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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
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
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
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
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
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
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
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
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
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
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
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
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
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
effect of congenitally acquired neospora caninum infection on risk of abortion and subsequent abortions in dairy cattle.to 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
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
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
examination of red foxes (vulpes vulpes) from belgium for antibody to neospora caninum and toxoplasma gondii. 19979330477
[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
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
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
experimental infection of non-pregnant and pregnant sheep with neospora caninum.in 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 dense granule protein (ncdg1) gene from neospora caninum. 19979247937
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
serological diagnosis of bovine fetal neosporosis.to 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
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
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
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
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
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
novel elisa for detection of neospora-specific antibodies in cattle.an 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
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
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
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
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
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
an indirect enzyme-linked immunoassay (elisa) for demonstration of antibodies to neospora caninum in serum and milk of cattle.an 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
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
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
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
effect of neospora caninum infection on milk production in first-lactation dairy cows.to determine whether cows seropositive to neospora caninum produced less milk during their first lactation than seronegative cows.19979054999
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
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
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
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
stillbirth/perinatal weak calf syndrome: serological examination for evidence of neospora caninum infection. 19968953695
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
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
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 cows.to 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
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
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
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
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
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
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
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
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
[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
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
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 pyrimethamine.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
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
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
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
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
serologic responses of cattle and other animals infected with neospora caninum.to examine cross-reactivity among neospora caninum and closely-related apicomplexans.19968669764
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
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
what is your neurologic diagnosis? neospora caninum-induced myositis. 19968617618
an immunohistochemical method for detecting bradyzoite antigen (bag5) in toxoplasma gondii-infected tissues cross-reacts with a neospora caninum bradyzoite antigen.the previously cloned gene of a bradyzoite-specific antigen (bag5) of toxoplasma gondii was used to express a fusion protein for subsequent antiserum production in rabbits. the bag5 antiserum was used in an immunohistochemical procedure to look for reactive epitopes in bradyzoites and tachyzoites of t. gondii within animal tissues. encysted bradyzoites in brain were stained deeply and diffusely. although most unencysted organisms in brain were not stained, occasional free organisms had mild to d ...19968604117
fatal transplacental neosporosis in a deer (cervus eldi siamensis).neospora caninum tissue cysts were found in sections of the brain from a full-term stillborn deer of eld (cervus eldi siamensis) from a zoo in france. there was n. caninum-associated nonsuppurative encephalitis and the diagnosis was confirmed in immunohistochemical staining with antibodies specific to n. caninum.19968604111
neospora caninum: specific oligonucleotide primers for the detection of brain "cyst" dna of experimentally infected nude mice by the polymerase chain reaction (pcr).both tachyzoites and bradyzoites in tissue cysts of neospora caninum are morphologically difficult to distinguish from those of other cyst-forming apicomplexan parasites such as toxoplasma gondii. thus, molecular tools may contribute to easy identification of the parasite. based upon an n. caninum-specific dna fragment that we have recently cloned, 5 sense (np1, np3, np5, np7, np21) and 4 antisense (np2, np4, np6, np8) oligonucleotides were designed for a sensitive and specific polymerase chain ...19968604096
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
direct abc immunohistochemistry to encephalitozoon cuniculi.among the sera from 9 rabbits spontaneously infected with encephalitozoon cuniculi, a serum which revealed a high titer for e. cuniculi by indirect protein a-gold (ipag) immunohistochemistry and reacted with the outer layer of the shell of e. cuniculi spores on immunoelectron microscopical examination, was biotinylated. the biotinylated rabbit anti-e. cuniculi igg reacted immunohistochemically with e. cuniculi, but not with other protozoa tested, namely neospora caninum, toxoplasma gondii and sa ...19938513018
neospora caninum infection in three labrador littermates.neospora caninum is a recently identified protozoan parasite which was previously confused with toxoplasma gondii. neosporosis in puppies commonly causes signs referable to parasitic encephalomyelitis and myositis. the parasite was identified in tissues from 3 9-week-old labrador littermates which showed signs of progressive hind limb hyperextension and paralysis. the diagnosis was confirmed, utilising a specific avidin-biotin immunohistochemical technique. attempts to treat the pups with clinda ...19938496897
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
differentiation of toxoplasma gondii from closely related coccidia by riboprint analysis and a surface antigen gene polymerase chain reaction.the tachyzoite of the human pathogen toxoplasma gondii is morphologically indistinguishable from the proliferative stages of some other zoonotic coccidia, including sarcocystis. to determine the identity of such coccidia obtained from human tissues and other sources, we compared riboprints (through restriction enzyme analysis of the polymerase chain reaction [pcr]-amplified small subunit rrna gene) of the following protozoa: the rh and ts-4 strains of t. gondii, lines oh3 and s11, which are two ...19938470780
visceral toxoplasmosis in dogs from brazil.toxoplasma gondii was identified in tissues of two dogs (3 and 10 months of age) from brazil. primary lesions consisted of necrotizing intestinal myositis associated with numerous tachyzoites. parasites in tissues reacted with anti-t. gondii serum but not with neospora caninum serum.19938447074
prevalence of antibodies to neospora caninum in a population of urban dogs in england.of 163 dogs, randomly selected from those examined at the university of liverpool small animal hospital, 12.9 per cent had antibody titres > or = to 1/200 to neospora caninum in an indirect fluorescent antibody test. none was apparently suffering clinical neosporosis. there was no association between the occurrence of neospora antibodies and either toxoplasma antibodies measured by the dye test, sex, age, type of feeding or the presence of other dogs in the household. antibody was detected at ti ...19938447050
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
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
[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
isolation of neospora caninum from a british dog. 19938310633
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
bovine neospora caninum abortion in the uk. 19938256426
evaluation of the indirect fluorescent antibody test for diagnosis of babesia gibsoni infections in dogs.we determined the extent of the serologic cross-reactivity in the indirect fluorescent antibody (ifa) test for babesia gibsoni, and the optimal cut-off titer for seropositivity in the test. the lowest titer to b gibsoni detected in a dog with naturally acquired clinical babesiosis was 1,280, and 7 of 12 dogs had titer between 10,240 and 20,480. two experimentally infected normosplenic dogs developed high titer (40,960 to 81,920) to b gibsoni, and the same sera reacted in ifa tests for b canis (t ...19938250380
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
neospora caninum in british dogs. 19948085319
the phylogeny of neospora caninum and toxoplasma gondii based on ribosomal rna sequences.neospora caninum is a newly described cyst-forming coccidium which is the cause of severe neurological disease in dogs. the parasite is morphologically similar to toxoplasma gondii, but the two species can be differentiated serologically. in order to define the phylogenetic position of n. caninum, we have determined 16s-like rrna sequences from three members of the family of sarcocystidae: n. caninum, t. gondii, and sarcocystis fusiformis. the 16s-like rrna genes from the three parasites were am ...19948039658
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
the phylogeny of neospora caninum.morphological studies by electron microscopy on the protozoan neospora caninum have shown that this organism possesses a subcellular structure typical of parasites classified in the family sarcocystidae, subclass coccidiasina of the phylum apicomplexa. using a strategy based on dna sequence analysis of products derived by asymmetric pcr to determine the nucleotide sequences, we have tested the validity of this classification by comparing the small subunit ribosomal rna (18s rrna) gene sequences ...19947935608
characterization of a murine monoclonal antibody generated against neospora caninum tachyzoites by use of western blot analysis and immunoelectron microscopy.a murine monoclonal antibody (mab) 6g7 generated against tachyzoites of neospora caninum recognized 8 major and several minor antigens, as observed by western blot analysis. relative rate of migration of the 8 major antigens ranged from 31 to 97.4 kd. in addition, mab 6g7 recognized a toxoplasma gondii tachyzoite antigen with a relative rate of migration of 107 kd. immunogold labeling of n caninum tachyzoites grown in human foreskin fibroblast cells indicated that mab 6g7 binds to micronemes, de ...19947887516
neospora caninum--request for specimens for research. 19957779045
canine neosporosis: a case report and literature review.a three-year-old, intact female vizsla presented for signs of an acute-onset, progressive spinal cord disease. postmortem examination revealed multifocal central nervous system (cns) lesions, severe pneumonia with pulmonary edema, and congestion of the liver. protozoal cysts were found in multiple spinal cord and brain stem sections. immunohistochemical staining positively identified these cysts as neospora caninum. a literature review of neospora caninum infection in the dog with summary of the ...19957773765
[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
neospora caninum pneumonia in an adult dog.neospora caninum was identified in a lung aspirate specimen from an adult dog with severe pneumonia. neosporosis was tentatively diagnosed by cytologic examination of a wright-giemsa-stained smear of the aspirate specimen, using light microscopy. the infection was confirmed by immunohistochemical examination of a section of lung tissue obtained at necropsy. neosporosis is usually a fatal ascending neurologic disease of dogs less than 1 year of age. neospora caninum infections are uncommon in adu ...19957768704
neospora caninum in dogs: detection of antibodies by elisa using an iscom antigen.an indirect enzyme linked immunsorbent assay (elisa) for detection of antibodies to neospora caninum in serum from dogs is described. extracted tachyzoite proteins incorporated into immunostimulating complexes (iscoms) were used as coating antigen. a mixture of a monoclonal antibody to dog immunoglobulin g and a horse radish peroxidase conjugated antibody to mouse ig was used to detect bound antibody. when the iscom preparation was analysed by means of sodium dodecyl sulphate polyacrylamide gel ...19947708430
mouse model for central nervous system neospora caninum infections.neospora caninum is a protozoan parasite that causes severe disease in transplacentally infected dogs and abortions in domestic ruminants. rodent models of neosporosis rely on treatment of hosts with methylprednisolone acetate (mpa) to enhance infections. the present study reports the development of an inbred balb/c mouse model that results in central nervous system neosporosis in the absence of mpa treatment. seven of 12 balb/c mice died 26-70 days after subcutaneous (s.c.) inoculation with tac ...19957707216
vertical transmission of neospora caninum in dogs.herein we report the development of a canine model to examine transplacental and/or transmammary transmission of neospora caninum. six pregnant bitches were experimentally infected with n. caninum on day 21 of gestation. one bitch successfully delivered a litter of 3 live pups. these pups showed slight proprioception deficits, increased muscle tone, and spasticity in both pelvic limbs; however, n. caninum was neither demonstrated by bioassay in cell culture nor seen in histological sections of t ...19957707195
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