demonstration of synergistic effects of sulfonamides and dihydrofolate reductase/thymidylate synthase inhibitors against neospora caninum tachyzoites in cultured cells, and characterization of mutants resistant to examine the efficacies of combinations of 7 sulfonamides and 5 dihydrofolate reductase/thymidylate synthase (dhfr/ts) inhibitors against tachyzoites of neospora caninum in cultured cells. mutant tachyzoites that were resistant to pyrimethamine were produced and examined for resistance to other dhfr/ts inhibitors. design and procedures: after 5 days of treatment, a cell culture flask lesion-based assay was used to determine efficacies of combinations of sulfonamides and dhfr/ts inhibitors agai ...19968720241
clinical aspects of 27 cases of neosporosis in dogs.twenty-seven cases of neosporosis in european dogs are described. the disease was confirmed by immunohistochemistry, electron microscopy, or a favourable response to treatment in the dogs with appropriate clinical signs, and by the presence of antibodies to neospora caninum but not to toxoplasma gondii. the affected dogs were two days to seven years old, and of 13 different breeds. both sexes were affected and in most cases littermates remained normal. twenty-one cases had an initial hindlimb pa ...19968931299
systemic infection with an unidentified toxoplasma-like protozoan in a neonatal lichtenstein's hartebeest (sigmoceros lichtensteinii).an unidentified toxoplasma gondii-like disseminated infection was found in tissues of a 2-day-old hartebeest. protozoal tachyzoites were about 3.5 x 1.7 microns, had electron-dense rhoptries, and divided by endodyogeny. the organism did not stain with polyclonol antibodies to t. gondii, neospora caninum, or sarcocystis cruzi.19968636866
stillbirth/perinatal weak calf syndrome: serological examination for evidence of neospora caninum infection. 19968953695
sudden death associated with neospora caninum myocarditis in a dog.a 10-month-old female bull mastiff dog was found dead without reports of any prior clinical signs of disease. necropsy revealed lesions in the myocardium, which consisted of a large 2 x 2.3-cm brownish area and a few small similar lesions. microscopically, neospora caninum tachyzoites were found in the lesions characterized by necrosis and interstitial myocarditis. diagnosis was confirmed by immunohistochemical staining with anti-n caninum serum.19938226237
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
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
prevalence of neospora caninum and toxoplasma gondii antibodies in coyotes (canis latrans) and experimental infections of coyotes with neospora caninum.antibodies to neospora caninum were detected in 5 (10%) of 52 coyotes from texas. antibodies to toxoplasma gondii were detected in 32 (62%) of 52 samples from these same coyotes. four (80%) of the 5 coyotes that were seropositive for n. caninum also had antibodies to t. gondii. nineteen (37%) of the coyotes did not have antibodies to either parasite. three coyote pups were inoculated with the brains from mice infected with 3 strains of n. caninum originally isolated from dogs. none of the pups d ...19968691381
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
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
identification of a major surface protein on neospora caninum tachyzoites.neospora caninum is a recently identified coccidian parasite that is closely related to toxoplasma gondii. molecules associated with the surface of n. caninum tachyzoites are likely to be involved in the process of adhesion and invasion of host cells. they probably also participate in the interaction of the parasite with the immune system, and they could play an important role in the pathogenesis of the parasite. to identify such surface molecules, we performed subcellular fractionation studies ...19968832729
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
fetal loss in balb/c mice infected with neospora caninum.the suitability of mice as a model for reproductive loss due to neospora caninum infection was investigated. groups of mice were infected with 2 x 10(6) n. caninum before pregnancy (10 days) and during pregnancy (days 5 and 10 of gestation). in mice infected before and during early pregnancy, fetal loss was evaluated throughout gestation, and pregnancy loss was evaluated by enumeration of fetal resorptions and total fetuses. in mice infected before pregnancy, no difference was present in resorpt ...19968691368
subcellular localization and functional characterization of nc-p43, a major neospora caninum tachyzoite surface protein.neospora caninum is a recently identified coccidian parasite which shares many features with, but is clearly distinct from, toxoplasma gondii. n. caninum tachyzoites infect a wide range of mammalian cells both in vivo and in vitro. the mechanisms by which infection is achieved are largely unknown. recent evidence has suggested that a receptor-ligand system in which one or several host cell receptors bind to one or several parasite ligands is involved. parasite cell surface-associated molecules s ...19968926100
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
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
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
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
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
separation and cryopreservation of neospora caninum tissue cysts from murine brain.a protocol was developed for the separation, concentration enumeration, and cryopreservation of neospora caninum tissue cysts from mouse brains. brains from chronically infected mice were homogenized and tissue cysts counted in 10-microliters aliquots. tissue cysts were separated from brain homogenates by centrifugation at 4,400 g on 35% (v/v) percoll/phosphate-buffered saline (pbs) continuous-density gradients. after removal of the brain layer, the separated tissue cysts were concentrated by di ...19979105320
seroprevalence of antibodies to neospora caninum in belgian dogs.sera from 300 dogs from ghent and antwerp were tested for antibodies to neospora caninum using an indirect fluorescent antibody test. overall, 11 per cent (9.5 to 13 per cent; confidence interval of 95 per cent) of dogs were seropositive, at titres of 1:50 to 1:800. no sex or breed differences were detected, but there was an increase in seropositivity with age.19979121127
results of a survey to determine whether neospora is a significant cause of ovine abortion in england and wales.between january and april 1995, the brains and hearts of 281 aborted lambs derived from 209 submissions to veterinary investigation centres in england and wales were examined histologically. one-hundred-and-seventy-nine samples of fetal pleural fluid from these lambs and 141 from lambs not examined histologically were examined for antibodies to neospora by an indirect fluorescent antibody test. non-suppurative myocarditis and encephalitis were present in nine lambs. immunocytochemistry using ant ...19979055394
distribution of neospora caninum within the central nervous system and other tissues of six dogs with clinical neosporosis.six cases of neosporosis in dogs were diagnosed on the basis of clinical signs, serology and immunohistochemistry. the brains and spinal cords, at several levels, and various other tissues were examined using anti-neospora caninum serum by an immunoperoxidase technique. parasite density varied markedly from case to case. although found most consistently in the cerebrum, parasites were distributed throughout the central nervous system (cns), both within the grey and white matter and within nerve ...19968981277
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
what is your neurologic diagnosis? neospora caninum-induced myositis. 19968617618
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
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
comparison of the internal transcribed spacer, its 1, from toxoplasma gondii isolates and neospora caninum.the internal transcribed spacer (its1) region and the 5' part of the 5.8s ribosomal rna gene of the ribosomal dna repeat from 20 toxoplasma gondil isolates was sequenced and found to be identical in all isolates, independent of host origin or virulence to mice. the its1 region from the closely related coccidian parasite neospora caninum differed in 22% of its nucleotides. hence, the its1 region provides a good marker for the distinction of t. gondii and n. caninum but is not useful for epidemiol ...19979089727
neospora caninum infection in a napolitan mastiff dog from spain.fetal neosporosis-associated myeloencephalitis was diagnosed in a 4-month-old napolitan mastiff dog from spain. neospora caninum tachyzoites and tissue cysts were observed in lesions in the central nervous system and the diagnosis was confirmed by immunohistochemical staining with anti-n. caninum monoclonal and polyclonal antibodies.19968893485
experimental infection of nude mice as a model for sarcocystis neurona-associated encephalitis.the development of a rodent model for the study of sarcocystis neurona encephalitis is described. animal models have been developed for a number of protozoal parasites; however, no such model exists for s. neurona. the approach used in this study is similar to that employed for other closely related protozoal parasites such as neospora caninum and toxoplasma gondii. a time course of infection was examined, and histopathology, immunohistochemistry, and parasite isolation were used to examine the ...19979272562
[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
identification and partial characterization of a 36 kda surface protein on neospora caninum tachyzoites.neospora caninum, the causative agent of neosporosis, is a recently identified apicomplexan parasite which is structurally and biologically closely related to, but antigenically distinct from, toxoplasma gondii. molecules associated with the surfaces of n. caninum tachyzoites are likely to participate in the host cell entry process, could be involved in the interaction of the parasite with the immune system, and they could influence the pathogenesis of neosporosis. isolated n. caninum tachyzoite ...19979364563
the expression of toxoplasma proteins in neospora caninum and the identification of a gene encoding a novel rhoptry protein.genes for the toxoplasma gondii dense granule and rhoptry proteins nucleoside triphosphate hydrolase 3 and rop2 were expressed at high levels in the closely related parasite n. caninum. the protein products were processed appropriately and were targeted to their correct secretory organelles. ntpase 3 was secreted into the parasitophorous vacuole. the utility of this system was demonstrated in the analysis of a new open reading frame identified upstream of two identical copies of the rop2 gene. t ...19979364966
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
expression of toxoplasma gondii genes in the closely-related apicomplexan parasite neospora caninum.we have established the feasibility of using neospora caninum as a heterologous system for the expression of genes from the closely-related parasite toxoplasma gondii. plasmid construct containing the lacz gene from escherichia coli driven by t. gondii promoters were electroporated into n. caninum parasites, and expression of beta-galactosidase (beta-gal) activity was assayed enzymatically. in transient assays, expression of beta-gal driven by the gra1 promoter was approximately 10-fold higher t ...19979178265
development of molecular genetics for neospora caninum: a complementary system to toxoplasma gondii.the development of molecular genetics has greatly enhanced the study of toxoplasma gondii, and investigations into the biology and pathology associated with neosporosis will be similarly benefited by the development of molecular tools for neospora caninum. we have demonstrated the feasibility of using the existing dna vectors developed for t. gondii to transfect and transform the nc-1 strain of neospora. we have also shown that t. gondii proteins are faithfully expressed and targeted in n. canin ...19979405196
examination of red foxes (vulpes vulpes) from belgium for antibody to neospora caninum and toxoplasma gondii. 19979330477
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
diagnosis of neospora caninum and toxoplasma gondii infection by pcr and dna hybridization immunoassay.a recently described pcr test for the identification of neospora caninum and toxoplasma gondii has been further developed and optimized in view of its practicability for routine diagnostic application. the n. caninum-specific pcr was adapted to the diagnostic operating standard of the t. gondii-specific pcr in that the uracil dna glycosidase system was introduced, which eliminates potential carry-over contaminations of amplified target dna from previous reactions. furthermore, both pcr tests wer ...19968897199
immunohistochemical diagnosis of toxoplasma gondii: potential for cross-reactivity with neospora caninum.a monoclonal antibody (mab 3f5) was compared with a commercial polyclonal antibody for specificity for toxoplasma gondii and cross-reactivity with neospora caninum in paraffin-embedded tissue sections. both antibody preparations reliably recognized t. gondii tachyzoites (rh isolate) in animal tissues but did not always label tissue cysts (me-49 isolate). the commercial antibody strongly cross-reacted with n. caninum tachyzoites, but mab 3f5 did not when the immunoperoxidase, immunofluorescence, ...19979194824
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
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
a dense granule protein (ncdg1) gene from neospora caninum. 19979247937
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
epizootic disseminated toxoplasmosis in captive slender-tailed meerkats (suricata suricatta).fatal disseminated toxoplasmosis was diagnosed in seven captive slender-tailed meerkats (suricata suricatta) according to clinicopathologic findings and immunohistochemistry. five of nine meerkats died during an outbreak in late 1994. these included four kits (2.5 to 4.5 months old) and a 4-year-old meerkat. two other meerkats, both adults, died in 1992 and 1995. respiratory insufficiency (4/7) and incoordination (3/7) were the most consistent clinical signs. although two of seven meerkats died ...19979150539
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
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
a protocol for the production of neospora caninum tissue cysts in mice.identification of a definitive host for neospora caninum has been inhibited by lack of an efficient method for producing bradyzoites, needed for oral infectivity trials. an improved protocol for producing bradyzoite-containing tissue cysts in mouse brains is described. six variables, including mouse strain (balb/c, cba/ca, and icr), sex, n. caninum isolate (nc-2 and nc-liverpool), tachyzoite inoculum dose, immunosuppression with methylprednisolone acetate (mpa), and sulfadiazine treatment were t ...19979267406
examination of extraintestinal tissue cysts of isospora belli.relapse is common in immunocompetent and immunosuppressed humans infected with isospora belli and is believed to be associated with the presence of extraintestinal stages. in the present study, we examined this important stage in an aids patient using histological, immunohistological, histochemical, and ultrastructural methods to better understand the development and structure of this stage and to develop better means of detecting infections. antisera made in rabbits to isospora suis, toxoplasma ...19979267401
prevalence of antibodies to neospora caninum in different canid populations.a total of 1,554 dogs from 5 countries on 3 continents were tested for antibodies to neospora caninum using an indirect fluorescent antibody test. in australia, overall, 42/451 (9%, 95% confidence interval [ci] 6-12%) dogs were seropositive (melbourne 11/207 [5%, 95% ci 2-9%]; sydney 18/150 [12%, 95% ci 7-18%]; perth 13/94 [14%, 95% ci 8-22%]). antibodies to n. caninum were also detected in dogs in south america (uruguay [20%, 95% ci 16-24%, n = 414]) and sub-saharan africa (tanzania [22%, 95% c ...19979406778
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
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
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
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
molecular analysis and characterization of a protein involved in the replication of intracellular toxoplasma gondii.previous studies in our laboratory have identified a cytoplasmic protein (p97) of t. gondii that is involved in the process of intracellular parasite replication. monoclonal antibody inhibits parasite replication in vitro and recognizes a protein of approximate 97 kda by western blot analysis. using biotinylation, we demonstrate that p97 is not expressed on the surface of the tachyzoite. polyclonal sera raised against the purified native protein was used to isolate a cdna of 3.3 kb from a librar ...19979476788
seroprevalence of antibodies to neospora caninum and toxoplasma gondii in water buffaloes (bubalus bubalis) from egypt.sera from 75 water buffaloes from egypt were examined using a direct agglutination test incorporating mercaptoethanol for antibodies to neospora caninum and toxoplasma gondii. antibodies to n. caninum were found in 51 (68%) of 75 buffaloes in titres of 1:20 (six buffaloes), 1:40 (15 buffaloes), 1:160 (one buffalo), 1:320 (one buffalo) and > or = 1:640 (28 buffaloes), using n. caninum formalin-preserved whole tachyzoites as antigen. antibodies to t. gondii were not found in a 1:100 dilution of se ...19989559371
phylogenetic analysis of coccidia based on 18s rdna sequence comparison indicates that isospora is most closely related to toxoplasma and neospora.the phylogenetic relationships and taxonomic affinities of coccidia with isosporan-type oocysts have been unclear as overlapping characters, recently discovered life cycle features, and even recently discovered taxa, continue to be incorporated into biological classifications of the group. we determined the full or partial 18s ribosomal rna gene sequences of three mammalian isospora spp., isospora felis, isospora ohioensis and isospora suis, and a sarcocystis sp. of a rattlesnake, and used these ...19989561772
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
antibody response to hepatozoon canis in experimentally infected dogs.canine hepatozoonosis is a disease caused by the tick-borne protozoan hepatozoon canis. five puppies were inoculated by ingestion of rhipicephalus sanguineus ticks experimentally infected with h. canis, and all became infected with h. canis: gametocytes were detected in blood smears from four dogs and schizonts were observed in the spleen and bone marrow of the fifth. antibodies reactive with h. canis gametocytes were detected by the indirect fluorescent antibody test (ifa), with igm detected in ...19989561714
characterization of a cdna-clone encoding nc-p43, a major neospora caninum tachyzoite surface protein.neospora caninum is an apicomplexan parasite of veterinary importance which invades many different cell types and tissues. n. caninum tachyzoites proliferate intracellularly by endodyogeny. eventually the massive proliferation of tachyzoites leads to host cell lysis and the newly formed parasites are released and invade neighbouring cells. tachyzoite cell surface molecules could serve as ligands, mediating host cell adhesion and invasion. nc-p43 is a recently identified n. caninum tachyzoite sur ...19979488869
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
application of iscom antigen preparations in elisas for diagnosis of neospora and toxoplasma infections.immunostimulating complexes (iscoms) are cage-like structures of about 40 nm composed of quil a, cholesterol, phospholipids and antigen. their main area of use has been as adjuvants and carriers of immunogens in vaccines. iscoms can also be used for selection of surface membrane proteins of micro-organisms for use in immunoassays, thus decreasing the number of internal proteins that might cause problems with non-specific binding and cross-reactivity. enzyme-linked immunoassays (elisas) utilising ...19989504345
antigen-specific cd8+ t cells protect against lethal toxoplasmosis in mice infected with neospora caninum.neospora caninum is a coccidial protozoan parasite that appears morphologically indistinguishable from toxoplasma gondii and that infects a large range of mammals. both inbred and outbred strains of mice exhibit a high degree of resistance to infection with n. caninum. three inbred strains of mice (a/j, balb/c, and c57bl/6) that were infected intraperitoneally with n. caninum were protected against a lethal challenge from t. gondii. vaccine-induced protection was neospora dose dependent. a rise ...19989529081
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
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
naturally occurring vertical transmission of neospora caninum in dogs.vertical transmission of neospora caninum was studied in naturally infected, privately owned dogs, using antibody detection by ifat to identify infected individuals. retrospective studies were undertaken in litters from six bitches of the hamiltonstövare breed, and on litters from seven bitches of other breeds--in both cases following diagnosis of clinical disease in puppies--and prospective studies were carried out on 17 seropositive bitches of other breeds. puppies were classified as infected ...19989504335
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
identification and characterisation of a dense granule-associated protein in neospora caninum tachyzoites.neospora caninum is an apicomplexan parasite which is morphologically and ultrastructurally very similar to toxoplasma gondii. in order to identify molecules involved in host cell entry and subsequent modification of the parasitophorous vacuole, a polyclonal antiserum directed against n. caninum tachyzoites was raised in a rabbit. subcellular fractionation of tachyzoites was performed using the non-ionic detergent triton-x-114. membrane fractions were analysed by immunoblotting using the polyclo ...19989559361
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 inoculation of cats with tissue cysts of neospora test the hypothesis that cats are definitive hosts of neospora caninum.19989563628
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
differential expression of cell surface- and dense granule-associated neospora caninum proteins in tachyzoites and bradyzoites.morphologically, the tachyzoites and the tissue cysts of neospora caninum are difficult to distinguish from those of other cyst-forming apicomplexan parasites such as toxoplasma gondii. several stage-specific antigens have been identified in t. gondii tachyzoites and bradyzoites, and respective antibodies are useful tools for discriminating between the 2 stages during tachyzoite-bradyzoite interconversion in t. gondii infections. whereas several cell surface- and dense granule-associated protein ...19989714206
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
prevalence of neospora caninum and toxoplasma gondii antibodies in sera from camels from egypt.sera from camels from egypt were examined by the direct agglutination tests incorporating mercaptoethanol for antibodies to neospora caninum and toxoplasma gondii. antibodies to n. caninum were found in 6 of 161 camels in titers of 1:40 (2 camels) and 1:80, 1:160, 1:640, and 1:1280 in 1 camel each, using n. caninum formalin preserved whole tachyzoites as antigen. antibodies to t. gondii were found in 17.4% of 166 camels in titers of 1:25 (3 camels), 1:50 (18 camels). and > 1:500 (8 camels) using ...19989637230
experimental porcine neosporosis.six gilts were inoculated intramuscularly with 2.5x10(6) tachyzoites of neospora caninum on three different days of gestation to study the pathogenic effect of neospora infection in pigs, including possible transplacental transmission. the gilts were euthanized 59, 30, and 9/10 days postinoculation (p.i.), corresponding to days 107, 102/106 and 110/111 of pregnancy. with the exception of one animal (euthanized day 9 p.i.) all gilts seroconverted as measured by the indirect, fluorescent antibody ...19989637270
the pathogenesis of experimental neosporosis in pregnant sheep.three groups of eight pregnant sheep were inoculated with tachyzoites of the ncl isolate of neospora caninum at 45 (group 1), 65 (group 2) or 90 (group 3) days' gestation. a further six animals (group 4) served as controls. fourteen of the infected ewes developed a fever, which in two cases was biphasic. in six ewes in group 1, the fetuses died and were resorbed, and in the other two the fetuses were aborted. in group 2, one ewe resorbed her fetus, six aborted dead fetuses and one produced a liv ...19989651804
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
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
isolation of the cdna encoding a dense granule associated antigen (ncdg2) of neospora caninum. 19989662039
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
dogs are definitive hosts of neospora caninum.dogs were investigated to determine if they are definitive hosts of neospora caninum. four dogs were fed n. caninum tissue cysts in infected mouse tissue, and two negative control dogs were fed uninfected mouse tissue. dog faeces were examined daily for 30 days using a sucrose flotation technique. three challenged dogs shed spherical to subspherical unsporulated oocysts, measuring 10 to 11 microns in diameter. oocysts sporulated within 3 days and contained two sporocysts, each with four sporozoi ...19989770635
neospora caninum-associated abortion in a dairy herd in argentina. 19989770768
vaccination of mice with neospora caninum: response to oral challenge with toxoplasma gondii oocysts.neospora caninum is a protozoan parasite that can cause severe disease in mammals. two experiments were conducted to examine the effects of subcutaneous (s.c.) vaccination with hank's balanced salt solution (hbss), 1 x 10(5) n. caninum nc-1 strain tachyzoites or 1 x 10(5) toxoplasma gondii ts-4 strain tachyzoites on challenge oral infections in mice with sporulated veg strain t. gondii oocysts (1 x 10(3) oocysts exp. 1 and 5 x 10(3) oocysts exp. 2). an additional study, experiment 3, evaluated s ...19989576504
comparison of intracerebral parasite load, lesion development, and systemic cytokines in mouse strains infected with neospora caninum.neospora caninum, an apicomplexan parasite closely related to toxoplasma gondii, causes abortion, stillbirths, and congenital neurologic disease in multiple animal species. the present study focuses on the development of encephalitis and intracerebral parasite load that occurs 6 wk postinfection (pi). utilizing balb/c, c57bl/6, and b10.d2 mice, an initial investigation was undertaken to determine the relative resistance of inbred strains to n. caninum-induced encephalitis. relative resistance wa ...19989576505
polymerase chain reaction approaches for the detection of neospora caninum and toxoplasma gondii.this review summarizes existing knowledge on the development and use of the polymerase chain reaction for the detection of dna from neospora and toxoplasma. several strategies which utilise the polymerase chain reaction for the diagnosis of toxoplasmosis in humans and livestock have been described and they principally target the b1 repetitive sequence, the p30 gene or ribosomal dna. experience has shown that the polymerase chain reaction has proven insufficiently robust to serve as a diagnostic ...19989724876
bovine abortion, neospora caninum and dogs. 19989795406
neospora caninum: tachyzoites express a potent type-i nucleoside triphosphate hydrolase.we have identified type i nucleoside triphosphate hydrolase (ntpase; ec 3.6. 1.3) activity, previously thought to be restricted to the virulent strains of toxoplasma gondii, in the cell extracts of neospora caninum tachyzoites. sequence analysis of a complete cdna from nc-1 strain indicated that n. caninum ntpases shared approximately 69% identity to the ntpases of t. gondii and are most similar to the ntpase-i isozyme. southern blot analysis of genomic dna and sequence analysis of two independe ...19989806873
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
canine neosporosis: clinical signs, diagnosis, treatment and isolation of neospora caninum in mice and cell culture.clinical signs, diagnosis, treatment and isolation of neospora caninum from two littermate dogs are described. three of six pups from a labrador bitch developed paralysis. neosporosis was diagnosed ante mortem by serological examination in two of the affected pups. at necropsy, tissue cysts were seen in unstained smears and in histologic sections of their brains. tissue cysts were often thin-walled (approximately 1 micron) but antigenically and ultrastructurally identified as n. caninum. further ...19989762578
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
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
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
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 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
antibody reaction of human anti-toxoplasma gondii positive and negative sera with neospora caninum antigens.anti-neospora caninum antibody was detected in anti-toxoplasma gondii positive and negative human sera by elisa, western blot and immunofluorescence assay (ifa). twelve cases out of 172 (6.7%) toxoplasma-positive sera cross-reacted with both t. gondii and n. caninum antigens, and one out of 110 toxoplasma-negative sera reacted with n. caninum antigen by elisa. by western blot, all 12 sera reacted with t. gondii antigens with various banding patterns but specifically at 30 kda (sag1) and 22 kda ( ...19989868893
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
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
Displaying items 101 - 200 of 1864