| cloning and expression of cystatin, a potent cysteine protease inhibitor from the gut of haemonchus contortus. | a cdna encoding a cysteine protease inhibitor (cystatin) was identified by immunoscreening a haemonchus contortus cdna library with antisera from lambs vaccinated with a protective membrane protein complex (h-gal-gp) derived from the gut of the parasite. the cdna sequence, designated cys-1, showed significant levels of similarity with cystatins from several species of nematode as well as with human cystatin. recombinant h. contortus cystatin was expressed in escherichia coli in a soluble and fun ... | 2001 | 11289073 |
| presence of mycobacterium avium subspecies paratuberculosis in suspensions of ovine trichostrongylid larvae produced in faecal cultures artificially contaminated with the bacterium. | a reference strain of mycobacterium avium subspecies paratuberculosis was added to faecal larval cultures of haemonchus contortus, ostertagia circumcincta and trichostrongylus colubriformis. samples of the larvae produced were cultured for the presence of the bacterium in modified bactec 12b medium, both before and after exposure to gamma irradiation. the water used to wash the larvae off the faecal cultures was also tested for the presence of the bacterium. positive growth was confirmed as m. a ... | 2001 | 11292085 |
| cross-protection studies with gut membrane glycoprotein antigens from haemonchus contortus and teladorsagia circumcincta. | gel profiles of the peanut and cona lectin binding integral membrane glycoproteins of teladorsagia circumcincta and haemonchus contortus were compared and found to be considerably different. however, some of the teladorsagia polypeptides were recognized by antisera specific for haemonchus amino-, metallo- or aspartyl peptidases, enzymes which are known to be protective antigens for that parasite. as expected, an experimental vaccine containing these haemonchus proteases was extremely effective a ... | 2001 | 11298297 |
| characterisation of haemonchus contortus-derived cell populations propagated in vitro in a tissue culture environment and their potential to induce protective immunity in sheep. | cell populations derived from viable haemonchus contortus l(3) larvae were propagated in vitro in a tissue culture environment for a prolonged period (>48 months). microscopic evaluation of h. contortus-derived cell populations revealed gross morphological characteristics highly analogous to those described for cell types originating from species of plant nematodes propagated in vitro in a tissue culture environment for a briefer period of time (<6 months). the characterisation of extracts harve ... | 2001 | 11306114 |
| studies on the immunoglobulin e responses to teladorsagia circumcincta in sheep: purification of a major high molecular weight allergen. | studies on the immunoglobulin (ig)e immune responses to the gastric nematode, teladorsagia circumcincta, have demonstrated a major high molecular weight allergen (hmwtc). cross reactive allergens of similar mw were demonstrated for trichostrongylus colubriformis and cooperia curticei, but not for haemonchus contortus. purification of hmwtc was achieved by gel-filtration chromatography, and nonreducing sds-page and western blot analysis revealed two closely associated bands with a molecular weigh ... | 2001 | 11309133 |
| effect of refrigeration on the antinematodal efficacy of ivermectin. | several observations have suggested that the anthelmintic ivermectin can affect nematodes by non-oral entry into the nematode body. to investigate this possibility further, we refrigerated caenorhabditis elegans at 5 c to prevent its locomotion and to block the pharyngeal pumping that is so prominent a feature of its feeding. worms were exposed to ivermectin (1-25 microg/ml) at that temperature for 1 hr, after which the medium was replaced by unmedicated medium at room temperature. after 1 hr at ... | 2001 | 11318586 |
| prevalence of coccidia and gastrointestinal nematode infections in cross bred goats in the dry areas of sri lanka. | the prevalence and intensity of oocysts of coccidia, particularly eimeria species, and eggs of gastrointestinal nematodes in kids (2-4 months), young goats (5-12 months) and adult goats (>1 year) were determined in five large herds managed extensively in five villages in the dry zone. of the representative samples examined, oocysts were found in 88% of kids, 91% of young goats and 83% of adults. seven species of eimeria were identified in faecal samples by salt flotation. eimeria ninakohlyakimov ... | 2001 | 11323207 |
| selection of different genotype larvae and adult worms for anthelmintic resistance by persistent and short-acting avermectin/milbemycins. | to understand the factors that influence selection for anthelmintic resistance, it is necessary to examine the impact of drug treatment, particularly persistent drugs, on all phases of the worm life cycle. the efficacy of various avermectin/milbemycin anthelmintics was determined against resident worms, incoming larvae (l3) and development of eggs in faecal culture. homozygote-resistant and maternal and paternal f1-heterozygote genotypes of haemonchus contortus were used to infect sheep before o ... | 2001 | 11336754 |
| latrophilin-like receptor from the parasitic nematode haemonchus contortus as target for the anthelmintic depsipeptide pf1022a. | | 2001 | 11344131 |
| molecular analysis and nematode resistance association of a polymorphism at the 5' end of the sheep ige gene. | previous work using southern analysis of genomic dna detected a polymorphism at the 5' end of the sheep and cattle ige gene. identical length differences found between fragments following digestion with restriction enzymes indicated that the basis for the polymorphism was an insertion/deletion event. to characterise the polymorphism, the entire cattle and sheep cvarepsilon genes were sequenced including 668bp of 5' untranslated dna. sequence comparison revealed a high degree of similarity betwee ... | 2001 | 11356247 |
| multispecific resistance of trichostrongyles to benzimidazoles in a goat herd in germany. | anthelmintic resistance of nematodes to benzimidazoles and ivermectin was suspected from field observations in an angora goat herd in northern hesse. larvae of the caprine trichostrongyle isolate were used for artificial infections of helminth-naive sheep. groups of the lambs were treated with albendazole (3.8 mg/kg p.o.) or ivermectin (0.2 mg/kg s.c.) four weeks after infection or remained untreated as controls and were necropsied one week later. albendazole reduced the mean faecal egg counts b ... | 2001 | 11367880 |
| high-affinity ivermectin binding to recombinant subunits of the haemonchus contortus glutamate-gated chloride channel. | glutamate-gated chloride channels (glucls) are targets for the avermectin anthelmintics. a family of five glucl subunit genes encoding seven subunits has been identified in caenorhabditis elegans. we have previously shown that two orthologous genes in the parasite, haemonchus contortus, encode three glucl subunits (hcgluclbeta, hcgbr-2a and hcgbr-2b) with high amino-acid identity (>80%) to their c. elegans counterparts. we amplified and cloned a further subunit cdna, hcgluclalpha, from h. contor ... | 2001 | 11378196 |
| a multiplex pcr assay for differentiating economically important gastrointestinal nematodes of cattle. | a multiplex polymerase chain reaction (pcr) test was developed for identifying gastrointestinal (gi) nematodes that commonly infect cattle. this assay was developed using adult-derived genomic dna and shown capable of discriminating parasite eggs from the feces of experimentally-infected animals at both the species and genus levels. sequence data from internal (its) and external (ets) transcribed spacers of the ribosomal dna (rdna) repeats as well as the 3'-end of the small subunit rdna and 5'-e ... | 2001 | 11390072 |
| cloning and structural analysis of partial acetylcholine receptor subunit genes from the parasitic nematode teladorsagia circumcincta. | nematode nicotinic acetylcholine receptors (nachrs) are the sites of action for the anthelmintic drug levamisole. recent findings indicate that the molecular mechanism of levamisole resistance may involve changes in the number and/or functions of target nachrs. accordingly, we have used an rt-pcr approach to isolate and characterise partial cdna clones (tca-1 and tca-2) encoding putative nachr subunits from the economically important trichostrongyloid, teladorsagia circumcincta. the predicted tc ... | 2001 | 11390086 |
| preliminary observations on the potential of gut membrane proteins of haemonchus contortus as candidate vaccine antigens in sheep on naturally infected pasture. | in a trial lasting 11 months in south africa, faecal egg counts and haematocrits of sheep vaccinated with gut membrane proteins of adult haemonchus contortus were compared with unvaccinated controls grazing pasture contaminated with the parasite. vaccination reduced egg output by >82% on average during one 4 month period of the trial and simultaneously significantly reduced the degree of anaemia and deaths due to haemonchosis. although vaccine immunity was not sufficiently long lasting to preven ... | 2001 | 11423186 |
| comparison of ivermectin, doramectin, selamectin, and eleven intermediates in a nematode larval development assay. | chemical substitutions at pharmacologically relevant sites such as c-5, c-13, c-22,23, and c-25 were examined in ivermectin, doramectin, selamectin, and a series of 11 other intermediates using a larval development assay with haemonchus contortus. a range of activities spanning 5 orders of magnitude were manifest with small changes in the substituents to the 14 avermectins. within this compound series, there was no major potency advantage or disadvantage to a disaccharide over a monosaccharide s ... | 2001 | 11426737 |
| amplified fragment length polymorphism analysis of genetic diversity of haemonchus contortus during selection for drug resistance. | for the first time we used amplified fragment length polymorphism on individual nematode parasites to analyse the genetic diversity between and within isolates during consecutive stages of increased benzimidazole resistance and of increased levamisole resistance of haemonchus contortus. the genetic diversity of the h. contortus genome turned out to be unusually high, within and between the isolates. the difference between individuals of an isolate could be as high as between individuals of two d ... | 2001 | 11429180 |
| assessment of benzimidazole binding to individual recombinant tubulin isotypes from haemonchus contortus. | one a- and 2 beta-tubulin isotypes (isotypes 1 and 2) from the parasitic nematode haemonchus contortus were artificially expressed in e. coli and purified to obtain tubulin that was capable of polymerizing into microtubules. binding of [14c] mebendazole (mbz), a benzimidazole compound, to each individual unpolymerized isotype and to microtubules polymerized from recombinant alpha- and beta-tubulin was assessed and kd and bmax values determined. mebendazole bound to the individual tubulin isotype ... | 2001 | 11444621 |
| assessment of genetic variability of resistance to gastrointestinal nematode parasites in creole goats in the humid tropics. | goat production is widespread in the tropics. goats are very susceptible to gastrointestinal nematode infection, but there is less evidence of their genetic resistance. genetic resistance of creole goats to gastrointestinal nematodes has been studied at guadeloupe in the french west indies since 1995. the objective of this research was to investigate genetic variation for resistance to gastrointestinal nematode infection, in order to introduce this trait into breeding schemes. genetic variabilit ... | 2001 | 11465357 |
| age-related protective immunity after vaccination with haemonchus contortus excretory/secretory proteins. | protection against an experimental challenge infection by immunization with excretory/secretory products (es) from haemonchus contortus, containing predominantly proteins of 15 and 24 kda, depends on the age of the sheep. vaccinated sheep 9 and 6 months of age had reduced final worm burdens of 82 and 77, respectively. no reduction in worm burden was found in 3-month-old lambs. nine-month-old sheep had significantly higher es-specific serum immunoglobulin (ig)g1 and iga during immunizations and a ... | 2001 | 11489165 |
| direct anthelmintic effects of condensed tannins towards different gastrointestinal nematodes of sheep: in vitro and in vivo studies. | in vitro and in vivo studies were conducted to determine possible direct anthelmintic effects of condensed tannins towards different ovine gastrointestinal nematodes. a larval development/viability assay was used to investigate the effect of a condensed tannin extract (quebracho) towards larvae of haemonchus contortus, teladorsagia circumcincta and trichostrongylus vitrinus. the development to infective larvae and their viability was assessed in all three species and ld 50 values were calculated ... | 2001 | 11502368 |
| analysis of developmentally regulated genes of the parasite haemonchus contortus. | differential regulation of gene expression in the development of haemonchus contortus was analysed using rna arbitrarily-primed pcr. a study of third-stage larval and adult h. contortus revealed large differences between the two stages; 32 and 30% unique third-stage larval and adult rna arbitrarily-primed pcr products, respectively. this finding is consistent with a high degree of differential gene expression between these developmental stages. a number of adult products were sequenced, revealin ... | 2001 | 11513893 |
| parasite vaccines--a reality? | over the last decade, the anti-parasitics market has been the fastest growing sector of the overall $18 billion animal health market. while drugs for the treatment of parasites of livestock still dominate this sector and will continue to be developed or re-formulated, because of consumer demands for chemical-free food and of concerns regarding the environment and animal welfare there is a growing interest in the development of safe and effective vaccines. there is also a call for vaccines in the ... | 2001 | 11516584 |
| cathepsin b-like cysteine proteases and caenorhabditis elegans homologues dominate gene products expressed in adult haemonchus contortus intestine. | proteins expressed by nematode intestinal cells are potential targets for parasite control by immune or chemical based strategies. to expand our knowledge on nematode intestinal proteins, expressed sequence tags were generated for 131 cdna clones from the intestine of adult female haemonchus contortus. an estimated 55 distinct protein genes or gene families were identified. predicted proteins represented diverse functions. several predicted polypeptides were related to h. contortus proteins impl ... | 2001 | 11522349 |
| vaccination against gastrointestinal nematode parasites of ruminants using gut-expressed antigens. | to date, proteins isolated from the surface of the gut of gastrointestinal nematodes, particularly haemonchus contortus, have generally proved to be useful protective antigens and several are being progressed towards recombinant protein-based vaccines. this paper describes the properties of some of the most promising antigens and summarises their performance in laboratory and field based trials. the antigens described include contortin, h11, h-gal-gp, gpi and cysteine proteinases. in addition, t ... | 2001 | 11522403 |
| genetic variability following selection of haemonchus contortus with anthelmintics. | genetic diversity in nematodes leads to variation in response to anthelmintics. haemonchus contortus shows enormous genetic diversity, allowing anthelmintic resistance alleles to be rapidly selected. anthelmintic resistance is now a widespread problem, especially in h. contortus. here, i compare the genes involved in anthelmintic resistance in h. contortus with those that confer susceptibility or resistance on the free living nematode caenorhabditis elegans. i also discuss the latest knowledge o ... | 2001 | 11530357 |
| haemonchus contortus sl2 trans-spliced rna leader sequence. | | 2001 | 11551637 |
| in vitro metabolism of moxidectin in haemonchus contortus adult stages. | we studied the implication of cytochrome p450 enzymes in the in vitro metabolism of moxidectin (mxd) in homogenates of haemonchus contortus adult stages (susceptible isolate, weybridge, uk). after homogenisation in a phosphate buffer, 2 ml of homogenates (equivalent to 1 g of nematodes) were incubated with 5 microg [14c] mxd at 37 degrees c for 24 h. mxd and its metabolites were separated by hplc with radiodetection on-line. only one metabolite was detected and its production was inhibited by ca ... | 2001 | 11570553 |
| isolation, characterisation and expression of mrnas encoding the ovine cc chemokines, monocyte chemoattractant protein (mcp)-1alpha and -2. | cc chemokines are important mediators of immune responses, orchestrating the differential recruitment of various leukocyte populations. despite the large number of known cc chemokines in other species, no cdna encoding ovine cc chemokines have been isolated. a homology cloning strategy was utilised to isolate the cdna of ovine cc chemokines. full-length monocyte chemoattractant protein (mcp)-1alpha and -2 cdna have been isolated. the predicted ovine mcp-1alpha amino acid sequence shares 87 and 7 ... | 2001 | 11587731 |
| pathological and immunohistochemical study of the abomasum and abomasal lymph nodes in goats experimentally infected with haemonchus contortus. | histopathological changes and the distributions of t and b lymphocytes and igg producing plasma cells were recorded in the abomasum and abomasal lymph nodes of goats 3, 7 and 21 weeks post-infection (wpi) after an experimental infection with h. contortus. the low rate of worm recovery by 3 wpi (5.6%) might have been due to larvae death as suggested by the presence of granulomas in the abomasal mucosa at 3 and 7 wpi, or simply due to a poor larval establishment. marked increase in the secretion o ... | 2001 | 11592616 |
| cloning and characterisation of thrombospondin, a novel multidomain glycoprotein found in association with a host protective gut extract from haemonchus contortus. | | 2001 | 11606236 |
| the influence of protein supplementation on the immune response to haemonchus contortus. | a major protective mechanism in lambs against the abomasal parasite ostertagia (teladorsagia) circumcincta appears to be the immunoglubulin (ig)a-mediated suppression of worm growth and fecundity. the present study indicates that iga may play a similar role in the control of another abomasal parasite haemonchus contortus. hampshire down lambs were offered one of two diets: (i) a basal diet and (ii) a diet supplemented with additional protein. lambs were then 'trickle' infected with h. contortus ... | 2001 | 11696163 |
| the contribution of molecular biology to the development of vaccines against nematode and trematode parasites of domestic ruminants. | rapid developments in molecular biology have had an enormous impact on the prospects for the development of vaccines to control the major nematode and trematode infestations of livestock. vaccine candidates are purified using conventional protein chemistry techniques but the limitations imposed by the scarcity of parasite material provide an insurmountable barrier for commercial vaccine production by this means. the ability to purify mrna from different parasite life-cycle stages and to prepare ... | 2001 | 11707304 |
| synthesis and anthelmintic activity of thioamide analogues of cyclic octadepsipeptides such as pf1022a. | the tetra- and mono-thionated cyclic octadepsipeptides represent novel cyclic octadepsipeptide derivatives with broad-spectrum activity against parasitic nematodes in mice and sheep. some of these show better activity than the potent natural anthelmintic cyclic octadepsipeptide pf1022a against hymenolepis nana, heterakis spumosa and trichinella spiralis larvae in mice. in particular, they show improved efficacy against haemonchus contortus and trichostrongylus colubriformis in sheep compared wit ... | 2001 | 11721515 |
| haemonchus contortus utilises catalase in defence against exogenous hydrogen peroxide in vitro. | the toxicity of activated oxygen species towards adult haemonchus contortus nematodes was examined in in vitro assays using ingestion of [3h]inulin to assess nematode viability. both glucose/glucose oxidase (generation of hydrogen peroxide) and xanthine/xanthine oxidase (generation of superoxide anion) systems showed concentration-dependent toxicity to the nematodes. both adult and larval haemonchus contortus enzyme preparations showed significant catalase activities. adult nematodes exposed to ... | 2001 | 11730782 |
| the potential of nematophagous fungi to control the free-living stages of nematode parasites of sheep: towards the development of a fungal controlled release device. | studies showed that chlamydospores of the nematophagous fungus, duddingtonia flagrans, are capable of surviving pressures of several tonnes when incorporated into matrices and pressed into tablets for the manufacture of prototype intraruminal controlled release devices (crds). they remain viable in this tabletted form for at least 9 months when stored at 4 degrees c. in vitro studies demonstrated that there was no effect on spore viability of prolonged exposure to either room or elevated tempera ... | 2001 | 11731073 |
| evaluation of duddingtonia flagrans in reducing infective larvae of haemonchus contortus in feces of sheep. | consequences of nematode infections due to haemonchus contortus are a serious constraint for the sheep industry worldwide. development of anthelmintic resistance and increasing concern about the impact of anthelmintic use dictate the need of alternative control. such an alternative is using the nematode trapping fungus duddingtonia flagrans to reduce infective larvae levels on pasture. two trials were conducted to determine the effect of d. flagrans in reducing infective larvae (predominantly h. ... | 2002 | 11750119 |
| selection for resistance to macrocyclic lactones by haemonchus contortus in sheep. | an anthelmintic-sensitive haemonchus contortus strain was selected for moxidectin and ivermectin resistance concurrently for 22 generations. treatment with 0.002 mg moxidectin/kg bw or 0.02 mg ivermectin/kg bw produced >99% efficacy against the susceptible parent strain passaged for 22 generations without any anthelmintic exposure. however, to obtain similar efficacy the moxidectin-selected and the ivermectin-selected strains of h. contortus required 0.05 mg moxidectin/kg bw or 0.4 mg ivermectin ... | 2002 | 11751006 |
| molecular cloning and characterization of ac-mep-1, a developmentally regulated gut luminal metalloendopeptidase from adult ancylostoma caninum hookworms. | a zinc metalloendopeptidase cdna (ac-mep-1) was cloned from ancylostoma caninum adult hookworms. ac-mep-1 is encoded by a 2.8 kb mrna with a predicted open reading frame (orf) of 870 amino acids (predicted pi=5.5, m.w.=98.7 kda) that contains four potential n-linked glycosylation sites and predicted zinc-binding domains (hexxh and enxadxgg). these domains represent signature sequences of the neutral endopeptidase 24.11 (neprilysin) family of enzymes. the orf corresponding to ac-mep-1 exhibited s ... | 2002 | 11755191 |
| clinical evaluation of anaemia in sheep: early trials. | trials were conducted on a farm in mpumalanga province in south africa to test the possibility of grading the colour of the ocular mucous membranes of sheep as an indication of the extent to which the animals are affected by haemonchus contortus infection. the range of observed colour shades were classified into five categories, from red, through red-pink, pink and pink-white to white. over a period of 125 days routine drenching of a flock of 388 sheep on irrigated kikuyu (pennisetum clandestinu ... | 2001 | 11769347 |
| potency of three haemonchus contortus antigens in the diagnosis of ovine haemonchosis. | one hundred faecal specimens and corresponding blood samples were evaluated for haemonchus contortus infection in sheep by elisa utilizing somatic, circulating and coproantigens. results proved that coproantigen was more potent than the others in diagnosis of sheep haemonchosis. sds-polyacrylamide gel electrophoresis demonstrated that the three antigens are structurally related. immunoblot analysis revealed that somatic antigen contained 6 polypeptides of molecular weights 234, 205, 178, 83, 48 ... | 2001 | 11775097 |
| genetic resistance to gastrointestinal nematode parasites in rhön sheep following natural infection. | genetic parameters of resistance to gastrointestinal nematodes were estimated in rhön sheep, a local sheep breed in germany. in the first year, a total of 131 lambs (born between january and february 1998) from five rams were evaluated. faecal egg counts (fec) (n=1528) were measured in all lambs every 2 weeks until 4 months of age and every 4 weeks until 12 months of age in female lambs. in the second year, a total of 129 lambs (born between january and february 1999) from the same rams were eva ... | 2001 | 11777605 |
| excretory/secretory products of haemonchus contortus inhibit aminopyrine accumulation by rabbit gastric glands in vitro. | abomasal parasites inhibit gastric acid secretion and reduce the number of acid secreting parietal cells either through physical contact with gastric tissue, the release of inhibitory excretory/secretory (es) products or by initiating the host inflammatory response. to examine the role of parasite es products, adult haemonchus contortus were incubated in a medium based on hank's balanced salt solution and three incubates were tested for the presence of inhibitors of acid secretion by dispersed r ... | 2002 | 11812620 |
| expression of acquired immunity to a local isolate of haemonchus contortus by the nigerian west african dwarf goat. | the capacity of young nigerian west african dwarf (wad) goats to express good acquired immunity to their native geographic strain of haemonchus contortus and the correlates of this responsiveness were studied in a laboratory experiment involving forty 7-8 month old kids. a primary immunising infection with 2000 l3 (equivalent to 260-450 l3/kg body weight) with or without challenge on d42 with 2000 l3 resulted in a mild chronic infection with a pre-patent period of 18-20 days and little or no red ... | 2002 | 11812621 |
| a cooperia punctata gene family encoding 14 kda excretory-secretory antigens conserved for trichostrongyloid nematodes. | a polymorphic set of 14 kda excretory-secretory (e-s) antigen-encoding cdnas, with similarity to a previously characterized 15 kda e-s antigen of haemonchus contortus, was cloned from cooperia punctata. five cdnas encoding predicted proteins of 70-80% identity were sequenced. genomic analyses of individuals proved the existence of three 14 kda e-s antigen-encoding genes, excluding that the differences reflected polymorphisms between individuals in a population. southern blots indicated the prese ... | 2001 | 11814050 |
| prevalence of anthelmintic resistance in gastrointestinal nematodes of dairy goats under extensive management conditions in southwestern france. | the occurrence of benzimidazole (bz) and levamisole resistance was investigated in 18 randomly selected dairy goat herds located in southwestern france and characterized by extensive management. on each of the 18 farms, 45 adult goats were randomly allocated into three groups of 15 animals each: an untreated control group, a group that was orally administered fenbendazole (10 mg kg(-1) body weight) and a group that received orally a levamisole drench (12 mg kg(-1) body weight). individual faecal ... | 2001 | 11818048 |
| strategies for nematode transmission: selective migration of trichostrongylus tenuis infective larvae. | successful transmission of macroparasites is dependent on exposure of susceptible hosts to free-living infective stages. when these hosts are herbivores that feed mostly on a single food plant then natural selection should favour those infective larvae that selectively ascend this main food plant. red grouse feed predominantly on heather, calluna vulgaris, so we predict that the infective larvae (l3) of the caecal nematode trichostrongylus tenuis selectively locate and ascend heather plants. to ... | 2001 | 11818056 |
| reduced efficacy of ivermectin, abamectin and moxidectin against field isolates of haemonchus contortus. | to investigate the reduced efficacy of ivermectin, abamectin and moxidectin against two field isolates of haemonchus contortus. these isolates were identified on separate properties in the new england region of new south wales. | 2001 | 11837906 |
| mechanisms of immunity to haemonchus contortus infection in sheep. | in two separate experiments, sheep were immunized by nine to 12 weekly immunizing infections with 4000 haemonchus contortus third stage larva (l3), drenched with anthelminthics and maintained free of h. contortus infection for a further 12 weeks. the anamnestic cellular immune responses in both the abomasal lymph node (aln) and mucosa of the immunized sheep were examined 3 and 5 days post challenge with 50 000 h. contortus l3. sheep in the two experiments clearly segregated out in two distinct g ... | 2002 | 11856445 |
| helminth intensity and diversity in organic meat sheep farms in centre of france. | a helminthological study was undertaken at five sheep meat organic farms in the centre of france. the data obtained were compared with two extensive (contemporary of present study) or semi-intensive (literature data) conventional sheep meat farms. the nematode fauna of the region could be characterised by the presence of trichostrongylus axei alongside with the dominant species recorded in other areas (teladorsagia circumcincta and trichostrongylus colubriformis with few haemonchus contortus). t ... | 2002 | 11879965 |
| response to carbon dioxide by the infective larvae of three species of parasitic nematodes. | the response of infective third-stage larvae (l3) of three species of parasitic nematodes, ancylostoma caninum, strongyloides stercoralis, and haemonchus contortus to carbon dioxide (co(2)) at physiological concentrations was investigated. l3 of the skin-penetrating species, a. caninum and s. stercoralis, were stimulated by co(2) at the concentration found in human breath (3.3-4%); these larvae responded by crawling actively, but not directionally. crawling was not stimulated by breath passed th ... | 2002 | 11880227 |
| the dynamics, prevalence and impact of nematode infections in organically raised sheep in sweden. | a three-year survey (1997-99) was carried out on organically reared sheep flocks throughout sweden. the aim was to determine the prevalence and intensity of nematode infections and to establish relationships between sheep management practices and parasite infections. faecal samples from ewes and lambs were collected from 152 organic flocks around lambing-time and during the grazing-period for analysis. results were compared with the different management practices that farmers use to prevent para ... | 2001 | 11887398 |
| a glutamate-gated chloride channel subunit from haemonchus contortus: expression in a mammalian cell line, ligand binding, and modulation of anthelmintic binding by glutamate. | glutamate-gated chloride channels (glucls) are inhibitory ion channels that are sensitive to the antiparasitic drugs ivermectin (ivm) and moxidectin (mox). we have transiently transfected cos-7 cells with a subunit of a glucl (hcglucla) from the parasitic nematode haemonchus contortus. this subunit bound [3h]-ivm and [3h]-mox with k(d) values of 0.11+/-0.021 and 0.18+/-0.02nm, respectively. displacement analysis revealed that ivm and mox bind to the same site on hcglucla and that this site is li ... | 2002 | 11931838 |
| use of lectin binding characteristics to identify gastrointestinal parasite eggs in faeces. | identification of the presence and abundance of species is important when choosing therapies and control strategies for internal parasitism of livestock. here we examine lectin binding characteristics of eggs isolated from sheep faeces as a means for identifying the parasite genera contributing to infection. the intensity of lectin staining varied with incubation time, incubation volume, concentration of lectin and concentration of eggs. formalin fixed eggs had greater autofluorescence but exhib ... | 2002 | 11934462 |
| the effect of pasture species on parasitism and performance of lambs grazing one of three grass-white clover pasture swards. | lamb parasitism and performance were compared on three pasture treatments: browntop/white clover, yorkshire fog/white clover, and ryegrass/white clover swards maintained at a sward height of 5cm in each of two years by using continuous variable stocking management. in year 1, lamb performance (both suppressively drenched (sd) and trigger drenched (td)) was similar on ryegrass and browntop swards but was poorer (p<0.05) on yorkshire fog swards. in year 2, lamb performance (both sd and td) was mar ... | 2002 | 11983305 |
| estimating genetic differences in natural resistance in rhön and merinoland sheep following experimental haemonchus contortus infection. | genetic parameters of natural resistance were estimated in rhön and merinoland (german merino) sheep following experimental infection with haemonchus contortus. a total of 133 rhön and 244 merinoland lambs descending from 5 and 6 rams, respectively, were evaluated. each helminth-naive lamb was orally infected with 5000 infective third-stage larvae (l(3)) of the nematode h. contortus at 12 weeks of age. faecal egg counts (fec) and haematocrit values were measured in all lambs at 16 and 20 weeks o ... | 2002 | 11992711 |
| benzimidazole binding to haemonchus contortus tubulin: a question of structure. | | 2002 | 11998698 |
| characterization and purification of cytosolic and membrane-bound protease(s) in adults of haemonchus contortus. | the activity of protease(s) was observed separately in cytosolic and membrane-bound protease(s) from male and female hae monchus contortus (nematoda: trichostrongylidae). different fractions showed optimum protease activity at 37 degrees c, ph 8.5 and 8.0 mg casein concentration. the female fractions had a particularly high activity of protease(s) in comparison with the male fractions, especially of membrane-bound enzymes in the anterior half. inhibition, activation studies revealed the presence ... | 2002 | 12002422 |
| anthelmintic activity of preparations derived from myrsine africana and rapanea melanophloeos against the nematode parasite, haemonchus contortus, of sheep. | myrsine africana l. and rapanea melanophloeos l. belong to the plant family myrsinaceae. various rural communities in kenya, such as smallholder farmers and pastoralists, use them to treat their livestock. the anthelmintic effects/activities of leaves and fruits of m. africana and fruits of r. melanophloeos were tested in sheep experimentally infected with the nematode parasite haemonchus contortus. male lambs were infected with 3000-5000 third stage larvae of h. contortus and treated 28 days af ... | 2002 | 12007709 |
| protection studies with recombinant excretory/secretory proteins of haemonchus contortus. | the efficacy of two recombinant proteins of haemonchus contortus was studied in both adult sheep and young lambs. these 15 and 24 kda excretory/secretory proteins were given combined, either supplemented or not with a glycan-rich insect cell extract. in 9-month-old sheep (trial 1), faecal egg output and worm burden were reduced by 49% and 55%, respectively, after vaccination with rec15/24, and by 46% and 65% after vaccination with rec15/24 and glycan extract. no reduction in egg output or number ... | 2002 | 12010484 |
| benefit of the control of gastrointestinal nematode infection in goats in the dry zone of sri lanka. | the benefit of gastrointestinal nematode control in cross-bred goats in the dry area of sri lanka was studied throughout 1 year by comparing the performances of three groups: group 1 animals (n = 11) were left untreated against gastrointestinal nematodes; group 2 animals (n = 11) were given monthly anthelmintic treatment. doramectin, at the dose rate of 300 microg/kg bodyweight during the entire study period; group 3 animals (n = 11) were also given monthly doramectin treatment at the dose rate ... | 2002 | 12019940 |
| the parasitic hematophagous worm haemonchus contortus inhibits human platelet aggregation and adhesion: partial purification of a platelet inhibitor. | blood sucking parasites elaborate mechanisms to counteract the hemostatic system of their victim. haemonchus contortus worms use several mechanisms directed against the normal platelet hemostatic function. platelet adhesion onto collagen and fibrinogen, and the ristocetin-mediated interaction of von willebrand factor with glycoprotein (gp) ib were inhibited by the protein extract of adult worms. also platelet aggregation induced by collagen, thrombin, adp, ristocetin or a23187 was inhibited. alt ... | 2002 | 12038795 |
| effectiveness of copper oxide wire particles for haemonchus contortus control in sheep. | to assess the efficacy of copper oxide wire particles (cowp) for the control of h contortus infections in grazing sheep. | 2002 | 12054286 |
| hcstk, a caenorhabditis elegans par-1 homologue from the parasitic nematode, haemonchus contortus. | a putative serine/threonine protein kinase (hcstk) from the parasitic nematode haemonchus contortus was characterised at the mrna and amino acid levels. hcstk displays a high level of identity (85-93% in the catalytic domain) with proteins of the par-1/mark serine/threonine protein kinase (stk) subfamily, which represent signal transduction molecules involved in establishing and maintaining polarity in proliferating and differentiating cells. the transcript of hcstk is expressed in different dev ... | 2002 | 12062493 |
| diversity of benzimidazole-resistance alleles in populations of small ruminant parasites. | the resistance of gastro-intestinal nematodes of small ruminants (sheep and goat) to benzimidazole anthelmintic drugs seems to be linked primarily to a single mutation in the isotype 1 beta-tubulin gene. this study was carried out to investigate the origin and diversity of benzimidazole-resistance alleles in trichostrongylid nematodes. we sequenced a 550 bp fragment of the isotype 1 beta-tubulin gene from several benzimidazole-resistant teladorsagia circumcincta populations isolated from dairy g ... | 2002 | 12062563 |
| the effects of ivermectin and moxidectin on egg viability and larval development of ivermectin-resistant haemonchus contortus. | the in vivo effects of ivermectin and moxidectin on egg viability and larval development of ivermectin-resistant haemonchus contortus were examined over time after anthelmintic treatment of sheep. twenty merino sheep, (12 months old) were allocated to five treatment groups and infected with ivermectin-resistant h. contortus. thirty one days later, the sheep were treated with intraruminal ivermectin capsules, oral ivermectin, oral moxidectin or injectable moxidectin at the manufacturer's recommen ... | 2002 | 12072216 |
| a cathepsin l protease essential for caenorhabditis elegans embryogenesis is functionally conserved in parasitic nematodes. | proteolytic enzymes are involved in processes important to development and survival of many organisms. parasite proteases are considered potential targets of parasite control yet, for most, their precise physiological functions are unknown. validation of potential targets requires analysis of function. we have recently identified a cathepsin l (cpl) cysteine protease, ce-cpl-1, which is essential for embryonic development of the free-living nematode caenorhabditis elegans. we now show that cpl g ... | 2002 | 12076767 |
| genetic parameters for resistance to haemonchus contortus in merino sheep in south africa. | resistance to natural infections of haemonchus contortus (wireworm) was studied in merino sheep. from february 1995 to july 1996 data were collected from the otk merino stud on the farm wildebeesfontein near hendrina in mpumalanga province. from march 1998 to january 2000 another merino flock at irene in gauteng province was included in the study. in both cases, 50 randomly-chosen animals from each group of lambs weaned were sampled weekly for faecal egg count (fec) until a mean of 2500 eggs per ... | 2002 | 12088074 |
| high affinity as a disease determinant factor in anti-gm(1) antibodies: comparative characterization of experimentally induced vs. disease-associated antibodies. | elevated titers of serum anti-gm(1) antibodies of igg isotype are found frequently in patients with guillain-barré syndrome. much evidence indicates that these autoantibodies are involved in disease progression, but their exact function and the mechanism of their appearance are still unclear. in an attempt to reproduce "ganglioside syndrome", the experimental model of neuropathy developed by nagai et al. (neurosci. lett. 2 (1976) 107), rabbits were intensively immunized with gm(1) in complete fr ... | 2002 | 12098512 |
| localization of p-glycoprotein mrna in the tissues of haemonchus contortus adult worms and its relative abundance in drug-selected and susceptible strains. | membrane transporter p-glycoproteins (pgps) are present in a number of nematode species, including haemonchus contortus. allelic variation in some pgp genes has been found to be associated with resistance to the anthelmintic ivermectin (ivm), although functional verification of a role for pgps in ivm resistance has yet to be demonstrated. by in situ hybridization, the distribution of pgp mrna was visualized in transverse cryosections of adult h. contortus, using a digoxigenin-labeled cdna probe ... | 2002 | 12099436 |
| identification of immunodominant antigens of adult haemonchus contortus (nematoda: trichostrongylidae). | | 2002 | 12121049 |
| kinetics of exsheathment of infective ovine and bovine strongylid larvae in vivo and in vitro. | the aim of the study was to investigate the longitudinal changes of exsheathment of ovine and bovine 3rd-stage strongylid larvae in an artificial rumen (rusitec) and to compare the results with in vivo data obtained from rumen-fistulated sheep. infective larvae were incubated in nylon mesh bags in the sheep rumen or the rusitec apparatus for periods of 1, 6 and 12 h, respectively. the 12 h exsheathment rates in the rumen and the rusitec apparatus (in parentheses) were as follows: haemonchus cont ... | 2002 | 12166522 |
| analysis and partial reversal of multidrug resistance to anthelmintics due to p-glycoprotein in haemonchus contortus eggs using lens culinaris lectin. | our previous work has shown that drug efflux pumps close to mdr1 p-glycoprotein (pgp) can regulate anthelmintic efflux in nematodes in a way similar to that of the mutidrug resistance system (mdr) in vertebrate cancer cells. in the present study, the role of the glycosylation of pgp was studied using a lectin specific for the alpha-mannosyl residues ( lens culinaris agglutinin, lca). highly significant reversion (up to 50%) in the resistance to thiabendazole of eggs pre-treated with the lectin w ... | 2002 | 12172813 |
| susceptibility of trypanotolerant west african dwarf goats and f1 crosses with the susceptible sahelian breed to experimental trypanosoma congolense infection and interactions with helminth infections and different levels of diet. | forty pure west african dwarf (wad) goats and 35 of its f1 crosses with the sahelian breed were used in a multifactorial experimental design to evaluate the effects of an experimental trypanosoma congolense infection and interactions with natural helminth infections and different levels of diet on health and productivity of these two breeds. trypanosome infection caused a severe drop in packed cell volume (pcv), but this was not significantly affected by breed. neither deworming nor diet had any ... | 2002 | 12208040 |
| secreted metalloprotease gene family of microsporum canis. | keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. microsporum canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. using aspergillus fumigatus metalloprotease genomic sequence (mep) as a probe, three genes (mep1, mep2, and mep3) were isolated from an m. canis genomic library. they presented a quite-high percentage of identity with both a. fumigatus mep and aspergillus oryzae neutral protease i genes. ... | 2002 | 12228297 |
| high-level ivermectin resistance in a field isolate of haemonchus contortus associated with a low level of resistance in the larval stage: implications for resistance detection. | the ivpro isolate of haemonchus contortus was isolated in 1999 after significant numbers of the parasite survived an ivermectin capsule treatment of grazing sheep acquiring a natural infection at prospect, nsw, australia. the isolate shows high-level resistance to ivermectin (faecal egg count is unaffected by ivermectin oral treatment at 0.2mg kg(-1)). the larval lc(50), as assessed by larval development assays (ldas), is only approximately two-fold higher than several susceptible isolates, maki ... | 2002 | 12237144 |
| response of corriedale and crioula lanada sheep to artificial primary infection with haemonchus contortus. | clinical, parasitological and biochemical parameters were evaluated in corriedale and crioula lanada sheep after a single experimental infection with haemonchus contortus. ten 4-month-old worm-free lambs, of each breed, were infected with 200 l3 h. contortus per kg live weight and four uninfected animals of each breed were used as controls. every week, the animals were weighed and blood and faecal samples were collected for measurement of packed cell volume (pcv), total serum protein (tsp) and a ... | 2002 | 12241098 |
| the effects of stage-specific selection on the development of benzimidazole resistance in haemonchus contortus in sheep. | resistance to the benzimidazole (bdz) class of anthelmintics in nematodes of sheep has become a common and global phenomenon. the rate at which the selection process and development of resistance occurs is influenced by a number of factors. of these, the effects of stage-specific exposures to anthelmintic were investigated with a bdz-resistant strain of haemonchus contortus (hcr) over five parasite generations. sheep were infected at each generation with the hcr strain and were treated with thia ... | 2002 | 12383623 |
| anthelmintic activity of essential oil of ocimum gratissimum linn. and eugenol against haemonchus contortus. | the ovicidal activity of the essential oil of ocimum gratissimum linn. (labideae) and its main component eugenol was evaluated against haemonchus contortus, gastrointestinal parasite of small ruminants. the oil and eugenol were diluted in tween 20 (0.5%) at five different concentrations. in the egg hatch test, h. contortus eggs were obtained from feces of goats experimentally infected. at 0.50% concentration, the essential oil and eugenol showed a maximum eclodibility inhibition. these results s ... | 2002 | 12383625 |
| resistance to therapeutic treatment with macrocyclic lactone anthelmintics in ostertagia circumcincta. | eighty-eight lambs were allocated to one of four groups which were then dosed with 10,000 infective-stage larvae (l3) of one of four populations of ostertagia circumcincta; the first (s) was an isolate known to be anthelmintic-susceptible; the second (or) was a multiple anthelmintic-resistant isolate which had been recovered from the field following therapeutic failure of both ivermectin and moxidectin and subsequently maintained in the laboratory without further anthelmintic selection. the thir ... | 2002 | 12383628 |
| the famacha system for managing haemonchosis in sheep and goats by clinically identifying individual animals for treatment. | escalating anthelmintic resistance has made it essential to develop alternative ways of worm management for reducing selection for worm resistance, and one of the most promising approaches is to treat only those animals unable to cope with worm challenge, thus favouring unselected worms originating from untreated animals. only clinical evaluation of anaemia (famacha system) and the body condition score are regarded as being of practical value or having potential, respectively, for repeatedly exa ... | 2002 | 12387487 |
| sequence variation in the trichuris trichiura beta-tubulin locus: implications for the development of benzimidazole resistance. | benzimidazole resistance has evolved in a variety of organisms and typically results from mutations in the beta-tubulin locus at specific amino acid sites. despite widespread treatment of human intestinal nematodes with benzimidazole drugs, there have been no unambiguous reports of resistance. however, since beta-tubulin mutations conferring resistance are generally recessive, frequencies of resistance alleles less than 30% would be difficult to detect on the basis of drug treatment failures. he ... | 2002 | 12392917 |
| quantitative analysis of its2 sequences in trichostrongyle parasites. | real-time pcr assays were developed to identify and quantify common gastrointestinal nematodes of ruminants. the assays were based on genus-specific primer and probe combinations derived from the second internal transcribed spacer (its2) ribosomal dna transcription unit of haemonchus contortus, ostertagia leptospicularis, trichostrongylus colubriformis and cooperia curticei. the taqman probes for the first two species were labelled with 6-carboxyfluorescein and those for the latter two with vic ... | 2002 | 12392918 |
| study of the nematode putative gaba type-a receptor subunits: evidence for modulation by ivermectin. | two alleles of the hg1 gene, which encodes a putative gaba receptor alpha/gamma subunit, were isolated from haemonchus contortus. these two alleles were shown previously to be associated with ivermectin susceptibility (hg1a) and resistance (hg1e), respectively. sequence analysis indicates that they differ in four amino acids. to explore the functional properties of the two alleles, a full-length cdna encoding the beta subunit, a key functional component of the gaba receptor, was isolated from ca ... | 2002 | 12421359 |
| relative resistance of dorper crossbred ewes to gastrointestinal nematode infection compared with st. croix and katahdin ewes in the southeastern united states. | a study was conducted to evaluate relative resistance of dorper crossbred (do), katahdin (ka), st. croix (sc), and hampshire (ha) ewes to natural and experimental gastro-intestinal (gi) nematode infection over a 20-month period. the objective of experiment 1 was to evaluate breeds for resistance to infection acquired naturally from mixed grass pastures. in year 1 (may-december 2000) de-worming of ewes occurred during wet, hot conditions in july and during late pregnancy in december. in year 2 (j ... | 2002 | 12423938 |
| evolution of nematode community in grazing sheep selected for resistance and susceptibility to teladorsagia circumcincta and trichostrongylus colubriformis: a 4-year experiment. | field trials were undertaken to compare nematode population dynamics in two experimental flocks of rams selected for high and for low faecal egg counts (fecs) following two doses with 20000 infective larvae, 12000 teladorsagia circumcincta (tcirc) and 8000 trichostrongylus colubriformis (tcol) separated by a treatment. the selection was done by dosing 200 ram lambs (inra 401 breed) and fecs proceeded with egg identification on days 28 and 35 post-each-infection. the 30 lambs with the lowest fecs ... | 2002 | 12423939 |
| a novel cathepsin b active site motif is shared by helminth bloodfeeders. | this study compared specific protein sequence motifs present within cathepsin b-like cysteine proteases from a number of helminth parasites. we have focused our efforts on cathepsin b-like proteases of haemonchus contortus, caenorhabditis elegans, schistosoma mansoni, schistosoma japonicum, ostertagia ostertagi, and ancylostoma caninum. the goal of this work is to correlate specific features, or proposed roles, of the cathepsin b-like proteases with primary sequence motifs discovered within the ... | 2002 | 12427461 |
| synthesis of anthelmintically active n-methylated amidoxime analogues of the cyclic octadepsipeptide pf1022a. | the n-methylated amidoxime analogues of the cyclic octadepsipeptide pf1022a represent novel derivatives with activity against trichinella spiralis owen and nippostrongylus brasiliensis lane in vitro and against parasitic nematodes in mice and sheep. some of them show better activity against hymenolepis nana siebold, heterakis spumosa schneider and heligmosomoides polygyrus dujardin in mice than the natural product pf1022a. in particular an improved efficacy against haemonchus contortus rudolphi ... | 2002 | 12476993 |
| amphidial structure of ivermectin-resistant and susceptible laboratory and field strains of haemonchus contortus. | the development of anthelmintic resistance by nematode parasites is a growing problem for veterinarians, pet owners, and producers. the intensive use of the macrocyclic lactones for the treatment of a variety of parasitic diseases has hastened the development of resistance to this family of parasiticides. as a result, resistance to ivermectin, moxidectin, nemadectin, and doramectin by haemonchus contortus has been documented throughout the world. sensory neurons located in the cephalic end of ne ... | 2003 | 12482650 |
| susceptibility to ivm in a field strain of haemonchus contortus subjected to four treatments in a closed sheep-goat flock in kenya. | susceptibility to ivm (ivm) of "strain a" haemonchus contortus which had been exposed to ivm four times over a 2-year period was compared to ivm susceptibility of "strain c" h. contortus which had no prior field exposure to ivm, by in vivo and in vitro methods. in vivo, the percentage reduction in faecal egg counts (fec) and the total worm counts (twc) were compared between control animals (lambs and kids) and animals treated with low dose ivm (20 microg/kg). in vitro susceptibility to ivm was e ... | 2003 | 12482652 |
| nematophagous fungi as a biological control agent for nematode parasites of small ruminants in malaysia: a special emphasis on duddingtonia flagrans. | approximately 2,800 fresh dung samples from animals, mainly ruminant livestock, were screened for the presence of nematophagous fungi in malaysia. arthrobotrys spp. was noted on numerous occasions, but only one isolate of duddingtonia flagrans was made. for the purposes of producing sufficient quantities of this fungus for feeding trials in sheep, various, commonly available, cheap plant materials were tested as possible growth substrates. this showed that cereal grains (wheat, millet and rice) ... | 2002 | 12498569 |
| kinetics of antibody response by dot-elisa in rabbits immunized with adult haemonchus contortus antigen. | whole adult soluble extract of haemonchus contortus as an antigen along with freund's complete adjuvant, was used to immunize rabbits. antisera from immunized rabbits were collected at intervals of 30, 60, 90, 120, 150 and 180 days. for the detection and titration of anti-h. contortus antibodies in these sera, dot-elisa was developed. sera collected 30 days post-immunization exhibited a titre of 1:5,000 in all the rabbits except one, where a titre of 20,000 was recorded. later, all the rabbits a ... | 2002 | 12514952 |
| morbidity and mortality factors in key deer (odocoileus virginianus clavium). | the population health of endangered key deer (odocoileus virginianus clavium) was monitored from 10 february 1986 to 28 september 2000 by necropsy of animals that were killed by vehicles, euthanized because of terminal injuries or disease conditions, or found dead. the predominant mortality factor during the period was collision with motor vehicles; however, several infectious diseases were diagnosed, including infections with arcanobacterium pyogenes, haemonchus contortus, salmonella spp., and ... | 2002 | 12528433 |
| vertical migration by the infective larvae of three species of parasitic nematodes: is the behaviour really a response to gravity? | vertical migration by infective larvae (l3) of 3 species of nematodes was investigated. upright truncated agarose cones were used to test upward migration, and comparable truncated cone-shaped agarose hollows were used to test downward migration. flat agarose plates were control surfaces. when placed at the bases of upright cones, 74% of ancylostoma caninum l3 migrated up, whereas only 16.5% migrated down the indented cones; this latter value was not significantly different from larval migration ... | 2002 | 12553574 |
| experimental haemonchosis in goats: effects of single and multiple infections in the host response. | histopathological changes and the distribution of t lymphocytes (cd3), b cells (cd79alpha) and igg secreting plasma cells were recorded in the abomasum and abomasal lymph nodes of goats during early and late post-infection stages with one to four doses of haemonchus contortus l3. the infiltration of eosinophils, mast cells, cd3(+) t lymphocytes, cd79alpha(+)b cells and igg(+) plasma cells in the abomasal mucosa increased dramatically from 10dpi onwards, whereas globule leukocytes were observed o ... | 2003 | 12559712 |
| diagnosis of gastrointestinal nematodes infecting sheep in qalubia governorate by infective thrid stage larvae. | a total of 300 faecal samples obtained from living sheep in qalubia governorate, 128 (42.66%) harboured eggs of nematodes. the gastrointestinal nematodes had been differentiated through the infective third stage larvae. details of the general and differential categories of each were given. the recovered species were trichostrongylus axei, t. colubriformis, ostertagia circumcincta, haemonchus contortus, bunostomum trigonocephalum and oesophagostomum venulosum. | 1999 | 12561888 |
| comprehensive analysis of the secreted proteins of the parasite haemonchus contortus reveals extensive sequence variation and differential immune recognition. | haemonchus contortus is a nematode that infects small ruminants. it releases a variety of molecules, designated excretory/secretory products (esp), into the host. although the composition of esp is largely unknown, it is a source of potential vaccine components because esp are able to induce up to 90% protection in sheep. we used proteomic tools to analyze esp proteins and determined the recognition of these individual proteins by hyperimmune sera. following two-dimensional electrophoresis of es ... | 2003 | 12576473 |
| efficacy of eprinomectin pour-on against gastrointestinal nematode infections in sheep. | two field trials were conducted in two farms (farms a and b) in southern italy, to assess the efficacy of eprinomectin applied topically at the dose rate of 500 micro g/kg to sheep with naturally occurring infections of gastrointestinal nematodes (gin). the nematode population determined by necropsy consisted of teladorsagia circumcincta, haemonchus contortus, trichostrongylus vitrinus, t. capricola, nematodirus sp., and chabertia ovina in sheep from farm a, and of t. circumcincta, t. vitrinus, ... | 2003 | 12591196 |
| enhancing immunity to nematode parasites in single-bearing merino ewes through nutrition and genetic selection. | the effectiveness of protein supplementation and genetic selection to enhance the resistance of periparturient merino ewes to infection from gastrointestinal parasites was tested in a replicated grazing experiment. one hundred and twenty ewes from lines selected for increased resistance (r) to haemonchus contortus or at random (c) were subjected to one of the three supplement groups that provided 0 or 250 g per day cottonseed meal for 5 weeks prior to, or for 6 weeks after the start of lambing. ... | 2003 | 12591197 |
| distinct characteristics of two intestinal protein compartments discriminated by using fenbendazole and a benzimidazole resistant isolate of haemonchus contortus. | the intestine of haemonchus contortus is hypersensitive to the effects of the anthelmintic fenbendazole (fbz). the effects are postulated to stem from disruption of microtubules and interference with apical secretory vesicle transport, followed by release of digestive enzymes into the intestinal cell cytoplasm. here, fbz caused marker proteins for both apical (pepsinogen-like protease, pep-1) and basal (cystatin-like protein) protein compartments to became homogeneously distributed in the cytopl ... | 2002 | 12594960 |