment potential in sheep. | different authors have reported that eosinophils are capable of immobilising infective larvae of different species of nematodes in vitro. however, classifying larvae as mobile or immobile is so subjective that it does not always mean all apparently immobile larvae are dead or those that are mobile are capable of surviving further immune responses if administered to their natural hosts. the objective of this experimental study was therefore to substantiate the role of eosinophils in the killing o ... | 2007 | 17682295 |
| haemonchosis and teladorsagiosis in a scottish sheep flock putatively associated with the overwintering of hypobiotic fourth stage larvae. | the cause of ill thrift and deaths was investigated in a group of 40 scottish lowground ewes, which had been treated with levamisole and then turned onto clean grazing after lambing, 6-8 weeks previously. concurrent haemonchosis and teladorsagiosis were diagnosed, putatively associated with the spring maturation of large numbers of hypobiotic larvae. ill thrift due to parasitic gastroenteritis consequently occurred in the lambs which had been turned onto the 'clean' grazing with their dams, desp ... | 2007 | 17531390 |
| abomasal nematodes of the red deer cervus elaphus in north-eastern italy. | the composition of the abomasal helminth fauna and parasite diversity were studied in 298 red deer collected during 1997-2000 from three different sectors (bolzano, trento and sondrio provinces) of the stelvio national park, one of the main protected areas of north-eastern italy. the association between parasite burdens and geographical areas of the hosts was assessed using the negative binomial regression. a variety of abomasal helminths, both host specific and generalist, was found in all sect ... | 2007 | 17594740 |
| gender-enriched transcripts in haemonchus contortus--predicted functions and genetic interactions based on comparative analyses with caenorhabditis elegans. | in the present study, a bioinformatic-microarray approach was employed for the analysis of selected expressed sequence tags (ests) from haemonchus contortus, a key parasitic nematode of small ruminants. following a bioinformatic analysis of est data using a semiautomated pipeline, 1885 representative ests (rests) were selected, to which oligonucleotides (three per est) were designed and spotted on to a microarray. this microarray was hybridized with cyanine-dye labelled crna probes synthesized f ... | 2008 | 17707841 |
| microsatellite analysis reveals marked genetic differentiation between haemonchus contortus laboratory isolates and provides a rapid system of genetic fingerprinting. | many of the haemonchus contortus isolates currently used for experimental work were originally derived from different regions of the world and are commonly exchanged between laboratories. in most cases, these are largely genetically uncharacterised other than the analyses conducted on specific genes of interest. we have used a panel of eight microsatellite markers to genetically characterise five different commonly used h. contortus isolates including mhco3 (ise), the isolate chosen for full gen ... | 2008 | 17727857 |
| the effect of dietary protein supplementation on the pathophysiology of haemonchus contortus infection in west african dwarf goats. | the effect of dietary protein on the pathophysiology of haemonchus contortus infection in reproducing first pregnancy west african dwarf (wad) goats was studied. eighteen 10-12-month-old pubertal female wad goats divided into two equal groups were used and confined separately. one group was maintained on high-protein diet (hpd) while the other was maintained on low-protein diet (lpd) from day 1 of pregnancy up to week 6 post-partum. each animal was infected with 600 infective larvae of h. contor ... | 2007 | 17689870 |
| anthelmintic macrolactams from nonomuraea turkmeniaca ma7364. | two new macrolactams, 6-desmethyl-n-methylfluvirucin a1 (1) and n-methylfluvirucin a1 (2), have been isolated from the acetone extract of nonomuraea turkmeniaca ma7364. these compounds were isolated by bioassay-guided fractionation as part of our search for new anthelmintics. the structures of these compounds were elucidated by comparison of their nmr and ms data to those of previously reported fluvirucins and confirmed by 2d nmr. compound 1 exhibited in vitro activity (ec(90) 15 +/- 5 microg/ml ... | 2007 | 17636954 |
| in vitro detection of benzimidazole resistance in haemonchus contortus: egg hatch test versus larval development test. | the present study was designed to compare the egg hatch test (eht) and the larval development test (ldt) as in vitro tools for detection of benzimidazole (bz) resistance in haemonchus contortus, a nematode parasite of small ruminants. comparisons were made during a course of infection and changes in both eht and ldt were monitored to measure the correlation between resistance and susceptibility in different parasite stages (eggs and larvae). in addition, mixed doses of known numbers of susceptib ... | 2007 | 17697753 |
| performance and nematode infection of ewe lambs on intensive rotational grazing with two different cultivars of panicum maximum. | the daily live weight gain (dlwg), faecal nematode egg counts (fec), and packed cell volume (pcv) of suffolk, ile de france and santa inês ewe lambs were evaluated fortnightly for 56 days in the dry season (winter) and 64 days in the rainy season (summer) of 2001-2002. the animals were distributed in two similar groups, one located on aruana and the other on tanzania grass (panicum maximum), in rotational grazing system at the instituto de zootecnia, in nova odessa city (sp), brazil. in the dry ... | 2007 | 17847820 |
| moisture requirements for the free-living development of haemonchus contortus: quantitative and temporal effects under conditions of low evaporation. | the key influence of moisture availability on development of the free-living stages of haemonchus contortus is well-documented, although quantitative relationships between moisture variables and development are poorly defined. a factorial experiment (3x2x2) was conducted in programmable incubators to determine the effects of amount and distribution of simulated rainfall on h. contortus development at low evaporation rates (approximately 2 mm/day) under temperatures typical of summers on the nort ... | 2007 | 17920198 |
| the requirement for early exposure of haemonchus contortus larvae to bacillus thuringiensis for effective inhibition of larval development. | the potential for a nematocidal bacillus thuringiensis (bt) to target the free-living larval stages of haemonchus contortus was examined using in vitro larval development and migration assays. bt toxicity in larval development assays decreased as the time period between egg hatch and initial exposure to the bt was increased; a time lag of 48 h resulted in a 350-fold increase in the ic(50) (from 2.6 ng/ml to 910 ng/ml). the effects on larval migration largely paralleled the effects on larval deve ... | 2007 | 17951006 |
| anthelmintic activity of chenopodium album (l) and caesalpinia crista (l) against trichostrongylid nematodes of sheep. | the present study was carried out to determine the anthelmintic activity of caesalpinia crista (l.) (fabaceae) seed kernel and chenopodium album (l.) (chenopodiaceae) whole plant in order to justify their traditional use in veterinary medicine. | 2007 | 17826017 |
| prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern ethiopia. | a 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (gi) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern ethiopia. during may 2003 to april 2005, viscera including liver, lungs and gi tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of haramaya, harar, dire dawa and jijiga in eastern ethiopia. all animals were raised in the farming areas ... | 2007 | 17969715 |
| trichostrongylus colubriformis and haemonchus contortus infections in light bodyweight merino lambs. | objective; to show that low bodyweight is a predisposing cause of high trichostrongylus colubriformis and haemonchus contortus burdens and egg counts in merino lambs. | 2007 | 17970846 |
| gastrointestinal nematode challenge induces some conserved gene expression changes in the gut mucosa of genetically resistant sheep. | sheep have a varying ability to resist infection with gastrointestinal nematodes. this ability is due in part to genetic differences that exist between individuals. in order to define these differences we have used real-time pcr to quantify gene expression responses in the gut mucosal surface of genetically resistant and susceptible sheep, following a nematode challenge. expression profiles were determined in response to two different nematode species, haemonchus contortus and trichostrongylus c ... | 2008 | 17826780 |
| a pair of adjacent genes, cry5ad and orf2-5ad, encode the typical n- and c-terminal regions of a cry5adelta-endotoxin as two separate proteins in bacillus thuringiensis strain l366. | a new dna sequence cry5ad/orf2-5ad (genbank accession number ef219060) was isolated from bacillus thuringiensis strain l366. this dna sequence contains two orfs: cry5ad (a previously unreported member of the cry5a gene family) and orf2-5ad. cry5ad is unique among cry5a genes in that it encodes only the n-terminal region of a typical cry5adelta-endotoxin. the cry5ad sequence includes homology blocks 1-5, which are present in most b. thuringiensisdelta-endotoxins. the usual c-terminal region of a ... | 2008 | 18028391 |
| experimental infection of haemonchus contortus strains resistant and susceptible to benzimidazoles and the effect on mast cells distribution in the stomach of mongolian gerbils (meriones unguiculatus). | establishment rate of haemonchus contortus in non-suppressed and immunosuppressed gerbils within 14 days post-infection was compared after inoculation with 1,000 third-stage larvae (l3), exsheathed bz-susceptible larvae. based on significantly higher number of larvae in gerbils receiving low doses of immunosuppressant agent hydrocortisone, development of benzimidazole (bz)-susceptible and bz-resistant strain of nematode in the stomach was studied on days 4, 7, 10, and 14 p.i. sections of stomach ... | 2008 | 18040719 |
| in vitro nematicidal effects of medicinal plants from the sierra de huautla, biosphere reserve, morelos, mexico against haemonchus contortus infective larvae. | twenty extracts from plants from sierra de huautla biosphere reserve, morelos, mexico were evaluated against haemonchus contortus infective larvae in an in vitro assay. the plant species evaluated were bursera copallifera, b. grandifolia, lippia graveolens, passiflora mexicana, prosopis laevigata, randia echinocarpa and urtica dioica. the plants were separated into their parts and macerated with different solvents (n-hexane, acetone, ethanol and methanol). an in vitro assay was used to evaluate ... | 2008 | 18053304 |
| biotransformation of flubendazole and selected model xenobiotics in haemonchus contortus. | haemonchus contortus is one of the most pathogenic parasites of small ruminants (e.g., sheep and goat). the treatment of haemonchosis is complicated because of frequent resistance of h. contortus to common anthelmintics. the development of resistance can be facilitated by the action of drug metabolizing enzymes of parasites that can deactivate anthelmintics and thus protect parasites against the toxic effect of the drug. the aim of this project was to investigate the phase i biotransformation of ... | 2008 | 18054171 |
| development under sterile conditions of the sheep stomach worm haemonchus contortus (nematoda). | | 1938 | 17821615 |
| genetic and phenotypic differences between isolates of haemonchus contortus in australia. | we believe this study is the first to consider the genetic and phenotypic divergence between isolates of haemonchus contortus in australia. microsatellite markers have been used to investigate genetic divergence, whilst phenotypic divergence has been considered through individual worm morphology, isolate life history traits and the effect of isolates upon the host. the results are discussed in the context of the likely introduction of h. contortus to australia, its recent isolation, and the char ... | 2008 | 18068173 |
| identification of a 55 kda haemonchus contortus excretory/secretory glycoprotein as a neutrophil inhibitory factor. | haemonchus contortus is an economically important gastric parasite infecting sheep and goats. the parasite survives the host immune attack by releasing protective molecules. in the present study, a 55 kda secretory glycoprotein (gp55) was identified that inhibited host neutrophils as judged by reduced h2o2 production by these cells. the binding of gp55 to neutrophils was confirmed by flow cytometry. this binding was mediated by cellular cd11b/cd18 integrin. the glycoprotein gp55 also bound to go ... | 2008 | 18086013 |
| parasiticidal 2-alkoxy- and 2-aryloxyiminoalkyl trifluoromethanesulfonanilides. | a series of novel 2-alkoxy- and 2-aryloxyiminoalkyl trifluoromethanesulfonanilide derivatives have shown significant in vitro parasiticidal activity against the ectoparasites ctenocephalides felis and rhipicephalus sanguineus. a number of these compounds also displayed significant in vitro endoparasite activity against the nematode haemonchus contortus. | 2008 | 18006308 |
| protection against high-dose homologous infection in calves immunized with intestine or membrane extracts from haemonchus placei. | control of haemonchus placei, one of the most important cattle nematodes in brazil, relies on the use of anthelmintics. however, there is a need for integrated control, which includes active immunization. the aim of this work was to assess the protection afforded to calves by immunization with adult h. placei extracts against a high-dose challenge infection, a condition frequently found in the tropics. holstein calves aged 8-10 months were immunized four times with intestinal extracts (group d) ... | 2008 | 18065148 |
| gender-enriched transcription of activation associated secreted proteins in ostertagia ostertagi. | activation associated secreted proteins (asp) are members of a nematode-specific protein family belonging to the scp/tpx-1/ag5/pr-1/sc7 family. three different types of molecules have been identified in this family: two-domain asps and single-domain asps showing homology to either the c-terminal or n-terminal domain of the two-domain asp. the function of these proteins is still unclear, but a role in transition to parasitism and a role as allergen are often suggested. here we report that the abo ... | 2008 | 17961575 |
| characterization of a galectin-like activity from the parasitic nematode, haemonchus contortus, which modulates ovine eosinophil migration in vitro. | the development of eosinophilia is a characteristic feature of helminth infection, although the exact nature of the interaction between eosinophils and parasites remains to be fully defined. previously, it has been reported that haemonchus contortus and other nematodes produce eosinophil-specific chemoattractants. this paper describes studies aimed at isolating and identifying the factor(s) responsible. initial studies showed that soluble extracts of infective larvae (l3) of h. contortus provoke ... | 2008 | 18187208 |
| using 454 technology for long-pcr based sequencing of the complete mitochondrial genome from single haemonchus contortus (nematoda). | mitochondrial (mt) genomes represent a rich source of molecular markers for a range of applications, including population genetics, systematics, epidemiology and ecology. in the present study, we used 454 technology (or the gs20, massively parallel picolitre reactor platform) to determine the complete mt genome of haemonchus contortus (nematoda: trichostrongylidae), a parasite of substantial agricultural, veterinary and economic significance. we validate this approach by comparison with mt seque ... | 2008 | 18190685 |
| effects of sainfoin (onobrychis viciifolia) extract and monomers of condensed tannins on the association of abomasal nematode larvae with fundic explants. | tannin-rich forages offer an alternative to anthelmintic chemicals to control gastrointestinal nematodes. however, the mode of action of such bioactive plants still needs to be assessed. previous studies have shown that extracts of tannin-rich plants interfere with the first phase of host invasion, i.e., the exsheathment of infective larvae (l3s). in the current study, we examined the hypothesis that exposure to tannins could also affect the second phase of larval establishment, i.e., the tissue ... | 2008 | 18093592 |
| a novel member of the ligand-gated chloride channel gene family from haemonchus contortus. | ligand-gated chloride channels (lgccs) are key components of the nervous system of parasitic nematodes and important targets for anthelmintics. here, we describe the isolation and characterization of a novel member of the lgcc gene family (hclgcc1) from the parasitic nematode haemonchus contortus. sequence analysis revealed that the channel subunit encoded by hclgcc1 is anion selective and a member of a group of channels characterized as having two cys-loops in the n-terminal ligand-binding doma ... | 2008 | 18093350 |
| the anthelmintic effect of phenothiazine administered in small daily doses to lambs bearing heavy infestations of haemonchus contortus. | | 1949 | 18119134 |
| genetic analysis of a relationship between macrocyclic lactone and benzimidazole anthelmintic selection on haemonchus contortus. | we have found that in a laboratory strain of the nematode parasite of ruminants, haemonchus contortus, repeated ivermectin treatment, in vivo in sheep, selected against ttc, coding for phe, and for tac, coding for tyr, at codon 200 in beta-tubulin isotype 1. this 200tyr single nucleotide polymorphism (snp) has been associated with benzimidazole anthelmintic resistance. in this study, we investigated the alpha-tubulin and beta-tubulin sequences of 17 different field and laboratory strains/isolate ... | 2008 | 18192899 |
| p-glycoprotein selection in strains of haemonchus contortus resistant to benzimidazoles. | anthelmintic resistance in parasitic nematodes of livestock is a chronic problem in many parts of the world. benzimidazoles are effective, broad-spectrum anthelmintics that bind to and selectively depolymerise microtubules. resistance to the benzimidazoles, however, developed quickly and is caused by genetic changes in genes encoding beta-tubulins, subunits of microtubules. in haemonchus contortus, resistance to avermectins has been correlated with genetic changes at a gene encoding a p-glycopro ... | 2008 | 18241994 |
| haemonchus contortus: development of a two-step, differential-display pcr to detect differential gene expression in nematodes from immune and naïve sheep. | haemonchus contortus is a blood-feeding nematode which parasitizes the abomasum of sheep and represents a serious constraint to sheep production. anthelmintics are currently the most common method of worm control but the worldwide development of multiple-drug resistance and issues of residues in the food chain make alternatives to anthelmintics a priority. biotechnology-driven solutions to parasitism include vaccines and silencing of genes regulating nematode development. to pursue gene targets ... | 2008 | 18329022 |
| cellular phenotypes in the abomasal mucosa and abomasal lymph nodes of goats infected with haemonchus contortus. | the distribution of t-cell subsets (cd2, cd4, cd8, and gammadelta) and b cells (igm) was examined at 3, 6, 10 and 13 days post-infection (dpi) in the abomasal mucosa and abomasal lymph nodes of goats primarily infected with haemonchus contortus. in the abomasal mucosa a mild (3 and 6 dpi) or marked (10 and 13 dpi) increase of t cells, particularly cd4+ and gammadelta+ lymphocytes, was observed, whereas the increase in cd8+ cells was less pronounced. b cells and igg+ plasma cells also showed a ma ... | 2008 | 18295783 |
| vaccination against haemonchus contortus: performance of native parasite gut membrane glycoproteins in merino lambs grazing contaminated pasture. | in a replicated trial, parasitological and antibody responses of grazing weaner merino sheep were assessed following vaccination with gut membrane proteins prepared from adult worms of the gastrointestinal nematode, haemonchus contortus. each vaccinated animal received 100 microg native h11 and 100 microg native h-gal-gp combined together in 5mg quil a administered intramuscularly on days 0, 34, 80 and 127. control animals received 5mg quil a alone on the same days. vaccinated and unvaccinated c ... | 2008 | 18337013 |
| haemonchus contortus infection in sheep: parasite fecundity correlates with worm size and host lymphocyte counts. | two experiments were conducted to elucidate the timing and nature of the sheep immune response to haemonchus contortus (barber's pole worm). the first experiment examined the establishment of h. contortus populations and the immune response by comparing a bolus infection of third-stage larvae in naïve sheep with a group previously primed by a trickle infection. the second experiment used staggered doses of ivermectin-resistant larvae to compare the development of adult worms during different dur ... | 2008 | 18337014 |
| haemonchus contortus: evaluation of two signal sequence trapping systems for detection of secreted molecules. | given that signal sequences between secreted proteins of different species can be interchanged, it is reasonable to expect that both mammalian and yeast signal sequence trapping (sst) systems would secrete haemonchus contortus proteins with similar efficiency and quality. to determine if h. contortus cdnas that contain a signal sequence could re-establish secretion of a reporter protein, mammalian and yeast sst vectors were designed, 10 h. contortus genes selected, and their respective cdnas clo ... | 2008 | 18267320 |
| lc-ms-ms identification of albendazole and flubendazole metabolites formed ex vivo by haemonchus contortus. | resistance of helminth parasites to common anthelminthics is a problem of increasing importance. the full mechanism of resistance development is still not thoroughly elucidated. there is also limited information about helminth enzymes involved in metabolism of anthelminthics. identification of the metabolites formed by parasitic helminths can serve to specify which enzymes take part in biotransformation of anthelminthics and may participate in resistance development. the aim of our work was to i ... | 2008 | 18344069 |
| nitrogen and mineral balance of lambs artificially infected with haemonchus contortus and fed tanniferous sainfoin (onobrychis viciifolia). | tanniferous temperate legumes are assumed to possess anthelmintic properties, but it is unclear whether this is the direct result of condensed tannins (ct) or is mediated indirectly via an improved metabolic protein supply. a metabolism experiment was conducted to differentiate between these factors by feeding the ct plant sainfoin (19.7% cp in dm) to lambs infected with the abomasal blood-sucking nematode hemonchus contortus. a total of 18 infected lambs were fed sainfoin either untreated or tr ... | 2008 | 18375660 |
| in vitro larval migration and kinetics of exsheathment of haemonchus contortus larvae exposed to four tropical tanniniferous plant extracts. | as for some temperate forage, some tropical tanniniferous plants (ttp) from browsing might represent an alternative to chemical anthelmintic. the anthelmintic effect of four ttp (acacia pennatula, lysiloma latisiliquum, piscidia piscipula, leucaena leucocephala) on haemonchus contortus was measured using two in vitro assays. first, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200 microg/ml pbs) were tested on h. contortus larvae (l(3)) using the larval migrat ... | 2008 | 18378085 |
| genomic analyses of haemonchus contortus infection in sheep: abomasal fistulation and two haemonchus strains do not substantially confound host gene expression in microarrays. | to determine whether fistulation and differing strains of haemonchus contortus complicate genome analysis of the host response to infection, two pilot experiments examined parasite development and gene expression in the abomasal mucosa of parasitised sheep. no significant differentially-expressed genes were detected in a comparison between ivermectin-susceptible mcmaster and ivermectin-resistant cavr strains of h. contortus. this demonstrated that the sheep response was not significantly altered ... | 2008 | 18387746 |
| comparative experimental haemonchus contortus infection of two sheep breeds native to the canary islands. | this study compares the susceptibility to haemonchus contortus infection in two breeds of sheep endemic to the canary islands, the canaria hair breed sheep and the canaria sheep. sheep were experimentally infected with 20,000 larvae of h. contortus and animals killed on days 7 and 28 post-infection. no difference between sheep breeds were detected in immature worm counts at days 7 or 28 post-infection. however, in comparison to the canaria sheep breed, the canaria hair breed sheep showed lower m ... | 2008 | 18394807 |
| isolation and characterization of a gene encoding carbonic anhydrase from ostertagia ostertagi and quantitative measurement of expression during in vivo exsheathment. | the first event in the establishment of ostertagia ostertagi infection in cattle is exsheathment. exsheathment is the process whereby the l(2) cuticle retained from the previous molt is cast from the l3. for those trichostrongyle nematode species with a predilection site in the abomasum, such as o. ostertagi, exsheathment is initiated as the larvae pass through the rumen. although the stimulus for exsheathment is not known, previously reported biochemical studies suggest a major role for the enz ... | 2008 | 18400401 |
| discovery of amino-acetonitrile derivatives, a new class of synthetic anthelmintic compounds. | a new series of amino-acetonitrile derivatives (aad) have been discovered that exhibit high anthelmintic activity against parasitic nematode species such as haemonchus contortus and trichostrongylus colubriformis. significantly, these compounds also demonstrate activity against nematode strains resistant to the currently available broad-spectrum anthelmintics. the discovery, synthesis, structure-activity relationship and biological results are presented. | 2008 | 18400497 |
| anthelmintic macrolactams from nonomuraea turkmeniaca ma7381. | a new macrolactam, fluvirucin b0 (1), and two known macrolactams, sch 38516/fluvirucin b1 (2) and sch 39185/fluvirucin b3 (3), have been isolated from an acetone extract of a strain of nonomuraea turkmeniaca. these compounds were isolated by bioassay-guided fractionation as part of our search for new anthelmintics. the structures of these compounds were elucidated by comparison of their nmr and ms data to those of previously reported fluvirucins, and confirmed by 2d-nmr. 1approximately 3 exhibit ... | 2008 | 18408323 |
| thioredoxins of a parasitic nematode: comparison of the 16- and 12-kda thioredoxins from haemonchus contortus. | thioredoxins are a family of small proteins conserved through evolution, which are essential for the maintenance of cellular homeostasis. the "classic" thioredoxin, identified in most species, is a 12-kda protein with a cys-pro-gly-cys (cpgc) active site. however, in nematodes a larger protein, 16 kda, with a cys-pro-pro-cys (cppc) active site was identified. we report that in the parasitic nematode haemonchus contortus, both the 12-kda (hctrx1) and the 16-kda (hctrx3) species are expressed thro ... | 2008 | 18410747 |
| anthelmintic efficacy of achillea millifolium against gastrointestinal nematodes of sheep: in vitro and in vivo studies. | achillea millifolium linn., commonly called 'pehl-ghasa', is used by farmers in traditional animal health care as a vermifuge. the objective of this study was to evaluate the anthelmintic efficacy of crude aqueous extracts and crude ethanolic extracts of entire a. millifolium against the gastrointestinal nematodes of sheep. the worm motility inhibition assay was used for in vitro studies and faecal egg count reduction assay was used for in vivo studies. in vitro studies revealed significant anth ... | 2008 | 18419857 |
| development of a faecal occult blood test to determine the severity of haemonchus contortus infections in sheep. | haemonchus contortus commences feeding on host blood by day 11 of infection, which leads to the presence of blood in the host's faeces. this study examined the capacity for a faecal occult blood (fob) test to determine the severity of h. contortus infection in sheep at pasture, and to predict a rise in worm egg count (wec) as infection matures. diluted faeces were assayed with bayer hemastix and the change in colour of the reagent patch was scored on a 9-point scale from 1 (negative) to 5 in hal ... | 2008 | 18299173 |
| haemonchus contortus calreticulin binds to c-reactive protein of its host, a novel survival strategy of the parasite. | calreticulin (calr), a ca(2+) binding multifunctional protein, is secreted by the parasitic nematode haemonchus contortus. we have earlier observed binding of this protein to a 24-kda polypeptide (p24) present in an enriched preparation of prothrombin. in the present study, the identity of p24 was established as a c-reactive protein (crp) by several criteria. calr binding to crp is an elegant strategy devised by the parasite to survive in the host. the secreted calr may achieve this either by li ... | 2008 | 18422872 |
| detection of anti-haemonchus contortus antibodies in sheep by dot-elisa with immunoaffinity purified fraction of es antigen during prepatency. | haemonchosis is a very common disease in small ruminants caused by h. contortus, a blood sucking parasite causing anaemia that may be fatal particularly to young animals. therefore, detection of the infection during prepatent period is important for early treatment. excretory-secretory (es) protein of h. contortus was purified through immunoaffinity chromatography. dot -elisa was performed with crude es antigen as well as immunoaffinity purified fraction (f-1) with experimental and natural sera ... | 2008 | 18335806 |
| arrested development of sheep strongyles: onset and resumption under field conditions of central europe. | two tracer tests were conducted between august 2004 and march 2007 at an ecological farm in western bohemia. the first tracer test was performed for the summer-autumn grazing period (onset of arrested development), the second for spring (resumption of arrested development). in the first tracer test, the percentage of nematodes arresting development over the winter months reached 87.7% for teladorsagia circumcincta, 66.7% for haemonchus contortus, 89.9% for nematodirus filicollis, 21.6% for trich ... | 2008 | 18454350 |