| interaction between copper oxide wire particles and duddingtonia flagrans in lambs. | an experiment was completed to determine if copper oxide wire particles (cowp) had any effect on the activity of the nematode-trapping fungus duddingtonia flagrans in growing lambs. cowp has been used recently as a dewormer in small ruminants because of nematode resistance to anthelmintics. d. flagrans has been used to control free-living stages of parasitic nematodes in livestock. katahdin and dorper lambs, 4 months of age, were administered no or 4 g cowp (n=24/dose) in early october 2003. hae ... | 2005 | 16085365 |
| influence of dietary protein supply on resistance to experimental infections with haemonchus contortus in ile de france and santa ines lambs. | the effect of haemonchus contortus infection in sheep fed with a moderate and high protein content diet was evaluated in two breeds of sheep. forty-eight ile de france and santa ines lambs were maintained indoors since birth, in worm-free conditions. the lambs were allocated after weaning in four groups of six animals per breed, which were either infected or remain uninfected and given access to either a moderately or highly metabolizable protein diet. the moderately and highly metabolizable pro ... | 2005 | 16098676 |
| cells, cytokines and other molecules associated with rejection of gastrointestinal nematode parasites. | infections with gastrointestinal nematodes represent a major problem for human health and animal health and production. the physical size of the parasite, its changing life-cycle stages and the relative inaccessibility to host cells pose unique challenges to the immune system, which has evolved specialized strategies for parasite control. this paper reviews the work performed in the authors' laboratories to identify components that are involved in the natural rejection response against ruminant ... | 2005 | 16099054 |
| lack of effects of quebracho and sainfoin hay on incoming third-stage larvae of haemonchus contortus in goats. | the effects of tannins on adult populations of haemonchus contortus, trichostrongylus colubriformis and teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. in contrast, the impact of tannins on t. colubriformis or t. circumcincta third-stage larvae (l3) is associated with a significant reduction in worm establishment. the objective of the present study was to examine the effects of quebracho extract tannins on ... | 2005 | 16129346 |
| survey of nematophagous fungi in south africa. | three hundred and eighty-four samples of leaf litter, soil, faeces from domestic and game animals, compost and aqueous cultures of infective nematode larvae contaminated with unidentified fungi were plated out on water agar, baited with pure infective larvae of haemonchus contortus, incubated and examined for the presence of nematophagous fungi. duddingtonia flagrans was isolated from five samples, and 73 samples were positive for other nematophagous fungi. | 2005 | 16137137 |
| impact on productivity of peri-parturient rise in fecal egg counts in creole goats in the humid tropics. | the control of gastrointestinal nematodes requires an understanding of their epidemiology so that particular parasite stages can be targeted. dam infection during early lactation is one example of this in ruminant nematode infections. the existence of the peri-parturient relaxation in immunity and its impact on productivity were examined in a creole goat flock from guadeloupe, exposed to mixed natural infection (predominantly haemonchus contortus and trichostrongylus colubriformis). a total of 1 ... | 2005 | 16165278 |
| synthesis and anthelmintic properties of arylquinolines with activity against drug-resistant nematodes. | 2,4-disubstituted quinolines with additional substituents in positions 5-8 have been found to have anthelmintic properties. a number of 2,4-dimethoxy-6- or 8-arylquinolines have potent activity against the sheep nematode haemonchus contortus, with ld99 values of the same order of magnitude as levamisole. these arylquinolines maintain their activity against levamisole-, ivermectin- and thiabendazole-resistant strains of h. contortus. | 2005 | 16165359 |
| effect of bioactive compounds from sainfoin ( onobrychis viciifolia scop.) on the in vitro larval migration of haemonchus contortus: role of tannins and flavonol glycosides. | anthelmintic bioactivity against gastrointestinal nematodes has been associated with leguminous forages supporting the hypothesis of a role of condensed tannins. however, the possibility that other compounds might also been involved has received less consideration. using bio-guided fractionation, the current study aimed at characterizing the biochemical nature of the active compounds present in sainfoin (onobrychis viciifolia ), previously identified as an anthelmintic leguminous forage. the eff ... | 2005 | 16174418 |
| haemonchus contortus: molecular cloning, sequencing, and expression analysis of the gene coding for the small subunit of ribonucleotide reductase. | gastro-intestinal (gi) parasites are of great agricultural importance, annually costing the livestock industry vast amounts in resources to control parasitism. one such gi parasite, haemonchus contortus, is principally pathogenic to sheep; with the parasite's blood-feeding behaviour causing effects ranging from mild anaemia to mortality in young animals. current means of control, which are dependent on repeated treatment with anthelmintic chemicals, have led to increasing drug resistance. togeth ... | 2005 | 16183060 |
| improving resilience against natural gastrointestinal nematode infections in browsing kids during the dry season in tropical mexico. | the objective was to determine the effect of supplementary feeding on the resilience and resistance of criollo kids against natural gastrointestinal nematode (gin) infections, when browsing native vegetation during the dry season in tropical mexico. thirty-three two-month-old criollo kids, raised nematode free, were included at weaning in a 20-week trial. the kids were placed into four groups. two groups of eight kids were offered 100g/day soybean and sorghum meal (26%:74% respectively fresh bas ... | 2006 | 16203095 |
| anthelmintic resistance of nematode parasites of small ruminants in eastern ethiopia: exploitation of refugia to restore anthelmintic efficacy. | faecal egg count reduction tests (fecrt) were conducted in may 2003 to determine the efficacy of anthelmintics used for treatment against nematode parasites in separately managed sheep and goat flocks at alemaya university in eastern ethiopia. these tests revealed high levels of anthelmintic resistance to albendazole, tetramisole, the combination of these two drugs, and to ivermectin in the goat flock (predominantly infected by haemonchus contortus and trichostrongylus spp.), whereas all drugs w ... | 2006 | 16213096 |
| influence of the cyclooctadepsipeptides pf1022a and pf1022e as natural products on the design of semi-synthetic anthelmintics such as emodepside. | the 24-membered cyclooctadepsipeptide (codp) pf1022a, the active metabolite of the fungus imperfectus mycelia sterilia (rosellinia sp.) isolated from the plant camellia japonica in japan, is described as a powerful broad-spectrum anthelmintic natural product with low toxicity in animals. further codps such as pf1022b, c, d and e have been isolated from the same culture and their structures have been established. both pf1022a and pf1022e serve as valuable starting materials for the synthesis of s ... | 2005 | 16228266 |
| cyclohexadepsipeptides (chdps) with improved anthelmintical efficacy against the gastrointestinal nematode (haemonchus contortus) in sheep. | besides 24-membered cyclooctadepsipeptides (codps) with the most prominent member of this class emodepside, the structurally related 18-membered cyclohexadepsipeptides (chdps) were of interest with regard to their efficacy against the nematode h. contortus in sheep.the chdps prepared by a simple total synthesis represent enniatin derivatives with strong in vivo activity against h. contortus in sheep. the correlation between the nature of the chdp major conformers and their anthelmintic activitie ... | 2005 | 16228271 |
| putative g protein-coupled receptors in parasitic nematodes--potential targets for the new anthelmintic class cyclooctadepsipeptides? | parasitic nematodes cause major problems in livestock animals. resistances to the most commonly used drugs are arising. the cyclooctadepsipeptide emodepside belongs to a new class of anthelmintics. a receptor for emodepside, hc110-r, was previously identified in haemonchus contortus. we have identified the complete coding sequences of putative orthologues in cooperia oncophora and ostertagia ostertagi, tri-chostrongyles in cattle. the putative receptors were named depsiphilins. the deduced amino ... | 2005 | 16228272 |
| rna interference in haemonchus contortus: suppression of beta-tubulin gene expression in l3, l4 and adult worms in vitro. | we have used rnai to target two beta-tubulin genes in the parasitic stages of haemonchus contortus in vitro. soaking exsheathed-l3, l4 and adult worms in medium containing dsrna resulted in a significant decrease (greater than 1000-fold in some cases) in the expression of the specific beta-tubulin transcript, as measured by quantitative pcr. during the initial 24h exposure to the dsrna, the gene suppression effect was quite specific to the targeted gene. six days after initial exposure to dsrna, ... | 2006 | 16253354 |
| haemonchus contortus and trichostrongylus colubriformis in pen-trials with javanese thin tail sheep and kacang cross etawah goats. | weight gain costs due to infection were higher in sheep than goats, 28 and 17.5%, respectively, for trichostrongylus colubriformis and 48.7 and 32.2%, respectively, for haemonchus contortus. the extent of bodyweight cost attributed to anorexia in sheep infected with h. contortus was higher (13.5 g/day) than in sheep infected with t. colubriformis (2.3 g/day). on the other hand, bodyweight cost due to the other pathogenic effects in sheep infected with t. colubriformis were higher (35.6 g/day) co ... | 2006 | 16310309 |
| synergism of rotenone by piperonyl butoxide in haemonchus contortus and trichostrongylus colubriformis in vitro: potential for drug-synergism through inhibition of nematode oxidative detoxification pathways. | the anthelmintic properties of rotenone and its activity in combination with the cytochrome p450 inhibitor piperonyl butoxide, were examined in in vitro assays with adults and larvae of haemonchus contortus and larvae of trichostrongylus colubriformis. rotenone was toxic to larvae of both species, with lc(50) values in larval development assays of 0.54 and 0.64 microg/ml for h. contortus and t. colubriformis, respectively. the compound also caused complete cessation of movement in adult h. conto ... | 2006 | 16325340 |
| comparative efficacy of the nematode-trapping fungus duddingtonia flagrans against haemonchus contortus, teladorsagia circumcincta and trichostrongylus colubriformis in goat faeces: influence of the duration and of the temperature of coproculture. | amongst the alternative strategies to the use of anthelmintics, the administration of duddingtonia flagrans spores has already proved its efficacy in reducing the number of developing larvae of several nematode species in goat faeces. in this trial, the efficacy of this fungus against the larvae of the three major nematode species of goats was compared in various conditions of coproculture. twelve strongyle free goats were experimentally infected with either trichostrongylus colubriformis, telad ... | 2006 | 16328368 |
| phenotypic characterization of haemonchus contortus: a study of isolates from sweden and kenya in experimentally infected sheep. | the effects of cold storage of infective third-stage larvae (l3) of different isolates of the parasitic nematode haemonchus contortus were studied with respect to infectivity, pre-patent period and propensity for larval arrestment. two complementary experiments were conducted with 2 groups of lambs, each animal being inoculated with 2000 l3 of either swedish or kenyan origin. in a first experiment, l3s were cold treated at 5 degrees c for 9 months prior to infection, whereas in a second experime ... | 2006 | 16332287 |
| the nematode-trapping efficacy of two chlamydospore-forming fungi against haemonchus contortus in sheep. | an in vitro study was carried out to determine efficacy of indian isolates of the nematode-trapping fungi arthrobotrys musiformis and duddingtonia flagrans to capture infective larvae of haemonchus contortus. these fungi have previously been screened and selected for their survival in the gastrointestinal tract of sheep without losing growth and nematode capturing potential. following the feeding of chlamydospores of these two fungi alone or in combination in sheep experimentally infected with h ... | 2005 | 16336714 |
| the development and overwintering survival of free-living larvae of haemonchus contortus in sweden. | five complimentary studies were undertaken with the overall aim to examine the ability of free-living stages of haemonchus contortus to over-winter and tolerate cold stress. two studies deal with the development and long-term survival of eggs and infective larvae of two geographically different isolates (kenya and sweden). eggs and larvae were monitored in climatic chambers at temperatures that fluctuated daily between -1 degrees c and 15 degrees c, or at constant temperatures of 5 degrees c and ... | 2005 | 16336722 |
| rapid improvement of immunity to teladorsagia circumcincta is achieved through a reduction in the demand for protein in lactating ewes. | protein supplementation can improve the resistance to parasites of periparturient ewes, as indicated by reduced nematode egg excretion and worm burdens. however, the rate at which this improvement can occur is largely unknown. we investigated the rate of improvement by assessing temporal changes in faecal egg counts after we experimentally reduced nutrient demand. three groups of nine pregnant ewes each were trickle infected with teladorsagia circumcincta from day(-70) to day(16) (parturition is ... | 2006 | 16337633 |
| cloning and characterization of the cu/zn superoxide dismutase of trichinella pseudospiralis. | copper/zinc (cu/zn) superoxide dismutase (sod) activity was identified for the first time in both crude somatic extracts (ce) and excretory/secretory (e/s) products of trichinella pseudospiralis. it was the dominant sod in infective-stage larvae. native polyacrylamide gel electrophoresis of ce and e/s products yielded a prominent band, which was cyanide-sensitive and was partly inhibited by hydrogen peroxide in sod assay. cytosolic cu/zn sod was cloned. the 471-bp full-length cdna sequence conta ... | 2006 | 16341881 |
| an immunogenic cathepsin f secreted by the parasitic stages of teladorsagia circumcincta. | teladorsagia circumcincta is a common, pathogenic abomasal nematode of sheep. in order to improve disease control in parasite isolates resistant to several anthelmintics, alternative methods must be sought. sheep develop acquired immunity to t. circumcincta so vaccination is a valid option for control. for this reason, we are investigating parasite excretory/secretory products for molecules, which have potential to invoke protective immunity against t. circumcincta. here, we describe experiments ... | 2006 | 16387304 |
| effects of four tanniferous plant extracts on the in vitro exsheathment of third-stage larvae of parasitic nematodes. | the anthelmintic properties of tanniferous plants and of their secondary metabolites represent one possible alternative to chemotherapy that is currently being explored as a means of achieving sustainable control of gastrointestinal nematodes in ruminants. previous in vivo and in vitro results suggest that tanniferous plants can have direct anti-parasitic effect against different stages of nematodes. however, the mode of action of the bioactive plant compounds remains obscure. the objectives of ... | 2006 | 16388690 |
| in vitro and in vivo anthelmintic activity of nicotiana tabacum l. leaves against gastrointestinal nematodes of sheep. | the in vitro and in vivo anthelmintic activity of nicotiana tabacum l. leaves was studied to rationalize its traditional use. live haemonchus contortus were used to assess the in vitro anthelmintic effect of a crude aqueous extract (cae) and a methanol extract (cme) of n. tabacum. the in vitro inhibitory effect of both the extracts was evident from the paralysis and/or mortality of worms noted at 6 h post-exposure. for the in vivo studies, cae and cme were administered in increasing doses (1.0-3 ... | 2006 | 16397920 |
| towards the eradication of haemonchus contortus from sheep flocks in sweden. | previous studies have shown that between-year transmission of haemonchus contortus in swedish sheep flocks is almost entirely as over-wintered populations within housed animals, and not on pasture. this suggests that eradication of this parasite is a realistic possibility. thus, two sheep farms with a history of h. contortus infection on the swedish island of oland were selected for study. during the winter housing period of 2003/2004 all ruminants (sheep and cattle) on both farms were treated w ... | 2006 | 16406331 |
| eosinophil interactions with haemonchus contortus larvae in the ovine gastrointestinal tract. | sheep were immunized by weekly oral infections with haemonchus contortus for 9 weeks followed by anthelmintic treatment. they were challenged either 9 or 22 weeks later with pbs (sham controls) or one million exsheathed l3 surgically injected in the abomasum, and killed 24 h or 48 h later. sheep challenged 9 weeks after immunization displayed varying degrees of tissue eosinophilia that showed a significant inverse relationship with the number of intra-epithelial mast cells (globule leucocytes). ... | 2006 | 16441509 |
| testing the efficacy of rna interference in haemonchus contortus. | rna interference (rnai) is widely used in caenorhabditis elegans to identify gene function and has been adapted as a high throughput screening method to identify genes involved in essential processes. we have been examining whether rnai could also be used on the strongylid parasitic nematode haemonchus contortus to study gene function. eleven genes were targeted in l1 and exsheathed l3 h. contortus larvae with rnai methodologies which have been shown to be effective in c. elegans and parasitic n ... | 2006 | 16469321 |
| a modified larval migration assay for detection of resistance to macrocyclic lactones in haemonchus contortus, and drug screening with trichostrongylidae parasites. | we have developed a modified migration assay system in 96-well plate format which is able to detect resistance to the macrocyclic lactone group of drugs in haemonchus contortus. the assay involves exposure of infective stage larvae to drug for a 24 h period, then counting the numbers of larvae that are able to migrate through an agar and filter mesh system over a further 48 h. the agar barrier greatly increased the sensitivity of the assay for resistance detection compared to use of filter mesh ... | 2006 | 16472922 |
| management and control of nematode parasites of small ruminants in the face of total anthelmintic failure. | total failure of modern broad spectrum anthelmintics to control nematode parasites of sheep and goats is a reality, of rapidly increasing dimension, on many farms in the tropical / subtropical regions of the world. this is primarily associated with the highly pathogenic, blood sucking parasite, haemonchus contortus, and where it now cannot be controlled by chemotherapy, annual mortalities exceeding 20% of the flock can be expected. thus sheep and goat enterprises become totally unsustainable, un ... | 2004 | 16493393 |
| identification of secreted cysteine proteases from the parasitic nematode haemonchus contortus detected by biotinylated inhibitors. | seven cathepsin b-like cysteine proteases (cbls) were identified from the immunoprotective excretory-secretory products of haemonchus contortus. two-dimensional (2-d) zymography and biotinylated inhibitors were employed to localize active cbls in 2-d protein gels. mass spectrometry provided the identification of ac-4, hmcp1, hmcp2, and gcp7 as well as three novel cbls encoded by clustered expressed sequence tags. | 2006 | 16495580 |
| haemonchus contortus: prokaryotic expression and enzyme activity of recombinant hcstk, a serine/threonine protein kinase. | members of the par-1/mark serine/threonine protein kinase (stk) subfamily are important regulators of the cytoskeleton, and their characterization can provide insights into a number of critical processes relating to the development and survival of an organism. we previously investigated the mrna expression for and organization of a gene (hcstk) representing hcstk, an stk from the parasitic nematode haemonchus contortus. in the present study, a recombinant form of hcstk was expressed and characte ... | 2006 | 16500645 |
| experimental haemonchosis in white-tailed deer. | white-tailed deer (odocoileus virginianus) were successfully infected with haemonchus contortus of sheep origin. individual deer in each of three groups were inoculated with 0, 25,000, and 100,000 larvae respectively. severity of infection was related to dose and signs of infection were most obvious in the heavily inoculated animals. infected deer were weak, emaciated, and anemic, similar to the clinical response in sheep. hemoglobin, packed cell volume, and total serum protein values for both i ... | 1970 | 16509128 |
| effects of legume forages on ovine gastrointestinal parasite development, migration and survival. | lambs grazing certain legumes have reduced parasite intensities compared to lambs grazing ryegrass swards. eighteen replicates of white clover (cv. aberherald), lucerne (cv. luzelle), red clover (cv. merviot) and perennial ryegrass (cv. abersilo) were sown at equivalent field rates in 25 cm diameter pvc pots and maintained outside for 6 months. on day 0, forage in each pot was cut to 50 mm from soil level and the pots were placed in a glasshouse (at 19-25 degrees c and 70% humidity) in a randomi ... | 2006 | 16516388 |
| effect of cd4+ t lymphocyte depletion on resistance of gulf coast native lambs to haemonchus contortus infection. | it has been reported that cd4(+) t lymphocytes are important in acquired immunity to gastrointestinal nematode infection. whether these lymphocytes are also involved in the immune response of naturally resistant gulf coast native (gcn) sheep to haemonchus contortus infection remains to be defined. the objective of this study was to determine the role of cd4(+) t lymphocytes in this resistance. ten gcn lambs were randomly assigned to a control (n=5) or a treatment (n=5) group. the treatment consi ... | 2006 | 16516389 |
| identification of a 66 kda haemonchus contortus excretory/secretory antigen that inhibits host monocytes. | a 66 kda adult haemonchus contortus excretory/secretory (e/s) antigen was identified in western blot by reaction with sera from the infected goats. the protein was purified from the adult worm extract and e/s products by anion exchange and cona-sepharose chromatography. the purified protein inhibited monocyte function in vitro as judged by decreased production of hydrogen peroxide and nitric oxide in the culture medium. the protein also caused proliferation of peripheral blood mononuclear cells. ... | 2006 | 16517075 |
| caenorhabditis elegans ivermectin receptors regulate locomotor behaviour and are functional orthologues of haemonchus contortus receptors. | the target site for the anthelmintic action of ivermectin is a family of nematode glutamate-gated chloride channel alpha subunits (gluclalpha) that bind the drug with high affinity and mediate its potent paralytic action. whilst the action of ivermectin on the pharyngeal muscle of nematodes is relatively well understood, its effect on locomotor activity is less clear. here we use rnai and gene knockouts to show that four gluclalpha subunits are involved in regulating the pattern of locomotor act ... | 2006 | 16527366 |
| isolation and characterization of class ii myosin genes from haemonchus contortus. | in this study, cdnas encoding myosin from the parasitic nematode haemonchus contortus were isolated and characterized. several exhibited a considerable degree of sequence variation at the nucleotide and limited divergence at the amino acid levels within the various functional domains. the results suggest that the cdnas isolated represented a single myosin heavy chain, which, by comparison with a number of other myosins, is inferred to represent a homologue of a muscle myosin (cemhca) of the free ... | 2006 | 16547732 |
| control of gastrointestinal nematodes in goats on pastures in south africa using nematophagous fungi duddingtonia flagrans and selective anthelmintic treatments. | the effectiveness of selective anthelmintic treatments and use of nematophagous fungi duddingtonia flagrans in reducing levels of gastrointestinal nematodes in goats was investigated at onderstepoort, south africa. nineteen (19) naturally infected indigenous male goats, aged 10 months, were separated into four groups and grazed in separate previously ungrazed paddocks for two worm seasons (february 2002-march 2003). two groups of goats were fed d. flagrans chlamydospores daily and two groups did ... | 2006 | 16563632 |
| sericea lespedeza hay as a natural deworming agent against gastrointestinal nematode infection in goats. | infection with gastrointestinal nematodes (gin), particularly haemonchus contortus, is the biggest constraint to profitable goat production in the united states (us). due to widespread prevalence of anthelmintic resistance in goat gin, alternative, non-chemical control methodologies are needed to increase profitability of small ruminant industries. a study was designed to test the efficacy of a high condensed tannin (ct) legume, sericea lespedeza [sl, lespedeza cuneata (dum.-cours. g. don)] agai ... | 2006 | 16564132 |
| detection of benzimidazole resistance in haemonchus contortus using rflp-pcr technique. | benzimidazole (bz) resistance in haemonchus contortus is linked primarily with the mutation in the beta-tubulin isotype 1 gene that substitute phenylalanine (phe) to tyrosine (tyr) at 200 codon of the gene. in the present study, a new restriction fragment length polymorphism-polymerase chain reaction (rflp-pcr) technique has been developed for detection of bz resistance in the beta-tubulin isotype 1 gene of h. contortus. the technique utilizes two primers viz. avikaf and avikar to amplify the re ... | 2006 | 16567043 |
| the ever-expanding neuropeptide gene families in the nematode caenorhabditis elegans. | neuropeptides act as chemical signals in the nervous system to modulate behaviour. with the ongoing est projects and dna sequence determination of different genomes, the identification of neuropeptide genes has been made easier. despite the relatively 'simple' repertoire of behaviours in the nematode caenorhabditis elegans, this worm contains a surprisingly large and diverse set of neuropeptide genes. at least 109 genes encoding over 250 potential neuropeptides have been identified in c. elegans ... | 2005 | 16569285 |
| resistance as a tool for discovering and understanding targets in parasite neuromusculature. | the problem of anthelmintic resistance prevents efficient control of parasites of livestock and may soon compromise human parasite control. research into the mechanisms of resistance and the quest for diagnostic tools to aid control has required research that focuses on field resistance. on the other hand, resistant worms, including those kept in the laboratory, provide useful tools for studying drug action, especially at neuromuscular targets in worms. while the needs and directions of these re ... | 2005 | 16569289 |
| evaluation of multiple low doses of copper oxide wire particles compared with levamisole for control of haemonchus contortus in lambs. | high levels of anthelmintic resistance in gastrointestinal nematodes (gin) of small ruminants have created the need for alternative approaches to parasite control. copper oxide wire particles (cowp; 2g) have proven effective in decreasing gin infection in lambs. however, the risk of copper toxicity has limited the usefulness of this approach. recently, smaller doses (0.5 and 1g) have proven effective in gin control, reducing the risk of toxicity. the objective of this study was to examine the ef ... | 2006 | 16574324 |
| immunological aspects of nematode parasite control in sheep. | gastrointestinal nematode parasitism is arguably the most serious constraint affecting sheep production worldwide. economic losses are caused by decreased production, the costs of prophylaxis and treatment, and the death of the infected animals. the nematode of particular concern is haemonchus contortus, which can cause severe blood loss resulting in anemia, anorexia, depression, loss of condition, and eventual death. the control of nematode parasites traditionally relies on anthelmintic treatme ... | 2006 | 16582083 |
| anthelmintic activity of leucaena leucocephala seed extract on haemonchus contortus-infective larvae. | | 2006 | 16603554 |
| segregation of natural and experimental gastrointestinal nematode infection in f2 progeny of susceptible suffolk and resistant gulf coast native sheep and its usefulness in assessment of genetic variation. | gastrointestinal nematode parasitism is a concern to small ruminants worldwide. productivity has been compromised because such nematodes, particularly haemonchus contortus, have developed resistance to available anthelmintics. some sheep breeds and lines within breeds are relatively resistant to infection, a trait that may be useful for developing control strategies. suffolk sheep, which are susceptible to infection, were crossed with gulf coast native sheep, which are more resistant to infectio ... | 2006 | 16621290 |
| ovicidal and larvicidal activity of melia azedarach extracts on haemonchus contortus. | haemonchus contortus is responsible for severe economic losses in sheep and goat breeding in the northeast of brazil. however, the effectiveness of control is compromised due to anthelmintic resistance and misuse. in the search for natural anthelmintics, melia azedarach l., a plant indigenous to india but now distributed throughout brazil, was selected due to the reported anthelmintic properties of its seeds. the aim of this study was to evaluate the anthelmintic activity of the seed and leaf ex ... | 2006 | 16621294 |
| further protection studies using recombinant forms of haemonchus contortus cysteine proteinases. | significant levels of protection against haemonchus contortus have been achieved in sheep by vaccination with a cysteine proteinase-enriched fraction (tsbp) isolated from the gut of adult parasites. protection is associated with three cathepsin b-like cysteine proteinases (hmcp 1, 4 & 6). lambs vaccinated with these proteinases, expressed in bacteria as glutathione s-transferase fusion proteins, had significantly reduced (38%) worm burdens compared to challenge controls although, intriguingly, e ... | 2006 | 16629707 |
| identification and characterization of an asparaginyl proteinase (legumain) from the parasitic nematode, haemonchus contortus. | asparaginyl proteinases (or legumains) are a recently identified, novel class of cysteine proteinase which specifically hydrolyse peptide bonds after asparagine residues. legumains have been implicated in the activation of cysteine proteases, particularly cathepsin b-like proteinases which are thought to help degrade the bloodmeal in blood-feeding helminths such as schistosomes, hookworms and other nematode species. an est sequence representing a full-length legumain was identified from the haem ... | 2006 | 16650340 |
| characterisation of teladorsagia circumcincta microsatellites and their development as population genetic markers. | there is a need to develop tools to study the genetics of parasitic nematodes. this is particularly urgent for those species in which anthelmintic resistance is common such as the sheep parasite teladorsagia (ostertagia) circumcincta. the lack of information on the population genetics of such parasites severely limits our ability to study the genetic basis of anthelmintic resistance. this paper presents the results of three approaches used to isolate microsatellite markers from t. circumcincta a ... | 2006 | 16687182 |
| managing anthelmintic resistance in small ruminant livestock of resource-poor farmers in south africa. | gastrointestinal parasitism is one of the most important disease complexes of sheep and goats impacting on the resource-poor livestock farmer. of the responsible nematodes, haemonchus contortus, a blood-sucking worm of the abomasum, poses possibly the greatest threat. over the past several decades, the worm has been controlled through the use of anthelmintics, but the emergence of anthelmintic resistance has threatened this chemotherapeutic approach. in africa, the overall prevalence of anthelmi ... | 2006 | 16700468 |
| haemonchus contortus (nematoda: trichostrongylidae) infection in lambs elicits an unequivocal th2 immune response. | selection of resistant animals and host immunization have been proposed as alternative methods for the control of gastrointestinal nematode parasites. however, a better knowledge of the mechanisms involved in protective immunity against these parasites is required for the development of optimal strategies. in this study, 3 month old inra 401 lambs (n = 81) were allocated into three groups: uninfected control, challenged either once (primary-infected animals) or twice (previously-infected animals ... | 2006 | 16701066 |
| survey of helminths in adult sheep in heilongjiang province, people's republic of china. | the prevalence of helminths in adult sheep was investigated in heilongjiang province, people's republic of china between january 1999 and september 2003. a total of 326 adult sheep representing local breeds (xingjiang fine wool sheep, dongbei fine wool sheep) as well as introduced breeds (merino and charollais) from representative geographical locations in heilongjiang province were slaughtered and examined for the presence of helminths. the worms were examined, counted and identified to species ... | 2006 | 16713098 |
| effect of biological control through the daily application of spores of duddingtonia flagrans in lambs kept under an evasive grazing system in the netherlands. | in 2004, an experiment was carried out to evaluate the effect of biological control through feeding spores of duddingtonia flagrans on parasitic gastroenteritis in lambs, kept under an evasive grazing system. in total 66 lambs were used. forty naturally infected 3-month old ram lambs were weaned in mid june, and divided into four groups of 10 lambs. on 21 june, g1-g4 were moved to four separate virtually clean plots, they were moved after 4 and 8 weeks to similar plots, and housed after 12 weeks ... | 2006 | 16713679 |
| control of haemonchus contortus in goats with a sustained-release multi-trace element/vitamin ruminal bolus containing copper. | the objective of this study was to determine the effectiveness of a sustained-release multi-trace element/vitamin ruminal bolus (teb) containing copper administered to mature does for control of gastrointestinal nematodes (gin) during summer months and during late gestation. haemonchus contortus was the predominant nematode during these trials. in experiment 1, yearling spanish does were untreated or administered teb (n=11/group) on day 0 (august 2005) prior to breeding. in experiment 2, spanish ... | 2006 | 16716521 |
| in vitro screening of six anthelmintic plant products against larval haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay. | because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. phytotherapy could be one of the major options to control these pathologies. extracts or ingredients of six different plant species were tested against exsheathed infective larvae of haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (mtt) reduction assay. pyrantel tartrate was use ... | 2006 | 16725288 |
| [resistance of teladorsagia circumcincta in goats to ivermectin in the netherlands]. | resistance of teladorsagia circumcincta in goats to ivermectin in 2005, suspected ivermectin resistance of gastrointestinal nematodes was investigated in 17 goats on a farm in the netherlands, using a faecal egg count reduction test combined with faecal larval cultures. eight goats were treated orally with 0.2 mg/ kg ivermectin on 1 august 2005 and the other nine goats served as untreated controls. faeces were collected from all goats on 1 august and on 12 august. faecal egg counts were reduced ... | 2006 | 16736643 |
| effect of nutritional status and fat reserves on the periparturient immune response to haemonchus contortus infection in sheep. | a study was made of the effect of body fat stored by ewes in early pregnancy on the subsequent immune response to gastrointestinal parasites around parturition. pregnant ewes were given access to a lucerne pelleted diet either ad libitum (h) or at approximately 0.70 of their maintenance requirements (l) from the 42nd day of pregnancy in order to achieve a clearly differentiated level of body reserves by the 90th day of pregnancy. then, all animals were put on the same plane of nutrition till 3 w ... | 2006 | 16737779 |
| molecular characterization of a family of metalloendopeptidases from the intestinal brush border of haemonchus contortus. | substantial protection against the economically important parasitic nematode haemonchus contortus has been achieved by immunizing sheep with a glycoprotein fraction isolated from the intestinal membranes of the worm (h-gal-gp). previous studies showed that one of the major components of h-gal-gp is a family of at least 4 zinc metalloendopeptidases, designated meps 1-4. this paper describes aspects of the molecular architecture of this protease family, including the proteomic analysis of the mep ... | 2006 | 16740178 |
| prospects for exploring molecular developmental processes in haemonchus contortus. | haemonchus contortus of small ruminants is a parasitic nematode of major socio-economic importance world-wide. while there is considerable knowledge of the morphological changes which take place during the life cycle of h. contortus, very little is understood about the molecular and biochemical processes which govern developmental changes in the parasite. recent technological advances and the imminent genomic sequence for h. contortus provide unique opportunities to investigate the molecular bas ... | 2006 | 16759659 |
| naturally occurring variability in some phenotypic markers and correlates of haemonchotolerance in west african dwarf goats in a subhumid zone of nigeria. | west african dwarf (wad) goats of the nigerian subhumid zone generally show strong resistance and resilience to haemonchus contortus in laboratory experiments, although a relatively small proportion are susceptible to infection. little is known about these extremes of response phenotype in nature. therefore, a survey was carried out of gastrointestinal nematode infections in wad goats, with emphasis on abomasal worms, at three goat markets in southern nigeria during the rainy season. faecal samp ... | 2006 | 16764992 |
| towards the implementation of the "basket of options" approach to helminth parasite control of livestock: emphasis on the tropics/subtropics. | the virtual reliance on anthelmintic drugs alone to control internal parasites of livestock is inappropriate and ultimately unsustainable. in the tropics and subtropics, widespread and high levels of anthelmintic resistance, particularly in nematode parasites of small ruminants, is rife. but more to the point, many farmers in these regions of the world are resource poor and cannot afford, or are reluctant to purchase drugs that may also be of dubious quality. as it is with any intervention, the ... | 2006 | 16764993 |
| abundant variation in microsatellites of the parasitic nematode trichostrongylus tenuis and linkage to a tandem repeat. | an understanding of how genes move between and within populations of parasitic nematodes is important in combating the evolution and spread of anthelmintic resistance. much has been learned by studying mitochondrial dna markers, but autosomal markers such as microsatellites have been applied to only a few nematode species, despite their many advantages for studying gene flow in eukaryotes. here, we describe the isolation of 307 microsatellites from trichostrongylus tenuis, an intestinal nematode ... | 2006 | 16765463 |
| targeted selective treatment for worm management--how do we sell rational programs to farmers? | seriously escalating global anthelmintic resistance in gastrointestinal nematodes of small ruminants has spawned a variety of alternatives to anthelmintics for worm management, based on the need for sustainable integrated parasite management (sipm). pivotal to the sipm approach is the concept of refugia, the proportion of a given parasite population that escapes exposure to control measures. by balancing drug applications with the maintenance of refugia, the accumulation of anthelmintic resistan ... | 2006 | 16774807 |
| synthesis and anthelmintic activity of substituted (r)-phenyllactic acid containing cyclohexadepsipeptides. | the substituted (r)-phenyllactic acid containing cyclohexadepsipeptides (chdps) represent novel enniatin derivatives with strong in vivo activities against the parasitic nematode haemonchus contortus rudolphi in sheep. 2d nmr spectroscopic analysis revealed for the substituted (r)-phenyllactic acid containing chdps one major conformer with an unsymmetrically folded conformation lacking a cis-amide bond. a correlation between the substitution pattern and its anthelmintic activity was found. here ... | 2006 | 16781154 |
| anthelmintic activity of swertia chirata against gastrointestinal nematodes of sheep. | this paper describes in vitro and in vivo anthelmintic activities of swertia chirata. in vitro studies revealed that at 25 mg/ml (p>/=0.05) the crude aqueous (cae) and methanolic extracts (cme) of s. chirata whole plant showed an anthelmintic effect on live haemonchus contortus. moreover, in the in vivo study, the whole plant of s. chirata administered as crude powder (cp), cae and cme at the dose of 3 g/kg to sheep naturally infected with mixed species of gastrointestinal nematodes, showed a si ... | 2006 | 16815639 |
| influence of sex on the resistance of sheep lambs to an experimental haemonchus contortus infection. | 36 intact male and 69 female lambs of two breeds (n = 63 merinoland; n = 42 rhön) aged 12 weeks were orally infected with 5000 infective-stage larvae, l3, of the nematode haemonchus contortus. after 4 and 8 weeks faecal egg counts (fec), haematocrit values and plasma testosterone levels were determined. all lambs were slaughtered at 20 weeks of age. the gastrointestinal tracts were examined for the presence of adult stages of h. contortus. male lambs showed significantly higher log fec (p < 0.00 ... | 2006 | 16821560 |
| accuracy of an anaemia scoring chart applied on goats in sub-humid kenya and its potential for control of haemonchus contortus infections. | we tested the practical application of an anaemia scoring chart (the famacha chart) as a method for controlling haemonchus contortus in goats kept under smallholder conditions in a sub-humid area of central kenya. the objectives were: (1) to test the accuracy of the famacha chart in identifying anaemic goats (pcv< or =18); (2) to quantify the proportion of goats left untreated at farm level when using the chart. on each of two farms, small east african goats of various ages were allocated to two ... | 2006 | 16824684 |
| heterosis analysis of haemonchus contortus resistance and production traits in rhoen sheep, merino land sheep and crossbred lambs. | a crossbreeding program was conducted to evaluate the resistance status to haemonchus contortus in reciprocal crossbred (f(1)) lambs and their merino land sheep (ml) and rhoen sheep (rh) purebred counterparts. a total of 406 lambs were included in the study. faecal egg counts (fec) and haematocrit values (hc) of all the lambs were collected 4 and 8 weeks after an artificial infection with h. contortus. famacha scores were given at the same time. worm counts of all lambs were obtained after slaug ... | 2006 | 16828228 |
| [evaluation of nematode predacious fungus duddingtonia flagrans on infective haemonchus contortus and strongyloides papillosus larvae of goats]. | one brazilian isolate of nematode-trapping fungus duddingtonia flagrans ac 001 was evaluated regarding the capacity of supporting passage through the gastrointestinal tract of goats without losing the ability to entrap infective haemonchus contortus and strongyloides papillosus larvae (l3). ten saneen goats of eight months old, males and infected naturally were divided in two groups of five animals. in the group 1, the animals received orally 20 g of pellets of the d. flagrans. in the group 2 (c ... | 2006 | 16834900 |
| effect of sericea lespedeza (lespedeza cuneata) fed as hay, on natural and experimental haemonchus contortus infections in lambs. | parasitic infection is one of the leading economic constraints in small ruminant production. this problem is exacerbated as the resistance of nematode populations to chemical treatment (anthelmintics) becomes increasingly more common. condensed tannin (ct) containing plants are being investigated as alternative solutions to address these problems. this investigation was conducted to evaluate the effect of the ct containing forage, lespedeza cuneata (sericea lespedeza, sl) fed as hay, on haemonch ... | 2006 | 16857320 |
| characterization of hc58cdna, a putative cysteine protease from the parasite haemonchus contortus. | because of the complexity of the cathepsin b-like (cbl) family, an information on the biological and biochemical characteristics of individual cbl genes is lacking. in this study, we investigated the degradative effects of the recombinant hc58 protein isolated from haemonchus contortus parasites on protein substrates over a broad ph range in vitro. this protein, which hydrolyzed the synthetic peptide substrates z-fr-amc and z-rr-amc, had characteristics of the cysteine protease class of proteins ... | 2006 | 16871019 |
| cloning and characterization of genes encoding alpha and beta subunits of glutamate-gated chloride channel protein in cylicocyclus nassatus. | the invertebrate glutamate-gated chloride channels (glucls) are receptor molecules and targets for the avermectin-milbemycin (am) group of anthelmintics. mutations in glucls are associated with ivermectin resistance in the soil dwelling nematode caenorhabditis elegans and the parasitic nematode cooperia oncophora. in this study, full-length cdnas encoding alpha and beta subunits of glucl were cloned and sequenced in cylicocyclus nassatus, a common and important cyathostomin nematode parasite of ... | 2006 | 16872692 |
| haemonchus contortus: parasite problem no. 1 from tropics - polar circle. problems and prospects for control based on epidemiology. | there is no doubt that on a global basis, haemonchus contortus is by far the most important parasite of small ruminants (sheep and goats). this is particularly more so now, with the development of high levels of resistance to both the broad and narrow spectrum anthelmintic drugs in h. contortus throughout the world. epidemiological studies describe the lower environmental limits for haemonchosis to occur in sheep, as being a mean monthly temperature of 18c and approximately 50mm rainfall. thus i ... | 2005 | 16883278 |
| isolation and insecticidal/anthelmintic activity of xanthonol, a novel bis-xanthone, from a non-sporulating fungal species. | xanthonol, a novel dimeric xanthone, was isolated from a fermentation broth of a non-sporulating fungal species using sephadex lh20 followed by hplc and the structure elucidated by spectral analysis. xanthonol exhibited insecticidal and anthelmintic activities against larvae of lucilia sericata, aedes aegypti, and haemonchus contortus with ld90 of 33, 8, and 50 microg/ml, respectively. | 2006 | 16883778 |
| [some aspects of the immune response of polish wrzosówka sheep against gastrointestinal nematodes infection]. | the paper presents different aspects of natural gastrointestinal nematode infection in this primitive, prolific polish wrzosówka breed of sheep. the study was carried out on the flock located at the farm run by warsaw agricultural university at zelazna (central poland) in 1995-1998. egg counts per gram of faeces, larval differentiation, total white blood cell counts, blood eosinophil counts, interleukin-5 concentration, lymphocyte blastogenic activity and igg immune response were discussed. the ... | 2000 | 16886364 |
| understanding anthelmintic resistance: the need for genomics and genetics. | anthelmintic resistance is a major problem for the control of many parasitic nematode species and has become a major constraint to livestock production in many parts of the world. in spite of its increasing importance, there is still a poor understanding of the molecular and genetic basis of resistance. it is unclear which mutations contribute most to the resistance phenotype and how resistance alleles arise, are selected and spread in parasite populations. the main strategy used to identify mut ... | 2006 | 16889782 |
| [the occurrence of intestinal parasites of roe deer and red deer in the western pomerania voivodeship]. | the aim of the study was to establish the parasite prevalence of roe deer and red deer in western pomerania. | 2005 | 16913504 |
| effect of sainfoin (onobrychis viciifolia) silage and hay on established populations of haemonchus contortus and cooperia curticei in lambs. | the objective of the study was to examine the effect of dried and ensiled sainfoin (onobrychis viciifolia) on established populations of haemonchus contortus (abomasum) and cooperia curticei (small intestine) in lambs under controlled conditions. twenty-four parasite naïve lambs were inoculated with a single dose of infective larvae of these parasites 28 days prior to the start of the feeding experiment. twenty-four days post-infection, 4 days prior to the start of the feeding experiment, animal ... | 2006 | 16934938 |
| global patterns reveal strong population structure in haemonchus contortus, a nematode parasite of domesticated ruminants. | we have examined the global population genetic structure of haemonchus contortus. the genetic variability was studied using both amplified fragment length polymorphism (aflp) and nad4 sequences of the mitochondrial genome. to examine the performance and information content of the two different marker systems, comparative assessment of population genetic diversity was undertaken in 19 isolates of h. contortus, a parasitic nematode of small ruminants. a total of 150 individual adult worms represen ... | 2006 | 16950266 |
| epidemiology and seasonal dynamics of gastrointestinal nematode infections of sheep in a semi-arid region of eastern ethiopia. | a study on the epidemiology and seasonal dynamics of gastrointestinal nematode infections of sheep was carried out in a semi-arid region of eastern ethiopia for 2.5 years (may 2003 to september 2005). the experimental flock comprised a total of 60 black head ogaden sheep, consisting of four equal groups of young male and female and old male and female sheep. these grazed on communal pastures together with a larger university flock, as well as with animals owned by neighbouring small-holder farme ... | 2007 | 16965858 |
| rnai in haemonchus contortus: a potential method for target validation. | rna interference (rnai) is a method for the functional analysis of specific genes, and is particularly well developed in the free-living nematode caenorhabditis elegans. there have been several attempts to apply this method to parasitic nematodes. in a recent study undertaken in haemonchus contortus, geldhof and colleagues concluded that, although a mechanism for rnai existed, the methods developed for rnai in c. elegans had variable efficacy in this parasitic nematode. the potential benefits of ... | 2006 | 16971180 |
| endomesoderm specification in caenorhabditis elegans and other nematodes. | the endomesoderm gene regulatory network (grn) of c. elegans is a rich resource for studying the properties of cell-fate-specification pathways. this grn contains both cell-autonomous and cell non-autonomous mechanisms, includes network motifs found in other grns, and ties maternal factors to terminal differentiation genes through a regulatory cascade. in most cases, upstream regulators and their direct downstream targets are known. with the availability of resources to study close and distant r ... | 2006 | 16998834 |
| [experiences with the famacha-eye-colour-chart for identifying sheep and goats for targeted anthelmintic treatment]. | the bloodsuckling abomasal parasite haemonchus contortus is the most pathogenic worm in sheep and goats. high prevalences of anthelmintic-resistant isolates make h. contortus difficult to control. detecting the most anaemic animals could support a targeted selective treatment approach. leaving the rest of the flock untreated would generate a refuge for anthelmintic-sensitive parasites. south-african researchers tried the famacha-eye-colour-chart for anaemic sheep and goats with good success. fie ... | 2006 | 17007472 |
| ivermectin selection on beta-tubulin: evidence in onchocerca volvulus and haemonchus contortus. | ivermectin resistance is common in trichostrongylid nematodes of livestock, such as haemonchus contortus. this anthelmintic is the only drug approved for mass administration to control onchocerciasis caused by the nematode parasite, onchocerca volvulus. in parts of west africa up to 18 rounds of ivermectin treatment have been administered to communities and there are reports of poor parasitological responses to treatment. understanding ivermectin resistance and ivermectin selection is an importa ... | 2006 | 17007942 |
| feasibility of genus-specific real-time pcr for the differentiation of larvae from gastrointestinal nematodes of naturally infected sheep. | results of real-time pcr analysis of coproculture third stage larvae (l3) using genus specific taqman minor groove binder probes were compared with the results of morphological differentiation of l3 after coprocultured and direct morphological worm differentiation from gastrointestinal samples of eight sheep with naturally acquired nematodes infections. faecal egg counts prior to postmortem confirmed infections with trichostrongyles with a geometric mean count of 4828 eggs per gram for all sheep ... | 2006 | 17009713 |
| ecology of the free-living stages of major trichostrongylid parasites of sheep. | significant developments over recent decades make it timely to review the ecology of the major gastrointestinal nematode (gin) species of sheep. these include the relentless development and spread of anthelmintic resistance in all of the major sheep production regions of the world, and the consequent drive towards integrated parasite management (ipm) systems incorporating non-chemotherapeutic strategies such as grazing management. the success of such programs is dependent on a detailed understan ... | 2006 | 17011129 |
| anthelmintic action of eprinomectin in lactating anglo-nubian goats in brazil. | eprinomectin is the only avermectin approved for use to control gastrointestinal nematodes in lactating cows. some studies in the usa and europe have also demonstrated that this drug is highly effective in small ruminants. the aim of the present work was to evaluate the anthelmintic efficacy of pour-on eprinomectin in anglo-nubian goats at the end of lactation. twenty-four goats were used, naturally infected with gastrointestinal nematodes, and divided into two groups: control and treated with e ... | 2007 | 17031697 |
| effects of condensed tannin from acacia mearnsii on sheep infected naturally with gastrointestinal helminthes. | the effect of tannins on endoparasite control in hair sheep was investigated using 20 entire lambs of the santa inês breed. at the beginning of the experiment these animals were 6-months old and weighed 22.5kg+/-4.7. the treatments used were (10 animals each): gt (animals receiving 18g of acácia negra containing 18% of condensed tannin/animal/week) and gc (animals not receiving tannin). the experiment lasted 84 days, with animals kept on an andropogon gayanus pasture. faeces were collected weekl ... | 2007 | 17067741 |
| evaluation of a recombinant excretory secretory haemonchus contortus protein for use in a diagnostic enzyme-linked immunosorbent assay. | the nematode haemonchus contortus (h. contortus) is one of the most pathogenic and economically important parasites of sheep. a 24 kda protein is one of the important components in h. contortus excretory/secretory (es), which was shown to have important biological function. in our research, the cdna of its open reading frame (es24) was obtained and analyzed. then the es24 was sub-cloned into pet-30a expression vector. the recombinant vector that codes hexahistidyl peptide fusion protein (his-es2 ... | 2007 | 17069805 |
| a combined bioinformatics and chemoinformatics approach for the development of new antiparasitic drugs. | a modern concept for the development of novel antiparasitic drugs is the combination of bioinformatics and chemoinformatics approaches. this covers, for example, the identification of target proteins serving as molecular points of attack for parasiticides--the idea is that, owing to some essential role, inhibition of a target protein should eradicate the parasite. to prevent toxicity problems for vertebrate host organisms, it is advantageous that these proteins show significant differences from ... | 2007 | 17070005 |
| gastrointestinal nematodes of small ruminants: life cycle, anthelmintics, and diagnosis. | strongylid gastrointestinal nematodes are an important cause of disease and economic loss in small ruminants. these parasites are particularly important in the eastern united states where the bloodsucking parasite haemonchus contortus is the predominant species. sheep and goats are infected with gastrointestinal nematodes while grazing and the biology of the infective larvae on the pastures is important in planning effective control programs. fecal egg counts can be used to monitor control progr ... | 2006 | 17071351 |
| 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 |
| helminths in sympatric populations of mountain reedbuck (redunca fulvorufula) and gray rhebok (pelea capreolus) in south africa. | helminths of mountain reedbuck (redunca fulvorufula fulvorufula) and gray rhebok (pelea capreolus) were investigated in south africa between june 1999 and february 2002. forty-one mountain reedbuck were culled at sterkfontein dam nature reserve over 8 different periods, and 25 mountain reedbuck were culled at tussen die riviere nature reserve over 3 different periods. a total of 17 kinds of helminths were found at the 2 sites, including 15 nematodes, 1 trematode, and 1 cestode. at sterkfontein, ... | 2005 | 17089756 |
| direct and indirect anthelmintic effects of condensed tannins in sheep. | anthelmintic activity of condensed tannins (ct) was evaluated both in vitro and in vivo. in vitro tests included egg hatch test and paralysis/mortality assay on adult haemonchus contortus. in vivo anthelmintic effect was determined by faecal egg count reduction test in lambs. to this end, 18 lambs were divided into three groups (low tannin, high tannin and control). the lambs of low and high tannin groups were fed diets containing 2 and 3% ct while the control group was fed on diets without ct. ... | 2007 | 17097807 |
| 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 |
| [a new control method for haemonchus contortus: famacha]. | famacha is a method that has been developed against haemonchus contortus which causes anemia in sheep and goats especially in tropical and subtropical areas. the basic principle of the method is the detection of the color changes in the mucous membrane of the eye that is caused by anemia. according to the famacha anemia guide, (fag), the mucous membranes of the eyes of animals are inspected for color differences at two or three week intervals. the criteria are used for treating the animals. thus ... | 2006 | 17106855 |
| 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 |