PMID(sorted ascending)
digital image analysis and identification of eggs from bovine parasitic microscopy and multivariate statistics were used to establish and evaluate a procedure for identification of bovine strongylid eggs. ostertagia ostertagi, cooperia oncophora, haemonchus placei, trichostrongylus axei, and oesophagostomum radiatum eggs were obtained from faeces voided by monospecifically infected calves. images of single eggs (400 x magnification) were recorded by a ccd camera fitted onto a microscope and digitized on a pc. after separation of eggs from the image ...19968960211
seasonal pattern of inhibition of ostertagia ostertagi in calves in northeast mississippi.the composition of, and seasonal changes in, populations of gastrointestinal parasites of calves in northeast mississippi were determined for 10 months post-weaning. after weaning on 15 october, 20 mixed breed beef steers were grazed together on a 4 ha fescue/bermudagrass pasture. from november through august of the following year, two of the calves were removed each month for necropsy and counting of gastrointestinal nematodes. eight species of worms were found: haemonchus placei, ostertagia os ...19968983154
bovine humoral immune responses to haemonchus placei excretory secretory antigens.the immune response of calves against excretory secretory (es) products of adult haemonchus placei was studied. the es products of adult h. placei comprise at least ten polypeptides with molecular weights ranging from 10 to over 100 kda. a primary infection of calves with h. placei did not result in a marked elevation of igg serum antibodies reactive to es antigens as demonstrated by elisa. immunoblotting experiments revealed that sera of primary infected calves recognised a 50 kda antigen in mo ...19968983155
the epidemiology of gastrointestinal nematode infections in communal cattle and commercial beef cattle on the highveld of epidemiological study of gastrointestinal nematode infections of cattle was conducted on the highveld of zimbabwe from june 1993 to may 1995. the study was carried out in two communal areas, two conventional beef farms and two commercial beef farms with irrigated pastures. on all farms/areas, faecal egg counts were low (< 500 eggs per g faeces) during the dry season. during the rainy season faecal egg counts were highest in communal areas and lowest in conventional beef farms. those of irriga ...19969011020
eprinomectin: a novel avermectin for use as a topical endectocide for cattle.eprinomectin (mk-397 or 4"-epi-acetylamino-4"-deoxy-avermectin b1) is a novel avermectin selected for development as a topical endectocide for all cattle, including lactating dairy cows. herein, we show its anthelmintic, insecticidal and miticidal activity. to determine its anthelmintic capabilities, eprinomectin was tested topically on jersey calves at 0.08, 0.2, or 0.5 mg kg-1 in a probe formulation against experimental infections of adult haemonchus placei, ostertagia ostertagi, trichostrongy ...19969024867
persistent efficacy of abamectin and doramectin against gastrointestinal nematodes of assess the persistent activity of injectable formulations of abamectin and doramectin against gastrointestinal nematodes of cattle.19979034496
efficacy of doramectin for treatment of experimentally induced infection with gastrointestinal nematodes in determine the efficacy of injectable doramectin against experimentally induced infections with adult and larval (l4) stages of gastrointestinal nematodes in calves.19979055975
efficacy of a pour-on formulation of eprinomectin (mk-397) against nematode parasites of cattle, with emphasis on inhibited early fourth-stage larvae of ostertagia evaluate efficacy of topically applied eprinomectin against inhibited early fourth-stage larvae (il4) of ostertagia spp in calves.19979099383
nematocidal efficacy of eprinomectin, delivered topically, in naturally infected assess the nematocidal efficacy of eprinomectin in naturally infected cattle.19979185967
effect of simulated rain, coat length and exposure to natural climatic conditions on the efficacy of a topical formulation of eprinomectin against endoparasites of cattle.a series of five controlled studies involving 114 cattle were conducted in australia, north america and the united kingdom to examine the effect of simulated rain, coat length and exposure to natural climatic conditions, on the efficacy of a topical formulation of eprinomectin against nematode parasites of cattle. in all trials infections were induced with a range of bovine nematode species and treatment was applied when the majority of nematodes were mature. in one study, simulated rain was app ...19979187034
use of cloned excretory/secretory low-molecular-weight proteins of cooperia oncophora in a serological assay.the potential of cooperia oncophora excretory/secretory (es) proteins as antigens in a serological assay which aims to establish exposure levels in cattle was assessed. es proteins were analyzed by one- and two-dimensional polyacrylamide gel electrophoresis and immunoblotting. the n-terminal domains of two es proteins were sequenced, and the corresponding cdnas were cloned. two cdnas, designated coes14.0 and coes14.2, were expressed in escherichia coli. the recombinant proteins were tested in an ...19979196182
morantel resistance by haemonchus placei in cattle. 19979402723
haemonchus placei and haemonchus contortus are distinct species based on mtdna evidence.debates continue over the extent to which the parasitic trichostrongylids haemonchus placei and haemonchus contortus hybridise in nature, and whether they deserve species status. mitochondrial nd4 gene sequences from individuals of each putative species collected from populations around the united states indicate that the two species are highly differentiated at the mtdna level. furthermore, there was no evidence of introgressive hybridisation occurring in wild populations.19979421728
epidemiology of mecistocirrus digitatus and other gastrointestinal nematode infections in cattle in mindanao, philippines.over a period of 14 months, faecal and serum samples were collected monthly from cattle of 1 to 30 months old on three ranches (20-25 animals ranch-1 sample-1) in mindanao, philippines. individual faecal egg counts, serum pepsinogen levels and mecistocirrus digitatus specific antibodies were determined, and infective larvae from pooled faecal samples were examined. post mortem worm counts were carried out on tracer calves (n = 16) that had been kept for 30 days with the herds on two of the ranch ...19989493308
host range and the maintenance of haemonchus spp. in an adverse arid climate.three haemonchus species (haemonchus contortus, haemonchus placei and haemonchus longistipes) live in sympatry in sahelian areas such as mauritania (west africa). four host species (dromedary, zebu cattle, sheep and goats) share the same pastures for several months per year. experimental infection by h. contortus or h. placei was achieved only poorly in dromedaries, and h. contortus or h. longistipes infection failed to establish in zebu cattle. conversely, h. placei and h. longistipes successfu ...19989512988
demonstration of shared carbohydrate epitopes in intestinal proteins of some bovine gastrointestinal nematodes.the presence of shared carbohydrate intestinal epitopes in bovine gastrointestinal nematodes was demonstrated. proteins were extracted from the intestinal tissue of a laboratory strain of adult haemonchus placei and used to produce monoclonal antibodies (mab). analysis of this detergent extract by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed 7-9 bands ranging from approximately 39 to 298 kda. the mabs reacted with periodate-sensitive epitopes and, in western blots, recogniz ...19989645850
comparisons of two polymorphic species of ostertagia and phylogenetic relationships within the ostertagiinae (nematoda: trichostrongyloidea) inferred from ribosomal dna repeat and mitochondrial dna sequences.the first internal transcribed spacer dna (its-1) (rdna) and the mitochondrial (mt) dna-derived cytochrome oxidase i gene (cox-1) were enzymatically amplified, cloned and sequenced from 6 nominal species of ostertagiinae as well as haemonchus contortus and haemonchus placei. the portion of the cox-1 gene analyzed was 393 base pairs (bp) in length and contained 33 within species polymorphic base changes at 28 synonymous sites. the its-1 rdna consensus sequences ranged from 392 bp (ostertagia oste ...19989714215
an abattoir survey of gastrointestinal nematode infections in cattle in the central highlands of kenya.the gastrointestinal tracts of 672 crossbred cattle were obtained from various abattoirs in kiambu district, kenya from august 1992 to july 1993, and examined for the presence of gastrointestinal nematodes. eight nematode species were found in 583 (86.8%) of the animals. the nematodes were, in order of prevalence: haemonchus placei (67.0%), cooperia pectinata (53.0%), cooperia punctata (41.7%), oesophagostomum radiatum (38.4%), trichostronglyus axei (24.3%), nematodirus helvetianus (19.6%), tric ...19989778778
differential in vitro pathogenicity of predatory fungi of the genus monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus monacrosporium (5 m. sinense isolates, 3 m. appendiculatum and 1 m. thaumasium isolate) for a phytonematode (second stage juveniles from meloidogyne incognita, race 3), a free-living nematode (panagrellus spp), and two gastrointestinal parasitic nematodes of cattle (infective larvae of cooperia punctata and haemonchus placei). a suspension containing 2,000 nematodes from each species was add ...199910347773
gastro-intestinal parasites of cattle in the communal grazing system of botshabelo in the free state.twelve bonsmara tracer calves (aged 6-12 months) were used to monitor helminth infections in the communal farming system of botshabelo in the free state. one calve was slaughtered each month from december 1995 to november 1996 and processed for helminth recovery. all the calves harboured worms, but the numbers were always low. the order of prevalence of the major parasites was trichostrongylus axei, haemonchus placei, cooperia punctata and cooperia pectinata.199910486833
persistent activity of doramectin injectable formulation against experimental challenge with haemonchus placei in cattle.two studies were conducted in north america to evaluate the persistent activity of doramectin injectable formulation against experimental challenge with haemonchus placei. in both studies, calves were randomly assigned to 1 of 4 treatment groups (n = 10 per group) or a larval viability group (n = 2). calves were treated subcutaneously in the lateral midline of the neck with saline (1 ml/50 kg) on day 0, or with doramectin (200 mg/kg = 1 ml/50 kg) on day 0, 7, or 14. animals used to assess larval ...199910489196
description of haemonchus placei (place, 1893) (nematoda, trichostrongylidae, haemonchinae), identification and intra-specific morphologic variability.haemonchus placei in cattle has never been completely described, possibly due to great morphological similarity with small ruminants haemonchus contortus. it is newly described on one isolate from argentina. it has clear distinct morphological features from sheep and goats haemonchus contortus and presents only two female morphotypes (linguiform and knobbed) instead of three recorded in h. contortus. a key is proposed to identify females. female as well as male haemonchus placei from new world ( ...199910633504
vaccination of calves with haemonchus placei intestinal homogenate.the ability of adult haemonchus placei intestinal homogenate to confer protection against homologous challenge infection was evaluated. calves were immunized twice with 100 microg h. placei intestinal protein in 5% dextran-sulfate/pbs (vaccinates) or pbs alone (controls) and were challenged with approximately 3300 infective h. placei larvae. there was no significant difference between groups in the total number of nematodes recovered but significantly fewer (p < 0.001) adult females were recover ...200010714462
ostertagia ostertagi challenge of calves vaccinated with haemonchus placei intestinal homogenate.the protective capacity of vaccination with haemonchus placei whole gut homogenate against challenge with the non-blood-feeding nematode ostertagia ostertagi was evaluated in calves. ten helminth-free calves were randomly assigned to two groups. group 1 received 100microg h. placei intestinal homogenate in the adjuvant 5% dextran sulfate/pbs, while group 2 received the adjuvant alone. injections were administered subcutaneously on days 0 and 28. all calves were challenged with approximately 26,1 ...200010828516
a hybridisation technique to identify anthelmintic resistance genes in haemonchus.the identification of genes associated with anthelmintic resistance can be facilitated in haemonchus contortus by the ability of this species to hybridise with haemonchus placei. although the hybrid males are sterile, the lines can be rescued by backcrossing the females to either parental species. resistance genes can be retained in haemonchus hybrids, while the unwanted contortus background is removed through backcrossing to h. placei and anthelmintic selection of the progeny. under this select ...199910961854
in vitro activity of brazilian strains of the predatory fungi arthrobotrys spp. on free-living nematodes and infective larvae of haemonchus vitro tests were carried out to assess the activity of 26 brazilian isolates of predatory fungi of the genus arthrobotrys on a free-living nematode (panagrellus sp.) and on infective larvae of haemonchus placei, a parasitic gastrointestinal nematode of cattle. the results showed that the free-living nematode panagrellus sp. was the most preyed upon, compared to h. placei, for all the fungal treatments. also, variable predatory capacity was observed for different fungal isolates belonging to t ...200011080778
persistent efficacy of topical eprinomectin against nematode parasites in cattle.six studies were conducted to evaluate the persistent efficacy of eprinomectin pour-on against experimental challenges with infective nematode larvae in calves. in each study, calves were randomly assigned to one untreated group and up to four test groups, which were treated with eprinomectin at 500 microg/kg body weight at weekly intervals before single bolus challenge. the calves were necropsied approximately 4 weeks after challenge infection for nematode recovery. eprinomectin pour-on provide ...200011097305
experimental cross-infections of haemonchus placei (place, 1893) in sheep and examine effects on biology and morphology, haemonchus placei infections were propagated in cattle or sheep and infective larvae were introduced into the same or opposite host. ovine source larvae had a geometric mean (gm) prepatent period of 26.5 days regardless of host species, compared to 30.6 days for bovine source larvae regardless of host species. similarly, ovine source h. placei had a higher gm percentage establishment versus bovine source larvae (9.6% versus 3.4%) regardless of host s ...200111113549
the epidemiology of gastrointestinal nematodes of dairy cattle in central kenya.the epidemiology of h. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in kiambu district, central kenya during each of 13 one-month periods from april 1993 to april 1994. on each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. twelve of the animals were designated for bimonthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood an ...200111360797
a multiplex pcr assay for differentiating economically important gastrointestinal nematodes of cattle.a multiplex polymerase chain reaction (pcr) test was developed for identifying gastrointestinal (gi) nematodes that commonly infect cattle. this assay was developed using adult-derived genomic dna and shown capable of discriminating parasite eggs from the feces of experimentally-infected animals at both the species and genus levels. sequence data from internal (its) and external (ets) transcribed spacers of the ribosomal dna (rdna) repeats as well as the 3'-end of the small subunit rdna and 5'-e ...200111390072
titration of subcutaneously administered eprinomectin against mature and immature nematodes in cattle.eprinomectin has been approved for use as a topically applied endectocide for beef and dairy cattle. to determine if eprinomectin has utility as an injectable anthelmintic, it was titrated at 0.05, 0.1, and 0.2 mg/kg s.c. against adult (trial 1) and at 0.05, 0.1, 0.14, and 0.2 mg/kg s.c. against immature (trial 2) stages of lung and gastrointestinal nematodes in cattle. in trial 1, every dose of subcutaneously delivered eprinomectin showed maximal or near-maximal (> or = 99%) efficacy against ha ...200111780839
multispecies and multiple anthelmintic resistance on cattle nematodes in a farm in argentina: the beginning of high resistance?there are very few resistance records on cattle nematodes. south american successive records have been increasing rapidly since the year 2000. in argentina, increasing dissatisfaction based on the exclusive use of macrocyclic lactones has prompted the use of benzimidazoles in the pampean region. the studied farm is located in the argentina humid pampas and had apparently poor results after anthelmintic treatments. evaluation of resistance was firstly based on faecal egg reduction after treatment ...200312911862
the role of the larval stages of haemonchus placei infections of cattle in immunity. 196314053281
gastrointestinal nematodes in indigenous zebu cattle under pastoral and nomadic management systems in the lower plain of the southern highlands of tanzania.this study aimed to determine the prevalence and intensity of gastrointestinal nematode infections in indigenous zebu cattle in the lower plain (lowland zone) of the southern highlands of tanzania. gastrointestinal tracts were randomly purchased at the iringa regional abattoir and at kihesa and ipogolo slaughter slabs in different seasons of the year. the contents of the abomasum, small intestine and large intestine were processed separately to recover the worms. the results indicated that 140 o ...200314509451
host specificity of haemonchus spp. for domestic ruminants in the savanna in northern ivory coast.three haemonchus species (haemonchus contortus, haemonchus placei and haemonchus similis) live in sympatry in the savanna of north côte d'ivoire. four domestic ruminant hosts (zebu-cattle, taurine-cattle, sheep and goats) share the same pastures throughout the year. our post-mortem data imply that a haemonchus spp. circulation exists among the different hosts species in the savanna of north côte d'ivoire. under field conditions, mixed congeneric infections were the rule except in sheep where mon ...200314519319
therapeutic and persistent efficacy of moxidectin 1% nonaqueous injectable formulation against natural and experimentally induced lung and gastrointestinal nematodes in cattle.four controlled trials were conducted to evaluate the therapeutic and persistent efficacy of a new moxidectin formulation (moxidectin 1% nonaqueous injectable) against nematode parasites in cattle. this injectable moxidectin formulation, given as a single subcutaneous injection at a dose rate of 0.02 ml/kg bw to provide 0.2 mg moxidectin/kg bw, was highly efficacious (>90-100%) against larval and/or adult stages of many species of nematodes in cattle including, dictyocaulus viviparus, ostertagia ...200415063941
purifying selection and demographic expansion affect sequence diversity of the ligand-binding domain of a glutamate-gated chloride channel gene of haemonchus placei.ninety-five genomic sequences of the ligand-binding domain of glutamate-gated chloride channel genes of three populations of the parasitic nematode h. placei were evaluated for patterns of diversity, demography, and selection. these genes code for subunits of ion channels, which are involved in the mode of action of the most commonly used antiparasitic drugs, the macrocyclic lactones. an extremely high frequency of unique segregating sites in exons and introns was observed, with significantly ne ...200415114425
epidemiology of gastrointestinal nematodes in cattle on traditional, small-scale dairy and large-scale dairy farms in iringa district, tanzania.a longitudinal study was carried out to determine the prevalence, distribution and intensity of gastrointestinal (gi) nematodes in traditional, small-scale dairy and large-scale dairy cattle farms in iringa district, southern highlands of tanzania. coprological examination of cohorts for gi nematode eggs in faeces, tracer worm counts and pasture larval counts were performed monthly for 1 year. results indicated that the type of management, especially the grazing habit has a significant influence ...200415710529
parasites of domestic and wild animals in south africa. xlv. helminths of dairy calves on dry-land kikuyu grass pastures in the eastern cape province.successive pairs of approximately 4-month-old friesland bull calves, raised under worm-free conditions, were exposed to helminth infection for 14 days on dry-land kikuyu grass pastures at 28-day to monthly intervals, on a coastal farm in a non-seasonal rainfall region of the eastern cape province. with the exception of one pair of calves exposed for 28 days, this procedure was repeated for 28 consecutive months from december 1982 to march 1985. the day after removal from the pastures one calf of ...200415732456
persistent anthelmintic activity of abamectin injection in cattle.the duration of the anthelmintic activity of abamectin administered by subcutaneous injection at 200 microg/kg was determined using induced infections of haemonchus placei, ostertagia ostertagi, cooperia spp., and oesophagostomum radiatum in cattle. twenty-four friesian calves, raised under worm-free conditions, were assigned to four groups of six animals using a randomised block design based on bodyweight. one group acted as untreated controls and the other three were treated with abamectin 14, ...199216031652
[forming of gastro-intestinal nematodes fauna of free ranging european bison in bialowieza primeval forest during last 17 years (1984-2001)].28 european bison of both sexes and in different age shot in białowieza primeval forest in january 1984, (10 animals), january 1992 (10 animals) and in january and the beginning of february 2001 (8 animals) have been necropsied. the examined animals in mentioned years were of similar age. there were examined abomasa and duodena of shot animals. all necropsied bison were infected with gastro-intestinal nematodes. the highest intensity of infection with nematodes of abomasum was found in 1992 year ...200216894720
species diversity and acquisition of gastrointestinal parasites in calves aged 0-13 months in periurban livestock production in inspections on 51 calves were conducted to investigate acquisition and spectrum of gastrointestinal parasites in young calves in periurban livestock production in mali. generalized linear models with herd as a repeated effect were used to test the influence of management, age and season of birth on parasite numbers and diversity. parasite number and burden increased with age. in the age class 4-13 months animals carried already up to eight different gastrointestinal parasite species. ...200716934937
field study on nematode resistance in nelore-breed cattle.the present study evaluated nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. one hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from october 2003 to february 2004. faecal and blood samples were collected for parasitological, haematological and immunological tests. in february 2004, the 10 most resistant and the 10 most susceptible animals were selected based on individual means of nematode faecal ...200717659839
protection against high-dose homologous infection in calves immunized with intestine or membrane extracts from haemonchus placei.control of haemonchus placei, one of the most important cattle nematodes in brazil, relies on the use of anthelmintics. however, there is a need for integrated control, which includes active immunization. the aim of this work was to assess the protection afforded to calves by immunization with adult h. placei extracts against a high-dose challenge infection, a condition frequently found in the tropics. holstein calves aged 8-10 months were immunized four times with intestinal extracts (group d) ...200818065148
endectocide activity of a new long-action formulation containing 2.25% ivermectin+1.25% abamectin in cattle.the present work aimed to evaluate the endectocide activity of a new injectable long-action formulation, containing ivermectin (ivm) and abamectin (aba). in each one of the four experiments performed, the following groups were formed: group i: 2.25% ivm (450 microg/kg)+1.25% aba (250 microg/kg), group ii: 3.15% ivm (630 microg/kg) and group iii: control. eighteen bovine naturally infected by gastrointestinal nematoda were selected for anthelmintic evaluation and necropsied on posttreatment day ( ...200818562119
fecal egg count reduction and control trial determinations of anthelmintic efficacies for several parasiticides utilizing a single set of naturally infected 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 ...200919615822
evaluation of the persistent activity of moxidectin (10%) long-acting (la) injectable formulation against dictyocaulus viviparus, haemonchus placei, trichostrongylus axei and oesophagostomum radiatum infections in cattle.two controlled studies were conducted to evaluate the persistent efficacy of moxidectin (10%) long-acting (la) injectable formulation against dictyocaulus viviparus, haemonchus placei, trichostrongylus axei and oesophagostomum radiatum in cattle. the moxidectin la injectable formulation was administered as a single subcutaneous injection into the proximal third of the ear at a dose rate of 0.01ml/kg bw to provide 1.0mg moxidectin/kg bw. the product had persistent efficacy of >90% against d. vivi ...201019896772
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 ...200919897305
the identification of cattle nematode parasites resistant to multiple classes of anthelmintics in a commercial cattle population in the us.resistance to modern anthelmintics by ruminant nematode parasites is an increasing problem throughout the world. to date the problem has largely been reported in parasites of small ruminants, but there are increasing reports of such resistance in nematodes recovered from cattle. until now there have been no published reports of drug resistant parasites from cattle in north america. in 2002 a producer in the upper midwest who backgrounds young cattle acquired from the southeastern us experienced ...200919900760
reduced efficacy of macrocyclic lactone treatments in controlling gastrointestinal nematode infections of weaner dairy calves in subtropical eastern australia.faecal egg count reduction tests (fecrts) for macrocyclic lactone (ml) and levamisole (lev) drenches were conducted on two dairy farms in the subtropical, summer rainfall region of eastern australia to determine if anthelmintic failure contributed to severe gastrointestinal nematode infections observed in weaner calves. subtropical cooperia spp. were the dominant nematodes on both farms although significant numbers of haemonchus placei were also present on farm 2. on farm 1, moxidectin pour-on ( ...201019932565
cytokine gene expression in response to haemonchus placei infections in nelore cattle.this study aimed to evaluate the expression of a subset of cytokine genes in response to haemonchus placei infections in nelore cattle presenting different degrees of resistance to natural infections. one hundred weaned bulls, initially 11-12 months old, were evaluated and kept on the same pasture. faecal and blood samples were collected for parasitological and immunological assays. the seven most resistant and the eight most susceptible animals were selected based on nematode faecal egg counts ...201020409640
fasciola gigantica: production and characterization of a monoclonal antibody against recombinant cathepsin b3.a number of monoclonal antibodies (moabs) against a recombinant cathepsin b3 (rcatb3) of fasciola gigantica were produced in balb/c mice. reactivity and specificity of these moabs were assessed by indirect elisa and immunoblotting techniques. six stable clones, namely 1c4, 1e9, 2e5, 2f9, 5b4, 5d7 were obtained. all moabs reacted with rcatb3 at molecular weight (mw) 37 kda as well as the glycosylated peptide at 55-75 kda and with the native catb3 at mw 37 kda in wb extracts of metacercariae (met) ...201120736007
seasonal prevalence of gastrointestinal nematode parasites of sheep in northern region of nile delta, egypt.over 1 year, from january to december 1999, a total of 173 slaughtered sheep at al-mahala abattoir were examined for presence of nematode parasites. eighteen sheep (10.4%) were infected with eight different species of nematodes. the prevalence rates of detected nematode parasites were; haemonchus contortus (3.5%), haemonchus placei (1.7%), trichuris ovis (5.8%), parabronema skrjabini (2.9%), ostertagia trifurcata (1.2%), chabertia ovina (0.6%) and strongyloides papillosus (0.6%), and graphidiops ...201020922430
mrna profile of nellore calves after primary infection with haemonchus placei.haemonchus parasites are responsible for many losses in animal production. however, few studies are available, especially of zebu cattle. in this study, we investigated mrna differences of immune response genes in naïve nellore calves infected with haemonchus placei, relating these differences to patterns of cellular infiltrate. calves were infected with 15,000 h. placei l3 larvae and after 7 days lymph node and abomasum tissues were collected. il-2, il-4, il-8, il-12, il-13, ifn-γ, mcp-1, lysoz ...201021144661
characterization and localization of saposin-like protein-2 (sap-2) in fasciola gigantica.fasciola gigantica saposin-like protein-2 (fgsap-2) belongs to a family of lipid-interacting proteins that are involved in the cytolysis of target cells. in this study, we have cloned and expressed fgsap-2 and produced the antibody against this recombinant protein. rabbit antiserum against rfgsap-2 reacted with a similar native protein in the whole body extracts of the 4-week-old juvenile and adult stage, as well as a protein in their excretion-secretion, but not in the tegument. in situ hybridi ...201021188603
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 ...201121210152
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
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 ...201121739380
why is it important to correctly identify haemonchus species?parasitic gastroenteritis caused by haemonchus spp. is a major cause of economic losses in the livestock industry because it impairs weight gain and increases mortality in cattle and small ruminants, especially in tropical and subtropical areas. the proper identification of the various species, as well as knowledge regarding the epidemiology of parasitic gastroenteritis, is essential for the establishment of sustainable strategies of parasite control. this review focuses on the use of easily app ...201122166378
genetic diversity patterns of haemonchus placei and haemonchus contortus populations isolated from domestic ruminants in brazil.parasitic nematodes of the genus haemonchus infect a range of ruminant hosts and are of major veterinary and economic importance. in this study, the genetic variability of seven isolates of haemonchus placei and haemonchus contortus was evaluated using the mitochondrial gene cytochrome oxidase subunit i and the nuclear gene b-tubulin isotype 1. a total of 156 specimens were obtained from cattle, sheep, goat and buffalo herds raised on commercial properties from the southern and southeastern regi ...201222787588
production and characterization of a monoclonal antibody against recombinant saposin-like protein 2 of fasciola gigantica.a monoclonal antibody (moab) against recombinant fasciola gigantica saposin-like protein 2 (rfgsap-2) was produced by hybridoma technique using spleen cells from balb/c mice immunized with rfgsap-2. this moab is an igg1, κ light chain isotype. by immunoblotting and indirect elisa, the moab reacted specifically with rfgsap-2, the natural fgsap-2 at 10kda in whole body (wb) and excretory-secretory (es) fractions of f. gigantica. it did not cross react with antigens in wb fractions from other paras ...201323164839
resistance against gastrointestinal nematodes in crioulo lageano and crossbred angus cattle in southern brazil.gastrointestinal nematode (gin) infection is a major cause of production losses in cattle. this study was carried out to evaluate the natural resistance against nematode infection in crioulo lageano and crossbred angus male calves. crioulo lageano is a local cattle breed in the state of santa catarina, in southern brazil. ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between july 2009 and december 2010. once every 28 days, we collected feca ...201323177359
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 ...201223273781
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 ...201223273928
control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected 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 ...201323380250
unexpected occurrence of haemonchus placei in cattle in southern western australia.haemonchus placei is an abomasal parasite of cattle, primarily in tropical and subtropical areas of the world. in australia, this nematode can be extremely pathogenic in summer rainfall areas, particularly in the hot, sub-tropical kimberley region, in the far north of the state of western australia (wa). although cattle are occasionally transferred to southern parts of wa, it was believed that h. placei did not occur in southern regions of wa, as it is less cold-adapted than haemonchus contortus ...201424189197
a review of the epidemiology and control of gastrointestinal nematode infections in cattle in this review, the main gastrointestinal nematodes infecting cattle in zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in zimbabwe. the main genera reported to date are cooperia, haemonchus, trichostrongylus and oesophagostomum and the dominant species are cooperia pectinata, cooperia punctata, haemonchus placei and trichostrongylus axei. ...201324396919
evaluation of clinical safety and anthelmintic efficacy of aurixazole administed orally at 24 mg/kg in cattle.the current study evaluated, in vivo, the clinical safety and the anthelmintic efficacy of 24% aurixazole (24 mg/kg), administered orally, in bovines. two experiments were conducted: the first one evaluating the clinical safety of 24% aurixazole (24 mg/kg) in cattle, and a second one evaluating the anthelmintic efficacy of aurixazole (24 mg/kg) against gastrointestinal nematodes on naturally infected cattle. based on the results of clinical safety, no alterations on clinical and haematological s ...201424656344
immune response to haemonchus contortus and haemonchus placei in sheep and its role on parasite specificity.two trials were conducted to determine the prepatent and the patent period of haemonchus contortus and haemonchus placei in santa ines crossbred sheep and to determine whether serial infections with both species confer protection against homologous or heterologous challenge. to evaluate the prepatent and patent periods of infection, five lambs received a single infection with 4000 h. contortus-infective larvae (l3), and another five received a single infection with 4000 h. placei l3. h. contortu ...201424670867
production and characterization of a monoclonal antibody against recombinant cathepsin l1 of fasciola gigantica.monoclonal antibodies (moabs) against a recombinant cathepsin l1 of fasciola gigantica (rfgcatl1) were produced in vitro by fusion of balb/c mice spleen cells immunized with rfgcatl1 and mouse myeloma cells. reactivity and specificity of these moabs were evaluated by indirect elisa and immunoblotting techniques. seven moab clones were selected from the stable hybridoma clones, namely 1e10, 1f5, 3d11, 4b10, 4d3, 4e3 and 5e7. clones 1e10, 1f5 and 3d11 were igm, whereas clones 4b10, 4d3, 4e3 and 5e ...201424736227
relative potency of macrocyclic lactones in in vitro assays with larvae of susceptible and drug-resistant australian isolates of haemonchus contortus and h. placei.the present study used in vitro assays to determine the relative potency of commercial macrocyclic lactone (ml) anthelmintics against larvae of drug-susceptible and drug-resistant australian isolates of important parasites of sheep and cattle, haemonchus contortus and haemonchus placei, respectively. cattle pour-on products containing abamectin, ivermectin, eprinomectin, doramectin or moxidectin were diluted in dmso and used in larval development assays. abamectin was the most potent chemical (l ...201424813746
the presence of benzimidazole resistance mutations in haemonchus placei from us cattle.haemonchus populations were collected from cattle from mid-western and eastern southern us (four and six populations, respectively) to determine the relative prevalence of haemonchus contortus and haemonchus placei and the frequency of the three isotype-1 β-tubulin polymorphisms associated with benzimidazole resistance. a minimum of 32 individual adult worms were genotyped at position 24 of the rdna its-2 for each population to determine species identity (296 worms in total). one population from ...201424916341
vaccination of grazing calves with antigens from the intestinal membranes of haemonchus contortus: effects against natural challenge with haemonchus placei and haemonchus similis.a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in three groups of eight 5 months old grazing calves, naturally infected by haemonchus similis, haemonchus placei and other gastrointestinal nematodes. vaccinated calves received 5 or 50μg of the antigen and 1mg of saponin adjuvant, while the controls received adjuvant alone, initially three times, 3 weeks apart and then four more times at 6 weeks intervals. three weeks after the last im ...201424960373
nematode resistance to ivermectin (630 and 700μg/kg) in cattle from the southeast and south of brazil.two high doses of ivermectin (630μg/kg and 700μg/kg) that are sold commercially in brazil were evaluated in dose-and-slaughter trials with 144 naturally nematode-infected cattle from eight regions within the states of minas gerias, são paulo and rio grande do sul in brazil. treatment groups were based on fecal egg counts 1, 2, and 3days before treatment; all animals studied had a minimum egg count of at least 500 eggs per gram of feces (epg). post-mortem analyses were conducted on day 14. the hi ...201425130588
p-gp modulating drugs greatly potentiate the in vitro effect of ivermectin against resistant larvae of haemonchus placei.since its production in the 1980s, ivermectin (ivm) has been used indiscriminately and the selection pressure to which bovine gastrointestinal nematodes have been exposed has been intense, resulting in considerable economic losses due to parasitic resistance. one possibility for the control of resistant parasites is the use of p-glycoprotein (p-gp) modulators, because one of the main biochemical changes in ivermectin-resistant parasites is the increased activity of membrane proteins responsible ...201425178553
genetic evidence for hybridisation between haemonchus contortus and haemonchus placei in natural field populations and its implications for interspecies transmission of anthelmintic resistance.genetic hybridisation between parasitic nematode species has potentially important consequences. it could lead to the introgression of genes between species including those involved in pathogenicity, host specificity, transmission and drug resistance. it could also complicate diagnosis and control. however, there are few compelling examples of its occurrence in parasites in the field. haemonchus contortus and haemonchus placei are two closely related parasitic nematode species that predominantly ...201525449043
differentiation of haemonchus placei from haemonchus contortus by pcr and by morphometrics of adult parasites and third stage larvae.molecular and morphological methods were evaluated to distinguish between haemonchus contortus and haemonchus placei species. a total of 141 h. contortus and 89 h. placei male adult specimens collected from artificially infected lambs were identified individually by pcr analysis, using a species-specific primer pair. these pcr results were used as gold standard for haemonchus spp. identification. haemonchus placei presented higher mean spicule and barb lengths than h. contortus (p<0.05). however ...201725517528
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 ...201525541483
absence of detectable benzimidazole-resistance associated alleles in haemonchus placei in cattle in nigeria revealed by pyrosequencing of β-tubulin isotype 1.trichostrongyles are gastrointestinal parasites that occur globally and can cause subclinical to severe, sometimes life-threatening, infections in ruminants, particularly young animals. benzimidazoles (bz) are commonly used for the treatment of gastrointestinal parasites in ruminants. increasing spread of worm populations with anthelmintics resistance has been reported and is considered a consequence of highly frequent and longstanding use of anthelmintics. to obtain initial information regardin ...201525782679
anthelmintic resistance in gastrointestinal nematodes from grazing beef cattle in campeche state, mexico.production of beef cattle is one of the most important economic activities in mexico. however, anthelmintic resistance (ar) has affected animal productivity. the aim of this study was to determine the presence of ar in gastrointestinal nematodes (gin) of beef cattle in candelaria municipality of campeche state, mexico. sixty-five-month-old beef calves were selected for the faecal egg count reduction test (fecrt) and the inhibition of egg hatch (ieh) assay. these parameters were determined using ...201525876195
the effect of gastrointestinal nematode infection level on grazing distance from dung.avoiding grazing near feces is an efficient strategy to prevent parasitic infection and contamination; therefore, in the evolution of herbivorous species, this behavior may have developed as a mechanism to protect the host against infection by gastrointestinal nematodes. the aim of this study was to assess whether grazing distance from dung is related to the level of parasitic infection in cattle. based on fecal egg count (fec) means, 18 castrated male steers, aged 18 months, were divided into t ...201526039729
multispecies resistance of cattle gastrointestinal nematodes to long-acting avermectin formulations in mato grosso do sul.the use of long-acting avermectins (avms) in cattle to treat infections with gastrointestinal nematodes was common in brazil until its prohibition by state authorities. the prohibition; however, was rescinded in 2015, but a scientific discussion of the pros and cons of the use of these formulations is necessary. we evaluated the levels of resistance to 1.0 and 3.5% doramectin and to 3.15% ivermectin in cattle. the worms in animals treated with 3.5% doramectin were characterized by the suppressio ...201526129974
endectocide activity of a pour-on formulation containing 1.5 per cent ivermectin +0.5 per cent abamectin in cattle.the present work aimed to evaluate, through ten different studies, the therapeutic efficacy of a new pour-on formulation, containing 1.5 per cent ivermectin +0.5 per cent abamectin, against parasites of cattle. results obtained on trials against rhipicephalus (boophilus) microplus showed that the pour-on combination of 1.5 per cent ivermectin +0.5 per cent abamectin obtained superior efficacy indexes against this ectoparasite, when compared with formulations containing 0.5 per cent ivermectin, 1 ...201526392893
experimental infection of calves with haemonchus placei and haemonchus contortus: assessment of parasitological parameters.the present study evaluated the viability and possible effects of haemonchus contortus infections in experimentally prime infected calves, comparing them to infections by haemonchus placei. ten male holstein newborns were used. all calves were individually weighed for subsequent group formation, in which two animals were kept as a control group, inoculated with water (gi); four animals were inoculated with 10,000 third stage (l3) haemonchus contortus larvae (gii); and the remaining four calves w ...201626827856
the identification of haemonchus species and diagnosis of haemonchosis.diagnosis is often equated with identification or detection when discussing parasitic diseases. unfortunately, these are not necessarily mutually exclusive activities; diseases and infections are generally diagnosed and organisms are identified. diagnosis is commonly predicated upon some clinical signs; in an effort to determine the causative agent, identification of genera and species is subsequently performed. both identification and diagnosis play critical roles in managing an infection, and ...201627238005
influence of massive and long distance migration on parasite epidemiology: lessons from the great wildebeest migration.very little is known about the influence of massive and long distance migration on parasite epidemiology. migration can simultaneously minimize exposure to common parasites in their habitats and increase exposure to novel pathogens from new environments and habitats encountered during migration, while physiological stress during long distance movement can lead to immune suppression, which makes migrants vulnerable to parasites. in this paper, we investigated the diversity, prevalence, parasite l ...201627554373
experimental infection of calves with haemonchus placei or haemonchus contortus: assessment of clinical, hematological and biochemical parameters and histopathological characteristics of abomasums.the present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with haemonchus contortus or h. placei. ten male holstein newborns were subdivided in three groups (gi placebo; gii infected with h. contortus; giii inoculated with h. placei). eye mucosa staining was evaluated. hematological and biochemical tests were performed on animals. the ...201627693223
production and characterization of a monoclonal antibody specific to 16 kda antigen of paramphistomum gracile.a number of monoclonal antibodies (moabs) against the 16 kda antigen of paramphistomum gracile (16 kdaagpg) were produced in vitro by hybridoma technique. reactivity and specificity of these moabs were evaluated by elisa and immunoblotting assays. seven moab clones were selected from the stable hybridoma clones, namely 1d10, 2d7, 3b10, 3d9, 4f1, 4g4, and 5g12. it was found to be igm and kappa light chain isotypes. by immunoblotting and elisa, all moabs reacted with purified 16 kdaagpg at molecul ...201727770198
pcr primers for straightforward differentiation of haemonchus contortus, haemonchus placei and their hybrids.haemonchus contortus and haemonchus placei are among the major parasites of small ruminants and cattle. although infection with these nematodes is host-specific, with h. placei predominating in cattle and h. contortus in sheep, cross-infections are observed in areas where both parasites are sympatric, and hybrid offspring can occur. therefore, a fast and precise method is required for differentiating the parasites. identification based on spicule morphometry is the most common technique for diff ...201728069083
can haemonchus placei-primary infected naïve lambs withstand haemonchus contortus infections?an experiment was conducted with the objective of evaluating whether a 5000 l3 larvae haemonchus placei primary infection, a less pathogenic parasite species for sheep, could attenuate highly pathogenic haemonchus contortus infections in lambs. thirty nine 6-month-old lambs were divided in three primary-infection groups: (hcpi) h. contortus-primary infected lambs, (hppi) h. placei-primary infected lambs, and (ctrl) non-infected control lambs. later, these same individuals, then aged 10-month old ...201728391070
the use of nemabiome metabarcoding to explore gastro-intestinal nematode species diversity and anthelmintic treatment effectiveness in beef deep amplicon sequencing, or metabarcoding, has revolutionized the study of microbial communities in humans, animals and the environment. however, such approaches have yet to be applied to parasitic helminth communities. we recently described the first example of such a method - nemabiome sequencing - based on deep-amplicon sequencing of internal transcribed spacer 2 (its-2) rdna, and validated its ability to quantitatively assess the species composition of cattle gastro-intestin ...201728797791
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