| local inflammation as a possible mechanism of resistance to gastrointestinal nematodes in angus heifers. | understanding mechanisms of resistance to gastrointestinal nematodes is important in developing effective and sustainable control programs. a resource population of angus cattle consisting of approximately 600 animals with complete pedigree records has been developed. the majority of these animals were completely characterized for their resistance to natural challenge by gastrointestinal nematodes. as the first step towards understanding the molecular basis of disease resistance, we investigated ... | 2007 | 17182188 |
| a longitudinal survey of anti-ostertagia ostertagi antibody levels in individual and bulk tank milk in two dairy herds in normandy. | the ostertagia-specific antibody levels in milk were monitored in 2 dairy herds to investigate seasonal variations and the relationship between individual and bulk tank milk antibody levels. bulk tank and individual milk samples from all lactating animals were collected over a 1-year period at weekly and monthly intervals, respectively. the ostertagia-specific antibody levels were measured with an indirect elisa and the test results were expressed as optical density ratios (odr). a clear seasona ... | 2007 | 17258252 |
| helminth parasites of gemsbok (oryx gazella) in the klein karoo. | the number and species of helminth parasites from three gemsbok (oryx gazella) were recorded, and their faecal nematode egg counts and the level of pasture contamination determined. six nematode genera were recovered and four species identified, of which trichostrongylus rugatus was the most prevalent. other nematode species recovered were cooperia sp., agriostomum sp., haemonchus contortus, nematodirus spathiger and ostertagia ostertagi. none of the worms were present in all animals studied, an ... | 2006 | 17283732 |
| a small heat shock protein of ostertagia ostertagi: stage-specific expression, heat inducibility, and protection trial. | in this study, we isolated and analyzed a small heat shock protein (hsp) of ostertagia ostertagi (oo-hsp18). oo-hsp18 is encoded by a single-copy gene and the full-length cdna represents an 18-kda protein. the expression of oo-hsp18 is highly stage specific and restricted to the adult stage. the protein is synthesized in a tissue-specific manner and localized in the body muscle layer. the levels of oo-hsp18 mrnas are sharply induced by heat shock but not by other stressors such as levamisole and ... | 2006 | 17304801 |
| evaluation of reference genes for quantitative real-time pcr in ostertagia ostertagi by the coefficient of variation and genorm approach. | | 2007 | 17434213 |
| [gastrointestinal nematodes and their seasonal distribution in cattle raised in central afyonkarahisar, turkey]. | this study was conducted during the period of september 2004-august 2005 in two villages with simple raising of cattle located in the center of the afyonkarahisar province. fecal samples collected from 985 cattle and the gastrointestinal tracts of 24 cattle were inspected. strongyle types of eggs were observed in 26.39% of the fecal samples. the infection was found to be less prevalent in the spring (22%) and most prevalent in autumn (32.53%). the genus of larvae observed in fecal cultures were ... | 2007 | 17471413 |
| vaccination against ostertagia ostertagi with subfractions of the protective es-thiol fraction. | previous vaccination trials against ostertagia ostertagi in cattle have demonstrated the protective capacity of a protein fraction termed es-thiol, which is enriched for activation-associated secreted proteins (asps) and cysteine proteases. in this study, es-thiol was subfractionated through q-sepharose anion exchange chromatography to determine whether the asps and/or the cysteine proteases are responsible for the induced protection. calves (seven/group) were immunized three times intramuscular ... | 2007 | 17881131 |
| identification and characterization of a novel specific secreted protein family for selected members of the subfamily ostertagiinae (nematoda). | it has been shown that the bovine abomasal parasite, ostertagia ostertagi, drastically modulates its microenvironment, causing epithelial cell damage, accumulation of inflammatory cells and ph changes in the stomach. the mechanisms used by the parasite to change the abomasal environment are largely unknown, but an important role has been attributed to excretory-secretory (es) products from the parasite. in this study we have identified proteins representing a novel es protein family, characteriz ... | 2008 | 17908364 |
| experimental selection for ivermectin resistance in ostertagia ostertagi in cattle. | recent reports of suspected ivermectin (ivm) resistance in ostertagia ostertagi have highlighted the need for research into the mechanisms of ivm resistance. however, there are no reports of resistant field isolates of o. ostertagi, which have been characterized for molecular research. therefore, an anthelmintic susceptible o. ostertagi population was selected for ivm resistance by repeatedly exposing the population to subtherapeutic and therapeutic levels of ivm over 10 generations. in each sel ... | 2007 | 17949912 |
| gender-enriched transcription of activation associated secreted proteins in ostertagia ostertagi. | activation associated secreted proteins (asp) are members of a nematode-specific protein family belonging to the scp/tpx-1/ag5/pr-1/sc7 family. three different types of molecules have been identified in this family: two-domain asps and single-domain asps showing homology to either the c-terminal or n-terminal domain of the two-domain asp. the function of these proteins is still unclear, but a role in transition to parasitism and a role as allergen are often suggested. here we report that the abo ... | 2008 | 17961575 |
| vaccine testing of a recombinant activation-associated secreted protein (asp1) from ostertagia ostertagi. | previous vaccination trials against the economically important cattle parasite ostertagia ostertagi have indicated the protective capacity of activation-associated secreted proteins (asps). the further development of these antigens into a commercial vaccine will require their recombinant expression. the aim of the current study was to clone and express oo-asp1 in a baculovirus expression system and to evaluate the protective capacity of the recombinant protein against an o. ostertagi challenge i ... | 2008 | 18086018 |
| development and evaluation of a recombinant antigen-based elisa for serodiagnosis of cattle lungworm. | an optimised enzyme-linked immunosorbent assay (elisa) for the detection of dictyocaulus viviparous-specific antibodies was developed and evaluated following the testing of various microtitration plates and anti-bovine ig-conjugates. based on recombinant major sperm protein (msp) expressed as a glutathione-s-transferase (gst) fusion protein in escherichia coli, sera collected from 112 cattle experimentally infected with d. viviparus, from 129 helminth-naïve calves, 8 calves experimentally infect ... | 2008 | 18155839 |
| isolation and characterization of a gene encoding carbonic anhydrase from ostertagia ostertagi and quantitative measurement of expression during in vivo exsheathment. | the first event in the establishment of ostertagia ostertagi infection in cattle is exsheathment. exsheathment is the process whereby the l(2) cuticle retained from the previous molt is cast from the l3. for those trichostrongyle nematode species with a predilection site in the abomasum, such as o. ostertagi, exsheathment is initiated as the larvae pass through the rumen. although the stimulus for exsheathment is not known, previously reported biochemical studies suggest a major role for the enz ... | 2008 | 18400401 |
| the efficacy of an ivermectin/closantel injection against experimentally induced infections and field infections with gastrointestinal nematodes and liver fluke in cattle. | three studies were performed to test the efficacy of an ivermectin/closantel injection (200 microg/kg(-1) ivermectin and 5 mg/kg(-1) closantel) in cattle. two were experimentally induced infections of ostertagia ostertagi, cooperia oncophora and fasciola hepatica in calves, and the third had natural field infections in cattle with several species of gastrointestinal nematodes and f. hepatica. in the two studies with artificial infections, four groups of 8 calves were used. all calves were infect ... | 2008 | 18562120 |
| analysis of the transthyretin-like (ttl) gene family in ostertagia ostertagi - comparison with other strongylid nematodes and caenorhabditis elegans. | the transthyretin-like (ttl) gene family is one of the largest conserved nematode-specific gene families, coding for a group of proteins with significant sequence similarity to transthyretins (ttr) and transthyretin-related proteins (trp). in the present study, we investigated the ttl family in ostertagia ostertagi (a nematode of the abomasum of cattle). mining of expressed sequence tag (est) databases revealed the presence of at least 18 ttl genes in o. ostertagi (oo-ttl), most of which are con ... | 2008 | 18571174 |
| hybrid n-glycans on the host protective activation-associated secreted proteins of ostertagia ostertagi and their importance in immunogenicity. | previous vaccination trials with calves have shown that intramuscular immunization with natively purified activation-associated secreted proteins (asps) of ostertagia ostertagi induces protection against a homologous challenge infection with a 74% reduction in cumulative faecal egg counts and a significant reduction in worm length. recently, o. ostertagi asp1 was recombinantly expressed using a baculovirus system and tested in a vaccination trial. however, immunized calves failed to recognize na ... | 2008 | 18585797 |
| a survey of the exposure to ostertagia ostertagi in dairy cow herds in europe through the measurement of antibodies in milk samples from the bulk tank. | measurement of antibodies to ostertagia ostertagi in bulk tank milk (btm) has value as a diagnostic indicator for potential production losses and anthelmintic treatment responses in dairy herds. most of the recent data on o. ostertagi antibodies in milk have been generated in belgium and canada; the purpose of this study was to determine the range of o. ostertagi antibody levels in several european countries. btm samples were collected during the autumn of 2005 and 2006 from a total of 1185 dair ... | 2008 | 18692964 |
| observations on the pathogenicity and viability of ostertagia ostertagi. | | 1948 | 18895319 |
| monitoring the efficacy of ivermectin and albendazole against gastro intestinal nematodes of cattle in northern europe. | faecal egg count reduction tests (fecrt) using ivermectin (ivm) and benzimidazole (bz) were conducted to investigate the prevalence of anthelmintic resistance in gastro-intestinal nematodes on cattle farms in germany, belgium and sweden in 2006 and 2007. based on sufficient numbers of eggs prior to the study, between 3 and 10 farms per country were selected. 10-15 animals were randomly selected per farm and subcutaneously treated with 0.2 mg ivm/kg bodyweight (ivomec, merial). faecal samples wer ... | 2009 | 19062191 |
| toward practical biological control of parasitic nematodes in domestic animals. | in a series of laboratory and field experiments where the nematophagous fungus arthrobotrys oligospora was mixed directly with feces it has been demonstrated that it is possible to use nematophagous fungi for biological control of animal parasitic nematodes. a procedure used for selection of nematophagous fungi that can pass the digestive tract of ruminants, horses, and pigs is described. the selected fungus, duddingtonia flagrans, has been used in further field experiments, and the results have ... | 1996 | 19277128 |
| analysis of the translationally controlled tumour protein in the nematodes ostertagia ostertagi and caenorhabditis elegans suggests a pivotal role in egg production. | the translationally controlled tumour protein (tctp) is a conserved protein which has been described for a wide range of eukaryotic organisms including protozoa, yeasts, plants, nematodes and mammals. several parasitic organisms have been shown to actively secrete tctp during host infection as part of their immuno-evasive strategy. in this study, we have studied tctp in ostertagia ostertagi, a parasitic nematode of cattle, and in the free-living nematode caenorhabditis elegans. an analysis of th ... | 2009 | 19285501 |
| associations between blood gastrin, ghrelin, leptin, pepsinogen and ostertagia ostertagi antibody concentrations and voluntary feed intake in calves exposed to a trickle infection with o. ostertagi. | twenty-five, castrated male holstein-cross calves, between 4 and 5 months of age, weighing 156.5+/-12.2 kg and reared under conditions designed to minimise the risk of parasitic infection, were allocated to one of the five treatment groups on the basis of initial bodyweight. the groups were (1) ad libitum (ad lib) fed controls (alc); (2) ad lib fed infected (inf) and treated with topical eprinomectin on day 56; (3) controls pair-fed with the inf group (pfc); (4) ad lib fed controls treated with ... | 2009 | 19342178 |
| the transcriptomes of the cattle parasitic nematode ostertagia ostartagi. | ostertagia ostertagi is a gastrointestinal parasitic nematode that affects cattle and leads to a loss of production. in this study, we present the first large-scale genomic survey of o. ostertagi by the analysis of expressed transcripts from three stages of the parasite: third-stage larvae, fourth-stage larvae and adult worms. using an in silico approach, 2284 genes were identified from over 7000 expressed sequence tags and abundant transcripts were analyzed and characterized by their functional ... | 2009 | 19346077 |
| assessment of the within- and between-laboratory repeatability of a commercially available ostertagia ostertagi milk elisa. | the objectives of this study were (1) to assess the within- and between-laboratory repeatability of a commercially available antibody-detection ostertagia ostertagi elisa (svanovir(o). ostertagi-ab, svanova, uppsala) and (2) to investigate if the assay could be further simplified by reading optical density at a single instead of double wavelength. a total of 80 bulk-tank milk samples were divided into aliquots and tested in duplicate per elisa plate on 3 different days in 4 different laboratorie ... | 2009 | 19414219 |
| gastrointestinal nematode infections in adult dairy cattle: impact on production, diagnosis and control. | due to the intensification of dairy herds and the recognition of subclinical infections with a negative impact on production as disease, control of gastrointestinal (gi) nematodes in adult cows is becoming established in an increasing number of dairy herds. the objectives of this paper are to review the aspects related to the impact on production, diagnosis and control of gi nematodes in adult dairy cattle. during the last decade substantial evidence has been generated that gi nematodes can have ... | 2009 | 19414223 |
| standardization of the egg hatch test for the detection of benzimidazole resistance in parasitic nematodes. | the ability to reliably detect anthelmintic resistance is a crucial part of resistance management. if data between countries are to be compared, the same test should give the same results in each laboratory. as the egg hatch test for benzimidazole resistance is used for both research and surveys, the ability of different laboratories to obtain similar results was studied through testing of known isolates of cyathostomins, haemonchus contortus, ostertagia ostertagi, and cooperia oncophora in prog ... | 2009 | 19452165 |
| ostertagia ostertagi antibodies in milk samples: relationships with herd management and milk production parameters in two mediterranean production systems of spain. | the present study analyzed ostertagia ostertagi antibodies by indirect elisa in milk samples in two cattle systems in mediterranean spain to indirectly monitor gastrointestinal nematode (gi) parasitism effects on production. individual samples from 10 animals and the corresponding milk herd samples were collected from 133 herds in girona (intensive management) and 123 herds in minorca (extensive management). both locations showed high and significant positive relationships between average optica ... | 2009 | 19464718 |
| the complexity of the secreted npa and far lipid-binding protein families of haemonchus contortus revealed by an iterative proteomics-bioinformatics approach. | two different classes of small nematode specific lipid-binding proteins, the nematode polyprotein allergens/antigens (npas) and the fatty acid- and retinol-binding (far) proteins, are secreted by helminth parasites. until now, there was no evidence of the expression or secretion of these two families of proteins in haemonchus contortus. in this study, we applied proteomic and bioinformatic tools in an iterative manner to reveal the expression and complexity of these proteins in the excretory/sec ... | 2009 | 19615410 |
| fecal egg count reduction and control trial determinations of anthelmintic efficacies for several parasiticides utilizing a single set of naturally infected calves. | in this study, a single set of naturally infected calves was used for the conduct of a fecal egg count reduction test (fecrt) immediately followed by a control trial; all, to evaluate the efficacies of several commonly used, non-generic anthelmintics. ten animals were allocated into each of the five treatment groups; untreated control (utc), injectable 1% moxidectin given at 0.2 mg kg(-1)bw (mxd), injectable 1% ivermectin given at 0.2 mg kg(-1)bw (ivm), 9.06% oxfendazole given orally at 4.5 mg k ... | 2009 | 19615822 |
| the use of bulk-tank milk elisas to assess the spatial distribution of fasciola hepatica, ostertagia ostertagi and dictyocaulus viviparus in dairy cattle in flanders (belgium). | fasciola hepatica, ostertagia ostertagi and dictyocaulus viviparus are helminth parasites with a wide distribution and an important economic impact in cattle in temperate climates. this paper describes the spatial distribution of f. hepatica, o. ostertagi and d. viviparus in dairy herds in flanders (belgium). one thousand eight hundred herds were selected at random from the flemish dairy population (n=7002), stratified on community level to obtain a sample representative for the entire study are ... | 2009 | 19656630 |
| preliminary study on the use of a teladorsagia circumcincta bulk milk elisa test in dairy goats under experimental conditions. | an elisa test for the detection of anti-teladorsagia circumcincta antibodies in goat milk samples (both individual and bulk milk samples) has been developed in dairy goats experimentally infected with a trickle infection. the results observed were compared with those obtained when some other standard methods for the detection of animals infected with gastrointestinal nematodes (gin), such as faecal egg counts (fec) and serum pepsinogen levels. some factors that could affect the final results of ... | 2009 | 19828255 |
| measurement of antibodies to gastrointestinal nematodes and liver fluke in meat juice of beef cattle and associations with carcass parameters. | in an effort to develop non-invasive methods for the diagnosis of ostertagia ostertagi and fasciola hepatica infection in beef cattle, this study was undertaken to evaluate antibody-detection elisas in meat juice samples and to investigate the associations between test results and carcass parameters. preliminary tests were carried out to determine optimal working dilutions of meat juice samples. the pearson correlation coefficients between elisa results (expressed as odr) of serum and meat juice ... | 2009 | 19836140 |
| further characterization of a cattle nematode population with demonstrated resistance to current anthelmintics. | we previously documented the appearance of cattle nematode parasites resistant to avermectins, milbemycin, and a benzimidazole at the end of a grazing season in a backgrounding operation in the upper midwestern us. to further characterize the pattern of drug resistance, we extended the study to (1) monitor the animals over the course of the grazing season; (2) increase the number of animals slaughtered at the end of the season to minimize the effect of potential outlying observations; (3) increa ... | 2009 | 19897305 |
| evaluation of anti-ostertagia ostertagi antibodies in individual milk samples as decision parameter for selective anthelmintic treatment in dairy cows. | the aim of this study was to explore whether anti-ostertagia ostertagi antibody levels measured by elisa in individual milk samples hold promise as a decision parameter for either herd-level decisions or selective anthelmintic treatments by investigating (1) the relationship between individual and bulk-tank milk elisa results; (2) the relationships of individual milk elisa results with non-parasitic cow factors and (3) the relationship between individual milk elisa results and the milk productio ... | 2010 | 19913315 |
| the impact of milk handling procedures on ostertagia ostertagi antibody elisa test results. | the impact of various milk handling stressors were analyzed using a commercially available enzyme-linked immunosorbent assay (elisa) test measuring ostertagia ostertagi antibodies in milk from dairy cattle (svanovir). an indirect elisa has the ability to determine the amount of milk production losses related to intestinal parasitism. the elisa test recommends fresh defatted milk, however, milk collected from dairy herd improvement (dhi) programs in north america undergo many stressors, including ... | 2010 | 20053502 |
| adaptation and evaluation of three different in vitro tests for the detection of resistance to anthelmintics in gastro intestinal nematodes of cattle. | three different in vitro methods, the larval development test (ldt), the larval migration inhibition test (lmit) and the micromotility meter test (mmt) have been adapted to detect anthelmintic resistance in cattle nematodes. nematode eggs and third stage larvae of different ostertagia ostertagi and cooperia oncophora isolates were obtained from faecal cultures of experimentally infected calves. additionally, adult c. oncophora were evaluated in the mmt for the detection of resistance to ivermect ... | 2010 | 20189310 |
| teladorsagia circumcincta: activation-associated secreted proteins in excretory/secretory products of fourth stage larvae are targets of early iga responses in infected sheep. | a detailed proteomic analysis of excreted/secretory (es) proteins derived from fourth stage larvae (l4) of teladorsagia circumcincta identified a number of components, including n-type and c-type single domain activation-associated secreted proteins (asps). immunoblotting of l4 es extracts with abomasal mucus derived from infected, immune sheep demonstrated the immunogenicity of some of these components, including an n-type single-domain asp, designated tci-asp-1. the full-length cdna encoding t ... | 2010 | 20206168 |
| anthelmintic resistance of ostertagia ostertagi and cooperia oncophora to macrocyclic lactones in cattle from the western united states. | in june 2008, 122 yearling heifers with a history of anthelmintic resistance were obtained from pastures in northern california and transported to a dry lot facility in southwestern idaho, usa. fifty heifers with the highest fecal egg counts were selected for study enrollment. candidates were equally randomized to treatment with either injectable ivermectin (ivomec, merial, 0.2 mg kg(-1) bw), injectable moxidectin (cydectin), fort dodge, 0.2 mg kg(-1) bw), oral fenbendazole (safe-guard), interve ... | 2010 | 20347229 |
| ostertagia ostertagi in first-season grazing cattle in belgium, germany and sweden: general levels of infection and related management practices. | the objective of this study was to determine the prevailing levels of infection with ostertagia ostertagi in first-season grazing calves and related management factors in three european countries (belgium, germany and sweden). a cross-sectional survey was performed in first-season grazing dairy cattle during 2 consecutive years. levels of infection with o. ostertagi were assessed by a standardized serum pepsinogen assay at the end of the grazing periods 2006 and 2007 and information on control m ... | 2010 | 20378253 |
| short communication: genetic and nongenetic factors influencing ostertagia ostertagi antibodies in uk holstein-friesian cattle. | the purpose of this study was to estimate and discuss the genetic variation, heritability, and effects of nongenetic factors on the ability of holstein-friesian cows to produce an immune response by producing igg antibodies to ostertagia ostertagi. total igg (igg(1) and igg(2)) antibody levels were determined using an elisa and measured using optical density ratio (odr=od(sample) - od(negative control)/od(positive control) - od(negative control)) from milk samples collected from 1,276 holstein-f ... | 2010 | 20412939 |
| antibodies to major pasture borne helminth infections in bulk-tank milk samples from organic and nearby conventional dairy herds in south-central sweden. | the objective of this randomised pairwise survey was to compare the regional distribution of antibody levels against the three most important helminth infections in organic and conventional dairy herds in sweden. bulk-tank milk from 105 organic farms and 105 neighbouring conventional dairy farms with access to pasture in south-central sweden were collected in september 2008. samples were also collected from 8 organic and 8 conventional herds located in a much more restricted area, on the same as ... | 2010 | 20466488 |
| epidemiology and risk factors for exposure to gastrointestinal nematodes in dairy herds in northwestern europe. | in this survey, the epidemiology of gastrointestinal (gi) nematodes in dairy herds in five northwestern european countries was studied using a standardized ostertagia ostertagi elisa applied on bulk-tank milk, and a common questionnaire. the levels of exposure to gi nematodes were high in belgium, the uk and ireland, intermediate in germany and low in sweden, with a mean (95% confidence interval) elisa result (odr) of 0.83 (0.82-0.84) in belgium, 0.82 (0.79-0.84) in the uk and 0.80 (0.78-0.83) i ... | 2010 | 20688435 |
| protective immunization of calves against ostertagia ostertagi using fourth stage larval extracts. | cona lectin was used to isolate glycoproteins from detergent extracts of fourth stage ostertagia ostertagi larvae. this preparation contained proteins additional to those observed in a similar fraction prepared from adult o. ostertagi. two vaccine trials were conducted with this preparation, and sub-fractions thereof, in groups of 6-8 worm-free calves. all groups were challenged with 50,000 o. ostertagi larvae 1 week after the final immunization, and protection was assessed by comparing the egg ... | 2010 | 20691017 |
| [on the conspecificity of ostertagia ostertagi and ostertagia lyrata (nematoda: ostertagiinae)]. | partial sequences of the second internal transcribed spacer (its-2) rdna were obtained for ostertagia ostertagi and o. lyrata, which are supposedly constitute two morphologically distinct variants of the species. the 1.4% level of difference between the its-2 sequences of o. ostertagi and o. lyrata was reported, whereas the sequences derived from worms of the same morph were completely identical. the data obtained prevent an attribution of o. ostertagi and o. lyrata to the same species. | 2010 | 20795486 |
| a calcium-activated nucleotidase secreted from ostertagia ostertagi 4th-stage larvae is a member of the novel salivary apyrases present in blood-feeding arthropods. | apyrases (atp-diphosphohydrolase) comprise a ubiquitous class of glycosylated nucleotidases that hydrolyse extracellular atp and adp to orthophosphate and amp. one class of newly-described, ca2+-dependent, salivary apyrases known to counteract blood-clotting, has been identified in haematophagous arthropods. herein, we have identified a gene (oos-apy-1) encoding a protein that structurally conforms to the ca2+-activated apyrase from the bed bug, cimex lectularius, by immunologically screening an ... | 2011 | 20809998 |
| standardization of the larval migration inhibition test for the detection of resistance to ivermectin in gastro intestinal nematodes of ruminants. | resistance to anthelmintics is an increasing problem in sheep, goat and cattle industries worldwide. for parasite management on farms reliable methods for the detection of resistance are required and it is important that tests give comparable, reproducible and reliable results in different laboratories. the ability of the larval migration inhibition test (lmit), to detect ivermectin resistance in cattle and sheep nematodes has been evaluated through ring testing in up to six different laboratori ... | 2010 | 20850930 |
| localized complement activation in the development of protective immunity against ostertagia ostertagi infections in cattle. | the abomasal nematode ostertagia ostertagi is a major causal agent contributing to production inefficiencies in the cattle industry in temperate regions of the world. protective immunity to infections develops very slowly and resistance to reinfection manifests only after prolonged exposure. mechanisms underlying the development of protective immunity remain largely unexplored. immune animals, which have significantly reduced worm burdens, were developed after multiple drug-attenuated experiment ... | 2010 | 20884121 |
| anthelmintic resistance in cattle nematodes on 13 south-west victorian properties. | to report the level of anthelmintic resistance on 13 commercial cattle properties in south-west victoria, australia. | 2010 | 21091463 |
| a calcium-activated apyrase from teladorsagia circumcincta: an excretory/secretory antigen capable of modulating host immune responses? | a cdna representing the gene teladorsagia circumcincta apyrase-1 (tci-apy-1) was isolated, by pcr, from a t. circumcincta fourth-stage larval (l4) cdna library. the closest orthologue of this gene is a ca(2+)-dependent apyrase from ostertagia ostertagi, with 92% amino acid identity across all 339 residues. tci-apy-1 is transcribed in a stage-specific manner, the transcript being predominant in l4, detectable in the adult cdna, but absent from eggs and infective third-stage larvae (l3). the prote ... | 2011 | 21208222 |
| development of graphidium strigosum (nematoda, haemonchidae) in its natural host, the rabbit (oryctolagus cuniculus) and comparison with several haemonchidae parasites of ruminants. | the morphogenesis (studied for the first time) and the chronology of the life cycle of graphidium strigosum (dujardin, 1845) were studied in detail in its natural host, oryctolagus cuniculus. naive rabbits were each infected per os with g. strigosum infective larvae (l3). animals were euthanized each day for the first 10 days after infection (dai), then every 2 days from 12 to 40 dai. the free living period lasted 5-8 days at 24°c. by 1 dai, all the larvae were exsheathed in the stomach. the thi ... | 2011 | 21210152 |
| licking behaviour induces partial anthelmintic efficacy of ivermectin pour-on formulation in untreated cattle. | licking behaviour in cattle has been reported to account for the disposition of topically administered macrocyclic lactones. however, its impact on anthelmintic efficacy remains to be established. therefore, we evaluated the impact of ivermectin exchange between cattle on the reduction in the faecal egg count (fec) after pour-on administration in a group of 10 heifers experimentally infected with ostertagia ostertagi and cooperia oncophora. four treated (500 μg/kg, pour-on) and six untreated ani ... | 2011 | 21232538 |
| effect of an ostertagia ostertagi infection on the transcriptional stability of housekeeping genes in the bovine abomasum. | quantitative real-time pcr (qrt-pcr) is a widely used tool to study host responses against parasites. a crucial step in the gene quantification process is the normalization of the expression data against stable housekeeping genes (hkgs). however, in recent years, several reports have showed that the transcriptional levels of such hkgs can change dramatically, especially when cellular changes appear in the tissues investigated. the aim of the current study was to assess the variability of 11 puta ... | 2011 | 21561716 |
| infection with the gastrointestinal nematode ostertagia ostertagi in cattle affects mucus biosynthesis in the abomasum. | abstract: the mucus layer in the gastrointestinal (gi) tract is considered to be the first line of defense to the external environment. alteration in mucus components has been reported to occur during intestinal nematode infection in ruminants, but the role of mucus in response to abomasal parasites remains largely unclear. the aim of the current study was to analyze the effects of an ostertagia ostertagi infection on the abomasal mucus biosynthesis in cattle. increased gene expression of muc1, ... | 2011 | 21569362 |
| attempts to immunise sheep against teladorsagia circumcincta using fourth stage larval extracts. | a concanavilina (cona) binding fraction of a detergent soluble membrane extract from teladorsagia circumcincta (formerly ostertagia circumcincta) fourth stage larvae was isolated and two vaccine trials were conducted with this preparation in groups of 7 worm free sheep. all groups were challenged with a total of 5000 t. circumcincta larvae from one week after the final immunisation and protection assessed by comparing the egg and worm counts, and length of developing worms, of the immunised grou ... | 2011 | 21793859 |
| comparative efficacy of trichlorphon and trichlorphon/ivermectin combination treatment against anthelmintic-resistant cattle nematodes in argentina. | twenty-four holando argentino male calves were treated orally with 50 mg/kg body weight trichlorphon (tcf); 0.2 mg/kg body weight subcutaneous ivermectin (ivm); a combination of tcf+ivm at the same doses and administration routes; or remained untreated (control group). all calves were necropsied at day 14 post treatment for counting and identification of worms from abomasum, small and large intestines and lungs to determine the absolute efficacy (controlled efficacy test) for each treatment. usi ... | 2011 | 21739380 |
| immunologically based control strategies for ostertagiosis in cattle: where do we stand ? | ostertagia ostertagi is one of the most important gastrointestinal parasites infecting millions of cattle in temperate climate areas. since infection leads to significant losses in productivity, farmers are pushed, due to the on-going intensification of the livestock production systems, to frequently administer anthelmintics in order to minimize the exposure of their animals to this parasite. however, whether such approach is sustainable in the long term, especially in an era of emerging drug re ... | 2011 | 21722144 |
| altered avr-14b gene transcription patterns in ivermectin-resistant isolates of the cattle parasites, cooperia oncophora and ostertagia ostertagi. | ivermectin (ivm) resistance is an emerging problem for the control of gastrointestinal nematodes of cattle such as cooperia oncophora and ostertagia ostertagi. although there is still a poor understanding of the molecular basis of macrocyclic lactone (ml)-resistance, it is clear that ivm exerts its activity by binding to glutamate-gated chloride (glucl) channels within the parasite's neuromuscular system. one of the glucl genes (avr-14) encodes, via alternative splicing, two subunits, avr-14a an ... | 2011 | 21683704 |
| condensed tannins act against cattle nematodes. | the use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (gin) in ruminants. direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat gin. these anthelmintic properties are mainly associated with condensed tannins. in the present study, we evaluated possible in vitro effects of three tannin-containing plants against bovine gin. effects of onobrychis viciifolia, lotus pedunculatus and lotus cornic ... | 2011 | 21726942 |
| parasites of chamois in new zealand. | abstract sir, - andrews'((2)) checklist of helminth parasites of wild ruminants in new zealand recorded the presence of 10 species of gastrointestinal nematodes in chamois (rupicapra rupicapra rupicapra l.) from "central south island". in october 1978 we examined 28 freshly-shot chamois cadavers from the harper-avoca watershed in the headwaters of the rakaia river. six of the nematode species reported by andrews were found again; viz. ostertagia ostertagi, o. circumcincta, o. trifurcata, nemat ... | 1981 | 22133071 |
| Metagenome plasticity of the bovine abomasal microbiota in immune animals in response to Ostertagia ostertagi infection. | Infections in cattle by the abomasal nematode Ostertagia ostertagi result in impaired gastrointestinal function. Six partially immune animals were developed using multiple drug-attenuated infections, and these animals displayed reduced worm burdens and a slightly elevated abomasal pH upon reinfection. In this study, we characterized the abomasal microbiota in response to reinfection using metagenomic tools. Compared to uninfected controls, infection did not induce a significant change in the mic ... | 2011 | 21931709 |
| Use of diagnostic markers to monitor fasciolosis and gastrointestinal nematodes on an organic dairy farm. | A 12-month study was conducted to assess and monitor gastrointestinal tract nematodes and liver fluke in cohorts of cattle on a Scottish organic dairy farm. Various diagnostic markers for helminth parasites of cattle from different age groups were assessed monthly from April 2007 to March 2008. First season grazing stock were subjected to significant challenge from Ostertagia ostertagi nematodes as reflected in serum pepsinogen concentrations, which rose markedly in the second half of the grazin ... | 2011 | 21908552 |
| optimization of in-house elisa based on recombinant major sperm protein (rmsp) of dictyocaulus viviparus for the detection of lungworm infection in cattle. | the aim of this study was to optimize an in-house elisa based on a recombinant version of the major sperm protein (msp) of dictyocaulus viviparus for routine diagnosis of lungworm infection in cattle. a recombinant msp (rmsp) was cloned into pgex-6p-1 vector and expressed as a glutathione-s-transferase (gst) fusion protein in escherichia coli bl21 (de3) chemically competent cells. the product was then employed as capture antigen in an elisa, and validated against 304 samples of known status (216 ... | 2011 | 22019470 |
| galectin-11 induction in the gastrointestinal tract of cattle following nematode and protozoan infections. | galectin-11 (lgals11) has been suggested to play an important role in protective immunity against gastrointestinal nematodes in ruminants. however, in cattle, this molecule has not been characterized in detail. in the current study, it was shown that transcription of lgals11 was highly inducible in the bovine abomasal mucosa after an ostertagia ostertagi infection. lgals11 protein expression was also increased in the abomasal mucosa following o. ostertagi infection and localized to the nucleus a ... | 2011 | 21958368 |
| Effects of farm management practices and environmental factors on bulk tank milk antibodies against gastrointestinal nematodes in dairy farms across Canada. | Enzyme-linked immunosorbent assays (ELISAs) have been used as a diagnostic tool to quantify levels of gastrointestinal nematodes in dairy cattle by measuring Ostertagia ostertagi antibodies in milk. Higher levels of O. ostertagi antibodies measured by ELISA methods, referred to as optical density ratios (ODRs), are associated with decreased milk production in dairy cattle. On-farm management practices (e.g. pasturing techniques and anthelmintic usage) can influence the exposure of cattle to nema ... | 2011 | 22018549 |
| the activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the netherlands. | summary the activity of albendazole against gastrointestinal helminths in naturally infected calves in the netherlands was tested. the calves were in their fist grazing season and kept in two groups of ten. one of these groups was grazed alternately with sheep. five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (november 1). before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were mad ... | 1979 | 22039826 |
| [taxonomic revision of the genus orloffia (nematoda: ostertagiinae) based on an its-2 rdna study]. | a comparative study of its-2 rdna of the nematodes of the genera orloffia, ostertagia, teladorsagia, and trichostrongylus was performed. the obtained results allow us to consider orloffia, ostertagia, and teladorsagia as closely related but distinct genera. the results of the study indicate that o. bisonis is the only valid species in the genus orloffia, which has two morphologically distinct forms of males: o. bisonis (major morph) and o. kasakhstanica (minor morph). the percentage of similarit ... | 2011 | 22292291 |
| nematode burdens of pastured cattle treated once at turnout with eprinomectin extended-release injection. | the efficacy of eprinomectin in an extended-release injection (eri) formulation was evaluated against infections with third-stage larvae or eggs of gastrointestinal and pulmonary nematodes in cattle under 120-day natural challenge conditions in a series of five studies conducted in the usa (three studies) and in europe (two studies). for each study, 30 nematode-free (four studies) or 30 cattle harboring naturally acquired nematode infections (one study) were included. the cattle were of various ... | 2012 | 23273928 |
| the efficacy of eprinomectin extended-release injection against naturally acquired nematode parasites of cattle, with special regard to inhibited fourth-stage ostertagia larvae. | the efficacy of eprinomectin in an extended-release injection (eri) formulation in the treatment of cattle harboring naturally acquired nematode populations (including inhibited nematodes) was evaluated. five studies were conducted under a similar protocol in the usa, the uk, and in germany. all study animals were infected by grazing naturally contaminated pastures. the adequacy of pasture infectivity was confirmed by examining tracer calves prior to allocation and treatment of the study animals ... | 2012 | 23273781 |
| an eprinomectin extended-release injection formulation providing nematode control in cattle for up to 150 days. | a series of 10 dose confirmation studies was conducted to evaluate the persistent activity of an extended-release injectable (eri) formulation of eprinomectin against single point challenge infections of gastrointestinal and pulmonary nematodes of cattle. the formulation, selected based on the optimal combination of high nematode efficacy, appropriate plasma profile, and satisfactory tissue residue levels, includes 5% poly(d,l-lactide-co-glycolic)acid (plga) and is designed to deliver eprinomect ... | 2012 | 23273777 |
| ostertagia ostertagi macrophage migration inhibitory factor is present in all developmental stages and may cross-regulate host functions through interaction with the host receptor. | macrophage migration inhibitory factor (mif) of ostertagia ostertagi, an abomasal parasite of cattle, was characterised in the present study. phylogenetic analysis identified at least three o. ostertagi mifs (oos-mifs), each encoded by a distinct transcript: oos-mif-1.1, oos-mif-1.2 and oos-mif-2. oos-mif-2 is only distantly related to oos-mif-1s, but has higher sequence similarity with the caenorhabditis elegans mif2. oos-mif-1.1 and oos-mif-1.2 are similar (93%) and thus collectively referred ... | 2014 | 24583184 |
| granule exocytosis of granulysin and granzyme b as a potential key mechanism in vaccine-induced immunity in cattle against the nematode ostertagia ostertagi. | ostertagia ostertagi is considered one of the most economically important bovine parasites. as an alternative to anthelmintic treatment, an experimental host-protective vaccine was previously developed on the basis of asp proteins derived from adult worms. intramuscular injection of this vaccine, combined with quila as an adjuvant, significantly reduced fecal egg counts by 59%. however, the immunological mechanisms triggered by the vaccine are still unclear. therefore, in this study, the differe ... | 2013 | 23478322 |
| molecular cloning and characterization of a nematode polyprotein antigen/allergen from the human and animal hookworm ancylostoma ceylanicum. | nematodes are unable to synthesize fatty acids de novo and must acquire them from the environment or host. it is hypothesized that two unique classes of fatty acid and retinol binding proteins that nematodes produce (fatty acid and retinol binding (far) and nematode polyprotein antigen/allergen (npa)) are used to meet this need. a partial cdna has been cloned corresponding to four subunits of a putative ancylostoma ceylanicum npa (acenpa). the translated amino acid sequence of acenpa shares sequ ... | 2014 | 25481749 |
| the usefulness of dna derived from third stage larvae in the detection of ashworthius sidemi infection in european bison, by a simple polymerase chain reaction. | ashworthius sidemi, a blood-sucking nematode, is a primary parasite of asiatic cervides, primarily sika deer (cervus nippon). as a. sidemi infections are common in bison, red and roe deer, and gastrointestinal nematodes are often exchanged between animals, it is possible that other farm animals such as cows and sheep that may use the same pastures can be infected. hence, histopathological changes observed in the walls of the abomasa and duodena of infected wildlife caused by a strong parasite pr ... | 2014 | 24886355 |
| effects of gastrointestinal parasites on parasite burden, rectal temperature, and antibody titer responses to vaccination and infectious bovine rhinotracheitis virus challenge. | thirty-three colostrum-deprived holstein bull calves (initial bw of 131 ± 4 kg) were used to determine the effect of timing of anthelmintic administration relative to vaccination on antibody titer response to vaccine component antigens. when calves were at least 3 mo of age, they were sorted randomly into individual pens and assigned to 1 of 3 treatment groups, treatments consisted of 1) dewormed 2 wk before vaccination (dpv), 2) dewormed at the time of vaccination (dv), or 3) control, vaccinate ... | 2012 | 22648753 |
| activity of ivermectin long-acting injectable (ivomec(®) gold) in first-season grazing cattle exposed to natural challenge conditions in germany. | the persistent activity of ivermectin long-acting injection (ivm lai; ivomec® gold, merial; 3.15% ivermectin w/v) against nematode infections of cattle was evaluated under natural challenge conditions. seventy nematode-free brown swiss calves were blocked by pre-treatment bodyweight and allocated randomly to seven groups of 10 animals each: saline (control) at 1 ml/50 kg bodyweight once on day 0 or ivm lai at 1 ml/50 kg bodyweight (630 mcg ivm/kg) on either days 0, 7, 14, 21, 28, or 35. after ho ... | 2015 | 25280515 |
| reevaluation of efficacy against nematode parasites and pharmacokinetics of topical eprinomectin in cattle. | a study was conducted to confirm the efficacy of topical eprinomectin against nematodes and to evaluate the pharmacokinetics in cattle prevented from having physical contact with other cattle and from self-grooming. sixteen male brown swiss calves were infected with larvae of recently isolated nematode parasites. inoculation was scheduled so that the nematodes were expected to be adults at the time of treatment. animals were blocked based on pretreatment body weight and randomly allocated to the ... | 2012 | 22638921 |
| a multiplex pcr-based method to identify strongylid parasite larvae recovered from ovine faecal cultures and/or pasture samples. | a multiplex pcr-based method was developed to overcome the limitations of microscopic examination as a means of identifying individual infective larvae from the wide range of strongylid parasite species commonly encountered in sheep in mixed sheep-cattle grazing situations in new zealand. the strategy employed targets unique species-specific sequence markers in the second internal transcribed spacer (its-2) region of ribosomal dna of the nematodes and utilises individual larval lysates as reacti ... | 2014 | 24373513 |
| first description of gastrointestinal nematodes of barbary sheep (ammotragus lervia): the case of camelostrongylus mentulatus as a paradigm of phylogenic and specific relationship between the parasite and its ancient host. | the gastrointestinal helminth fauna of 24 barbary sheep or aoudad (ammotragus lervia sahariensis) maintained in the parque de rescate de la fauna sahariana (prfs, csic, almeria, spain) was analyzed. most animals (87.5 %) were parasitized, and multiple infections were highly present. the following species were identified: camelostrongylus mentulatus, teladorsagia circumcincta, marshallagia marshalli, ostertagia ostertagi, o. leptospicularis, o. lyrata, haemonchus contortus, teladorsagia trifurcat ... | 2013 | 23616093 |
| helminths of roe deer (capreolus capreolus) in the middle black sea region of turkey. | fifteen roe deer were examined at necropsy from northern turkey in the period 2006-2010 for the helminth infections. totally 6470 helminth specimens were collected and identified by morphological criteria. twenty-five helminth species were identified (1 of the class trematoda, 1 of cestoda and 23 of nematoda). dicrocoelium dendriticum (prevalence 20%) was found in liver. cysticercus tenuicollis (6.6%) was found in mesentery. haemonchus contortus (53.3%), ostertagia leptospicularis (73.3%), o. le ... | 2012 | 22766455 |
| condensed tannins in the gastrointestinal tract of cattle after sainfoin (onobrychis viciifolia) intake and their possible relationship with anthelmintic effects. | condensed tannins' (cts) fate along the digestive tract of ruminants may account for the variable efficacy of cts against gastrointestinal nematodes. we analyzed cts in the digesta of cattle fed sainfoin. with the acetone-butanol-hcl assay, the total cts concentrations in the digesta were close to those in the diets (6.3 and 1.5% of dm in experiments 1 and 2, respectively); thus, cts remained potentially largely undegraded/unabsorbed. with the thiolysis assay, cts concentration was much higher i ... | 2017 | 28120611 |
| efficacy of ivermectin against gastrointestinal nematodes of cattle in denmark evaluated by different methods for analysis of faecal egg count reduction. | the efficacy of ivermectin (ivm) against gastrointestinal nematodes in danish cattle was assessed by faecal egg count reduction test (fecrt). six cattle farms with history of clinical parasitism and avermectin use were included. on the day of treatment (day 0), 20 naturally infected calves per farm (total n = 120) were stratified by initial faecal egg counts (fec) and randomly allocated to a treatment group dosed with 0.2 mg ivm kg(-1) body weight s.c. (ivm; n = 10) or an untreated control group ... | 2016 | 27835769 |
| the efficacy and plasma profiles of abamectin plus levamisole combination anthelmintics administered as oral and pour-on formulations to cattle. | in phase i, faecal egg count reduction tests (fecrt) were conducted on six commercial cattle farms to compare the performance of two pour-on and one oral combination anthelmintic. groups of 12-15 calves were sampled for faecal nematode egg count (fec) before treatment with either abamectin oral, levamisole oral, an abamectin+levamisole oral combination or one of two abamectin+levamisole combination pour-ons. samples were collected again 14days after treatment to calculate the percentage reductio ... | 2016 | 27523943 |
| anti-parasitic activity of pelleted sainfoin (onobrychis viciifolia) against ostertagia ostertagi and cooperia oncophora in calves. | increasing anthelmintic-resistance in nematodes of ruminants emphasises the need for sustainable parasite control. condensed tannin-containing legume forages such as sainfoin (onobrychis viciifolia) have shown promising anthelmintic properties in small ruminants but this has never been explored in cattle. therefore, our aim was to examine the efficacy of sainfoin against cattle nematodes in vivo. | 2016 | 27283323 |
| anthelmintic effects of forage chicory (cichorium intybus) against gastrointestinal nematode parasites in experimentally infected cattle. | two experiments studied the effects of dietary chicory against gastrointestinal nematodes in cattle. in experiment (exp.) 1, stabled calves were fed chicory silage (chi1; n = 9) or ryegrass/clover hay (ctl1; n = 6) with balanced protein/energy intakes between groups. after 16 days, all calves received 10 000 ostertagia ostertagi and 66 000 cooperia oncophora third-stage larvae (l3) [day (d) 0 post-infection (p.i.)]. in exp. 2, calves were assigned to pure chicory (chi2; n=10) or ryegrass/clover ... | 2016 | 27173405 |
| impact of chemical structure of flavanol monomers and condensed tannins on in vitro anthelmintic activity against bovine nematodes. | plants containing condensed tannins (ct) may have potential to control gastrointestinal nematodes (gin) of cattle. the aim was to investigate the anthelmintic activities of four flavan-3-ols, two galloyl derivatives and 14 purified ct fractions, and to define which structural features of ct determine the anti-parasitic effects against the main cattle nematodes. we used in vitro tests targeting l1 larvae (feeding inhibition assay) and adults (motility assay) of ostertagia ostertagi and cooperia o ... | 2016 | 26888630 |
| development of a multiplex fluorescence immunological assay for the simultaneous detection of antibodies against cooperia oncophora, dictyocaulus viviparus and fasciola hepatica in cattle. | a major constraint for the effective control and management of helminth parasites is the lack of rapid, high-throughput, routine diagnostic tests to assess the health status of individual animals and herds and to identify the parasite species responsible for these helminthoses. the capability of a multiplex platform for the simultaneous detection of three pasture associated parasite species was evaluated and compared to existing elisas. | 2015 | 26084663 |
| measuring larval nematode contamination on cattle pastures: comparing two herbage sampling methods. | assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. direct quantification of infective larvae (l3) on herbage is the most applied method to measure pasture larval contamination. however, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. the aim of this study was (1) to compare ... | 2015 | 25913455 |
| gene expression of abc transporters in cooperia oncophora after field and laboratory selection with macrocyclic lactones. | the most widespread helminth parasites of grazing cattle in northern europe are the gastrointestinal nematodes ostertagia ostertagi and cooperia oncophora. heavy reliance on the use of macrocyclic lactone (ml) in cattle has led to world-wide emergence of resistance to this drug class in c. oncophora. there is evidence that members of the atp-binding cassette (abc) transporter family, such as p-glycoproteins (p-gp) and multidrug-resistant proteins (mrp), play a role in resistance to ml. in this s ... | 2014 | 25619799 |
| anthelmintic resistance in nematodes of beef cattle in south-west western australia. | anthelminthic resistance in nematodes of beef cattle is an emerging issue globally with implications for effective parasite control. the prevalence of resistance in beef cattle in the mediterranean-style climatic zone of south-west western australia was assessed on 19 farms, using faecal egg count reduction tests. pre-treatment faecal worm egg counts were compared with counts at 14 days after treatments with ivermectin (injectable), fenbendazole (oral), or levamisole (oral). a separately grazed ... | 2015 | 25541483 |
| analysis of putative inhibitors of anthelmintic resistance mechanisms in cattle gastrointestinal nematodes. | effects of the cytochrome p450 inhibitor piperonyl butoxide and the p-glycoprotein inhibitor verapamil on the efficacy of ivermectin and thiabendazole were studied in vitro in susceptible and resistant isolates of the cattle parasitic nematodes cooperia oncophora and ostertagia ostertagi. the effects of combined use of drug and piperonyl butoxide/verapamil, respectively, were investigated in the egg hatch assay, the larval development assay and the larval migration inhibition assay. the effects ... | 2014 | 24907555 |
| limited efficacy of pour-on anthelmintic treatment of cattle under swedish field conditions. | a study on the effect of topical macrocyclic lactones (ml) against gastrointestinal nematodes (gin) in swedish first season grazing cattle (fsg) was performed during the grazing seasons of 2009 and 2010. herds were recruited through farming press and both dairy and beef cattle farms were invited. a questionnaire revealed that 64% of participating farmers dewormed their animals in previous years, and of these 76% used topical formulations with ml. four to six weeks after turnout, 107 (2009) and 6 ... | 2013 | 24533302 |
| a controlled study on gastrointestinal nematodes from two swedish cattle farms showing field evidence of ivermectin resistance. | anthelmintic resistance (ar) is an increasing problem for the ruminant livestock sector worldwide. however, the extent of the problem is still relatively unknown, especially for parasitic nematodes of cattle. the effect of ivermectin (ivm) (ivomec inj.®, merial) was investigated in swedish isolates of gastrointestinal nematode (gin) populations showing signs of ar in the field to further characterise the ar status by a range of in vivo and in vitro methods. | 2014 | 24401545 |
| gastrointestinal nematodes in grazing dairy cattle from small and medium-sized farms in southern poland. | this study aimed to estimate the prevalence of gastrointestinal nematodes and the intensity of infection in grazing dairy cattle from small and medium-sized farms in southern poland. the level of antibodies against ostertagia ostertagi in the bulk tank milk (btm) from the animals was also assessed. rectal fecal samples collected from 361 cows on 20 farms were examined using willis-schlaaf flotation and the mcmaster method. btm samples were tested for the presence of o. ostertagi antibodies using ... | 2013 | 23958284 |
| phylogenetic characterization of β-tubulins and development of pyrosequencing assays for benzimidazole resistance in cattle nematodes. | control of helminth infections is a major task in livestock production to prevent health constraints and economic losses. however, resistance to established anthelmintic substances already impedes effective anthelmintic treatment in many regions worldwide. thus, there is an obvious need for sensitive and reliable methods to assess the resistance status of at least the most important nematode populations. several single nucleotide polymorphisms (snps) in the β-tubulin isotype 1 gene of various ne ... | 2013 | 23950913 |
| real-time pcr detection for quantification of infection levels with ostertagia ostertagi and cooperia oncophora in cattle faeces. | a quantitative real-time polymerase chain reaction (qpcr) based on hydrolysis (taqman) probes is described for robust and sensitive detection of the infection levels with eggs and third stage larvae (l3) of cooperia oncophora and ostertagia ostertagi isolated from cattle faeces. the current microscopic method for identification of strongyle nematodes in cattle faeces is labour-intensive where reliable species determination also requires trained expertise, which is increasingly lacking. the goal ... | 2013 | 23764131 |
| in vitro effects of extracts and purified tannins of sainfoin (onobrychis viciifolia) against two cattle nematodes. | sainfoin (onobrychis viciifolia) is a condensed tannin (ct)-containing legume and has anthelmintic potential against gastrointestinal nematodes of ruminants. this study investigated in vitro effects of acetone/water extracts and derived ct fractions from different types of sainfoin (i.e. accessions) against larvae of cooperia oncophora and ostertagia ostertagi by applying the larval feeding inhibition assay (lfia). seven sainfoin accessions were extracted and tested with l1 larvae at 10 and 40 μ ... | 2013 | 23639199 |
| weight gain-based targeted selective treatments (tst) of gastrointestinal nematodes in first-season grazing cattle. | a three-year trial was performed in south-western sweden to compare animal performance and levels of parasite control in three grazing groups, each with 18-24 first-season grazing (fsg) calves in similar set-stocked pasture enclosures. these groups were subjected to: (1) no parasite control (nt), (2) monthly repeated doramectin (dectomax(®)) injections (sp), or (3) targeted selective weight gain-based anthelmintic treatments (tst) but only when individual calf performance was inferior to the ave ... | 2013 | 23608034 |
| transcriptome analyses reveal protein and domain families that delineate stage-related development in the economically important parasitic nematodes, ostertagia ostertagi and cooperia oncophora. | cooperia oncophora and ostertagia ostertagi are among the most important gastrointestinal nematodes of cattle worldwide. the economic losses caused by these parasites are on the order of hundreds of millions of dollars per year. conventional treatment of these parasites is through anthelmintic drugs; however, as resistance to anthelmintics increases, overall effectiveness has begun decreasing. new methods of control and alternative drug targets are necessary. in-depth analysis of transcriptomic ... | 2013 | 23432754 |
| control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected calves. | an anthelmintic efficacy study was performed with young, naturally infected beef-type calves obtained at local farms. presumably, the study calves had been recently weaned and had not been treated with a parasiticide prior to study acquisition. after blocking the 24 study calves in accordance with calculated cooperia spp epg counts, the calves were randomly allocated within each block to one of four treatment groups, resulting in 6 animals per treatment group (untreated controls, topical ivermec ... | 2013 | 23380250 |
| dexamethasone treatment interferes with the pharmacokinetics of ivermectin in young cattle. | an experiment was carried out to study the possible interaction between dexamethasone (dxm) treatment and the efficacy of ivermectin (ivm) treatment in young cattle. two groups, each of seven calves, were experimentally inoculated with an equal mixture containing 15,000 third stage larvae of cooperia oncophora and ostertagia ostertagi each, and with no history of being resistant to any anthelmintics. however, in this study c. oncophora was unexpectedly classified as ivm-resistant according to th ... | 2012 | 22959189 |