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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
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
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
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
comparison of the growth inhibitory effects of canine ifn-alpha, -beta and -gamma on canine cells infected with neospora caninum tachyzoites.the growth inhibitory effects of recombinant canine interferon alpha (ifn-alpha), beta (ifn-beta) and gamma (ifn-gamma) were examined on madin-darby canine kidney cells infected with neospora caninum tachyzoites. the parasite growth was inhibited by all ifns in a dose-dependent manner. ifn-gamma inhibited the parasite growth with greater efficacy than ifn-alpha or ifn-beta. moreover, the effect of ifns on n. caninum growth associated with the suppression of the host cell viability. the present s ...200111346181
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
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
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
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
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
seroprevalences of toxoplasma gondii and neospora caninum in swedish red foxes (vulpes vulpes).the prevalences of antibodies to the protozoan parasites toxoplasma gondii and neospora caninum were investigated by the direct agglutination test (dat) and elisa, respectively, in 221 red foxes (vulpes vulpes) from different parts of sweden. a total of 84 (38%) of the analysed sera had antibodies to t. gondii, but none of the foxes had antibodies to n. caninum. the results indicate that t. gondii infection is fairly common in swedish red foxes and that the infection is present in most parts of ...200111705663
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
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
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
structural analysis of free and protein-bound glycosyl-phosphatidylinositols of neospora caninum. 200010613708
[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
diagnosis and epidemiology of bovine neosporosis: a review.neospora caninum is a protozoan parasite that was first described in dogs in 1988. subsequently the parasite has been associated with abortion in cattle. evidence is accumulating that neosporosis is a major cause of reproductive failure in cattle all over the world. recent knowledge of neosporosis is reviewed with emphasis on the diagnosis and epidemiology of the disease in cattle. in addition, attention is paid to strategies for disease control and prevention.200010789513
molecular characterization of a novel microneme antigen in neospora caninum.the apical complex of the parasites belonging to the phylum sporozoa is believed to be critically involved in the events leading to host cell invasion. the characterization of the components of this subcellular structure is therefore an important step towards understanding how these parasites achieve host cell entry. affinity-purification of an anti-neospora caninum antiserum on a reactive protein band of approximately 40 kda following triton-x-114 extraction of parasite proteins, sds-page and w ...200010802317
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
isolation, characterization and expression of a gra2 homologue from neospora caninum.a cdna library derived from mrna of tachyzoites of neospora caninum (nc-liverpool strain) was screened with antisera from a cow naturally infected with n. caninum. the dna sequence of 1 recombinant isolated predicted a significant protein sequence homology of the gene product to the 28 kda (gra2) antigen of toxoplasma gondii. studies on the n. caninum gene coding for this antigen demonstrated the presence of a single intron flanked by 2 exons; the gene was also highly expressed in culture-derive ...200010811279
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
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
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
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
[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
neospora caninum seroprevalence and associated risk factors in beef cattle in the northwestern united states.a neospora caninum seroprevalence and risk factor survey of 2585 cows was conducted in 55 beef cow-calf herds located in five northwestern states of the usa. blood samples were collected by private veterinary practitioners and management practices were surveyed using a mail questionnaire. producers were randomly selected from those that employed these veterinarians to perform annual herd pregnancy examinations. questions were asked about animal management, grazing and feeding, immunization and r ...200010828508
[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
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
seroprevalence of neospora caninum infection in domestic dogs in turkey. 200010872789
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
histopathological survey of aborted bovine fetuses in scotland with special reference to neospora caninum. 200011132675
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
biological characterisation of sarcocystis neurona isolated from a southern sea otter (enhydra lutris nereis).sarcocystis neurona was isolated from the brain of a juvenile, male southern sea otter (enhydra lutris nereis) suffering from cns disease. schizonts and merozoites in tissue sections of the otter's brain reacted with anti-s. neurona antiserum immunohistochemically. development in cell culture was by endopolyogeny and mature schizonts were first observed at 3 days postinoculation. pcr of merozoite dna using primer pairs jnb33/jnb54 and restriction enzyme digestion of the 1100 bp product with dra ...200010779575
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 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
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
[progress in the research on the tachyzoite-bradyzoite conversion of toxoplasma gondii]. 200012567672
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
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
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
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
prevalence of neospora antibodies in beef cattle in new zealand.to estimate the prevalence of neospora infection in a sample of new zealand beef cattle.200016032142
neospora caninum infection in an aborted bovine foetus in brazil. 199916032066
maintenance of neospora caninum tachyzoites using mongolian gerbils (meriones unguiculatus). 199916032067
estimation of vertical and horizontal transmission parameters of neospora caninum infections in dairy cattle.transmission parameters of neospora caninum infections in dairy cattle were determined in six herds with a history of neospora-associated abortions, using an antibody-detection elisa to detect evidence of infection. a total of 124 seropositive dams and their calves were tested at calving to estimate vertical transmission, and 154 seronegative heifers were monitored prospectively from birth for evidence of post-natal infection. the probability of vertical transmission was very high; 95.2% (95% co ...199910608455
mathematical models of neospora caninum infection in dairy cattle: transmission and options for control.the transmission and control of neospora caninum infection in dairy cattle was examined using deterministic and stochastic models. parameter estimates were derived from recent studies conducted in the uk and from the published literature. three routes of transmission were considered: maternal vertical transmission with a high probability (0.95), horizontal transmission from infected cattle within the herd, and horizontal transmission from an independent external source. putative infection via po ...199910608456
neospora caninum infections in bovine foetuses and dairy cows with abortions in argentina.antibodies to neospora caninum were measured in bovine foetuses, dairy cows and beef cows in argentina using the ifat, the n. caninum agglutination test, and the recombinant ncdg1 and ncdg2 elisa. serum antibodies (ifat titre 1:80) were found in 20 of 82 (24.4%) dairy cow foetuses and one of 22 (4.5%) beef cow foetuses. microscopic lesions suggestive of neosporosis were seen in brains of seven of eight foetuses with ifat titres of 1:80. antibodies (ifat) were found in 122 of 189 (64.5%) dairy co ...199910608457
high prevalence of antibodies to neospora caninum in white-tailed deer (odocoileus virginianus).serum samples of 400 white-tailed deer (odocoileus virginianus) from 16 preserves in northeastern illinois were tested for neospora caninum antibodies in the n. caninum agglutination test using mouse-derived n. caninum tachyzoites and mercaptoethanol. antibodies were found in 162 deer with titres of 1:40 (47 deer), 1:80 (32 deer), 1:160 (17 deer), 1:200 (eight deer), 1:400 (19 deer), 1:800 (17 deer) and > or = 1:1600 (22 deer). there were no significant differences in prevalence between age or s ...199910608458
the in vitro development of neospora caninum bradyzoites.neospora caninum is a recently identified apicomplexan protozoan parasite that is closely related to toxoplasma gondii. neospora caninum is of significant economic importance as it causes neurological disease and abortion in numerous animals. antibodies to bag1/hsp30 (also known as bag5), a t. gondii bradyzoite-specific protein, have been demonstrated to react with n. caninum tissue cysts in vivo. bradyzoite differentiation of n. caninum in vitro was investigated using culture conditions previou ...199910608459
growth of and competition between neospora caninum and toxoplasma gondii in vitro.competitive interactions between neospora caninum and toxoplasma gondii were studied because both species appear to have identical ecological niches in vitro. tachyzoites of n. caninum (nc-1 isolate) and t. gondii (rh isolate) were compared in three in vitro studies: (1) rate of penetration of host cells; (2) generation time; and (3) competition between the two species when grown together in the same flask and allowed to compete for space. when tachyzoites of the two species were inoculated onto ...199910608460
predictive values of fetal histopathology and immunoperoxidase staining in diagnosing bovine abortion caused by neospora caninum in a dairy herd. 19999925219
herd-specific and age-specific seroprevalence of neospora caninum in 14 british dairy herds.all the cattle in 14 dairy herds in england were tested for neospora caninum-specific antibodies with a commercial elisa. three of the herds had had sporadic abortions, eight had had endemic abortions and three had had epidemic abortions associated with n caninum before the study. of 4295 cattle tested, 17.1 per cent were seropositive and the herd-specific prevalence ranged from 7.3 per cent to 44.8 per cent. no significant effect of either herd size (p = 0.988), endemic (p = 0.869) or epidemic ...199910371011
pathological and immunological findings of athymic nude and congenic wild type balb/c mice experimentally infected with neospora caninum.neospora is a cyst-forming coccidian parasite that causes abortions and neuromuscular disorders in a wide variety of mammals. japanese bovine isolate jpa1 was inoculated intraperitoneally into balb/c nu/ nu (athymic nude) and balb/c (congenic wild type) female mice to examine the distribution of parasites and resistance mechanisms to neospora infection. all the athymic nude mice died within 28 days after intraperitoneal injection of 2 x 10(5) jpa1 tachyzoites, whereas all the congenic wild type ...199910421099
[molecular and immunodiagnostic studies of bovine neosporosis in switzerland].cyst-forming coccidia may cause significant losses in livestock, primarily due to abortion, loss of young animals and neuromuscular diseases. rather recently, neospora caninum has been recognized as one of the major protozoal abortion-inducing parasites in cattle. the present study addressed the performance of different diagnostic tools (in vitro-cultivation; histology; immunohistochemistry; serology; pcr) suitable for the direct or indirect detection of n. caninum. by pcr, neospora-dna was dete ...199910028228
sequence and pcr-rflp analysis of the internal transcribed spacers of the rdna repeat unit in isolates of cryptosporidium from different hosts.the cryptosporidium its1, 5.8s and its2 rdna regions from a number of cryptosporidium isolates from different hosts and geographical areas were cloned and sequenced in order to investigate the extent of sequence heterogeneity between human and cattle-derived isolates from different geographical locations and also between isolates of cryptosporidium from different hosts such as cats, pigs, mice and a koala. calf-derived isolates from different continents were virtually identical as were human-der ...199910070661
bovine abortion associated with neospora caninum in northern spain.during 1996, aborted bovine fetuses from dairy herds in norther spain were examined by histopathological, immunohistochemical and serological methods for evidence of infection by neospora caninum. microscopical brain changes consistent with those of neosporosis were detected in 36 of 81 fetuses and specific antibodies (ifat titres > or = 1/16) in 32 of 63. eight fetuses with neurological lesions were seronegative, and eight without lesions were seropositive. in 25 of 34 fetal brains with lesions ...199910074662
characterization of temperature-sensitive strains of neospora caninum in mice.temperature-sensitive (ts) strains of the neospora caninum tachyzoites were selected by chemical mutagenesis and selection for growth at 32 c. three ts strains and the parental, n. caninum wild-type strain, nc-1, were examined in the present study for their ability to cause disease in inbred balb/c mice, outbred icr mice, and chemically immunosuppressed icr mice. in balb/c mice, all 3 strains failed to induce clinical disease, whereas infection with the nc-1 strain caused central nervous system ...199910207365
the host-parasite relationship in neosporosis.neospora caninum is an apicomplexan parasite which invades many different cell types and tissues. it causes neosporosis, namely stillbirth and abortion in cattle and neuromuscular disease in dogs, and has been found in several other animal species. n. caninum is closely related to toxoplasma gondii, and controversial opinions exist with respect to its phylogenetical status. initially, two stages of n. caninum had been identified, namely asexually proliferating tachyzoites and bradyzoites. the se ...199910214690
neospora caninum infection and repeated abortions in humans.to determine whether neospora caninum, a parasite known to cause repeated abortions and stillbirths in cattle, also causes repeated abortions in humans, we retrospectively examined serum samples of 76 women with a history of abortions for evidence of n. caninum infection. no antibodies to the parasite were detected by enzyme-linked immunosorbent assay, immunofluorescence assay, or western blot.199910221883
susceptibility of b-cell deficient c57bl/6 (micromt) mice to neospora caninum infection.neospora caninum is a coccidian parasite of veterinary importance by causing abortion or stillbirth in cattle among other problems in diverse animal species. we assessed an experimental murine model for its suitability to study the immune response to n. caninum infection. thus, wild-type (wt) c57bl/6 mice and b-cell (and consequently antibody)-deficient micromt mice were infected with n. caninum tachyzoites and sacrificed at days 10, 24 and 29-44 post infection (dpi). various organs were collect ...199910320620
comparison of the biological characteristics of two isolates of neospora caninum.this study compared the biological and genetic properties of a bovine (nc-sweb1) and a canine (nc-liverpool) isolate of neospora caninum. a mouse model for cns infection demonstrated marked differences in pathogenicity between the isolates. nc-liverpool induced severe clinical signs of neosporosis in 57/58 mice including discoordinated movement, hindlimb paralysis and coat ruffling with severe weight loss. in contrast nc-sweb1 induced similar but less severe symptoms in a much smaller proportion ...199910340326
repetitive abortion in neospora-infected ewes.pregnant ewes inoculated with cultured neospora caninum tachyzoites in 1995, 1996, or 1995 and 1996 aborted or delivered weak or clinically normal lambs in 1996. nine of 11 ewes in the study had previously produced infected lambs or fetuses after being experimentally infected in 1995. fetuses and lambs produced in 1996 showed histologic lesions and zoites indicative of neospora. serologic responses and production of infected fetuses/lambs indicated systemic neosporosis in the ewes during gestati ...199910348105
[diagnosis and epidemiology of neospora caninum-associated abortions in cattle].neospora caninum, a recently discovered protozoan parasite closely related to toxoplasma gondii, has world-wide been recognized as an important cause of bovine abortion. n. caninum possesses a wide host range. the dog can be a definitive host for n. caninum. in cattle, the infection is transmitted transplacentally with high efficiency, while the majority of congenitally infected calves is clinically normal at birth and thereafter. whether horizontal transmission occurs in cattle and whether this ...199910384703
confirmation that the dog is a definitive host for neospora caninum.two mixed-breed littermate dogs were fed mouse brains containing tissue cysts of the nc-beef isolate of neospora caninum. both dogs excreted n. caninum oocysts in their feces. dog 1 which was given methylprednisolone acetate (mpa) prior to ingesting tissue cysts, excreted oocysts on days 5 to 10 inclusive and on day 17 after ingesting tissue cysts. dog 1 had a serum antibody titer of 1:200 in the indirect fluorescent antibody test (ifat) 35 days after it was fed tissue cysts. dog 2, which was no ...199910384909
absence of serological evidence for human neospora caninum infection. 199910404607
significance of neospora caninum in british dairy cattle determined by estimation of seroprevalence in normally calving cattle and aborting cattle.a case control study was conducted to evaluate the significance of neospora caninum infections in cattle in england and wales. the prevalence of n. caninum in normally calving cattle (the control group; n = 418) and aborting cattle (n = 633) was estimated using a commercial antibody-detection elisa. prevalence estimates for bovine virus diarrhoea virus, infectious bovine rhinotracheitis virus and leptospira hardjo were also obtained by serology. the prevalence of n. caninum was significantly hig ...199910576570
towards evaluating the economic impact of bovine neosporosis.in spite of the global importance of neosporosis as a cause of bovine abortion, there is very little information about its economic consequences. the economic costs are a product of estimations of the quantity of the effects attributable to neospora infection, and the particular unit costs of those effects. in this brief review, which arose from a workshop on the economics of coccidiosis held at the cost 820 meeting, toledo 1998, we discuss the possible effects of neosporosis which are of econom ...199910576571
in vitro isolation of neospora caninum from a stillborn calf in the uk.neospora caninum was isolated in vero cell culture from the brain of a stillborn calf. this isolate (designated nc-livb1) is the first to be obtained from cattle in the united kingdom and was confirmed as n. caninum by immunofluorescence with specific antibodies and by internal transcribed spacer 1 (its1) sequence analysis. differences were found between nc-livb1, other bovine isolates and canine isolates of n. caninum and closely related protozoal parasites, using random amplified polymorphic d ...199910425249
neospora caninum continues to be implicated in bovine abortion cases. 199910452389
recent advances in neospora and neosporosis.neospora caninum has emerged as a major cause of abortion in cattle in many countries. this paper reviews recent advances in the life cycle and biology of neospora with the emphasis on bovine neosporosis. the role of the recently discovered oocyst stage of n. caninum in the epidemiology of neosporosis is discussed. progress made in serologic diagnosis of n. caninum infection is discussed. there is no vaccine for preventing neospora-induced abortions in cattle or to prevent oocyst shedding in dog ...199910456423
serological differences in neospora caninum-associated epidemic and endemic abortions.a sandwich enzyme-linked immunosorbent assay (elisa) for the sensitive and specific detection of bovine antibodies to neospora caninum was developed and evaluated using sera from cattle experimentally infected with n. caninum, toxoplasma gondii, sarcocystis cruzi, sarcocystis hominis, sarcocystis hirsuta, eimeria bovis, cryptosporidium parvum, babesia divergens, and field sera from naturally exposed animals. field sera were classified using a gold standard that included the results from an indir ...199910461950
serum antibody profile and reproductive performance during two consecutive pregnancies of cows naturally infected with neospora caninum.the objective of this study was to record how the antibody levels change over time during pregnancy in dairy cows naturally infected with the protozoan parasite neospora caninum, and relate this to the reproductive performance. eighteen cows with antibodies to n. caninum were serum sampled monthly during their first pregnancy and 13 of them were also followed for a second pregnancy. in all, five pregnancies ended in abortion and two in stillbirth. antibodies to n. caninum in serum were demonstra ...199910488725
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