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serological survey and first finding of neospora caninum in taiwan, and the detection of its antibodies in various body fluids of cattle.a serological survey for antibodies against neospora caninum in cattle, goats and farm dogs in taiwan was carried out. sera of 613 cattle from 25 dairy farms, 24 goats from six goat farms and 13 dogs from six dairy cattle farms were tested for antibodies against n. caninum using indirect fluorescence antibody test (ifat). the same sera were also tested for antibodies against toxoplasma gondii using latex agglutination test. of the 613 cattle sera, 44.9% (275/613) were found to have antibodies ag ...200010828511
in vitro isolation and characterization of bovine neospora caninum in korea.the brains of nine aborted bovine fetuses and two newborn calves born from dams suspected to be infected with neospora caninum were homogenized and inoculated into vero cells. all fetuses and calves were from cows determined as seropositive to n. caninum by an ifa test. sera and thoracic fluids of all fetuses and calves also revealed high antibody titer to n. caninum by ifat ranging from 1:800 to 1:3200. n. caninum was isolated from the brains of one aborted fetus and one newborn calf when the b ...200010828521
spatial associations among density of cattle, abundance of wild canids, and seroprevalence to neospora caninum in a population of beef calves.to determine the epidemiologic plausibility of a sylvatic transmission cycle for neospora caninum between wild canids and beef cattle.200011061391
neospora caninum-associated abortion in cattle: the time of experimentally-induced parasitaemia during gestation determines foetal survival.the parasite, neospora caninum is an important cause of abortion in cattle. it is transmitted vertically or horizontally and infection may result in abortion or the birth of a live, healthy but infected calf at full-term. only a proportion of infected cattle abort and the pathogenesis of abortion is not understood. groups of cattle were infected with 10(7) n. caninum tachyzoites intravenously at different times relative to gestation. intravenous inoculation was chosen to reproduce the putative h ...200011072897
effects of sequence alignment and structural domains of ribosomal dna on phylogeny reconstruction for the protozoan family sarcocystidae.finding correct species relationships using phylogeny reconstruction based on molecular data is dependent on several empirical and technical factors. these include the choice of dna sequence from which phylogeny is to be inferred, the establishment of character homology within a sequence alignment, and the phylogeny algorithm used. nevertheless, sequencing and phylogeny tools provide a way of testing certain hypotheses regarding the relationship among the organisms for which phenotypic character ...200011110900
isolation of neospora caninum from the brain of a naturally infected adult dairy cow.neospora caninum was isolated from the brain of a 2-year-old dairy cow that had aborted confirmed n. caninum-infected fetuses on two occasions. the cow had an indirect fluorescent antibody titer of 1:1600 to n. caninum. the cow was killed 24 days after its second abortion and the brain was bioassayed for n. caninum in nude mice. multifocal areas of perivascular cuffing and glial nodules were observed in the cerebrum and mesencephalon of the cow, but n. caninum was not identified in histological ...200010842005
serological investigation of an outbreak of neospora caninum-associated abortion in a dairy herd in southeastern united states.an outbreak of neospora caninum-associated abortion occurred in a south carolina dairy wherein greater than 10% of the herd aborted over a 4-month period. of the total number of cows at mid-late gestation, nearly 40% (28/71) aborted while the remaining 60% (43/71) gave birth to normal calves. immunohistochemical examination of brain tissue from a subset of aborted fetuses confirmed n. caninum as the causative agent of abortion in these animals. a variety of serological assays, including indirect ...200011078940
delivery of neospora caninum surface protein, ncsrs2 (nc-p43), to mouse using recombinant vaccinia virus.in order to develop a vaccine against neospora caninum in dogs and cattle, we constructed a recombinant vaccinia virus expressing the n. caninum surface protein, ncsrs2 (nc-p43). monoclonal antibodies to ncsrs2 and anti-n. caninum tachyzoite mouse serum recognized the ncsrs2 expressed by the recombinant vaccinia virus. in addition, recombinant ncsrs2 was transported to the cell surface. mice infected with the recombinant virus predominantly produced igg1 antibody (ab) to n. caninum, rather than ...200011097303
detection of igg antibody against neospora caninum in cattle in korea.a total of 492 cattle sera was screened by igg-elisa against neospora caninum (nc-1 strain and a korean isolate, kba-2) and toxoplasma gondii. out of 492, 113 sera (23.0%) reacted positively to either nc-1 or kba-2 strains of n. caninum. among the 113 positive sera, 92 sera (81.4%) reacted with antigens of both strains, but 6 sera (5.3%) with nc-1 and 15 sera (13.3%) with kba-2 strain only. and with t. gondii antigen, 6 sera (1.2%) were positive but all reacted with n. caninum antigen also. west ...200011138317
neospora then and now: prevalence of neospora caninum in maritime canada in 1979, 1989, and 1998.the seroprevalence of neospora caninum was compared among new brunswick, nova scotia, and prince edward island in 1998, 1989, and 1979. in 1998, the seroprevalence was lowest in prince edward island, where it was the same as in 1989. neospora caninum was present in 1979, but at a lower prevalence.200011126492
histopathological survey of aborted bovine fetuses in scotland with special reference to neospora caninum. 200011132675
a random amplified polymorphic dna polymerase chain reaction technique that differentiates between neospora species.neospora caninum is a recently described coccidial parasite that was first isolated from a dog in 1988 and has subsequently been shown to infect a wide range of mammals. neospora hughesi, a new species of this genus, has recently been isolated from the spinal cord of horses showing clinical signs of equine protozoal myeloencephalitis. the random amplified polymorphic dna polymerase chain reaction technique is capable of differentiating between n. caninum and n. hughesi.200011191920
neosporosis. aspects of epidemiology and host immune response.neospora caninum is a recently recognized protozoan parasite which has been described as causing a neuromuscular paralysis in dogs and is emerging as a major cause of bovine infertility and abortion worldwide. the parasite is known to infect a range of warm blooded animals but the disease predominates in dogs and cattle. it is not yet known if n. caninum can infect and cause disease in people. the dog has recently been identified as the definitive host and the parasite may be transmitted through ...200011193706
neospora caninum in cattle. m. mcallister et al. (2000) evidence of point-source exposure to neospora caninum and protective immunity in a herd of beef cows. j. am. vet. med. assoc. 217, 881-887 200011121844
small-subunit rdna sequencing of the italian bovine neospora caninum isolate (nc-pv1 strain).the small-subunit (ssu) rdna of the neospora sp. nc-pv1 strain isolated in italy from cattle has been sequenced and compared to the other five n. caninum strains ssu rdna sequences deposited in the data bases. the nc-pv1 strain sequence is identical to three published sequences. minor differences, respectively four nucleotide bases and one nucleotide base, have been found when comparing the nc-pv1 sequence with two other available sequences of n. caninum. according to these results, the neospora ...200011686077
[progress in the research on the tachyzoite-bradyzoite conversion of toxoplasma gondii]. 200012567672
structural analysis of free and protein-bound glycosyl-phosphatidylinositols of neospora caninum. 200010613708
molecular characterization of a thrombospondin-related anonymous protein homologue in neospora caninum.thrombospondin-related anonymous protein (trap) family members participate in attachment and invasion of host cells by apicomplexan parasites. a trap homologue in neospora caninum strain nc-1 (ncmic2) was cloned, sequenced and found to be 61% identical (75% similar) at the amino acid level to toxoplasma gondii mic2 (tgmic2). similar to tgmic2, the predicted amino acid sequence of ncmic2 contains one integrin-like domain (i or a domain), five thrombospondin (tsp) repeats, a putative transmembrane ...200010717300
immunization of balb/c mice with killed neospora caninum tachyzoite antigen induces a type 2 immune response and exacerbates encephalitis and neurological disease.balb/c mice were immunized subcutaneously with soluble neospora caninum tachyzoite antigen (nso) entrapped in nonionic surfactant vesicles (nisvs) or administered with freund's complete adjuvant (fca). following virulent parasite challenge, groups of mice immunized with nso and either nisvs or fca had clinical neurological disease and increased numbers of brain lesions compared to groups of mice inoculated with fca, nisvs, or phosphate-buffered saline (pbs) alone. increased numbers of brain lesi ...200011063494
neospora caninum: its oocysts and its identity: an opinion.a recently published opinion that hammondia heydorni, neospora caninum, and n. hughesi are a single species is not supported by genetic comparisons. furthermore, the suggestion that oocysts shed by dogs after experimental infection with n. caninum might have been of another organism is not consistent with the finding that these oocysts induced n. caninum infections in mice.200011068821
vertical and horizontal transmission of neospora caninum in dairy herds in québec.neospora caninum is an important cause of abortion in dairy cattle. the objective of this observational study was to estimate the rate of vertical transmission of n. caninum in dairy herds in québec and to investigate horizontal transmission in the same herds. the genealogy of cows from 23 dairy herds were examined. prevalence of seropositive animals in herds studied varied from 4.3% to 61.8% (average, 21.9%). the overall rate of vertical transmission was estimated to be 44.4%, varying from 0% t ...200010857030
seroprevalence of neospora caninum infection in domestic dogs in turkey. 200010872789
canine neosporosis: clinical and pathological findings and first isolation of neospora caninum in germany.neosporosis was diagnosed in an 11-week-old puppy of the breed kleiner münsterländer with progressive hindlimb paresis. pathohistological and immunohistological examinations revealed a disseminated infection with neospora caninum. parasitic stages were demonstrated in the brain, spinal cord, retina, muscles, thymus, heart, liver, kidney, stomach, adrenal gland, and skin. immunohistochemistry investigations were carried out using polyclonal rabbit antisera developed against n. caninum tachyzoites ...200010669128
intergenic spacer (igs) polymorphism: a new genetic marker for differentiation of toxoplasma gondii strains and neospora caninum.the region between the 28s and 18s rrna genes, including the intergenic spacer (igs) region and the 5s rrna gene, from 32 strains of toxoplasma gondii and the nc1 strain of neospora caninum was amplified and used for dna sequencing and/or restriction fragment length polymorphism (rflp) analysis. the 5s rdna sequences from 20 strains of t. gondii were identical. the igs region between the 5s and 18s rrna genes (nontranscribed spacer 2 or nts 2) showed 10 nucleotide variations. six of the 10 varia ...200010958446
monoclonal antibody inhibition of neospora caninum tachyzoite invasion into host cells.monoclonal antibodies were produced against neospora caninum tachyzoites to identify antigens which may play a role during invasion of host cells. confocal laser microscopy showed that most antigens recognised by the mab were located on the surface, but one mab, 1a5, reacted to the apical end of the parasite. some mabs, which recognised 70, 42 and 36kda parasite proteins, significantly inhibited the invasion of the parasite in vitro. the mabs which recognised 42 and 36kda parasite protein, react ...200010675744
toxoplasmosis as a suspected cause of abortion in a greenland muskox (ovibos moshatus wardi).toxoplasma gondii tachyzoites were seen in the placenta of a late-term aborted greenland muskox (ovibos moschatus wardi) fetus in a captive herd at the san francisco zoo. the organism stained with anti-t. gondii polyclonal rabbit serum but not with anti-neospora caninum serum. the dam had a toxoplasma titer of > or =1:3,200 at the time of abortion and in each of the previous 3 yr (modified agglutination test). the muskox is a new host record for t. gondii.200010982143
gerbils (meriones unguiculatus) are highly susceptible to oral infection with neospora caninum oocysts.laboratory-reared gerbils (meriones unguiculatus) were found to be highly susceptible to oral infection with neospora caninum (nc-liv strain) oocysts. gerbils fed approximately 1000 oocysts became sick or died at 6-13 days post feeding of oocysts (pfo). n. caninum was isolated in cell culture and from gamma-interferon-knockout mice inoculated with homogenates of mesenteric lymph nodes of gerbils examined as early as 1 day pfo. numerous n. caninum tachyzoites were found in ulcerative lesions in t ...200010685849
evidence of point-source exposure to neospora caninum and protective immunity in a herd of beef cows.to determine whether cows with evidence of previous infection with neospora caninum were less likely to abort or give birth prematurely during an outbreak of neosporosis, compared with herdmates with evidence of primary infection.200010997162
growth-inhibitory effects of interferon-gamma on neospora caninum in murine macrophages by a nitric oxide mechanism.to clarify the effector pathway of neospora caninum growth-inhibitory activity induced by interferon-gamma (ifn-gamma) in murine macrophages we examined the relationship between ifn-gamma and nitric oxide (no). production of no was enhanced in cultures of macrophages supplemented with ifn-gamma, and dose-dependent growth inhibition was observed. these findings suggest that the inhibitory activity induced in macrophages by ifn-gamma is mediated no molecules. a competitive inhibitor of the l-argin ...200011002987
neospora caninum: is it really different from hammondia heydorni or is it a strain of toxoplasma gondii? an opinion.the published data concerning toxoplasma gondii, hammondia hammondi, h. heydorni and neospora caninum on one side and between t. gondii on the other were neglected by most authors. as conclusion we are convinced that there are only two valid species: isospora (toxoplasma) gondii and hammondia heydorni. the first includes as a strain h. hammondi and the latter n. caninum. in any case there is absolutely no reason (with respect to general zoological nomenclature) to create new genera!200010685850
progress in the serodiagnosis of neospora caninum infections of cattle.neospora caninum is an apicomplexan protozoan that has become the focus of significant research attention worldwide. this organism infects a range of host species, including dogs, from which it was originally reported in 1984, but it is most important as a major cause of bovine abortion. as a result of the global importance of n. caninum, researchers have developed a number of serological tests to investigate the epidemiology of infection and disease. in this article, robert atkinson, peter harp ...200010689330
neospora caninum and bovine virus diarrhoea virus infections in swedish dairy cows in relation to abortion.the protozoan parasite neospora caninum and bovine virus diarrhoea virus (bvdv) are recognized as important causes of bovine abortion and congenital disease worldwide. in this study, serological investigations were performed to estimate the prevalence of n. caninum infection in swedish dairy cattle, to assess to what extent it may affect abortion rates, and to determine possible effects of coinfection with bvdv. the overall n. caninum seroprevalence in swedish dairy cows was estimated at 2% (16/ ...200010712809
the role of cd4(+) or cd8(+) t cells in the protective immune response of balb/c mice to neospora caninum infection.the role of cd4(+) or cd8(+) t cells in the immune response of balb/c mice against neospora caninum infection was examined by using anti-cd4 and/or anti-cd8 monoclonal antibodies (mabs). mice were intraperitoneally inoculated with anti-cd4 and/or anti-cd8 mabs before and after infection with n. caninum and observed for 30 days after infection. most of the anti-cd4 mab-treated mice and all of the anti-cd4 and anti-cd8 mabs-treated mice died within 30 days post-infection (p.i.). in contrast, 100% ...200010841998
neosporosis in cattle.during the past decade, neospora caninum infection has emerged as an important reproductive disease in cattle throughout the world. abortion, occurring during the middle of gestation, is the primary clinical sign of the infection in cattle. surveys in several countries from three continents have identified n. caninum infection as the major diagnosed cause of bovine abortion. both endemic and epidemic patterns of abortion may occur in herds. an important feature of this disease is that the protoz ...200010844212
[neospora caninum and neosporosis--basic science at the institute of parasitology and possible implications]. 200010850161
neospora caninum infected the alimentary tract of nude mice and was transmitted to other mice by intraperitoneal inoculation with the intestinal contents.neospora caninum (bt-2 strain) that originated from the brain of a holstein calf was serially passaged through 10 generations of balb/c nude mice by intraperitoneal inoculation. histological examination of the mice revealed that numerous clusters of tachyzoites appeared in the pancreas, stomach and small intestine as well as in the central nervous system (cns) and skeletal muscles. intestinal contents of the infected mice were inoculated intraperitoneally into uninfected nude mice and 3 of the 1 ...200010852403
neosporosis in water buffalo (bubalus bubalis) in southern italy.a study was carried on 1377 water buffalo serum samples from 50 farms in southern italy to test the presence of neospora caninum antibodies by indirect fluorescence antibody test (ifat). rabbit anti-buffalo immunoglobulins conjugated to fluorescein were used in the test. fluorescence in sera dilutions above 1:200 was considered as indicative of the presence of n. caninum antibodies. the overall prevalence of infection in the animals was 34.6%. the prevalence increased in relation to the age of s ...200010889356
a european perspective on neospora caninum.since the identification of neospora caninum in 1984 as a parasite separate from toxoplasma gondii by bjerkas et al., and its subsequent characterization and classification in 1988 by dubey and co-workers, this parasite has attracted increasing attention, primarily as an important causative agent of abortion in cattle and neuromuscular disease in dogs, but also as a complementary model system to t. gondii for investigating the basic biology of intracellular parasitism. during november 11-14, 199 ...200010927081
neospora hughesi: experimental infections in mice, gerbils, and dogs.neospora hughesi is a recently described cause of equine protozoal myeloencephalitis (epm). a rodent model for pathogenicity would facilitate development of therapies to be used in horses. in the present study, we examined the susceptibility of balb/c gamma-interferon gene knockout (gamma-infko), balb/c, cd-1, and c57bl/6 strains of mice and gerbils to infection with tachyzoites of the nh-a1 strain of n. hughesi isolated from a horse from al, usa. only the gamma-ifnko mice developed severe clini ...200010946135
a polygen-adjuvanted killed neospora caninum tachyzoite preparation failed to prevent foetal infection in pregnant cattle following i.v./i.m. experimental tachyzoite challenge.cattle immunised with a polygen-adjuvanted killed neospora caninum tachyzoite preparation were previously shown to produce interferon (ifn)-gamma at levels similar to those of tachyzoite-infected cattle. in view of the critical role of ifn-gamma in resistance of mice to n. caninum infection, these results prompted us to test the polygen-adjuvanted preparation in pregnant cattle to determine whether it will be able to prevent foetal infection following an experimental tachyzoite challenge. seven ...200010980287
use of purified tachyzoite surface antigen p38 in an elisa to diagnose bovine neosporosis.affinity-purified 38 kda surface antigen of neospora caninum tachyzoites was used to develop an enzyme-linked immunosorbent assay (elisa) to diagnose n. caninum-associated abortion in cattle. the specificity of this antigen was demonstrated by using sera from cattle experimentally infected with other apicomplexan parasites. in a panel of field sera, serological differences could be demonstrated between herds with epidemic and endemic abortions. optimal elisa cut-offs were determined for the dete ...200010996331
immunization of dogs with a canine herpesvirus vector expressing neospora caninum surface protein, ncsrs2.in order to develop a vaccine against neospora caninum in dogs, we constructed recombinant canine herpesvirus (chv) expressing n. caninum surface protein, ncsrs2. indirect immunofluorescence indicated that the antigenic structure of the recombinant ncsrs2 was similar to the authentic parasite protein. the dogs immunised with recombinant virus produced igg antibody to n. caninum, and their sera recognised the parasite protein on western blot. the dogs inoculated with recombinant virus showed no c ...200011027782
[clinical neosporosis in the dog: a review].neospora caninum is an intracellular protozoan parasite that was first recognized in dogs in 1988. n. caninum may cause neuromuscular disease in dogs. later, it was discovered that n. caninum has a wide host range and is an important cause of abortion in cattle. in this article, the literature on n. caninum in the dog is reviewed, with emphasis on clinical signs, pathology, diagnosis, treatment, and prognosis.200011060927
[the role of the dog in the epidemiology of neosporosis in cattle].neospora caninum is an intracellular protozoan parasite that was discovered in a dog in 1988. since then, n. caninum has been demonstrated in a variety of animal species and it has been recognized as an important cause of abortion in cattle. an infection with n. caninum can be maintained in cattle herds for several generations by transplacental transmission from cow to calf. recently, it was demonstrated that dogs can act as definitive hosts of n. caninum and therefore may be a source of infecti ...200011060928
association of serologic status for neospora caninum with postweaning weight gain and carcass measurements in beef calves.to determine the seroprevalence for neospora caninum in a population of beef calves in a feedlot and the association of serologic status with postweaning weight gain and carcass measurements.200011061390
determination of the activity of diclazuril against sarcocystis neurona and sarcocystis falcatula in cell cultures.diclazuril is a benzeneacetonitril anticoccidial that has excellent activity against the extraintestinal stages of toxoplasma gondii and neospora caninum. it also is highly active against intestinal coccidia of poultry. the present study examined the efficacy of diclazuril in inhibiting merozoite production of sarcocystis neurona and sarcocystis falcatula in bovine turbinate cell cultures. diclazuril inhibited merozoite production by more than 80% in cultures of s. neurona or s. falcatula treate ...200010701584
neospora caninum infections in australia and new zealand.to review the current state of knowledge of neospora caninum infections with particular reference to australia and new zealand.200010840573
seroprevalence of neospora caninum infection following an abortion outbreak in a dairy cattle herd.to investigate the seroprevalence of neospora caninum infection in a commercial dairy cattle herd, 15 months after detection of an abortion outbreak.200010840574
serologic survey of neospora caninum infection in a closed dairy cattle herd in maryland: risk of serologic reactivity by production groups.prevalence of antibodies to neospora caninum was determined in a cross-sectional consensus survey of 1029 bovines in a dairy herd with endemic neospora-induced abortion. sera were screened by indirect fluorescent antibody test (ifat). the prevalence of n. caninum antibody in the ifat was 17.9% in 107 neonates, 26.2% in 233 yearling heifers and steers, 39.07% in 218 mature heifers, and 26.9% in 465 milking cows. serologic reactivity was associated with production grouping on the farm with the gre ...200010841997
neutralization of maternal il-4 modulates congenital protozoal transmission: comparison of innate versus acquired immune responses.il-4 levels were modulated in mice to test the hypothesis that induction of a maternal type 1 response would decrease the frequency of congenital neospora caninum transmission. this hypothesis tested the relationship between il-4 and both innate and adaptive immunity utilizing two basic experimental designs. in the first, maternal il-4 was neutralized with mab during pregnancy in naive mice concomitant with initial, virulent infection. in the second, maternal il-4 was neutralized before pregnanc ...200010779783
neospora caninum infection in a clinically healthy calf: parasitological study and serological follow-up.in this study a case of congenital infection in a clinically healthy calf is reported. the mother showed high antibody levels (ifat) at 230 days of gestation (igg titres > or = 1:1600, igm titres > or = 1:320) and the parasite was isolated from placental cotyledonary villi at calving. the igm values are indicative of a recent infection in the third trimester of gestation. the calf was monitored serologically for igm and igg from birth until slaughtering, at 8 months of age. igm titre showed a pe ...200010780172
[the occurrence of toxoplasma gondii and neospora caninum as regards meat hygiene].toxoplasma gondii and neospora caninum are phenotypically and phylogenetically closely related cyst-forming coccidia, both of which may cause abortion in livestock animals. t. gondii exhibits also zoonotic potential by causing diaplacental infections in the human fetus and harmful infections in immunosuppressed individuals. humans get infected either by consuming inappropriately prepared cyst-containing meat or by ingesting oocysts originating from cat feces. therefore, in order to assess infect ...200010748708
the inhibitory effect of interferon gamma and tumor necrosis factor alpha on intracellular multiplication of neospora caninum in primary bovine brain cells.primary culture of bovine brain cells was examined for its susceptibility to neospora caninum infections, and this model was used to investigate the effects of bovine interferon gamma (ifn-gamma) and tumor necrosis factors alpha (tnf-alpha) on tachyzoite growth. tachyzoites of n. caninum grew well in this culture, and tachyzoite growth in astroglia and microglia were confirmed by immunocytochemical staining. ifn-gamma inhibited the tachyzoite growth, and this inhibition was not reversed by the a ...200010770613
a stochastic model for disease transmission in a managed herd, motivated by neospora caninum amongst dairy cattle.a stochastic model for the spread of neospora caninum infection within a herd of dairy cattle is studied, in particular the long-term (equilibrium) behaviour of the model. the model incorporates the interesting feature that total herd size is constrained to lie within a fairly small interval, but not held exactly constant. approximations for the joint distribution of numbers of susceptible and infected individuals present in equilibrium are derived based upon a diffusion approximation to the inf ...200111292494
serological evidence for naturally occurring transmission of neospora caninum among foxes (vulpes vulpes).the study describes the time course of the neospora caninum-specific antibody response in experimentally infected foxes, in naturally n. caninum-seropositive vixens and their litters. an immunofluorescence test, a tachyzoite surface antigen based elisa and an immunoblot assay were established for this purpose. the immunoblot patterns of naturally seropositive and experimentally infected foxes revealed a high degree of similarity and resembled those reported for other intermediate host species. r ...200111306121
characterization of the oregon isolate of neospora hughesi from a horse.neospora hughesi was isolated in cell cultures inoculated with homogenate of spinal cord from a horse in oregon. tachyzoites of this oregon isolate of n. hughesi were maintained continuously by cell culture passage and tachyzoites were infective to immunosuppressed mice. gamma interferon gene knockout (ko) mice injected with tachyzoites developed fatal myocarditis and numerous tachyzoites were seen in lesions. gerbils (meriones unguiculatus) inoculated with tachyzoites developed antibodies (> or ...200111318565
specific detection of neospora caninum oocysts in fecal samples from experimentally-infected dogs using the polymerase chain reaction.neospora caninum oocysts, passed in the feces of a definitive host (dog), were isolated, and genomic dna was extracted. a polymerase cahin reaction (pcr) targeting the n. caninum-specific nc 5 genomic sequence was performed using the isolated dna. a synthesized competitor molecule containing part of the nc 5 sequence was included in the assay as a check against false-negative pcr results and to quantify n. caninum oocyst dna in fecal samples. a standard curve of the ratio of fluorescence intensi ...200111318571
myosin diversity in apicomplexa.a polymerase chain reaction (pcr) screen was used to examine the diversity of myosins in 7 apicomplexan parasites: toxoplasma gondii, plasmodium falciparum, neospora caninum, eimeria tenella, sarcocystis muris, babesia bovis, and cryptosporidium parvum. using degenerate pcr primers compatible with the majority of known myosin classes, putative myosin sequences were obtained from all of these species. all of the sequences obtained showed greatest similarity to previously identified apicomplexan m ...200111318578
cyclic transmission of neospora caninum: serological findings in dogs shedding oocysts.in a previous paper we demonstrated that hammondia heydorni-like oocysts isolated in 1996 from a naturally infected dog could not be distinguished from the isolate neospora caninum nc-1. the isolate, designated as h. heydorni-berlin-1996, was cyclically transmitted using dogs as the final hosts. the present study provides information on the antibody responses of the dogs used for the cyclical transmission of this isolate. the majority of dogs that had shed oocysts showed no sero-conversion with ...200111688895
comparative molecular investigation of nc5-pcr amplicons from neospora caninum nc-1 and hammondia heydorni-berlin-1996.the clinical relevance of neospora caninum as a cyst-forming coccidian parasite is increasingly acknowledged within veterinary medicine, although the pathways of transmission are far from being solved. the parasite is well known for causing diaplacental infections in cows associated with abortion and/or severe damage of the fetus. in addition, it may cause neuromuscular disease in dogs, which thus apparently act as intermediate hosts as well as final hosts. in our previous studies, we have demon ...200111688897
a swiss case-control study to assess neospora caninum-associated bovine abortions by pcr, histopathology and serology.neospora caninum is one of the most frequent infectious organisms causing abortion in cattle worldwide. the present case-control study was designed to assess the importance of bovine neosporosis for causing abortion in swiss cattle and to identify selected risk factors. infection was primarily diagnosed by a n. caninum-specific pcr and serology, complemented with histopathology and immunohistochemistry. a total of 113 case and 113 corresponding control-farms were studied for 1.5 year. during thi ...200111705647
neospora caninum in persistently infected, pregnant cows: spontaneous transplacental infection is associated with an acute increase in maternal antibody.nine cows which were naturally and persistently infected with neospora caninum were housed and observed intensively throughout pregnancy. no recrudescence of a latent infection was detected by pcr tests on maternal blood but fetal infection, implying a recrudescence of maternal parasitosis, was associated with a marked increase in maternal antibody. the increase occurred in the second half of pregnancy in five cows which infected their calves, and before mid-pregnancy in one cow which aborted. t ...200111688746
hammondia heydorni-like oocysts shed by a naturally infected dog and neospora caninum nc-1 cannot be distinguished.this study describes transmission experiments using hammondia heydorni-like oocysts isolated in 1996 from a naturally infected dog. the isolate was designated as h. heydorni-berlin-1996. examination of sera from infected intermediate hosts showed immunoblot reactions that resembled patterns observed after neospora caninum nc-1 infection. furthermore, n. caninum dna could be demonstrated in tissue samples (e.g. heart, brain) of experimentally infected intermediate hosts and in oocyst preparations ...200111688886
immune responses in pregnant cattle and bovine fetuses following experimental infection with neospora caninum.humoral and cell-mediated immune (cmi) responses [i.e. proliferative responses and gamma interferon (ifn-gamma) production], were elicited in five cows infected between 159 and 169 days of gestation by a combined intravenous-intramuscular inoculation of neospora caninum tachyzoites. analysis of antigen-specific immunoglobulin (igg) subclasses revealed a predominant igg2 response in two cows, a mixed igg1-igg2 response in two other cows and a predominant igg1 response in one cow. no correlation w ...200111688887
epidemiological pattern and risk factors associated with bovine viral-diarrhoea virus (bvdv) infection in a non-vaccinated dairy-cattle population from the asturias region of spain.a survey of bovine viral-diarrhoea virus (bvdv) infection was carried out in a non-vaccinated cattle population from the asturias region of spain in 1997 to assess seroprevalence and identify risk factors associated with infection. twenty-eight herds were included; 529 cows were bled. information regarding the herd and each animal sampled were recorded through a personal interview with the farmer. the true prevalence was estimated to be 21%. according to the antibody-age profiles and the herd-ma ...200111566379
protection against vertical transmission in bovine neosporosis.in this study we were interested to determine whether infection of cattle prior to pregnancy would afford any protection to the foetus if the dams were challenged with neospora caninum at mid-gestation. the experiment comprised four groups of cattle: group 1, uninfected controls; group 2, inoculated with n. caninum tachyzoites 6 weeks prior to mating and then challenged with n. caninum at mid-gestation; group 3, naive cattle challenged with n. caninum at mid-gestation and group 4 were infected w ...200111595240
neosporosis in bovine dairy herds from the west of france: detection of neospora caninum dna in aborted fetuses, seroepidemiology of n. caninum in cattle and dogs.neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. in this study, the role of n. caninum was investigated in groups of aborted cattle and dairy herds from the west of france. good correlation was found between parasite dna detection in fetuses and serologic statuses of dams. in groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropositive for n. caninum, and significant relationship b ...200111731070
placentophagia--an alternative way for horizontal transmission of neospora caninum in cattle? 200111756037
isolation of neospora caninum from the brain of a pregnant sheep.neospora caninum was isolated from the brain of a naturally infected pregnant sheep by inoculation of immunodeficient mice with a homogenate of the brain tissue. the ewe showed no clinical signs. tachyzoites were observed in the tissues of the nu/nu mice injected with the brain tissue homogenate and the diagnosis was confirmed by immunohistochemical staining with anti-n. caninum antibodies and by detecting n. caninum-specific dna by polymerase chain reaction.200111780846
isolation and characterization of two parasitic protozoa from a pacific harbor seal (phoca vitulina richardsi) with meningoencephalomyelitis.two species of protozoans were isolated from a harbor seal with fatal meninogoencephalitis. serologic reactivity was detected to both sarcocystis neurona and toxoplasma gondii. parasites associated with brain inflammation and necrosis reacted only with immunohistochemical stains utilizing polyclonal antisera raised against sarcocystis neurona. however, 2 distinct parasites were observed in cell cultures derived from the seal's brain tissue. these parasites were separated by mouse passage and lim ...200111534647
ranch-management factors associated with antibody seropositivity for neospora caninum in consignments of beef calves in texas, usa.a study was conducted with a 1998 retained-ownership population of texas (usa) beef calves to determine the ranch-management practices associated with calf seroprevalence to neospora caninum. management practices of 76 texas ranches that consigned 760 calves to a retained-ownership feedlot program were reviewed from a mailed questionnaire. ninety-nine of 760 (13%; 95% ci, 9.4%, 17.7%) calves were positive to n. caninum and 59% of the ranches consigned at least one positive calf. in the logistic ...200111566378
serodiagnosis of toxoplasma gondii infection in cats by enzyme-linked immunosorbent assay using recombinant sag1.the gene encoding surface antigen 1 (sag1, p30) of toxoplasma gondii (t. gondii) was cloned into the plasmid pgex-4t-3 and subsequently expressed in escherichia coli (e. coli) as a glutathione-s-transferase (gst) fusion protein. the recombinant sag1 (rsag1) was refolded using 8m urea solution followed by dialysis and thereafter evaluated in an enzyme-linked immunosorbent assay (elisa) for serological diagnosis of toxoplasmosis. the test sera were adsorbed with gst to block non-specific reactivit ...200111705650
first confirmed case of neospora caninum-associated abortion outbreak in portugal.in a dairy herd experiencing an abortion outbreak, 49% of the 119 cows were positive for neospora caninum antibodies and the remaining 51% were seronegative. using immunohistochemical analysis of foetal brain tissue, neospora cysts and bradyzoite clusters were identified in two of the 15 aborted foetuses submitted for testing. other agents that commonly cause abortions were not found. these results, coupled with neurological clinical symptoms in new-born calves, implicated n. caninum as the majo ...200111928926
neospora caninum microneme protein ncmic3: secretion, subcellular localization, and functional involvement in host cell interaction.in apicomplexan parasites, host cell adhesion and subsequent invasion involve the sequential release of molecules originating from secretory organelles named micronemes, rhoptries, and dense granules. microneme proteins have been shown to be released at the onset of the initial contact between the parasite and the host cell and thus mediate and establish the physical interaction between the parasite and the host cell surface. this interaction most likely involves adhesive domains found within th ...200111553593
protease activity and host cell binding of the 42-kda rhoptry protein from toxoplasma gondii after secretion.three proteases were identified in the excretory/secretory proteins (esp) from toxoplasma gondii by the gelatin acrylamide gel electrophoresis (gage), of which the molecular masses were 80, 70, and 42 kda. one of the proteases with 42 kda was reactive to a monoclonal antibody (mab), tg786 clone, which was localized in the rhoptry of t. gondii by immunohistochemistry. the protease was maximally active at the ph range between 7.5 and 8.5, and was sensitive to inhibition by tpck and egta. the gelat ...200111563841
prevalence of neospora caninum infection in dogs from beef-cattle farms, dairy farms, and from urban areas of argentina.prevalence of anti-neospora caninum antibodies was determined in sera of 320 dogs from argentina using the indirect fluorescent antibody test (ifat). antibodies to n. caninum were found in 121 of 320 (37.8%) sera with titers of 1:50 (21 dogs), 1:100 (23 dogs), 1:200 (23 dogs), 1:400 (17 dogs), 1:800 (23 dogs), and > or = 1:1.600 (14 dogs). the seropositivity (ifat, > or = 1:50) was higher in dogs from dairy (48% of 125) and beef (54.2% of 35) farms than in dogs from urban areas (26.2% of 160). p ...200111534656
oocyst excretion in dogs fed mouse brains containing tissue cysts of a cloned line of neospora caninum.neospora caninum is an apicomplexan parasite that causes neonatal neuromuscular disease in dogs and abortions in cattle. bovine neosporosis is a major production problem worldwide. the parasite is transmitted to cattle via oocysts excreted by dogs or by transplacental transmission. dogs are the only proven definitive host for n. caninum. one of 3 dogs fed mouse brains containing tissue cysts of a wild-type n. caninum strain ck0160sc3b (cko) excreted oocysts in its feces. two of 3 dogs fed mouse ...200111534658
association between exposure to neospora caninum and milk production in dairy cows.to determine association between exposure to neospora caninum and milk production in dairy cows.200111549092
seroprevalence study of bovine neosporosis in mexico.an indirect enzyme-linked immunosorbent assay was used to obtain epidemiologic information on bovine neosporosis in dairy herds of the mexican central plateau. sera were collected from 1,003 cows from 50 dairy herds. forty-three herds (group a) had been experiencing a high abortion rate. the abortion rates for the remaining 7 herds (group b) were within normal limits for mexico. five-hundred sixty-one (56%) of the 1,003 sera were positive. the seroprevalence of neospora caninum antibodies was 72 ...200111580063
isolation of neospora caninum from the brain of a naturally infected dog, and production of encysted bradyzoites in gerbils.neospora caninum was isolated from the brain of an adult dog in brazil. cerebral tissue from the dog was inoculated into mongolian gerbils. gerbils were euthanized 3-4 months later and bradyzoite-containing tissue cysts were observed in their brains. n. caninum (designated nc-bahia) was isolated in cell culture after inoculation with tissue cysts from the gerbils. the identity of the parasite was confirmed by immunohistochemical examination and polymerase chain reaction (pcr). gerbils may be a u ...200111587828
validation of a commercially available monoclonal antibody-based competitive-inhibition enzyme-linked immunosorbent assay for detection of serum antibodies to neospora caninum in cattle.a previously described monoclonal antibody (mab)-based competitive-inhibition enzyme-linked immunosorbent assay (celisa) was modified to optimize performance, and the assay was validated in various defined cattle populations for detection of serum antibody to neospora caninum, a major cause of bovine abortion. modifications to the celisa included capturing native n. caninum antigen with a parasite-specific mab (mab 5b6-25) and directly conjugating the competitor mab (mab 4a4-2), with both mabs b ...200111682497
dogs shed neospora caninum oocysts after ingestion of naturally infected bovine placenta but not after ingestion of colostrum spiked with neospora caninum tachyzoites.an experiment was carried out to determine whether bovine colostrum or placenta could be a source of infection of neospora caninum for dogs. for this purpose, two dogs were fed bovine colostrum to which culture-derived n. caninum tachyzoites were added and two other dogs were fed placental cotyledonary tissue from n. caninum seropositive cows. one dog served as a negative control during the start of the experiment but this control dog was fed cotyledonary tissue later on. none of the dogs did pr ...200111403764
first isolation of neospora caninum from the feces of a naturally infected dog.neospora caninum is a major cause of abortion in cattle worldwide. cattle become infected with n. caninum by ingesting oocysts from the environment or transplacentally from dam to fetus. experimentally, dogs can act as definitive hosts, but dogs excrete few oocysts after ingesting tissue cysts. a natural definitive host was unknown until now. in the present study, n. caninum was isolated from the feces of a dog. gerbils (meriones unguiculatus) fed feces from the dog developed antibodies to n. ca ...200111426726
neosporosis in mexican dairy herds: lesions and immunohistochemical detection of neospora caninum in fetuses.of 211 aborted bovine fetuses collected from mexican dairy herds between january 1996 and march 1999, 73 showed microscopical lesions consistent with neosporosis. of these 73 fetuses, 58 (79%) showed lymphocytic myocarditis, 39 (53%) showed microgliosis and multifocal necrosis in the brain, 39 (53%) showed lymphocytic hepatitis, and 19 (26%) showed lymphocytic myositis. immunohistochemical examination of brain, myocardium and liver from 53 of the same 73 fetuses demonstrated neospora caninum ant ...200111437517
detection of igg antibodies to neospora caninum and toxoplasma gondii in dogs examined in a veterinary hospital from brazil.a total of 163 dogs with neuromuscular, respiratory and/or gastrointestinal disorders, was admitted at the veterinary hospital, federal university of uberlândia, brazil, and submitted to serology for toxoplasma gondii and neospora caninum. assays for t. gondii included indirect haemagglutination (iha), indirect fluorescent antibody (ifat-tg), immunoenzymatic (elisa), and immunoblotting (ib-tg). assays for n. caninum included ifat-nc and immunoprecipitation (ip-nc). based on concordant results by ...200111423182
serological diagnosis of neosporosis in a herd of dairy cattle in southern brazil.neospora caninum-specific antibodies were detected in 60 of 172 (34.8%) dairy cattle by enzyme-linked immunosorbent assay (elisa) in a herd from parana state, brazil. the seropositive animals included 47 of 126 (37.3%) adult cows, 7 of 29 (24%) heifers (1-2 yr), 4 of 15 (27%) heifers (5 mo-1 yr), and 2 precolostral samples. data collected over a 9-yr follow-up period revealed that the proportion of pregnancies ending in abortion was 20% (31/154) among elisa seropositive cows and 8% (15/193) amon ...200111780849
red foxes (vulpes vulpes) in ireland as hosts for parasites of potential zoonotic and veterinary significance.intestinal washes, faecal flotations and serological examinations for antibodies to toxoplasma gondii and neospora caninum were used to assess the prevalence of parasites in carcases of foxes killed on roads or shot in the dublin area and surrounding counties. the ascarids uncinaria stenocephala and toxocara canis were prevalent, as was the trematode alaria alata. taenia species, eggs of capillaria species and sporocysts of sarcocystis species were also found. only one fox out of 70 examined was ...200111808662
efficacy of toltrazuril and ponazuril against experimental neospora caninum infection in mice.neosporosis is a disease affecting predominantly fetal development in cattle and dog hosts; and it may cause neuromuscular disfunction in infected newborn calves and pups. predispositions--including, e.g. transient immunosuppression during pregnancy--may result in an increased dissemination of the parasite within the host or its offspring. chemotherapeutic treatment of neosporosis may be an issue, provided that an appropriate drug is made available. in this respect, we describe the use of a mous ...200111199848
prevalence of neospora hughesi and sarcocystis neurona antibodies in horses from various geographical locations.parasite-specific antibody responses to neospora antigens were detected using the immunofluorescent antibody test (ifat) and immunoblot analysis in select equine populations. for comparison, a naturally infected neospora hughesi horse and an experimentally inoculated neospora caninum horse were used. in addition, all samples were tested for antibodies to sarcocystis neurona by immunoblot analysis. a total of 208 samples was evaluated. the equine populations were derived from five distinct geogra ...200111223207
molecular comparison of the dense granule proteins gra6 and gra7 of neospora hughesi and neospora caninum.neospora hughesi is a recently described apicomplexan parasite that has been associated with several cases of equine protozoal myeloencephalitis. the biology of this new parasite is just beginning to be defined. towards this understanding, we report important differences between the nucleotide and deduced amino acid sequences of the dense granule proteins gra6 and gra7 of n. hughesi and neospora caninum. this information can be used to differentiate the two species and contribute to further unde ...200111226451
granulomatous encephalitis in a neurologically impaired goat kid associated with degeneration of neospora caninum tissue cysts.congenital neospora caninum infection was diagnosed in a saanen goat from a farm in southern brazil. the kid was unable to nurse and had difficulty rising, ataxia, and opistothotonos. the neurologic signs became more severe 3 days after birth, when it was euthanized. no gross lesions were observed at necropsy. multifocal infiltrates primarily of mononuclear cells, nodular microgliosis, and perivascular cuffs of lymphocytes, plasma cells, and few neutrophils were observed in the brain, mostly in ...200111580064
evidence of post-natal transmission of neospora caninum in dutch dairy herds.eighteen dairy herds with neosporosis-associated abortions were analysed for antibodies against neospora caninum. blood samples of all cows, heifers and calves were collected on the same day for each farm. a total of 2430 heads of cattle were examined. for each herd, the seropositive and seronegative animals were plotted against month of birth. analysis of seroprevalence in relation to age showed an equal distribution of seropositives in all age-groups in 10 herds. in contrast, in eight herds an ...200111239942
determination of antigenic domain in gst fused major surface protein (nc-p43) of neospora caninum.the antigenic domain of the major surface protein (nc-p43) of neospora caninum was examined by polymerase chain reaction of its gene fragments and recombinant expression as gst fusion proteins. the fragments of nc-p43 were as follow: a total open reading frame (ofr), t; ofr without signal sequence and c-terminal hydrophobic sequence, s; n-terminal 2/3 parts of s, a; c-terminal 2/3 parts, p; n-terminal 1/3 part, x; middle 1/3 part, y; and c-terminal 1/3 part, z, respectively. the dna fragments we ...200111590914
immunity to experimental neosporosis in pregnant sheep.neospora caninum is an important cause of fetal loss in cattle but has also infrequently been shown to cause disease in sheep and goats. experimental infection of pregnant sheep with n. caninum causes clinical and pathological changes very similar to those of neosporosis in cattle. an experiment in sheep was undertaken to examine whether infection with n. caninum before pregnancy conferred immunity to subsequent challenge with the parasite during pregnancy. primary inoculation of nc1 tachyzoites ...200111240899
prevalence of antibodies to neospora caninum in horses in france. 200111266072
characterization of neospora caninum surface protein ncsrs2 based on baculovirus expression system and its application for serodiagnosis of neospora infection.the baculovirus expression system has proved to be a useful tool for the production of recombinant proteins. here we have characterized the neospora caninum surface protein ncsrs2 produced by two types of the recombinant virus and also have developed an enzyme-linked immunosorbent assay (elisa) using recombinant ncsrs2 for the serologic diagnosis of neospora infection. western blot analysis showed two major protein bands that were detectable in insect cells infected with each recombinant baculov ...200111682519
seroprevalence of neospora caninum in beef cattle in northern alberta.blood samples were collected from 1806 pregnancy-tested cows from 174 herds at a northern alberta auction mart in the fall of 1998. one hundred sixty-two (9.0%) of these samples were positive for antibodies to n. caninum. thirty-five of 260 samples (13.5%) collected from the same region in the 1980s were also serologically positive for n. caninum.200111272457
toxoplasma gondii: molecular cloning and characterization of a novel 18-kda secretory antigen, tgmic10.hoff, e. f., cook, s. h., sherman, g. d., harper, j. m., ferguson, d. j. p., dubremetz, j. f., and carruthers, v. b. 2001. toxoplasma gondii: molecular cloning and characterization of a novel 18-kda secretory antigen, tgmic10. experimental parasitology, 97, 77-88. during host cell invasion, toxoplasma gondii secretes proteins from specialized organelles (micronemes and rhoptries) located at the apical end of the parasite. the contents of the micronemes appear to be crucial to t. gondii invasion, ...200111281704
rare detection of neospora caninum in placentas from seropositive dams giving birth to full-term calves.neospora caninum is thought to be transmitted to cattle by dogs, the only known definitive host. although aborted fetuses seem the most likely source of infective material for dogs, placentas from seropositive dams appear also as a potential source of infective material. the objective of the study was to evaluate the presence of n. caninum organisms in placentas of full-term calves born to seropositive cows. sixteen placentas, 11 from neospora-seropositive cows, were examined histologically and ...200111289218
naturally-occurring neospora caninum infection in an adult sheep and her twin fetuses.neospora caninum tissue cysts were found in the brains of surgically delivered twin fetuses at 119 days of gestation. in the brains of both fetuses, there was an inflammatory reaction involving perivascular cuffings of mononuclear cells, glial nodules. the dam of these fetuses died because of metritis. histopathological examination of the ewe revealed n. caninum tissue cysts and focal gliosis with mononuclear cell cuffings. a n. caninum-specific dna fragment was detected in a brain homogenate of ...200111318580
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