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design and synthesis of novel insecticides based on the serotonergic ligand 1-[(4-aminophenyl)ethyl]-4-[3-(trifluoromethyl)phenyl]piperazine (papp).1-[(4-aminophenyl)ethyl]-4-[3-(trifluoromethyl)phenyl]piperazine (papp) is a 5-ht(1a) agonist and was reported to display high affinity for serotonin (5-ht) receptor from the parasitic nematode haemonchus contortus . the present investigation explored the possibility of using papp as a lead compound of new insecticides with novel mode of action. on the basis of the papp scaffold, a series of 1-arylmethyl-4-[(trifluoromethyl)pyridin-2-yl]piperazine derivatives were designed, synthesized, and eval ...201020000410
the kunitz domain protein bli-5 plays a functionally conserved role in cuticle formation in a diverse range of nematodes.the cuticle of parasitic nematodes performs many critical functions and is essential for proper development and for protection from the host immune response. the biosynthesis, assembly, modification and turnover of this exoskeleton have been most extensively studied in the free-living nematode, caenorhabditis elegans, where it represents a complex multi-step process involving a whole suite of enzymes. the biosynthesis of the cuticle has an additional level of complexity, as many of the enzymes a ...201019716386
alterations in the expression level of a putative aspartic protease in the development of angiostrongylus cantonensis.aspartic proteases are a family of proteinases with catalytic aspartate residues in the active site. these enzymes have been reported to initialize the degradation of host hemoglobin in blood-feeding helminths. after identifying an expressed sequence tag representing an aspartic protease from an angiostrongylus cantonensis young adult dataset, this sequence was found to encode a protein with a predicted molecular mass of 46 kda. it also showed good homologies to aspartic proteases from caenorhab ...201019945419
collagen processing and cuticle formation is catalysed by the astacin metalloprotease dpy-31 in free-living and parasitic nematodes.the exoskeleton or cuticle performs many key roles in the development and survival of all nematodes. this structure is predominantly collagenous in nature and requires numerous enzymes to properly fold, modify, process and cross-link these essential structural proteins. the cuticle structure and its collagen components are conserved throughout the nematode phylum but differ from the collagenous matrices found in vertebrates. this structure, its formation and the enzymology of nematode cuticle co ...201019883650
immunoproteomic analysis of whole proteins from male and female adult haemonchus contortus.whole proteins of male and female adult haemonchus contortus were analysed by immunoproteomic techniques. approximately 662 and 680 spots were detected on proteome maps of male and female nematodes, respectively, stained with coomassie brilliant blue g-250. there were 609 shared spots. approximately 193 and 196 spots were recognised on western blot maps of male and female nematodes, respectively, using antiserum from naturally infected goats as the source of primary antibodies. there were 129 ge ...201019560953
gastro-intestinal nematode infections in goats relative to season, host sex and age from the kashmir valley, india.the present study aimed to investigate the seasonal epidemiological prevalence of gastro-intestinal nematodes (gins) of goats with respect to sex and age of the host in the kashmir valley from 1 february 2005 to 31 january 2007. a total of 1267 goats were examined [faecal examination: 938 (year 1: 470; year 2: 468); gastro-intestinal (git) examination: 329 (year 1: 175; year 2: 154)]. the overall prevalence of gin infection in these animals was 54.3% (year 1: 54.8%; year 2: 53.8%; p = 0.842). th ...201019627625
evaluation of three pakistani sheep breeds for their natural resistance to artificial infection of haemonchus contortus.this study was carried out to evaluate three pakistani sheep breeds (kachhi, lohi and thalli) for their natural resistance against artificial infection of haemonchus contortus. lambs were weaned at 3 months of age, housed in separate pens and treated with avermectin to eliminate gastrointestinal nematode infection. each lamb was infected orally with approximately 10,000 third stage larvae of h. contortus. selected breeds were compared on the basis of parasitological, haematological, biochemical ...201019939567
anthelmintic effects of prosopis laevigata n-hexanic extract against haemonchus contortus in artificially infected gerbils ( meriones unguiculatus).the anthelmintic effect of prosopis laevigata (mezquite) n-hexanic extract was evaluated against haemonchus contortus endoparasitic stages in artificially infected gerbils (meriones unguiculatus). prosopis laevigata leaves were collected from the sierra de huautla, ecological reserve of the biosphere, in morelos state, mexico; dehydrated under shade and macerated with n-hexane for 3 days, followed by distillation for 8 h. this procedure was repeated three times and the final extract was kept at ...201019619382
immune cell kinetics in the ovine abomasal mucosa following hyperimmunization and challenge with haemonchus contortus.sheep were sensitized by repeated infection with haemonchus contortus l3, followed by a 12 week rest period, and an abomasal cannula was surgically implanted in all sheep. seven of the sensitized sheep were subsequently challenged with 50 000 h. contortus l3 while 4 control sheep were challenged with saline. biopsy samples were taken using a fibreoptic endoscope on days 0, 1, 2, 3, 5, 7 and 28 after challenge and leukocyte subpopulations quantified by (immuno)histology. differential blood cell c ...201020167198
structural and functional characterisation of the fork head transcription factor-encoding gene, hc-daf-16, from the parasitic nematode haemonchus contortus (strongylida).despite their phylogenetic diversity, parasitic nematodes share attributes of longevity and developmental arrest (=hypobiosis) with free-living nematodes at key points in their life cycles, particularly in larval stages responsible for establishing infection in the host. insulin-like signalling plays crucial roles in the regulation of life span and arrest (=dauer formation) in the free-living nematode, caenorhabditis elegans. insulin-like signalling in c. elegans negatively regulates the fork he ...201019796644
expression of genes in gastrointestinal and lymphatic tissues during parasite infection in sheep genetically resistant or susceptible to trichostrongylus colubriformis and haemonchus contortus.resistance to an acute gastrointestinal nematode (gin) infection is dependent on the ability of the host to recognise the parasite and mount a protective th2 response. it is hypothesised that lambs which are genetically susceptible to gin will differentially up-regulate th1-type genes and therefore remain susceptible to chronic parasitism compared with genetically resistant lambs which will differentially up-regulate th2-type genes and clear the parasite infection. two selection flocks, in which ...201019825375
the use of dna markers to map anthelmintic resistance loci in an intraspecific cross of haemonchus contortus.the use of dna markers to track the development of anthelmintic resistance in parasites of livestock would allow informed choices for the management of this important problem. we describe a genetic mapping approach for the discovery of dna markers for anthelmintic resistance in haemonchus contortus. we crossed a multi-drug resistant field isolate of h. contortus with a well-characterized laboratory strain susceptible to 4 drug classes. the f2 were separately selected with 5 anthelmintics from 4 ...201019835651
efficacy of copper oxide wire particles against gastrointestinal nematodes in sheep and goats.profitable sheep and goat production in the usa is severely limited by gastrointestinal nematode (gin) parasitism, particularly by haemonchus contortus. copper oxide wire particles (cowp) have anti-parasitic properties in the diet of small ruminants, but efficacy of cowp may differ between sheep and goats. in a study with weaned kids (kiko x spanish cross, 6 months old) and lambs (katahdin or dorper x blackface crosses, 5 months old), grazing the same pasture area in central georgia, 2g of cowp ...201019931291
calreticulin transacylase: genesis, mechanism of action and biological applications.our earlier investigations have identified a unique enzyme in the endoplasmic reticulum (er) termed acetoxy drug: protein transacetylase (taase) catalyzing the transfer of acetyl group from polyphenolic acetates (pa) to certain receptor proteins (rp). an elegant assay procedure for taase was developed based on the inhibition of glutathione s-transferase (gst) due to acetylation by a model acetoxycoumarin, 7, 8-diacetoxy-4-methylcoumarin (damc). taase purified from various mammalian tissue micros ...201020109516
vaccination-induced igg response to galalpha1-3galnac glycan epitopes in lambs protected against haemonchus contortus challenge infection.lambs vaccinated with haemonchus contortus excretory/secretory (es) glycoproteins in combination with the adjuvant alhydrogel are protected against h. contortus challenge infection. using glycan micro-array analysis we showed that serum from such vaccinated lambs contains igg antibodies that recognise the glycan antigen galalpha1-3galnac-r and galnacbeta1-4(fucalpha1-3)glcnac-r. our studies revealed that h. contortus glycoproteins contain galalpha1-3gal-r as well as significant levels of galalph ...201019695255
estimates of genetic parameters for faecal egg count of haemonchus contortus infection and relationship with growth traits in avikalin sheep.genetic parameters for faecal egg count were estimated in naturally challenged avikalin sheep developed and maintained at central sheep & wool research institute, avikanagar, india, over a period of 4 years (2004-2007). the data on faecal egg count for 433 animals descended from 41 sires, and 151 dams were used for the study. genetic analyses were carried out using restricted maximum likelihood, fitting an animal model and ignoring or including maternal genetic or permanent environmental effects ...201019898999
in-vitro anthelminthic activity of crude aqueous extracts of aloe ferox, leonotis leonurus and elephantorrhiza elephantina against haemonchus contortus.aloe ferox (mill), leonotis leonurus (l) r. br; and elephantorrhiza elephantina (burch.) skeels are plants frequently used by resource-limited farmers in the eastern cape province to control gastrointestinal parasites in goats. a study was conducted to validate their anthelminthic activities in-vitro on the egg and larvae of the nematode parasite haemonchus contortus. the crude aqueous extracts of leaves of a. ferox and l. leonurus; and roots of e. elephantina were used. eggs and larvae of the p ...201019693685
the effect of sheep breed, age, and gender on the pharmacokinetics and efficacy of monepantel, an amino-acetonitrile derivative.this analysis investigated the influence of breed and gender on the pharmacokinetics of monepantel, and influence of breed, age, and gender on its efficacy against gastrointestinal nematodes of sheep. in a comparison of pharmacokinetic profiles from two studies, merino lambs had significantly greater maximum concentrations of monepantel and monepantel sulfone, and faster times to reach these concentrations than dorset cross lambs. males had a statistically greater area under the curve (0-504 h) ...201019898870
multiple anthelmintic resistance and the possible contributory factors in beetal goats in an irrigated area (pakistan).this paper presents the first report of multiple anthelmintic resistance in the gastrointestinal nematodes of goats and its possible contributory factors in an irrigated area (pakistan). a total of 18 privately owned beetal goat flocks were selected in order to determine the anthelmintic resistance against commonly used anthelmintics. forty to 48 animals from each flock were selected according to their weight and egg count. the three anthelmintics viz., oxfendazole, levamisole and ivermectin, we ...201019733870
protein acyltransferase function of purified calreticulin. part 1: characterization of propionylation of protein utilizing propoxycoumarin as the propionyl group donor.we have earlier reported that an endoplasmic reticulum luminal protein calreticulin (cr) mediated the acetylation of certain receptor proteins such as glutathione s-transferase (gst) by polyphenolic acetates, leading to irreversible inhibition. this function of calreticulin was termed calreticulin transacetylase. in this communication, we have demonstrated for the first time the ability of the purified recombinant calreticulin of a parasitic nematode haemonchus contortus to transfer propionyl gr ...201020071373
efficacy of duddingtonia flagrans and arthrobotrys robusta in controlling sheep parasitic gastroenteritis.the aim of this study was to evaluate the efficacy of formulations of sodium alginate matrix (pellets) of the nematode predatory fungi, duddingtonia flagrans (ac001 isolate) and arthrobotrys robusta (i-31 isolate), in the biological control of sheep gastrointestinal nematode infections. thirty young bergamacia ewes were allocated into three groups: in group 1 (control), the animals received 2 g/10 kg of live weight (l.w.) of pellets without fungus; in group 2, each animal received 2 g/10 kg of l ...201020237801
effect of repeated wattle tannin drenches on worm burdens, faecal egg counts and egg hatchability during naturally acquired nematode infections in sheep and goats.in vivo and in vitro experiments were carried out to investigate the effect of repeated wattle tannin (wt) drenches on faecal egg counts (fec), worm burdens and egg hatchability during a naturally acquired worm infection in sheep and goats. for the in vivo experiment, nematode-infected sheep and goats were orally drenched with wt at a dose of 1.3g and 1.6gwt/kg bodyweight per day for three consecutive days respectively while a control group received a placebo. fec and other worm infection parame ...201020083356
acetate formation in the energy metabolism of parasitic helminths and protists.formation and excretion of acetate as a metabolic end product of energy metabolism occurs in many protist and helminth parasites, such as the parasitic helminths fasciola hepatica, haemonchus contortus and ascaris suum, and the protist parasites, giardia lamblia, entamoeba histolytica, trichomonas vaginalis as well as trypanosoma and leishmania spp. in all of these parasites acetate is a main end product of their energy metabolism, whereas acetate formation does not occur in their mammalian host ...201020085767
in vitro anthelmintic activity of combretum molle (r. br. ex g. don) (combretaceae) against haemonchus contortus ova and larvae.parasitic nematodes, especially haemonchus contortus (rudolphi), are among the most common and economically important causes of disease in sheep and goats owned by pastoralists and small holder farmers in africa. the control of these infections relies mainly on the use of anthelmintic drugs. however, herbal preparations are widely used by pastoralists and small holder farmers for the treatment of their livestock against helminth parasites. the anthelmintic effect of acetone leaf extract and frac ...201020097010
lysine-scanning mutagenesis reveals an amendable face of the cyclotide kalata b1 for the optimization of nematocidal activity.cyclotides are a family of macrocyclic peptides that combine the unique features of a head-to-tail cyclic backbone and a cystine knot motif, the combination of which imparts them with extraordinary stability. the prototypic cyclotide kalata b1 is toxic against two economically important gastrointestinal nematode parasites of sheep, haemonchus contortus and trichostrongylus colubriformis. a lysine scan was conducted to examine the effect of the incorporation of positive charges into the kalata b1 ...201020103593
in vitro effects of tabernaemontana citrifolia extracts on haemonchus contortus.tabernaemontana citrifolia (apocynaceae) is traditionally used as an anthelmintic preparation for ruminants in guadeloupe (french west indies). this study was carried out to evaluate the in vitro effect of this plant against the parasitic nematode of small ruminants haemonchus contortus. three extracts (aqueous, methanolic and dichloromethane) of t. citrifolia fruit, leaf and root were tested on four developmental stages of the parasite, using egg hatch assay (eha), larval development assay (lda ...201020117808
drug target prediction and prioritization: using orthology to predict essentiality in parasite genomes.new drug targets are urgently needed for parasites of socio-economic importance. genes that are essential for parasite survival are highly desirable targets, but information on these genes is lacking, as gene knockouts or knockdowns are difficult to perform in many species of parasites. we examined the applicability of large-scale essentiality information from four model eukaryotes, caenorhabditis elegans, drosophila melanogaster, mus musculus and saccharomyces cerevisiae, to discover essential ...201020361874
vertical migration of haemonchus contortus infective larvae on cynodon dactylon and paspalum notatum pastures in response to climatic conditions.observations were made on vertical migration patterns of haemonchus contortus infective larvae on cynodon dactylon (bermudagrass) and paspalum notatum (bahiagrass) pastures under summer climatic conditions typical of east texas. ten thousand h. contortus infective larvae (l3) were introduced to 100 cm(2) subplots of each pasture species within a plot area of 1m(2). subplots were inoculated with larvae by applying them in an aqueous medium to the soil or mat beneath the vegetation. herbage from t ...201020149541
characterization of a caenorhabditis elegans glc seven-like phosphatase (gsp) orthologue from haemonchus contortus (nematoda).a full-length complementary dna (cdna; designated hc-stp-1) encoding a serine/threonine phosphatase (hc-stp-1) was isolated from haemonchus contortus, a strongylid nematode parasite of small ruminants. hc-stp-1 was shown to be transcribed in males of both adults and fourth-stage larvae, but not in females, early larval stages or eggs. the full-length gene (2854 bp) contained ten exons and nine introns, and encoded a cdna of 951 bp. comparisons of the conceptually translated protein (316 amino ac ...201020153820
the control of inhibited fourth-stage larvae of haemonchus contortus and teladorsagia spp. in sheep in australia with monepantel.monepantel is the first molecule from the amino-acetonitrile derivatives to be developed for controlling gastro-intestinal nematodes in sheep. two studies were undertaken to examine the drug's efficacy against inhibited fourth-stage larvae of haemonchus contortus and teladorsagia spp. in sheep when administered as an oral solution at 2.5mg/kg bodyweight. in study 1, efficacy was 99.7% against h. contortus (p<0.0001) and in study 2, 99.8% against teladorsagia spp. (p<0.0001). this population cons ...201020153932
ovicidal and larvicidal activity of crude extracts of melia azedarach against haemonchus contortus (strongylida).the rapid development of anthelmintic resistance, associated with the high cost of the available anthelmintic drugs, has limited the success of gastrointestinal nematodiosis control in sheep and goats and thus created interest in studying medicinal plants as an alternative source of anthelmintics. the aim of this study was carried out to evaluate the anthelmintic activity of the leaves and seed aqueous and hydro-alcoholic extracts of melia azedarach l. (meliaceae) were tested for in vitro ovicid ...201020177909
an unc-49 gaba receptor subunit from the parasitic nematode haemonchus contortus is associated with enhanced gaba sensitivity in nematode heteromeric channels.we have identified two genes from the parasitic nematode haemonchus contortus, hco-unc-49b and hco-unc-49c that encode two gaba-gated chloride channel subunits. electrophysiological analysis revealed that this channel has properties similar to those of the unc-49 channel from the free-living nematode caenorhabditis elegans. for example, the hco-unc-49b subunit forms a functional homomeric channel that responds to gaba and is highly sensitive to picrotoxin. hco-unc-49c alone does not respond to g ...201020180830
the accuracy of the famacha-method in detecting anaemia and haemonchosis in goat flocks in switzerland under field conditions.in this study, goats from six farms in central switzerland were examined for the evaluation of the famacha-method under middle european conditions. individual faecal egg counts were determined at a 4-week interval for a period of 6 months and the gastrointestinal nematode (gin) genera were differentiated using larval culture. simultaneously, the goats were bled for packed cell volume (pcv) determination and scored for anaemia of the conjunctiva according to the famacha-method. the three methods ...201020188478
quarantine treatment of sheep with monepantel--rapidity of fecal egg count reduction.in the presence of multiple anthelmintic resistance, effective quarantine treatment of sheep entering a farm has become a crucial tool in nematode management. in the present work, the use of the amino-acetonitrile derivative, monepantel as a quarantine treatment was investigated. of special interest was the rapidity of decrease in fecal egg counts (fec) compared to other anthelmintics used in sheep. in three different studies, sheep were either infected with haemonchus contortus of known resista ...201020207487
monosaccharide composition of fundic and duodenal mucins in sheep infected with haemonchus contortus or teladorsagia circumcincta.the effects on the monosaccharide composition of fundic and duodenal mucins of parasitism by haemonchus contortus or teladorsagia circumcincta were investigated in sheep at 4, 6 and 9 months of age. infected sheep were euthanased at days 21 and 28 post-infection respectively, together with uninfected controls. fundic and duodenal mucins were purified by gel filtration and cscl density gradient centrifugation and monosaccharides were released by heating at 95 degrees c for 6h in 2m hcl. thin-laye ...201020211529
association of ion-channel genotype and macrocyclic lactone sensitivity traits in haemonchus contortus.resistance to macrocyclic lactones in the strongylid parasite of sheep, haemonchus contortus, is associated with specific alleles of several genes, including those encoding ligand-gated chloride-channels. while previous functional studies of the ion-channels encoded by these resistant alleles have revealed alterations in ligand binding and response to the anthelmintics, we still do not know how these alleles are contributing to resistance in vivo. to understand the phenomenon of anthelmintic res ...201020211658
effect of a tropical tannin-rich plant lysiloma latisiliquum on adult populations of haemonchus contortus in sheep.bioactive plants with anthelmintic (ah) properties represent a promising alternative solution to chemical treatments. the ah effect of several mexican tannin-rich (tr) plants has been screened in vitro. the in vivo ah effect of one tr legume, lysiloma latisiliquum (tzalam) on nematode larval establishment was confirmed. the present trial aimed at evaluating the direct and indirect effects of l. latisiliquum fodder consumption on adult haemonchus contortus. twenty-two parasite-naïve hair sheep la ...201020605336
an ortholog of the ecdysone receptor protein (ecr) from the parasitic nematode haemonchus contortus.high concentrations (> or =4.2mm) of 20e inhibit the development of haemonchus contortus eggs to the l3 larval stage. we report the cloning of cdna encoding an ecr ortholog (hcecr) from h. contortus mrna expressed during l3. phylogenetically, this and the putative ecr from brugia malayi form a separate branch between arthropod ecrs and liver x receptors. two isoforms of hcecr differ in the inclusion/omission of a 3-residue segment in the a/b domain. single nucleotide polymorphisms at 49 position ...201020226216
maternal transference of passive humoral immunity to haemonchus contortus in goats.this study evaluated the transference of maternal-specific antibodies against haemonchus contortus and the humoral immune response of 32 goat kids to natural infection by the parasite, from birth to 5 months of age. all serum samples collected immediately after birth and before colostrum ingestion were negative for h. contortus antibodies, as demonstrated by elisa. however, 30 and 60 days after colostrum and milk ingestion, antibody detection was positive and faecal egg count (fec) was negative, ...201020236709
covariate selection in multivariate spatial analysis of ovine parasitic infection.gastrointestinal (gi) strongyle and fluke infections remain one of the main constraints on health and productivity in sheep dairy production. a cross-sectional survey was conducted in 2004-2005 on ovine farms in the campania region of southern italy in order to evaluate the prevalence of haemonchus contortus, fasciola hepatica, dicrocoelium dendriticum and calicophoron daubneyi from among other parasitic infections. in the present work, we focused on the role of the ecological characteristics of ...201021167615
cloning, expression and characterization of nad+-dependent glyceraldehyde-3-phosphate dehydrogenase of adult haemonchus contortus†glyceraldehyde-3-phosphate dehydrogenase (gapdh) regulates a wide range of biological processes, including pathogen evasion. in the present research, the gapdh gene of haemonchus contortus (hcgapdh) was cloned and characterized. specific primers for the rapid amplification of cdna ends (race) were designed based on the expressed sequence tag (est, aw670737) to amplify the 3′ and 5′ ends of hcgapdh. the full length of cdna from this gene was obtained by overlapping the sequences of 3′ and 5 ...201021205411
anthelmintic activity of botanical extracts against sheep gastrointestinal nematodes, haemonchus contortus.the source of chemical anthelmintics (levamisole, flubendazole, and thiabendazole) had limited the success of gastrointestinal nematodiasis control in sheep and goats and thus awakened interest in the study of medicinal plant extracts as alternative sources of anthelmintics. the egg hatching and larvicidal effect of indigenous plant extracts were investigated against the sheep parasite, haemonchus contortus. the purpose of the present study was to assess the efficacy of leaf, bark, and seed ethy ...201021161270
differences in efficacy of monepantel, derquantel and abamectin against multi-resistant nematodes of sheep.drug resistance has become a global phenomenon in gastrointestinal nematodes of sheep, particularly resistance to macrocyclic lactones. new anthelmintics are urgently needed for both the control of infections with multi-resistant nematodes in areas where classical anthelmintics are no longer effective, and the prevention of the spread of resistance in areas where the problem is not as severe. recently, two new active ingredients became commercially available for the treatment of nematode infecti ...201021161271
influence of gastrointestinal trichostrongylidosis on ram fertility.a study on the influence of gastrointestinal trichostrongyles on ram fertility was performed. two groups of semen donor rams (sarda breed) were utilized; one was experimentally infected with haemonchus contortus, trichostrongylus colubriformis and teladorsagia circumcincta and the other was used as a control group. in all animals, coprological, haematological and reproductive parameters were studied. the results suggest that the parasites had a limited effect with some changes in phosphorus, cho ...201021370756
structural and functional characterisation of the ovine interferon gamma (ifng) gene: its role in nematode resistance in rasa aragonesa ewes.the ovine interferon gamma (ifng) gene was structurally and functionally characterised, and the association between its variants and the response to haemonchus contortus infection was examined in resistant and susceptible rasa aragonesa ewes in different physiological conditions. sequential faecal egg counts (fecs) were performed on a naturally infected flock of 400 rasa aragonesa ewes and two groups of ewes selected for high (n=38) or low (n=33) fec, which were subsequently challenged with h. c ...201121419496
anthelmintic screening of fractions of elephantorrhiza elephantina root extract against haemonchus contortus.in the previous work conducted, it was found that the root extract of elephantorrhiza elephantina (bruch.) skeels. exhibited good anthelmintic efficacy against eggs and larvae of haemonchus contortus. this study was therefore undertaken to screen fractions of the extracts of e. elephantina for their anthelmintic activity against adult h. contortus using a bioactivity-guided assay. the adult worm bioassay was conducted using aqueous, hexane and ethyl acetate fractions of the plant extracts at con ...201121643660
proteases in blood-feeding nematodes and their potential as vaccine candidates.parasitic nematodes express and secrete a variety of proteases which they use for many purposes including the penetration of host tissues, digestion of host protein for nutrients, evasion of host immune responses and for internal processes such as tissue catabolism and apoptosis. for these broad reasons they have been examined as possible parasite control targets. blood-feeding nematodes such as the barber-pole worm haemonchus contortus that infect sheep and goats and the hookworms, ancylostoma ...201121660664
a comparison of two integrated approaches of controlling nematode parasites in small ruminants.control of gastrointestinal nematodes (gin) in small ruminants in regions of the world where anthelmintic resistance is prevalent must rely on more than just chemical deworming strategies. the objective of this experiment was to compare two integrated treatment protocols for control of gin (primarily haemonchus contortus in this region) using anthelmintics, copper oxide wire particles (cowp) and famacha(©), compared to traditional anthelmintic use only. three separate trials were conducted on ma ...201121333450
rumen function and digestion of merino sheep divergently selected for genetic difference in resistance to haemonchus contortus.the aim of this experiment was to investigate the effect of haemonchus contortus infection on rumen function and digestion of merino sheep from lines divergently selected for genetic resistance to h. contortus. rumen function and whole-tract digestibility were determined in 29 merino weaner wethers from the csiro haemonchus selection flock, increased resistance to haemonchus (irh), decreased resistance to haemonchus (drh) and random bred control (c) selection lines. wethers were fed a restricted ...201121376471
efficacy of an energy block containing duddingtonia flagrans in the control of gastrointestinal nematodes of sheep.the efficacy of the nematode-trapping fungus duddingtonia flagrans incorporated into an energy block was evaluated for the control of gastrointestinal nematodes in sheep. four naturally parasitised sheep with average nematode egg counts of 2,470 eggs per gram grazed by pairs on two similar parasite-free paddocks for 30-ádays. during that period, one pair of sheep (treated animals, t1) received an energy block containing chlamydospores of d. flagrans at a dose of 200,000 chlamydopores/kg bw/day, ...201121380576
evaluation of immune response to artificial infections of haemonchus contortus in gulf coast native compared with suffolk lambs.the gulf coast native (native) breed of sheep among many others is identified as being relatively resistant to haemonchus contortus, an abomasal nematode parasite of small ruminants. understanding the mode of immune response that helps these breeds of sheep control infection could help design and implement appropriate control programs. in this experiment, the components of the immune response during the early infection period in resistant native lambs were evaluated and compared with susceptible ...201121570191
direct immunization of the abomasum or rectum of goats induces local lymph node responses against haemonchus contortus mucosal antigens.we investigated several methods to immunize the abomasum (fourth and gastric stomach) of kid goats by direct (abomasal) or distal (rectal or nasal) routes utilizing mucosal antigens isolated from the abomasal parasite, haemonchus contortus. direct (ultrasound guided), immunization of the abomasal mucosa together with rectal immunization established lymphocyte proliferation responses in abomasal lymph nodes (alns), while distal methods, alone, produced equivocal results. the differential response ...201121333770
effect of dietary supplementation on resistance to experimental infection with haemonchus contortus in creole kids.the aim of the present study was to test the effect of dietary supplementation on resistance to experimental infection with haemonchus contortus in creole kids. one trial with three replicates involved a total of 154 female kids that were chosen from three successive cohorts of the creole flock of inra-gardel in 2007. the kids were placed into four treatments according to the amount of concentrate they received: g0 (no concentrate and a quality dichantium spp. hay ad libitum, hay), g1 (hay+100g ...201121349645
minimising the development of anthelmintic resistance, and optimising the use of the novel anthelmintic monepantel, for the sustainable control of nematode parasites in australian sheep grazing systems.to compare the risk of different treatment scenarios on selecting for anthelmintic resistance on australian sheep farms.201121495986
evaluation and application of a molecular method to assess the composition of strongylid nematode populations in sheep with naturally acquired infections.we evaluated the performance of a pcr method for the diagnosis of naturally acquired strongylid nematode infections in sheep (n = 470; in a temperate climatic zone of south-eastern australia), using a panel of 100 'negative control' samples from sheep known not to harbour parasitic helminths. we compared the diagnostic sensitivity (98%) and specificity (100%) of this assay against a conventional faecal flotation method and also established a system to rank the contribution of particular strongyl ...201121256979
atypical (rio) protein kinases from haemonchus contortus--promise as new targets for nematocidal drugs.almost nothing is known about atypical kinases in multicellular organisms, including parasites. supported by information and data available for the free-living nematode, caenorhabditis elegans, and other eukaryotes, the present article describes three rio kinase genes, riok-1, riok-2 and riok-3, from haemonchus contortus, one of the most important parasitic nematodes of small ruminants. analyses of these genes and their products predict that they each play critical roles in the developmental pat ...201121262337
fecundity in adult haemonchus contortus parasites is correlated with abomasal tissue eosinophils and ?d t cells in resistant canaria hair breed sheep.canaria hair breed (chb) sheep are more resistant than canaria sheep (cs) to experimental haemonchus contortus infection. protective responses appear effective against the adult stage of the parasite, not as commonly reported in other breeds against the larval stages. in this study we have quantified several abomasal immune cells and correlated these with parasitological variables for each breed. a significant negative correlation between cd4+ t cell numbers and worm burden or length at 28 dpi w ...201121277683
voluntary feed intake and diet selection of merino sheep divergently selected for genetic difference in resistance to haemonchus contortus.this research was designed to determine if divergent selection for resistance to haemonchus contortus had produced correlated changes in voluntary feed intake and diet selection. voluntary feed intake, diet selection and production were determined in 54 merino weaner rams from the csiro haemonchus selection flock, increased resistance to haemonchus (irh), decreased resistance to haemonchus (drh) and random bred control (c) selection lines. weaner rams were fed ad libitum either a high (9.2 mj me ...201121330058
vaccination of goats with dna vaccines encoding h11 and il-2 induces partial protection against haemonchus contortus infection.dna vaccines expressing haemonchus contortus h11 antigen with or without interleukin (il)-2 were tested for protection against h. contortus infection in goats. sixteen goats (8-10months of age) were allocated into four trial groups. on days 0 and 14, group 1 was immunised with a dna vaccine expressing h11 and il-2 and group 2 was immunised with a dna vaccine expressing h11 only. group 3 was an unvaccinated positive control group challenged with h. contortus third stage larvae (l3). group 4 was a ...201121330170
ovicidal and larvicidal activity of the crude extracts from phytolacca icosandra against haemonchus contortus.the development of anthelmintic resistance has impacted on the success of conventional anthelmintics (ah) for the control of gastrointestinal nematodes in grazing/browsing sheep and goats. medicinal plants from the traditional herbolary in mexico may provide new candidates that can be explored as alternative sources of ahs for ruminants. this study evaluated the leaf extracts derived from phytolacca icosandra against infective l(3) larvae and eggs from haemonchus contortus collected from sheep. ...201121439732
anthelmintic activity of trianthema portulacastrum l. and musa paradisiaca l. against gastrointestinal nematodes of sheep.evaluation of anthelmintic effects of trianthema (t.) portulacastrum l. (aizoaceae) whole plant and musa (m.) paradisiaca l. (musaceae) leaves against prevalent gastrointestinal worms of sheep was done that may justify their traditional use in veterinary clinical medicine. in vitro anthelmintic activity of the crude aqueous methanolic extract (came) of both the plants was determined using mature female haemonchus (h.) contortus and their eggs in adult motility assay (ama) and egg hatch test (eht ...201121440370
molecular cloning, expression and characterization of enolase from adult haemonchus contortus.enolase represents a multifunctional protein involved in basic energy metabolism. in the present research, the enolase gene of haemonchus contortus (hceno) was cloned and characterized. specific primers for the rapid amplification of cdna ends (race) were designed based on the expression sequence tag (est, genbank accession no. bf422728) to amplify the 3'- and 5'-ends of hceno. the full length of cdna from this gene was obtained by overlapping the sequences of 3'- and 5'-extremities and amplific ...201121444098
in vitro analysis of the anthelmintic activity of forage chicory (cichorium intybus l.) sesquiterpene lactones against a predominantly haemonchus contortus egg population.the anthelmintic activity of chicory (cichorium intybus l.) herbage has been attributed to sesquiterpene lactones. chicory leaves contain significant amounts of lactucin (lac), 8-deoxylactucin (dol), and lactucopicrin (lpic), but the proportions of these three sesquiterpene lactones vary among forage chicory cultivars. to determine whether the individual compounds differ in anthelmintic activity, we prepared sesquiterpene lactone-enriched extracts from leaves of two forage chicory cultivars, 'gr ...201121477927
ovicidal and larvicidal activity of cassia alata leaf acetone extract and fractions on haemonchus contortus: in vitro studies.the failure of modern anthelmintics to control nematode parasites of sheep and goats is a reality on many farms in the tropical/subtropical regions of the world. this necessitates chemotherapeutic control alternatives and plant secondary metabolite with activity is one of those potential solutions.201121501100
effects of myracrodruon urundeuva extracts on egg hatching and larval exsheathment of haemonchus contortus.the anthelmintic resistance has limited the control of gastrointestinal nematodes of small ruminants and thus has awakened interest in the study of tanniferous plants as a source of anthelmintics. these experiments were carried out to evaluate the in vitro efficacy of myracrodruon urundeuva leaf extract (le) and stem extract (se) against haemonchus contortus. an inhibitor of tannins, polyvinyl polypyrrolidone (pvpp), was used to verify if these metabolites are involved in the anthelmintic activi ...201121465262
functional reconstitution of haemonchus contortus acetylcholine receptors in xenopus oocytes provides mechanistic insights into levamisole resistance.background and purpose the cholinergic agonist levamisole is widely used to treat parasitic nematode infestations. this anthelmintic drug paralyses worms by activating a class of levamisole-sensitive acetylcholine receptors (l-achrs) expressed in nematode muscle cells. however, levamisole efficacy has been compromised by the emergence of drug resistant parasites, especially in gastrointestinal nematodes such as haemonchus contortus. we report here the first functional reconstitution and pharmaco ...201121486278
involvement of tannins and flavonoids in the in vitro effects of newbouldia laevis and zanthoxylum zanthoxyloïdes extracts on the exsheathment of third-stage infective larvae of gastrointestinal nematodes.the present study aimed at examining the possible role of tannins and flavonoids on the in vitro anthelmintic properties of the extracts of two plants from the southern area of western africa, i.e. newbouldia laevis and zanthoxylum zanthoxyloïdes. extracts of the two plants were prepared by use of acetone/water (70/30) and their anthelmintic activity was measured by use of the larval exsheathment inhibition assay (leia) applied on the abomasal species, haemonchus contortus and the intestinal spe ...201121497021
the haemonchus contortus unc-49b subunit possesses the residues required for gaba sensitivity in homomeric and heteromeric channels.hco-unc-49 is a gaba receptor from the parasitic nematode haemonchus contortus that has a relatively low overall sequence similarity to vertebrate gaba receptors but is very similar to the unc-49 receptor found in the free living nematode caenorhabditis elegans. while the nematode receptors do share >80% sequence similarity they exhibit different sensitivities to gaba. in addition, the unc-49c subunit appears to be a positive modulator of gaba sensitivity in the h. contortus heteromeric channel, ...201121524670
direct anthelmintic effects of cereus jamacaru (cactaceae) on trichostrongylid nematodes of sheep: in vivo studies.following claims of anthelmintic activity of cereus jamacaru dc (cactaceae) by a commercial farmer, in vivo studies were conducted to determine the possible direct anthelmintic effects of the plant on ovine gastrointestinal nematodes. eighteen sheep were infected with 4000 haemonchus contortus and 6000 trichostrongylus colubriformis larvae given in three divided doses over a period of three days. once the infections were patent, the sheep were allocated to three groups and were drenched once a w ...201121498000
protection of calves against haemonchus placei and haemonchus contortus after immunization with gut membrane proteins from h. contortus.a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in 4 groups of 9 worm free calves challenged with either 8,000 h. contortus or haemonchus placei infective larvae. vaccinates received 50 μg of the antigen and 1mg quila adjuvant three times 21 days apart, while the controls got adjuvant alone. the calves were challenged 7 days after the last immunization and killed for worm counts 43 days later. immunization resulted in high titre antib ...201121535018
caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use.the most challenging obstacles to testing products for their anthelmintic activity are: (1) establishing a suitable nematode in vitro assay that can evaluate potential product use against a parasitic nematode of interest and (2) preparation of extracts that can be redissolved in solvents that are miscible in the test medium and are at concentrations well tolerated by the nematode system used for screening. the use of parasitic nematodes as a screening system is hindered by the difficulty of keep ...201121680095
a stochastic model accommodating the famacha© system for estimating worm burdens and associated risk factors in sheep naturally infected with haemonchus contortus.a previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with haemonchus contortus over five consecutive haemonchus seasons (november to january/february) on a farm in the summer rainfall region in south africa, although only one season is discussed. the algorithm associates haemoglobin levels with worm counts in individual animals. variables were represented by distributions based on famacha(©) scores a ...201121334812
no loss of production due to larval challenge in sheep given continuous anthelmintic treatment via a controlled release capsule.this study aimed to quantify production loss due to larval challenge in sheep administered a controlled release albendazole capsule (crc) and thus determine the suitability of crc treated sheep as a proxy for worm-free sheep in grazing experiments. the experiment used an incomplete 2+ù3 latin square design with 81 merino wethers. sheep were either infected (inf) with mixed oral infection of albendazole-susceptible haemonchus contortus, trichostrongylus colubriformis, and teladorsagia circumcinct ...201121824729
proteomic analysis of secretory products from the model gastrointestinal nematode heligmosomoides polygyrus reveals dominance of venom allergen-like (val) proteins.the intestinal helminth parasite, heligmosomoides polygyrus bakeri offers a tractable experimental model for human hookworm infections such as ancylostoma duodenale and veterinary parasites such as haemonchus contortus. parasite excretory-secretory (es) products represent the major focus for immunological and biochemical analyses, and contain immunomodulatory molecules responsible for nematode immune evasion. in a proteomic analysis of adult h. polygyrus secretions (termed hes) matched to an ext ...201121722761
dual oxidase 2 and glutathione peroxidase gene expression are elevated in hyperimmunized sheep challenged with haemonchus contortus.a sequential biopsy sampling method was used to investigate oxidant and antioxidant gene responses in resistant sheep challenged with haemonchus contortus larvae or a sham saline challenge. the expression of key sheep oxidant and antioxidant producing genes were measured in sequential samples removed from the abomasums at days 0, 1, 2, 3, 5, 7 and 28 post challenge. gene expression levels at each time point were compared to expression at day 0, and levels of the various genes were also correlate ...201121444154
slo-1-channels of parasitic nematodes reconstitute locomotor behaviour and emodepside sensitivity in caenorhabditis elegans slo-1 loss of function mutants.the calcium-gated potassium channel slo-1 in caenorhabditis elegans was recently identified as key component for action of emodepside, a new anthelmintic drug with broad spectrum activity. in this study we identified orthologues of slo-1 in ancylostoma caninum, cooperia oncophora, and haemonchus contortus, all important parasitic nematodes in veterinary medicine. furthermore, functional analyses of these slo-1 orthologues were performed using heterologous expression in c. elegans. we expressed a ...201121490955
enzymes of the ornithine-glutamate-proline pathway in the sheep abomasal nematode parasites haemonchus contortus and teladorsagia circumcincta.a fully functional ornithine-glutamate-proline pathway was detected in l3 and adult haemonchus contortus and teladorsagia circumcincta, making the parasites capable of interconversion of these amino acids. ornithine aminotransferase (oat) (e.c. 2.6.1.13) was a reversible pyridoxal-5-phosphate (plp)-dependent enzyme with an optimum ph 8.5. hydroxylamine completely inhibited oat activity in both parasites. for all five enzymes, substrate affinity was similar for each species and life cycle stage, ...201121781965
in vitro anthelmintic activity of crude extracts of five medicinal plants against egg-hatching and larval development of haemonchus contortus.ethnopharmacological relevance: senna occidentalis, leonotis ocymifolia, leucas martinicensis, rumex abyssinicus, and albizia schimperiana are traditionally used for treatment of various ailments including helminth infection in ethiopia. materials and methods: in vitro egg hatch assay and larval development tests were conducted to determine the possible anthelmintic effects of crude aqueous and hydro-alcoholic extracts of the leaves of senna occidentalis, aerial parts of leonotis ocymifolia, leu ...201121605649
dose titration of sericea lespedeza leaf meal on haemonchus contortus infection in lambs and kids.the objective of three experiments was to determine the impact of supplementing sericea lespedeza (lespedeza cuneata; sl) in three concentrations in a loose or pelleted diet on gastrointestinal nematodes (gin) in small ruminants. experiments on lambs were conducted at the usda, agricultural research service in booneville, ar (exp. 1) and at louisiana state university in baton rouge, la (exp. 2); an experiment on goat kids occurred at university of maryland-eastern shore (exp. 3). exp. 1 used cro ...201121621921
haemonchus contortus protease inhibition by n-alkyl ferulates from maprounea guianensis.this report describes the inhibition of the proteolytic activity of haemonchus contortus lysate by a mixture of n-alkyl ferulates isolated from maprounea guianensis. these compounds were evaluated in vitro for the ability to inhibit the h. contortus proteases using sds-page copolymerized with gelatine (zymography) and by assaying the hemoglobinolytic activity of these enzymes in solution. the ferulates abrogated the proteolysis compared to e-64, suggesting the activity is the result of a cystein ...201121757211
dynamics of the free-living stages of sheep intestinal parasites on pasture in the north island of new zealand. 2. weather variables associated with development.to identify weather variables associated with the development of eggs of teladorsagia (=ostertagia) circumcincta, trichostrongylus colubriformis and haemonchus contortus to third-stage infective larvae (l3) under a range of climatic conditions on pasture in the north island of new zealand.201122040333
the efficacy of trichlorphon and naphthalophos against multiple anthelmintic-resistant nematodes of naturally infected sheep in argentina.an anthelmintic efficacy trial was conducted in sheep harbouring anthelmintic-resistant worms in argentina. seventy lambs were selected from a flock that had been grazed on pastures infected with trichostrongyles previously shown to be resistant to the main anthelmintic groups. lambs were allocated to comparable groups of ten animals each and treated with trichlorphon (50 mg/kg body weight (b.w.) orally); naphthalophos (50 mg/kg b.w. orally); ivermectin (0.2 mg/kg b.w. subcutaneously); fenbendaz ...201121739383
rnai effector diversity in nematodes.while rna interference (rnai) has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. to test if this is due to inter-species differences in rnai effector complements, we performed a primary sequence similarity survey for orthologs of 77 caenorhabditis elegans rnai pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were available, with all outputs subjected to domain-structure verification. our ...201121666793
comparison of molecular and mcmaster microscopy techniques to confirm the presence of naturally acquired strongylid nematode infections in sheep.patent strongylid nematode infections were identified using mcmaster worm egg counts (wec) and pcr assays (its-2 nuclear ribosomal dna) to screen genomic dna extracted directly from lamb faecal samples. lambs from four different farms in southern western australia were sampled rectally on two separate occasions, with mcmaster wecs and pcrs conducted on a total of 858 samples. negative controls (n=96) (wec<50eggs per gram [epg]) and positive controls (n=96) (faecal samples spiked with a 100++l su ...201121827796
a multi-species model to assess the effect of refugia on worm control and anthelmintic resistance in sheep grazing systems.objective  develop a computer simulation model that uses daily meteorological data and farm management practices to predict populations of trichostrongylus colubriformis, haemonchus contortus and teladorsagia (ostertagia) circumcincta and the evolution of anthelmintic resistance within a sheep flock. use the model to explore if increased refugia, provided by leaving some adult sheep untreated, would delay development of anthelmintic resistance without compromising nematode control. procedures  c ...201121595639
comparing the sensitivity of two in vitro assays to evaluate the anthelmintic activity of tropical tannin rich plant extracts against haemonchus contortus.the present trial aimed at comparing the sensitivity of two in vitro methods, i.e. the larval migration inhibition assay (lmia) and the larval exsheathment inhibition assay (leia), to evaluate the anthelmintic (ah) properties of tannin-rich plant extracts against haemonchus contortus infective larvae. the two assays were applied on the same batch of h. contortus infective larvae exposed to water/acetonic extracts obtained from four tropical plants with different tannin contents: acacia gaumeri, ...201121530082
influence of protein supplementation during late pregnancy and lactation on the resistance of santa ines and ile de france ewes to haemonchus contortus.this experiment aimed to evaluate the effect of periparturient metabolizable protein (mp) nutrition on resistance to haemonchus contortus in single rearing ile de france and santa ines ewes. the restriction-fed iso-energetic diet was calculated to provide either 0.8 (low mp diet) or 1.3 (high mp diet) times mp, from three weeks before parturition until eight weeks into lactation. the ewes were experimentally infected with 1000 h. contortus infective larvae (l3) three times a week (mondays, wedne ...201121726941
in vitro activities of acetonic extracts from leaves of three forage legumes (calliandra calotyrsus, gliricidia sepium and leucaena diversifolia) on haemonchus contortus.to assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, calliandra calotyrsus (c. calotyrsus), gliricidia sepium (g. sepium) and leucaena diversifolia (l. diversifolia) in vitro on haemonchus contortus (h. contortus).201121771435
glutamate-gated chloride channels of haemonchus contortus restore drug sensitivity to ivermectin resistant caenorhabditis elegans.anthelmintic resistance is a major problem in livestock farming, especially of small ruminants, but our understanding of it has been limited by the difficulty in carrying out functional genetic studies on parasitic nematodes. an important nematode infecting sheep and goats is haemonchus contortus; in many parts of the world this species is resistant to almost all the currently available drugs, including ivermectin. it is extremely polymorphic and to date it has proved impossible to relate any se ...201121818319
use of fluorescent lectin binding to distinguish teladorsagia circumcincta and haemonchus contortus eggs, third-stage larvae and adult worms.lectin binding to carbohydrates on parasite surfaces has been investigated as a method of distinguishing adult worms, eggs and sheathed and exsheathed l3 of teladorsagia circumcincta and haemonchus contortus, economically important abomasal parasites in temperate climates. both species were maintained as pure laboratory cultures of field isolates from new zealand. each of the four life cycle stages could be distinguished by the binding of at least one lectin: adult worms by sambucus nigra agglut ...201121732182
experiences with integrated concepts for the control of haemonchus contortus in sheep and goats in the united states.the generally warm, moist environmental conditions in the southern united states (u.s.) are ideal for survival and growth of the egg and larval stages of haemonchus contortus and other gastrointestinal nematodes (gin) of sheep and goats. consequently, infection with gin is the greatest threat to economic small ruminant production in this region. with anthelmintic resistance now reaching epidemic proportions in small ruminants in the u.s., non-chemical control alternatives are critically needed. ...201122178411
in vitro screening of plant lectins and tropical plant extracts for anthelmintic properties.lectins are plant secondary metabolites (psm) found in many forages and which may confer anthelmintic properties to gastrointestinal parasites through disrupting the development of parasitic larvae throughout its life cycle. in experiment 1, the ability of the plant lectins jacalin (jac), concanavalin a (con a), phytohemagglutinin e2l2 (pha-e2l2), phytohemagglutinin l4 (pha-l4), phytohemagglutinin e3l (pha-e3l), kidney bean albumin (kba), robinia pseudoacacia agglutinin (rpa), maackia amurensis ...201122130336
Molecular and biochemical characterisation of a Teladorsagia circumcincta glutamate dehydrogenase.A full length cDNA encoding glutamate dehydrogenase was cloned from Teladorsagia circumcincta (TcGDH). The TcGDH cDNA (1614 bp) encoded a 538 amino acid protein. The predicted amino acid sequence showed 96% and 93% similarity with Haemonchus contortus and Caenorhabditis elegans GDH, respectively. A soluble N-terminal 6xHis-tagged GDH protein was expressed in the recombinant Escherichia coli strain BL21 (DE3) pGroESL, purified and characterised. The recombinant TcGDH had similar kinetic propertie ...201121864529
vaccination of goats with a glutathione peroxidase dna vaccine induced partial protection against haemonchus contortus infection.due to their critical functions in worm physiology, glutathione peroxidases in haemonchus contortus are potential candidates for vaccine to control haemonchosis. however, information on the protection potential of these molecules is lacking. in this study, recombinant hc29 antigen was tested for protection against experimental h. contortus infections in goats. fifteen animals were allocated into three trial groups. the animals of hc29 group was vaccinated with a recombinant hc29 dna vaccine twic ...201121680097
norcantharidin analogues with nematocidal activity in haemonchus contortus.with the major problems with resistance in parasitic nematodes of livestock to anthelmintic drugs, there is an urgent need to develop new nematocides. in the present study, we employed a targeted approach for the design of a series of norcantharidin analogues (n=54) for activity testing against the barber's pole worm (haemonchus contortus) of small ruminants in a larval development assay (lda) and also for toxicity testing on nine distinct human cell lines. although none of the 54 analogues synt ...201121536433
efficacy of a combined oral formulation of derquantel-abamectin against the adult and larval stages of nematodes in sheep, including anthelmintic-resistant strains.derquantel (dql), a semi-synthetic member of a novel anthelmintic class, the spiroindoles, in combination with abamectin (aba) [as the combination product startect(-«)] is a new entry for the treatment and control of parasites in sheep. the 19 studies reported herein were conducted in australia, new zealand, south africa and the united kingdom to demonstrate the efficacy of derquantel-abamectin (dql-aba) against a broad spectrum of gastrointestinal and respiratory nematodes of sheep, and to supp ...201121684691
anthelmintic activity of cymbopogon martinii, cymbopogon schoenanthus and mentha piperita essential oils evaluated in four different in vitro tests.anthelmintic resistance is a worldwide concern in small ruminant industry and new plant-derived compounds are being studied for their potential use against gastrointestinal nematodes. mentha piperita, cymbopogon martinii and cymbopogon schoenanthus essential oils were evaluated against developmental stages of trichostrongylids from sheep naturally infected (95% haemonchus contortus and 5% trichostrogylus spp.) through the egg hatch assay (eha), larval development assay (lda), larval feeding inhi ...201121820807
small ruminant resistance against gastrointestinal nematodes: a case of haemonchus contortus.gastrointestinal nematode (gin) infections are a common constraint to small ruminant industry throughout the world, and among those, haemonchosis has its own significance. control of gin primarily relies on the use of anthelmintics, but this approach has become less reliable due to the development of resistance in gins against commonly used anthelmintics and an increased consumer demand for environmentally friendly animal products. these issues have stimulated investigations to find alternative ...201121842390
anthelmintic resistance in a dairy cattle farm in the state of minas gerais.eighty-four half-blood gir +ù holstein (f1) calves aged six months who were naturally infected by gastrointestinal helminths and maintained in rotational grazing received different anthelmintic treatments. group a received anthelmintics according to the usual management in the property (eight treatments, seven including a macrocyclic lactone agent). group b received strategic treatment (ivermectin 3.15%) at the beginning and at the end of the rainy period. eggs per gram of feces (epg) counts and ...201121722485
effect of six tropical tanniferous plant extracts on larval exsheathment of haemonchus contortus.tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. this experiment evaluated the effects of extracts from the leaf and stem of anadenanthera colubrina, leucaena leucocephala and mimosa tenuiflora on larval exsheathment of haemonchus contortus in vitro and verified the role of tannins in this process. third-stage larvae of h. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. the ext ...201121722491
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