development and characterization of monoclonal antibodies to first-generation merozoites of eimeria bovis.merozoites of eimeria bovis were harvested from bovine monocyte cell cultures and used to immunize balb/c mice. spleens from immunized mice were removed and the cells fused with mouse myeloma cells. supernates from resulting hybridoma cell lines were examined for antibodies to first-generation e. bovis merozoites using an indirect immunofluorescent antibody (ifa) assay. three positive cell lines were identified and cloned by limiting dilution. all three cell lines produced immunoglobulins of the ...19921281590
[abortions caused by protozoa in agricultural animals].a review is given on abortions in livestock caused by toxoplasma gondii, neospora caninum and sarcocystis spp. special emphasis is put on diagnostic procedures. t. gondii is considered to be a major cause of abortions in sheep and goats. diagnosis is based on the characteristic lesions in the cotyledons, histologic and immunohistochemical examination, and on the detection of specific antibodies in body fluids or serum of aborted fetuses. whether abortions in swine due to t. gondii are of practic ...19921396163
induced transplacental transmission of neospora caninum in cattle.three jersey cows were inoculated sc and im with 26 million neospora caninum tachyzoites at 129 (cow 1), 126 (cow 2), and 81 (cow 3) days after mating. cows remained clinically normal for at least 1 month after inoculation of n caninum. cow 1 was euthanatized 32 days after inoculation because of gangrenous mastitis. cow 1 had a live fetus with no gross lesions; however, microscopic lesions were seen in the fetus and consisted of severe nonsuppurative necrotizing encephalitis of the cerebral whit ...19921399772
[neospora abortion in cattle in the netherlands].three cases of bovine protozoal abortion at three different dairy farms are reported. multiple abortions had occurred, on two farms, and a sporadic abortion on the third farm. histopathological examination of foetal tissues revealed a distinctive multifocal necrotising encephalitis as well as focal inflammatory lesions in the myocardium, liver, kidney and lung. in one foetus protozoal tissue cysts were found in the brain and individual and clustered tachyzoites were seen in brain, and lung. in a ...19921440543
neosporosis in the aborted fetus and newborn calf.protozoal encephalitic lesions were found in four aborted fetuses and one dead newborn calf. the organism was identified as neospora caninum by immunoperoxidase. the brain lesions were of two forms. one was observed in three fetuses of 5 months gestation and was characterized by multifocal necrosis. the other was found in a 7-month fetus and in a newborn calf, and showed severe infiltration with macrophages and plasma cells containing igg. this association, between the age of fetus and inflammat ...19921452816
clinical neosporosis in a 4-week-old hereford calf.most reports of neosporosis associated with abortion in cattle are in dairy cattle and infected calves do not survive beyond 7 days of age. this paper reports neosporosis in a 4-week-old hereford calf. the calf was full term and appeared clinically normal at birth. at 2 weeks of age, the calf had weakened and was unable to nurse unassisted. the calf was killed at 4 weeks because of paralysis. the primary lesions were in the brain and were associated with neospora caninum tachyzoites. the diagnos ...19921496796
neospora-like protozoan infection as a major cause of abortion in california dairy cattle.ninety-five aborted bovine fetuses received from california dairies over a 4.5-year period had histologic lesions of focal encephalitis. protozoa that reacted with neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. it was concluded that a neospora-like cyst-forming coccidian may be a major cause of abortion in california dairy cattle.19912004983
neospora-like encephalomyelitis in a calf: pathology, ultrastructure, and immunoreactivity.protozoal encephalomyelitis was diagnosed in a 3-day-old calf that was stunted, weak, and recumbent. grossly, the calf had contracted tendons in the forelegs, a slightly doomed skull, a porencephalic cyst in the cerebellum, ulcerative esophagitis, and abomasitis. histologically, there was a multifocal nonsuppurative encephalomyelitis with clusters of protozoal tachyzoites and numerous protozoal cysts. the porencephalic cyst and gastrointestional lesions appeared to be unrelated to the protozoal ...19912039786
neospora-like protozoal infections associated with bovine abortions.eighty bovine fetuses with presumed protozoal infections from a previous 2-year retrospective study were examined by immunohistochemistry using antisera against neospora caninum. in 66 (83%) of the fetuses, protozoa were found that reacted positively with anti-n. caninum sera. in three (4%) additional fetuses, protozoa identified as sarcocystis species did not react, and in two fetuses (3%) single protozoal clusters were found only in hematoxylin and eosin-stained slides. a group of 20 fetuses w ...19912063512
congenital neospora caninum infection in a calf with spinal cord anomaly.neospora caninum was identified in a calf with spinal cord anomaly in australia. the calf was full-term and born dead. the caudal cervical and cranial thoracic segments of the spinal cord of the calf were asymmetric because of marked unilateral reduction of ventral gray matter and focal cavitation. mild focal disseminated nonsuppurative encephalomyelitis was associated with n caninum tissue cysts. tissue cysts were 16 to 35 microns x 10 to 27 microns, and the cyst walls were 1 to 3 microns thick ...19902243037
neosporosis-like abortions in a herd of dairy cattle.twenty-nine cows from a 240-cow drylot holstein dairy in north-central new mexico aborted over a period of approximately 5 months. nine aborted fetuses were necropsied, and all but 1 of the fetuses were between 5 and 7 months of gestation. microscopic examination of fetal tissues revealed focal necrotizing encephalitis and nonsuppurative myocarditis in 7 of the 9 fetuses. additional lesions observed in some fetuses were focal hepatic necrosis, nonsuppurative myositis, focal necrotizing placentit ...19892488345
neospora caninum-like protozoon associated with fatal myelitis in newborn calves.neospora caninum-like organisms were found in histologic sections of spinal cord of 4 paralyzed calves as reported by parish et al. (1987). tachyzoites divided by endodyogeny. tissue cysts were up to 62 microns wide and the cyst wall was up to 2.5 microns thick. the organism in calves was structurally distinct from toxoplasma gondii and sarcocystis species and reacted positively with anti-n. caninum serum in an immunoperoxidase test.19892493086
in vitro development of neospora caninum (protozoa: apicomplexa) from dogs.the development of neospora caninum isolated from naturally infected dogs was examined in mammalian cell cultures. tachyzoites developed by endodyogeny when inoculated onto bovine monocyte or bovine cardiopulmonary artery endothelial cell cultures. tachyzoites were 5.0 by 2.0 microns and had a posteriorly located nucleus. cytopathogenic effects of parasite development consisted of the formation of holes in the cell monolayer associated with the rupture of infected host cells. serial passage of t ...19892493088
a neospora-like protozoon found in an aborted bovine placenta.portions of the placenta and kidneys from a 5-month-old bovine fetus were examined histologically. the placental cotyledonary villi were necrotic and protozoa were found in lesions. the organisms were in trophoblasts, periodic acid schiff-negative and did not react in an immunoperoxidase test using anti-toxoplasma gondii serum. individual zoites were approximately 5 x 2 microns and the biggest collection was 45 x 35 microns. the organism in the present case was structurally distinct from sarcocy ...19892588466
evaluation of anti-coccidial drugs' inhibition of neospora caninum development in cell cultures.eight anti-coccidial drugs were examined for their efficacies in preventing development of neospora caninum in bovine monocyte cell cultures. lasalocid sodium (0.05 microgram/ml), monensin sodium (0.05 microgram/ml), piritrexim (0.01 microgram/ml), pyrimethamine (0.05 microgram/ml), and trimethoprim (5.0 micrograms/ml) were effective in preventing development of intracellular n. caninum tachyzoites (p less than 0.05). no differences (p greater than 0.05) in mean numbers of infected cells compare ...19892614609
abortions, fetal death, and stillbirths in pregnant pygmy goats inoculated with tachyzoites of neospora caninum.neospora caninum-induced abortion is a major production problem in the dairy cattle industry in the united states and worldwide. abortions attributable to naturally acquired n caninum infection also have been observed in pygmy goats. we studied experimentally induced infections with n caninum in pregnant pygmy does to determine whether abortions attributable to n caninum infection would occur after inoculation. seven pregnant pygmy does (1 control doe and 6 inoculated with n caninum) were studie ...19957486395
identification and characterization of neospora caninum tachyzoite antigens useful for diagnosis of neosporosis.the purpose of the present study was to identify antigens of the protozoan neospora caninum that could be useful for the diagnosis of neosporosis in domestic animals. as revealed by immunoblotting, immune sera from a wide range of animal species exhibited a similar recognition pattern of four major and several minor n. caninum antigens. in contrast to preinoculation sera, all tested immune sera recognized nonreduced immunodominant 17-, 29-, 30-, and 27-kda antigens. a 46-kda protein which showed ...19947496948
genetic comparison of neospora caninum with toxoplasma and sarcocystis by random amplified polymorphic dna-polymerase chain determine the relationship of neospora caninum to protozoa classified in the family sarcocystidae of the phylum apicomplexa, the genomes of n. caninum, three toxoplasma gondii strains (rha, cep, tpr) and three sarcocystis species (s. tenella, s. muris, s. gigantea) that were thought to be closely related coccidia were compared by the random amplified polymorphic dna (rapd) polymerase chain reaction (pcr) technique. the genomic dnas were amplified by the use of seven 10-mer arbitrary sequence ...19957501633
a survey of the incidence of neospora caninum infection in aborted and stillborn bovine fetuses in england and wales.selected brains and fetal viscera from 190 aborted or stillborn bovine fetuses submitted to veterinary investigation centres in england and wales between august 1992 and january 1993 were examined histologically. non-suppurative inflammation of the brain and/or myocardium and placental cotyledons was identified by light microscopy in 20 (10.5 per cent). an immunocytochemical examination of fixed tissue sections using antisera against neospora caninum, toxoplasma gondii and sarcocystis species re ...19957571263
an enzyme-linked immunosorbent assay (elisa) for serological diagnosis of neospora sp. infection in cattle.a kinetic enzyme-linked immunosorbent assay (elisa) was developed and optimized for detection of antibodies to neospora sp. in cattle. sonicated tachyzoites of neospora sp. isolated from an aborted bovine fetus were used as antigen. variability in immunoblot patterns among positive sera, and the fact that all life stages of the parasites are unknown, justified use of a multiple-antigen elisa to allow for maximum sensitivity. immunoblot analysis revealed negligible cross-reactions between toxopla ...19957578451
sequence analysis and comparison of ribosomal dna from bovine neospora to similar coccidial parasites.the nuclear small subunit ribosomal rna (nss-rrna) gene sequence of neospora spp. isolated from cattle was analyzed and compared to the sequences from several closely related cyst-forming coccidial parasites. double-stranded dna sequencing of 5 bovine neospora spp. isolates (bpa1-4), 2 neospora caninum isolates (nc-1 and nc-3), and 3 toxoplasma gondii isolates (rh, gt-1, ct-1) were performed and compared to each other, as well as to other sequences available in genbank for the nc-1 isolate, sarc ...19957623193
[cyst-forming coccidia: toxoplasma, neospora, sarcocystis].the most important cyst-forming coccidian parasites in human and veterinary medicine belong the genera of toxoplasma, neospora and sarcocystis. toxoplasma gondii shows its clinical relevance in congenital infections and opportunistic infections in immunodeficient patients. in veterinary medicine the parasite is predominantly the cause of important economic loss in livestock production. neospora causes diseases resembling toxoplasmosis; neosporosis is one of the most important causes of bovine ab ...19957770750
examination of the activities of 43 chemotherapeutic agents against neospora caninum tachyzoites in cultured cells.neospora caninum causes serious disease in dogs, and it, or a similar parasite, is a major cause of abortion in cattle. little is known about the susceptibility of this protozoan to antimicrobial agents. we studied several antimicrobial agents to determine which classes might have activity against this parasite. we also determined whether activity of such agents was coccidiocidal or coccidiostatic. a 2-day of treatment, monoclonal antibody-based enzyme immunoassay and a 5-day of treatment, cell ...19947978638
detection of neospora caninum in tissue sections using a murine monoclonal antibody.a murine monoclonal antibody (mab 6g7), isotype igg2a, produced against tachyzoites of neospora caninum (isolate nc-1) reacted specifically with tachyzoites of n. caninum in an indirect immunofluorescent antibody test. mab 6g7 did not react with tachyzoites of toxoplasma gondii, sporozoites of isospora suis, eimeria bovis, or e. tenella, or merozoites of e. bovis in the indirect immunofluorescent antibody test. mab 6g7 reacted positively with both tachyzoites and bradyzoites of n. caninum in an ...19938286458
[neospora caninum as a cause of lameness symptoms in young dogs].at the age of three weeks, two labrador retriever puppies, out of a litter of nine, suffered from diarrhoea and muscular weakness. one puppy died within two days. the other was killed after a tetraparalysis had developed. two weeks later a third puppy was killed because of a paretic hind leg. at the age of five months another dog had to be euthanized because of progressive hind limb ataxia. pathological examination revealed polyradiculoneuritis, multifocal encephalomyelitis and polymyositis. in ...19938322363
neospora caninum in aborted twin calves.neospora caninum was detected in the brains of twin aborted calves by means of a specific immunohistochemical test on formalin-fixed, wax-embedded tissues. microscopic lesions associated with this infection included multifocal necrosis and gliosis in the brain accompanied by a mononuclear, perivascular inflammatory reaction and meningitis; and severe, diffuse epicarditis and subepicardial myocarditis characterised by infiltration of macrophages, lymphocytes and plasma cells. this report document ...19938410939
use of infected cultured cells to compare ultrastructural features of neospora caninum from dogs and toxoplasma gondii.the ultrastructure of tachyzoites of 3 isolates of neospora caninum from dogs was examined, using transmission electron microscopy of infected cultured cells. ultrastructure of the 3 isolates was similar. tachyzoites had a pellicle, 22 subpellicular microtubules, a conoid, anterior and posterior polar rings, 8 to 12 electron-dense rhoptries, numerous micronemes, a single vesicular nucleus, tubular mitochondria, golgi complexes, ribosomes, endoplasmic reticula, an inactive micropore, electron-den ...19938427452
in vitro isolation and characterization of a neospora sp. from aborted bovine foetuses.a neospora sp. was isolated from the brains of two aborted bovine foetuses and grown continuously in vitro in bovine cell cultures. a comparison of the antigenic reactivity of in vitro cultivated tachyzoites with polyclonal antisera to neospora caninum, hammondia hammondi or toxoplasma gondii revealed that the bovine protozoal isolates were similar to n. caninum and antigenically distinct from t. gondii. tachyzoites of both bovine isolates had similar ultrastructural features, including an apica ...19938488061
characterization of the first european isolate of neospora caninum (dubey, carpenter, speer, topper and uggla).neospora caninum is an apicomplexan, protozoan parasite, which causes severe disease in dogs and cattle. it has previously been isolated only in the united states. a 5-week-old boxer pup with a progressive hindlimb paresis was diagnosed as suffering from neosporosis on the basis of clinical signs and the presence of anti-neospora antibodies in it, 2 litter-mates and its dam. despite treatment with sulphonamides, the pup was euthanased 3 days later. the diagnosis of neosporosis was confirmed by i ...19958559588
the prevalence of neosporosis in aborted bovine foetuses submitted to the allerton regional veterinary laboratory.combined histological examination and avidin-biotin immunohistochemical staining of formalin-fixed brain and myocardium from aborted bovine foetuses presented to the allerton regional veterinary laboratory were utilized for the diagnosis of bovine neosporosis. two out of 144 cases were diagnosed positive for neosporosis, indicating a low prevalence of infection and confirming neospora caninum to be a cause of sporadic abortion in the population surveyed.19958628575
serologic responses of cattle and other animals infected with neospora examine cross-reactivity among neospora caninum and closely-related apicomplexans.19968669764
the ultrastructure of bradyzoites and tissue cysts of neospora caninum in dogs: absence of distinguishing morphological features between parasites of canine and bovine origin.the fine structure of bradyzoites and tissue cysts of neospora caninum in dogs is described. original findings consisting of branching, septa-like structures of the cyst wall and peculiar, lipid-like inclusions in the cyst ground substance were described. tubulo-vesicular structures in the cyst ground substance and distinctive, vesicular organelles containing short, membranous segments and smaller vesicles, described in neospora parasites of bovine origin and previously undescribed in parasites ...19968686169
evaluation of two neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. the purpose of this study was to identify n. caninum cdna clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. two n. caninum tachyzoite cdna clones expressing antigens that we ...19968705668
serological diagnosis of bovine neosporosis by neospora caninum monoclonal antibody-based competitive inhibition enzyme-linked immunosorbent assay.neospora caninum, a protozoan parasite closely related to toxoplasma gondii, causes abortion and congenital infection in cattle. to investigate specific methods of antemortem diagnosis, the antibody responses of infected cows were evaluated by immunoblot assay and competitive inhibition enzyme-linked immunosorbent assay (ci-elisa) by using a monoclonal antibody (mab), mab 4a4-2, against n. caninum tachyzoites. mab 4a4-2 bound diffusely to the exterior surface of n. caninum tachyzoites and recogn ...19968735092
[detection of antibodies against neospora caninum in cows on hessian farms with abortion and fertility problems].to address the question whether n. caninum-infections occur in german cattle, 388 sera from dairy farms with abortions and fecundity problems in north hesse were tested for antibodies to n. caninum and seropositive farms epidemiologically analyzed. 16 sera (4.1%) with titres of > or= 1:400 from a total of 10 farms (45.5% of the farms) were considered neospora-positive. there was a conspicuous clustering of seropositive and indifferent animals in three farms. a history of abortion could not be es ...19968766905
detection of neospora caninum dna by the polymerase chain reaction.neospora caninum is a cyst-forming coccidian parasite which is now recognised as a major cause of abortion and neonatal mortality in cattle and other livestock. this study describes the primary dna structure of the transcribed spacer region of the rdna of n. caninum. of importance is that the sequence data generated have been used to develop a species-specific pcr test for n. caninum dna, which will prove valuable in epidemiology studies on neosporosis.19968773521
congenital neospora caninum infection in dairy cattle and associated calfhood mortality.a prospective cohort study was undertaken on two central california dairies, a and b, to estimate prevalence of congenital infection with neospora caninum, to characterize temporal variation in prevalence, to determine if occurrence of congenital infection was associated with specific dam and calf attributes, and to estimate the effect of congenital infection on calfhood mortality. of the 405 calves enrolled over a period of 2 1/2 y on dairy a and dairy b, 30.6% (85/278) and 53.5% (68/127), resp ...19968785719
rapid and sensitive identification of neospora caninum by in vitro amplification of the internal transcribed spacer 1.neospora caninum and n. caninum-like organisms are cyst-forming coccidian parasites known to cause neuromuscular disorders in dogs and abortion in cattle. in this article we report on the use of the polymerase chain reaction (pcr) for the detection of dna from n. caninum. after determining the sequence of the internal transcribed spacer 1 (its1) of n. caninum and toxoplasma gondii, and part of the sequences for 4 species of sarcocystis, we designed a primer set for the amplification of a 279-bas ...19968851857
adhesion and invasion of bovine endothelial cells by neospora caninum.neospora caninum is a recently identified coccidian parasite which was, until 1988, misdiagnosed as toxoplasma gondii. it causes paralysis and death in dogs and neonatal mortality and abortion in cattle, sheep, goats and horses. the life-cycle of neospora has not yet been elucidated. the only two stages identified so far are tissue cysts and intracellularly dividing tachyzoites. very little is known about the biology of this species. we have set up a fluorescence-based adhesion/invasion assay in ...19968851858
discrimination of neospora caninum from toxoplasma gondii and other apicomplexan parasites by hybridization and pcr.neospora caninum is a protozoan parasite which causes neurological problems in dogs and abortion in cattle. as n. caninum is difficult to distinguish morphologically from toxoplasma gondii, we developed a molecular tool capable of discriminating between the two parasites. genomic dna was isolated from in vitro cultured n. caninum tachyzoites and cloned into a plasmid vector. resulting colonies were subsequently screened by differential hybridization using n. caninum and t. gondii dna. two clones ...19968865177
culling associated with neospora caninum infection in dairy estimate the extent to which cows infected with neospora caninum were culled, compared with noninfected cows, and to identify differences in reasons for culling between infected and noninfected cows.19968915429
experimental neosporosis in pregnant ewes and their offspring.six groups of six pregnant ewes each were inoculated with 170,000 or 1,700,000 tachyzoites of neospora caninum on gestation day 65, 90, or 120. all ewes seroconverted, and none showed signs of illness other than abortion. regardless of the inoculum dose, all ewes inoculated on gestation day 65 aborted; ewes inoculated on gestation day 90 aborted, gave birth to weak lambs, or gave birth to clinically normal lambs; and all ewes inoculated on gestation day 120 gave birth to clinically normal lambs. ...19968952023
development of a polymerase chain reaction assay for the diagnosis of neosporosis using the neospora caninum 14-3-3 gene.neospora caninum is a recently described apicomplexan parasite which causes neuromuscular disease in dogs, and abortion and neonatal morbidity in cattle, sheep and horses. morphological similarities and serological cross-reactivity between n. caninum and the closely related parasite toxoplasma gondii, have resulted in the frequent misdiagnosis of neosporosis as toxoplasmosis. this report describes the isolation and characterization of an n. caninum cdna clone encoding a 14-3-3 protein homologue. ...19968992315
a review of neospora caninum and neosporosis.neospora caninum is a recently recognized protozoan parasite of animals, which until 1988 was misidentified as toxoplasma gondii. its life cycle is unknown. transplacental transmission is the only recognized mode of transmission. it has a wide host range, but its zoonotic potential is unknown. neosporosis is a major cause of abortion in cattle in many countries. it is also an important cause of neuromuscular paralysis in dogs. this paper reviews information on parasite structure, life cycle, bio ...19969011014
neospora caninum: role for immune cytokines in host immunity.neospora caninum is a coccidial protozoan parasite that infects a large range of mammals including dogs, cats, mice, and cattle. morphologically, n. caninum appears indistinguishable from toxoplasma gondii, although they are genetically distinct. to date there have been no reported cases of this infection in humans, although nonhuman primates may be susceptible to infection. inbred a/j mice develop no clinical and little histologic evidence of infection in spite of a high-dose inoculum of n. can ...19979024199
effect of neospora caninum infection on milk production in first-lactation dairy determine whether cows seropositive to neospora caninum produced less milk during their first lactation than seronegative cows.19979054999
neospora caninum antibodies in cows during pregnancy as a predictor of congenital infection and abortion.a cohort study was undertaken on a dairy experiencing endemic neospora caninum abortions, to characterize dam serologic variations during pregnancy, and to determine if dam n. caninum antibody levels during gestation predicted congenital infection or abortion. blood samples were collected monthly during pregnancies of 254 cows and precolostrally from 87 of their calves. antibody levels, as measured by an enzyme-linked immunosorbent assay, indicated 60.6% of cows were seropositive at some time du ...19979057701
efficacy of decoquinate against neospora caninum tachyzoites in cell cultures.neospora caninum is a major cause of abortion in dairy cattle in the united states and other countries. abortions and neonatal mortality also occur in other ruminant species. decoquinate is an anticoccidial that is approved for use in cattle and goats in the united states. we studied the efficacy of decoquinate against tachyzoites of n. caninum in a 5-day of treatment, cell culture flask lesion-based assay. decoquinate killed tachyzoites at concentrations of 0.1 and 0.01 microgram ml-1. decoquin ...19979066049
an indirect enzyme-linked immunoassay (elisa) for demonstration of antibodies to neospora caninum in serum and milk of indirect enzyme-linked immunosorbent assay (elisa) for detection of antibodies to neospora caninum in serum from cattle is described. extracted tachyzoite proteins incorporated into immunostimulating complexes (iscoms) were used as coating antigen and a mouse monoclonal antibody to bovine immunoglobulin g1 as conjugate. western blot analysis of the iscom preparation revealed a restricted number of antigens compared with whole parasite homogenates. when probed with a serum from an experimental ...19979066070
herd-based diagnosis of neospora caninum-induced endemic and epidemic abortion in cows and evidence for congenital and postnatal transmission.aborting and nonaborting cows and their dams or daughters were studied to determine if herd abortion problems were associated with the presence of neospora caninum antibodies and to estimate when aborting cows may have acquired the infection. cows were sampled from 20 herds that had experienced an abortion epidemic presumed to have been caused by n. caninum and from 2 herds experiencing endemic abortion. seroprevalence for 14 herds experiencing an epidemic ranged from 7% to 70%, as estimated by ...19979087924
characterization of a swedish bovine isolate of neospora caninum.the brain of a stillborn calf, seropositive to neospora caninum and born to a seropositive cow, was homogenized and cultured on vero cells, where growth of neospora-like tachyzoites was detected after 8 weeks. the ultrastructural features of the new isolate (nc-sweb1) corresponded to those of previously published neospora isolates. in indirect immunofluorescence tests, antigens on nc-sweb1 tachyzoites were recognized by antibodies raised to a canine n. caninum isolate (nc-1) but not by antibodie ...19979089715
phylogenetic relationships among eight eimeria species infecting domestic fowl inferred using complete small subunit ribosomal dna sequences.complete 18s ribosomal rna gene sequences were determined for 8 eimeria species of chickens and for eimeria bovis of cattle. sequences were aligned with each other and with sequences from 2 sarcocystis spp., toxoplasma gondii, neospora caninum, and 4 cryptosporidium spp. aligned sequences were analyzed by maximum parsimony to infer evolutionary relationships among the avian eimeria species. eimecia bovis was found to be the sister taxon to the 8 eimeria species infecting chickens. within the avi ...19979105308
novel elisa for detection of neospora-specific antibodies in enzyme-linked immunosorbent assay (elisa) to detect antibodies to neospora species in cattle was developed. whole formalin-fixed neospora caninum (nc-liverpool) tachyzoites were used as antigen and a monoclonal antibody to bovine immunoglobulin light chain and an anti-mouse horseradish peroxidase conjugate were used to reveal bound antibody. a panel of 46 sera, negative by the immunofluorescent antibody test (ifat), were used in the elisa at a serum dilution of 1:500 to calculate the negative ...19979106971
serological response over time to recombinant neospora caninum antigens in cattle after a neosporosis-induced abortion.recombinant neospora caninum tachyzoite antigens were evaluated in an enzyme-linked immunosorbent assay (elisa) for recognition by serum antibodies (ab) from neospora-infected cattle. serum samples were obtained every 2 to 3 weeks for 8 to 15 months from 10 cows with histories of neospora-associated abortion. serum samples were also obtained from offspring of these animals and from a large number of cows that had aborted a fetus, due to infection by neospora or other organisms, at various times ...19979144362
serological diagnosis of bovine fetal evaluate the efficacy of fetal serology in the diagnosis of bovine neosporosis abortion, sera from 48 fetuses with immunohistochemically confirmed neosporosis and 42 fetuses without demonstrable neospora caninum were examined in the indirect fluorescent antibody test (ifat). fetal sera were diluted 2-fold starting at a 1:25 dilution. antibodies to n. caninum were detected in 31 of 48 (65%) fetuses with confirmed neosporosis; the ifat antibody titers were 1:25 (5 fetuses), 1:50 (17 fetuses), 1 ...19979194848
bovine fetal neosporosis: a comparison of epizootic and sporadic abortion cases and different age classes with regard to lesion severity and immunohistochemical identification of organisms in brain, heart, and liver.eighty bovine fetuses with confirmed neosporosis were used to score lesion severity and presence of parasites in brain, heart, and liver. a comparison was made between epizootic and sporadic abortion cases. the possible influence of fetal age was also investigated. histologic lesions of multifocal encephalitis, myocarditis, and periportal hepatitis with or without focal hepatocellular necrosis were almost always observed. neospora caninum tachyzoites were identified immunohistochemically in 85% ...19979211238
experimental infection of non-pregnant and pregnant sheep with neospora an initial experiment, 21 sheep in groups of five or six were inoculated subcutaneously (sc) with 10(8), 10(6) or 10(4) neospora caninum tachyzoites (liverpool isolate), or with control inoculum, and monitored for clinical signs and for "seroconversion". animals given the two higher doses showed febrile responses and all three groups inoculated with the parasite showed seroconversion. in a second experiment, 12 pregnant sheep were each inoculated sc at 90 days' gestation with 10(6) tachyzoite ...19979263840
[neospora caninum causes abortions in a cattle herd in north rhine westphalia].in a cattle herd in north rhine-westphalia a series of eight abortions occurred between 15th august and 14th october, 1996. four of the aborted fetuses were histopathologically, virologically, bacteriologically and parasitologically examined. a multifocal necrotising encephalitis was observed in two fetuses. in addition, the liver of two fetuses and the placenta of one fetus contained infected foci. in three fetuses protozoan stages were detected which were identified as n. caninum by immunohist ...19979303853
effect of congenitally acquired neospora caninum infection on risk of abortion and subsequent abortions in dairy estimate the extent to which abortion risk in dairy cattle during subsequent pregnancies was associated with congenitally-acquired neospora caninum infection and previous abortions.19979401685
antibody responses of cows during an outbreak of neosporosis evaluated by indirect fluorescent antibody test and different enzyme-linked immunosorbent assays.serum samples from 70 (33 aborting and 37 non-aborting) dairy cows from a herd in california were analyzed for neospora caninum antibodies in different laboratories by various serologic assays including enzyme-linked immunosorbent assay (elisa) with recombinant antigens (nc4.1 and nc14.1), kinetic elisa, whole tachyzoite lysate elisa, immunostimulating complex (iscom) elisa, antigen capture competitive inhibition elisa, and by the indirect fluorescent antibody test. eighteen percent of pregnant ...19979406780
diagnostic studies of abortion in danish dairy herds.diagnostic findings in 218 aborted bovine foetuses are reported. the materials were examined in a matched case-control study of 69 danish dairy herds with a sudden increase in the number of abortions and a corresponding 69 control herds. foetuses aborted during the subsequent 6-month period were examined to identify the cause of abortion if possible. a total of 186 specimens were submitted from case herds and 32 from control herds. a likely cause of abortion was diagnosed in 73 foetuses. the mos ...19979465775
neosporosis and bovine abortion in scotland.serum samples were collected over a two-year period from aborting cows and their fetuses from throughout scotland; 465 maternal sera were examined using an immunofluorescent antibody test for igg antibody to neospora caninum and 547 fetal sera were examined for igm and igg antibody to the parasite; 355 of the maternal sera were paired with their respective fetal samples. the maternal titres ranged from 1/8 to 1/16,384, with 59 per cent (275) having titres of 1/128 or 1/256. of the 547 fetal sera ...19979466384
direct agglutination test for serologic diagnosis of neospora caninum infection.a direct agglutination test was evaluated for the detection and quantitation of igg antibodies to neospora caninum in both experimental and natural infections in various animal species. as compared with results obtained by the indirect fluorescent antibody test, the direct agglutination test appeared reliable for the serologic diagnosis of neosporosis in a variety of animal species. the direct agglutination test should provide easily available and inexpensive tools for serologic testing for anti ...19989491426
neosporosis-associated bovine abortion in pennsylvania.neospora caninum was found in fetal tissues of 34 of 688 cases of bovine abortion submitted to the pennsylvania animal diagnostic laboratory system during the period from may 1994 to november 1996. the aborted fetuses ranged in gestational age from 3 to 8 months. microscopic lesions consisted primarily of encephalitis and myocarditis. a labeled (strept) avidin-biotin staining procedure using anti-n. caninum polyclonal rabbit serum revealed n. caninum organisms within the fetal brain (27 of 27), ...19989561715
oral inoculation of cats with tissue cysts of neospora test the hypothesis that cats are definitive hosts of neospora caninum.19989563628
prevalence of antibodies to neospora caninum and toxoplasma gondii in cattle and water buffaloes in southern vietnam.serum samples from 200 dairy cattle and 200 beef water buffaloes were collected in southern vietnam during may to september 1995. the sera were analysed for antibodies to neospora caninum by an enzyme-linked immunosorbent assay and the indirect fluorescent antibody test, and for antibodies to toxoplasma gondii by the direct agglutination test. significant levels of n. caninum antibodies were detected in 5.5% of the cattle sera and in 1.5% of the water buffalo sera. 10.5% of the cattle sera and 3 ...19989566094
characterization of neospora caninum iscom antigens using monoclonal antibodies.neospora caninum is a cyst-forming coccidian parasite which in cattle can cause abortion and birth of feeble calves. for the serological diagnosis of neosporosis, antibodies directed to the parasite can be demonstrated by elisa, utilizing n. caninum proteins incorporated into iscoms (immunostimulating complexes) as antigen. electrophoretic and immunoblotting studies had earlier revealed that n. caninum iscoms contained a restricted number of proteins compared with soluble parasite extracts, but ...19989572050
hydrocephalus associated with neospora caninum infection in an aborted bovine fetus.this paper describes neospora caninum-associated hydrocephalus in an aborted hereford bovine fetus of 7 months' gestational age. numerous tachyzoites were observed in areas of the cerebrum with lesions of non-suppurative necrotizing encephalitis.19989573514
molecular and immunodiagnostic investigations on bovine neosporosis in switzerland.neospora caninum has gained considerable attention through its role in the aetiology of bovine abortion. due to its close phylogenetic relationship with toxoplasma gondii, respective unequivocal differential diagnosis deserves special consideration. in order to evaluate the diagnostic performance of molecular and immunodiagnostic techniques and to provide insights into the epidemiological significance of bovine neosporosis in switzerland, we conducted a study on 83 cases of bovine abortion: of t ...19989602392
a modified agglutination test for neospora caninum: development, optimization, and comparison to the indirect fluorescent-antibody test and enzyme-linked immunosorbent assay.current serologic tests used to detect antibodies to neospora caninum require species-specific secondary antibodies, limiting the number of species that can be tested. in order to examine a wide variety of animal species that may be infected with n. caninum, a modified direct agglutination test (n-mat) similar to the toxoplasma gondii modified direct agglutination test (t-mat) was developed. this test measures the direct agglutination of parasites by n. caninum-specific antibodies in serum, thus ...19989665950
protozoan infections (toxoplasma gondii, neospora caninum and sarcocystis spp.) in sheep and goats: recent advances.the protozoan parasite toxoplasma gondii is a serious cause of fetal mortality in sheep and goats. oocysts, the parasite stage responsible for initiating infection, are produced following a primary infection in cats. a primary infection in pregnant sheep and goats can establish a placental and fetal infection which may result in fetal death and resorption, abortion or stillbirth. diagnosis is aided by the clinical picture, the presence of characteristic small white necrotic foci in placental cot ...19989689743
detection of antibodies to neospora caninum in bovine postabortion blood samples from order to obtain data on the occurrence of the protozoan parasite neospora caninum as a potential factor in the aetiology of reproduction problems in cattle, 97 postabortion sera were examined by iscom elisa and ifat for the presence of antibodies in n. caninum. the results showed 10% and 9% seropositivity by the elisa and ifat, respectively. in 2 of the 10 seropositive cases no other fetopathogenic agents (such as chlamydia sp., leptospira spp. or bovine viral diarrhoea virus) were detected. ...19989713144
serological survey of antibody to neospora caninum in japanese dogs.prevalence of antibody to neospora caninum (nc) in japanese dogs were examined. the antibody was positive in 15 of 48 dogs (31.3%) reared in the dairy farms that had case of the abortions due to nc infection or had the cattle seropositive to nc, whereas the prevalence was 7.1% (14 of 198 dogs) among the dogs kept in urban areas. in one dog breeder, all 17 shetland sheepdogs older than 7 months were seropositive, and one pup was diagnosed as neosporosis 2 months before the first serological exami ...19989713815
western blot analysis of the igg responses of ruminants infected with neospora caninum and with toxoplasma gondii.the igg antibody responses of sheep, goats and cattle inoculated subcutaneously with live neospora caninum tachyzoites of the nc1 isolate were analysed by western blotting. antibodies were detected against a wide range of nc1 tachyzoite antigens (6.5 to 80 kda). the dominant antibody responses were directed against proteins at 36.5-38, 45.5-48.5, 52-53.5, 58, 58.5, 59.5, 60.5, 62, 63.5, 64, 66.5, 67, 67.5, 68.5 and 69.5 kda, with sera from all three species. these sera were also used to probe bl ...19989717126
identification of neospora antigens recognized by cd4+ t cells and immune sera from experimentally infected cattle.neospora caninum is recognized as a major cause of infectious abortion in cattle. very little is known about immunity to neospora. cell mediated responses have previously been shown to be important in the development of protective immunity to the closely related parasite toxoplasma gondii, and may therefore be an important component in the immune response to neospora. in this paper we report that a group of low molecular weight nci strain tachyzoite antigens (< or = 30 kda) separated by sds page ...19989717191
serodiagnosis of neosporosis in individual cows and dairy herds: a comparative study of three enzyme-linked immunosorbent assays.the performance of three enzyme-linked immunosorbent assays (elisa) for detection of antibodies to neospora caninum in bovine sera was evaluated by using various categories of sera. two commercial elisa methods, one based on chemically fixed intact tachyzoites and one based on a sonicate lysate of whole tachyzoites, were compared with an in-house elisa based on a detergent lysate of whole tachyzoites. a brief description of the development of the latter elisa is also given. there was good agreem ...19989729540
determination of the association between neospora caninum infection and reproductive performance in beef determine seroprevalence of neospora caninum infection in beef herds and the association between serologic status and rate of abortion, stillbirth, calf mortality, and reproductive failure.19989731264
neospora caninum infection in a bernese cattle dog from italy.a cutaneous nodule associated with neospora caninum infection was diagnosed in a 5-year-old male bernese cattle dog from italy. the ulcerative lesion was 2-3 cm wide located in the skin of the tarsal region. haematological values were normal and the dog did not show any neurological abnormalities. the dermal lesion consisted of a diffuse necrotic dermatitis with a dense infiltrate of mostly neutrophils and macrophages, surrounded by a fibrous wall. histological sections revealed numerous tachyzo ...19989735914
neospora caninum identification in an aborted bovine fetus in spain.neospora caninum tachyzoites were identified in areas of the cerebrum with lesions of non-suppurative encephalitis in an aborted bovine fetus in spain.19989746288
oral neospora caninum inoculation of neonatal calves.four calves born to cows seronegative for neospora caninum were dosed orally within 6 h after birth with tachyzoites of the bovine n. caninum nc-sweb1 isolate added to colostrum. two of the calves were dosed via stomach tube and two by feeding bottle. the latter two calves showed transient fever and passed blood-stained diarrhoea 1-2 weeks after inoculation. from 5 weeks after inoculation they developed a significant antibody response which remained high until the calves were euthanised and necr ...19989770634
a multiple antigen elisa to detect neospora-specific antibodies in bovine sera, bovine foetal fluids, ovine and caprine sera.neospora caninum is a cyst-forming coccidian parasite recently identified as a cause of abortion in cattle. the epidemiology of neosporosis is poorly understood, partly because accurate diagnosis of infection is difficult. in this paper we describe the development of a multiple antigen-based enzyme-linked immunosorbent assay (elisa) to detect antibodies to n. caninum in sera from cattle, sheep and goats as well as from bovine foetal fluids. a water-soluble fraction (wsf) of sonicated nc-1 strain ...19989777723
the p29 and p35 immunodominant antigens of neospora caninum tachyzoites are homologous to the family of surface antigens of toxoplasma gondii.neospora caninum is an apicomplexan parasite that is closely related to toxoplasma gondii and has been found to be associated with neurological disorders in dogs and congenital infections and abortions in cattle. we have identified two surface proteins of 29 and 35 kda (designated ncp29 and ncp35, respectively) from n. caninum tachyzoites that are the predominant antigens recognized by antisera from neospora-infected animals. monoclonal antibodies against ncp29 and ncp35 were used to analyze sev ...19989784539
description of a new neospora species (protozoa: apicomplexa: sarcocystidae).neospora hughesi n. sp. was isolated from the central nervous system tissue of an adult equine (equus caballus) from california. the tachyzoites are crescent-shaped, approximately 2 x 5 microm (1.8-3.0 x 4.0-7.0 microm), with characteristic apical complex structures consisting of an anterior polar ring, conoid, numerous rhoptries filled with a uniform electron-dense material, and 22 microtubules extending posteriorly from the polar ring. comparison of n. hughesi to canine and bovine neospora can ...19989794642
seroepidemiologic study of neospora caninum in dairy identify risk factors associated with neospora caninum infection in dairy herds in québec and to estimate seroprevalence in case and control herds.19989838960
the efficiency of vertical transmission of neospora caninum in dairy cattle analysed by serological techniques.the association of neospora caninum infections with cattle families was examined in a dairy cattle herd with sporadic abortions using three different serological tests. cattle seropositive for n. caninum clustered in six families, three of which encountered abortions. in absence of age-related differences in the n. caninum seroprevalence, the family association of n. caninum infection indicated that congenital infection represented the predominant route of transmission in this herd. fourteen (93 ...19989870361
the major 36 kda neospora caninum tachyzoite surface protein is closely related to the major toxoplasma gondii surface antigen.the tachyzoites and the tissue cysts containing bradyzoites of neospora caninum and toxoplasma gondii, respectively, are difficult to distinguish morphologically. specific antigens have been identified in t. gondii tachyzoites and bradyzoites, some of which are stage-specifically expressed, and different functions have been attributed to some of them. a tachyzoite stage-specifically expressed surface protein is the major surface antigen 1 (sag1) which has been shown to be involved in host cell a ...19989879890
an igg avidity elisa to discriminate between recent and chronic neospora caninum infection.the avidity of igg antibodies directed to neospora caninum was measured using an igg avidity enzyme-linked immunosorbent assay (elisa) employing n. caninum proteins incorporated into immunostimulating complexes as antigen. in this elisa, low-affinity antibodies were eluted by adding an incubation step with urea after the serum incubation. the antibody titers obtained with and without incubation with urea were then used to calculate the igg avidity values. analysis of sequential sera collected fr ...19999925210
cellular immune responses in cattle experimentally infected with neospora caninum.neospora caninum has recently been identified as an important cause of infectious abortion in cattle. the parasite is closely related to toxoplasma gondii, but the two species are antigenically distinct. to examine cell proliferative responses and the induction of ifn-gamma in experimentally infected cattle, four 2-4 months old calves were subcutaneously inoculated with n. caninum tachyzoites. peripheral blood mononuclear cells were collected regularly and stimulated in vitro with a crude lysate ...19989988308
[molecular and immunodiagnostic studies of bovine neosporosis in switzerland].cyst-forming coccidia may cause significant losses in livestock, primarily due to abortion, loss of young animals and neuromuscular diseases. rather recently, neospora caninum has been recognized as one of the major protozoal abortion-inducing parasites in cattle. the present study addressed the performance of different diagnostic tools (in vitro-cultivation; histology; immunohistochemistry; serology; pcr) suitable for the direct or indirect detection of n. caninum. by pcr, neospora-dna was dete ...199910028228
sequence and pcr-rflp analysis of the internal transcribed spacers of the rdna repeat unit in isolates of cryptosporidium from different hosts.the cryptosporidium its1, 5.8s and its2 rdna regions from a number of cryptosporidium isolates from different hosts and geographical areas were cloned and sequenced in order to investigate the extent of sequence heterogeneity between human and cattle-derived isolates from different geographical locations and also between isolates of cryptosporidium from different hosts such as cats, pigs, mice and a koala. calf-derived isolates from different continents were virtually identical as were human-der ...199910070661
bovine abortion associated with neospora caninum in northern spain.during 1996, aborted bovine fetuses from dairy herds in norther spain were examined by histopathological, immunohistochemical and serological methods for evidence of infection by neospora caninum. microscopical brain changes consistent with those of neosporosis were detected in 36 of 81 fetuses and specific antibodies (ifat titres > or = 1/16) in 32 of 63. eight fetuses with neurological lesions were seronegative, and eight without lesions were seropositive. in 25 of 34 fetal brains with lesions ...199910074662
the host-parasite relationship in neosporosis.neospora caninum is an apicomplexan parasite which invades many different cell types and tissues. it causes neosporosis, namely stillbirth and abortion in cattle and neuromuscular disease in dogs, and has been found in several other animal species. n. caninum is closely related to toxoplasma gondii, and controversial opinions exist with respect to its phylogenetical status. initially, two stages of n. caninum had been identified, namely asexually proliferating tachyzoites and bradyzoites. the se ...199910214690
neospora caninum infection and repeated abortions in determine whether neospora caninum, a parasite known to cause repeated abortions and stillbirths in cattle, also causes repeated abortions in humans, we retrospectively examined serum samples of 76 women with a history of abortions for evidence of n. caninum infection. no antibodies to the parasite were detected by enzyme-linked immunosorbent assay, immunofluorescence assay, or western blot.199910221883
susceptibility of b-cell deficient c57bl/6 (micromt) mice to neospora caninum infection.neospora caninum is a coccidian parasite of veterinary importance by causing abortion or stillbirth in cattle among other problems in diverse animal species. we assessed an experimental murine model for its suitability to study the immune response to n. caninum infection. thus, wild-type (wt) c57bl/6 mice and b-cell (and consequently antibody)-deficient micromt mice were infected with n. caninum tachyzoites and sacrificed at days 10, 24 and 29-44 post infection (dpi). various organs were collect ...199910320620
comparison of the biological characteristics of two isolates of neospora caninum.this study compared the biological and genetic properties of a bovine (nc-sweb1) and a canine (nc-liverpool) isolate of neospora caninum. a mouse model for cns infection demonstrated marked differences in pathogenicity between the isolates. nc-liverpool induced severe clinical signs of neosporosis in 57/58 mice including discoordinated movement, hindlimb paralysis and coat ruffling with severe weight loss. in contrast nc-sweb1 induced similar but less severe symptoms in a much smaller proportion ...199910340326
repetitive abortion in neospora-infected ewes.pregnant ewes inoculated with cultured neospora caninum tachyzoites in 1995, 1996, or 1995 and 1996 aborted or delivered weak or clinically normal lambs in 1996. nine of 11 ewes in the study had previously produced infected lambs or fetuses after being experimentally infected in 1995. fetuses and lambs produced in 1996 showed histologic lesions and zoites indicative of neospora. serologic responses and production of infected fetuses/lambs indicated systemic neosporosis in the ewes during gestati ...199910348105
neospora caninum: identification of 19-, 38-, and 40-kda surface antigens and a 33-kda dense granule antigen using monoclonal antibodies.neospora caninum, a coccidian parasite closely related to toxoplasma gondii, can infect a broad host range and is regarded as an important cause of bovine abortion worldwide. in the present study, four antigens of n. caninum were partially characterized using monoclonal antibodies. immunofluorescence of viable tachyzoites as well as the immunoprecipitation of antigens extracted from tachyzoites previously labeled by surface biotinylation revealed that three of these antigens with apparent molecu ...199910366536
herd-specific and age-specific seroprevalence of neospora caninum in 14 british dairy herds.all the cattle in 14 dairy herds in england were tested for neospora caninum-specific antibodies with a commercial elisa. three of the herds had had sporadic abortions, eight had had endemic abortions and three had had epidemic abortions associated with n caninum before the study. of 4295 cattle tested, 17.1 per cent were seropositive and the herd-specific prevalence ranged from 7.3 per cent to 44.8 per cent. no significant effect of either herd size (p = 0.988), endemic (p = 0.869) or epidemic ...199910371011
[diagnosis and epidemiology of neospora caninum-associated abortions in cattle].neospora caninum, a recently discovered protozoan parasite closely related to toxoplasma gondii, has world-wide been recognized as an important cause of bovine abortion. n. caninum possesses a wide host range. the dog can be a definitive host for n. caninum. in cattle, the infection is transmitted transplacentally with high efficiency, while the majority of congenitally infected calves is clinically normal at birth and thereafter. whether horizontal transmission occurs in cattle and whether this ...199910384703
pathological and immunological findings of athymic nude and congenic wild type balb/c mice experimentally infected with neospora caninum.neospora is a cyst-forming coccidian parasite that causes abortions and neuromuscular disorders in a wide variety of mammals. japanese bovine isolate jpa1 was inoculated intraperitoneally into balb/c nu/ nu (athymic nude) and balb/c (congenic wild type) female mice to examine the distribution of parasites and resistance mechanisms to neospora infection. all the athymic nude mice died within 28 days after intraperitoneal injection of 2 x 10(5) jpa1 tachyzoites, whereas all the congenic wild type ...199910421099
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