evidence of point-source exposure to neospora caninum and protective immunity in a herd of beef 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
experimental infection of nude mice as a model for sarcocystis neurona-associated encephalitis.the development of a rodent model for the study of sarcocystis neurona encephalitis is described. animal models have been developed for a number of protozoal parasites; however, no such model exists for s. neurona. the approach used in this study is similar to that employed for other closely related protozoal parasites such as neospora caninum and toxoplasma gondii. a time course of infection was examined, and histopathology, immunohistochemistry, and parasite isolation were used to examine the ...19979272562
immunization of dogs with a canine herpesvirus vector expressing neospora caninum surface protein, 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 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 determine the epidemiologic plausibility of a sylvatic transmission cycle for neospora caninum between wild canids and beef cattle.200011061391
antibody reaction of human anti-toxoplasma gondii positive and negative sera with neospora caninum antigens.anti-neospora caninum antibody was detected in anti-toxoplasma gondii positive and negative human sera by elisa, western blot and immunofluorescence assay (ifa). twelve cases out of 172 (6.7%) toxoplasma-positive sera cross-reacted with both t. gondii and n. caninum antigens, and one out of 110 toxoplasma-negative sera reacted with n. caninum antigen by elisa. by western blot, all 12 sera reacted with t. gondii antigens with various banding patterns but specifically at 30 kda (sag1) and 22 kda ( ...19989868893
the relationship of hammondia hammondi and sarcocystis mucosa to other heteroxenous cyst-forming coccidia as inferred by phylogenetic analysis of the 18s ssu ribosomal dna sequence.the complete sequence of the 18s small subunit (ssu) ribosomal dna of hammondia hammondi and sarcocystis mucosa was obtained and compared to ssu rdna sequences of neospora caninum, toxoplasma gondii, besnoitia besnoiti, 2 species of frenkelia, 3 species of isospora, and 13 species of sarcocystis. analyses showed that h. hammondi and t. gondii are monophyletic and that these taxa shared a common ancestor with n. caninum and b. besnoiti. the weight of evidence shows that s. mucosa, s. neurona, and ...199910466120
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
serological investigation of an outbreak of neospora caninum-associated abortion in a dairy herd in southeastern united 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 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
postnatal neosporosis in dairy cattle in northeast thailand.a total of 83 dairy cows in loei province (muang) and nong bua lamphu (nbl) province, northeast thailand were sampled three times within 6 months in 1998 and their sera were examined for antibodies to neospora caninum at a dilution of 1:100 in the indirect fluorescent antibody test (ifat). in muang the seroprevalence of n. caninum was 37.5% (june), 60% (august), and 62.5% (november). in nbl the prevalence was 50% (august) and 70% (november). in both areas abortions were observed between 1 and 3 ...200111113552
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
histopathological survey of aborted bovine fetuses in scotland with special reference to neospora caninum. 200011132675
do cows protect fetuses from neospora caninum transmission? 200111137733
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
protective efficacy of vaccination by recombinant vaccinia virus against neospora caninum infection.the recombinant vaccinia viruses expressing the surface protein of neospora caninum tachyzoite, ncsag1 or ncsrs2, were constructed. the vaccination with these recombinant viruses could protect effectively the parasite invasion in a mouse model system. the vaccine efficacy of ncsrs2 was higher than that of ncsag1. the present study indicated that a high level of igg1 ab production to parasite is important for clearance of parasite at the early stage of infection and that t cell response has a cru ...200111163660
isolation of neospora caninum genes detected during a chronic murine order to isolate genes coding for antigens of neospora caninum which are recognised by the host immune system during a chronic murine infection, a cdna library was immunoscreened with pooled sera from mice which survived three independent infections by n. caninum. two new genes from n. caninum were isolated and expressed in escherichia coli. the genes identified include one homologous to gra1 of toxoplasma gondii, plus another (ncp20) previously unknown in any taxon. both genes encode small p ...200111165273
prevention of vertical transmission of neospora caninum in balb/c mice by recombinant vaccinia virus carrying ncsrs2 gene.neospora caninum infection is the major cause of bovine abortion. to develop a vaccine against n. caninum infection, recombinant vaccinia viruses carrying ncsrs2 and ncsag1 genes (vv/nc-p43 and vv/nc-p36, respectively) were constructed and were tested in a mouse model. vaccination of dams with vv/nc-p43 appeared to confer effective protection against vertical transmission to offspring, though that with vv/nc-p36 only provided partial protection. moreover, the vv/nc-p43 vaccination provoked cellu ...200111166895
serological analysis of calves experimentally infected with neospora caninum: a 1-year study.a serological study was conducted with calves experimentally infected with the protozoan parasite neospora caninum. the animals were inoculated with either a low or high dose of n. caninum tachyzoites and temperature responses monitored daily for the first 2 weeks after inoculation. blood samples were collected before inoculation, and at regular intervals thereafter for 1 year. serological analysis was achieved using an indirect fluorescent antibody test (ifat), an enzyme-linked immunosorbent as ...200111182233
serological evidence of human infection with the protozoan neospora caninum.neospora caninum is a protozoan parasite that is closely related to toxoplasma gondii. dogs are a definitive host. prior to its discovery in 1988, n. caninum infection in animals was often mistakenly diagnosed as toxoplasmosis. neosporosis in animals is characterized by encephalitis, abortion, and other conditions that clinically and pathologically resemble toxoplasmosis. the potential of n. caninum to infect humans is unknown. therefore, evidence of human exposure to this parasite was sought by ...199910473533
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
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
characterization of a cdna encoding a subtilisin-like serine protease (nc-p65) of neospora caninum.the nc-p65 cdna is the first protease sequence cloned and described for neospora caninum. the full length cdna was isolated by 5'- and 3'-rapid amplification of cdna ends (race). nc-p65 was composed of 865 amino acids with a predicted signal sequence, a proposed pro-domain, and an internal region of conserved repeats. analysis of the deduced amino acid sequence revealed that this protein had homology to the serine proteases of the subtilisin-like superfamily (subtilases) and had a predicted acti ...199910551364
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
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
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
a previous infection with toxoplasma gondii does not protect against a challenge with neospora caninum in pregnant sheep.sheep immunized with toxoplasma gondii (toxovax) prior to pregnancy were tested for their ability to withstand a challenge at 90 days gestation with 107 neospora caninum (nc1) tachyzoites. the antibody responses in sheep following immunization with t. gondii were specific for t. gondii whereas peripheral blood mononuclear cells responded to both t. gondii and n. caninum antigen in vitro. this suggested that there was induction of crossreactive immune recognition in the sheep, at least at the cel ...200111240903
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
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
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
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
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
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
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
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
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
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
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
experimental studies on the transmission of neospora caninum between cattle.three studies were conducted to investigate the transmission of neospora caninum between cattle by the oral route. in the first study, six calves were dosed with 10(7)n caninum tachyzoites (nc livb1) in colostrum and/or milk replacer on four occasions. in the second study, two calves and two cows were fed placental tissues from n caninum -infected cows, and, in the third study, seven uninfected calves were fostered onto n caninum -infected dams. in the first study, all six calves developed antib ...200111356096
failure of dogs to shed oocysts after being fed bovine fetuses naturally infected by neospora caninum.neospora caninum is a protozoan that causes abortion in cattle. the dog has recently been identified as a definitive host for n. caninum. to verify if bovine fetuses can infect dogs, nine 2-4-month-old dogs were fed bovine fetuses naturally infected by n. caninum. none of the dogs excreted oocysts, seroconverted, had clinical signs or lesions compatible with n. caninum infection. additional studies will be necessary to determine the natural mode of infection of dogs by n. caninum.200111358630
neospora caninum infection associated with stillbirths in captive antelopes (tragelaphus imberbis).neosporosis was diagnosed in full-term stillborn twin calves of captive antelopes (tragelaphus imberbis) in a german zoo. in both calves a multifocal non-suppurative encephalitis was present and infection with neospora (n.) caninum was confirmed by foetal serology and pcr. n. caninum-dna was detected in brain, heart, lung, liver and spleen of a third full-term stillborn calf. histopathological lesions were absent in this calf and antibodies against n. caninum were not detected in pleural fluid. ...200111358631
prevalence of antibodies to neospora caninum and toxoplasma gondii in gray foxes (urocyon cinereoargenteus) from south carolina.little is known about the epidemiology of neospora caninum in wild mammal populations. it has been suggested that a sylvatic cycle exists for n. caninum. dogs and potentially other canids are a definitive host for n. caninum. the present study was done to determine the prevalence of antibodies to n. caninum in a population of gray foxes (urocyon cinereoargenteus) from a nonagricultural setting in south carolina. we also determined the prevalence of antibodies to toxoplasma gondii in these animal ...200111358632
reproductive performance of a cow-calf herd following a neospora caninum-associated abortion epidemic.this study examines the long-term impact of a neospora caninum-associated abortion outbreak in a large cow-calf herd in northern alberta. blood samples were collected 4 times from all bred females and heifer calves born during the spring before the outbreak: (1) at the time of the outbreak, (2) the following spring, (3) the subsequent fall, and, finally, (4) the second spring after the outbreak. the samples were analyzed using a commercially available enzyme-linked immunosorbent assay for n. can ...200111360856
evaluation of the embryo transfer procedure proposed by the international embryo transfer society as a method of controlling vertical transmission of neospora caninum in evaluate efficacy of embryo transfer into seronegative recipients, using the procedure proposed by the international embryo transfer society (iets), for preventing vertical transmission of neospora caninum in cattle.200111394835
bovine abortion associated with neospora caninum in hungary.the authors report the first case of bovine neosporosis in hungary based on investigations made on an aborted fetus. the diagnostic methods included traditional as well as molecular techniques. this record extends further the geographic range of the disease.200111402646
dogs shed neospora caninum oocysts after ingestion of naturally infected bovine placenta but not after ingestion of colostrum spiked with neospora caninum 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
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
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
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
immunohistochemical and ultrastructural evidence for neospora caninum tissue cysts in skeletal muscles of naturally infected dogs and cattle.protozoan stages were detected in the skeletal muscles of four dogs suffering from neosporosis and two neonatal calves with confirmed neospora caninum- infection which could be immunohistochemically labelled by an antiserum against the bradyzoite-specific antigen bag-5. in one calf, a tissue cyst was labelled by an antiserum against the n. caninum isolate nc-1. ultrastructurally, a 0.3-1 microm-thick cyst wall surrounded the labelled parasites. the cysts were located within myofibres and contain ...200111429181
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
prevalence of neospora caninum antibodies in wild ruminants from the italian alps. 200111442237
genetic and biological diversity among isolates of neospora caninum.neospora caninum is a protozoan parasite that causes bovine abortion. the epidemiology of n. caninum is poorly understood and little is known about the genetic diversity of the parasite, or whether individual isolates differ in virulence. such diversity may, among other factors, underlie the range of pathologies seen in cattle. in this study we analysed biological and genetic variation in 6 isolates of n. caninum originating from canine and bovine hosts by measurement of growth rate in vitro, we ...200111467779
interferon-gamma-induced apoptosis in host cells infected with neospora caninum.interferon-gamma (ifn-gamma) has a crucial role for host defence against parasite infection. it is not clear, however, how ifn-gamma affects the parasite-infected host cells. the effect of ifn-gamma on neospora caninum-infected cells was investigated in murine fibroblasts and canine kidney cells in vitro. in the presence of ifn-gamma, the viability of the infected host cell was decreased and apoptotic cell death occurred, as analysed by dna stainings with propidium iodide and a terminal deoxy-nu ...200111467780
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
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 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
isolation of the cdna encoding a dense granule associated antigen (ncdg2) of neospora caninum. 19989662039
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 determine association between exposure to neospora caninum and milk production in dairy cows.200111549092
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
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
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
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 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
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
[neospora caninum and neosporosis--basic science at the institute of parasitology and possible implications]. 200010850161
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
protection against vertical transmission in bovine 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
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
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
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 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
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
growth-inhibitory effects of interferon-gamma on neospora caninum in murine macrophages by a nitric oxide 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
prevalence of agglutinating antibodies to neospora caninum in raccoons, procyon lotor.neospora caninum is an apicomplexan parasite that causes neonatal neuromuscular disease in dogs and abortions in cattle. dogs are the only proven definitive host. little is known about the prevalence of antibodies to this parasite in wildlife. sera from 99 raccoons (procyon lotor) were examined for agglutinating antibodies to n. caninum using the modified agglutination test employing formalin-fixed tachyzoites as antigen. raccoons originated in florida (n = 24, collected in 1996), new jersey (n ...200111695399
association of serologic status for neospora caninum and postweaning feed efficiency in beef determine the effects of serologic status for neospora caninum on short-term weight gain, feed intake, and feed efficiency (feed intake/gain).200111697371
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
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
leishmania infantum and neospora caninum simultaneous skin infection in a young dog in italy.leishmania infantum, the agent of canine leishmaniasis in mediterranean countries, and neospora caninum, a recently recognized protozoal pathogen in dogs, were diagnosed in a 9-month-old argentine dogo dog. both skin lesions and neurological signs were present. histopathology of cutaneous lesions revealed a suppurative, diffuse dermatitis with numerous intracellular protozoa. serology was positive for both l. infantum (1:640) and n. caninum (1:800). double-label immunohistochemical staining of s ...200111705654
experimental porcine neosporosis.six gilts were inoculated intramuscularly with 2.5x10(6) tachyzoites of neospora caninum on three different days of gestation to study the pathogenic effect of neospora infection in pigs, including possible transplacental transmission. the gilts were euthanized 59, 30, and 9/10 days postinoculation (p.i.), corresponding to days 107, 102/106 and 110/111 of pregnancy. with the exception of one animal (euthanized day 9 p.i.) all gilts seroconverted as measured by the indirect, fluorescent antibody ...19989637270
prevalence of antibodies to neospora caninum in dogs.serum samples from 1077 dogs suspected of having neospora caninum infections from 35 states in the united states and 3 provinces in canada were tested for n. caninum igg antibodies by the indirect fluorescent antibody test. antibodies to n. caninum were found in 75 of 1077 (7%) of the samples. twenty of the positive dogs were females, 17 were males and the sex was not recorded on 38 dogs. chi square analysis indicated no differences (p > 0.05) based on sex were present. dogs from the southeast a ...199910488735
structural analysis of free and protein-bound glycosyl-phosphatidylinositols of neospora caninum. 200010613708
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
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
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
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
prevalence of antibodies to neospora caninum in horses in france. 200111266072
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
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
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
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
Displaying items 301 - 400 of 1864