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
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
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
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
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
placentophagia--an alternative way for horizontal transmission of neospora caninum in cattle? 200111756037
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
point source exposure of cattle to neospora caninum consistent with periods of common housing and feeding and related to the introduction of a dog.eight dairy herds with evidence of post-natal transmission of neospora caninum were used to test the hypothesis of a point source exposure by a retrospective analysis of the housing and feeding of infected age-groups. the first n. caninum-associated abortion or birth of n. caninum-seropositive offspring from the post-natally infected age-group was considered as the first indication of the infection. in seven of the eight dairy herds, a point source exposure to n. caninum of the infected age-grou ...200211900922
natural transmission routes of neospora caninum between farm dogs and cattle.twelve dairy herds with evidence of post-natal infection with neospora caninum were compared with 21 control herds with no evidence of post-natal infection. on the former farms, dogs consumed placenta or licked uterine discharge in 75 and 67% of the farms, respectively, while on control farms these activities occurred in 38 and 24% of the farms, respectively. on all control farms and all but three post-natally infected farms the dogs were fed colostrum or milk. defecation of dogs on the feeding ...200211900923
vaccine development against neospora caninum infection.neospora caninum is a recognized protozoan parasite of a wide range of mammalian hosts, and was reported for the first time in 1988. the isolation of its oocysts in dog's faeces in 1998 led to its establishment as a parasitic species undergoing typical coccidian life cycle. infection with n. caninum causes paralysis and death in young livestock and companion animals, and is associated with abortions and stillbirth in cattle, and neurologic disease in calves. considering the economic and agricult ...200211853138
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
neospora 2001.infection with the protozoan parasite neospora caninum is emerging as a major cause of reproductive loss in cattle worldwide. recent advances in research with the ultimate goal of devising effective and sustainable control measures were discussed at neospora 2001. neospora 2001 was held, 13-15 september 2001, at the moredun research institute, edinburgh, uk. the international meeting covered many aspects of bovine neosporosis including diagnosis, epidemiology and immunology.200211850000
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
serological diagnosis of neosporosis in a herd of dairy cattle in southern brazil.neospora caninum-specific antibodies were detected in 60 of 172 (34.8%) dairy cattle by enzyme-linked immunosorbent assay (elisa) in a herd from parana state, brazil. the seropositive animals included 47 of 126 (37.3%) adult cows, 7 of 29 (24%) heifers (1-2 yr), 4 of 15 (27%) heifers (5 mo-1 yr), and 2 precolostral samples. data collected over a 9-yr follow-up period revealed that the proportion of pregnancies ending in abortion was 20% (31/154) among elisa seropositive cows and 8% (15/193) amon ...200111780849
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
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
bovine neosporosis: immunoblot improves foetal serology.the purpose of the study is the comparative evaluation of the immunofluorescent antibody test (ifat) and an immunoblot (ib) test for the examination of foetal fluids for specific antibodies against neospora caninum. peritoneal and pleural fluids as well as abomasal contents were analysed. the results of the serological examinations were compared to those obtained by histological, immunohistochemical, and pcr analysis of foetal tissues as well as to the results of maternal serological examination ...200111731071
neosporosis as a cause of abortion in dairy cattle in rio grande do sul, southern brazil.forty-six aborted bovine fetuses submitted to the faculty of veterinary, department of clinical pathology, universidade federal do rio grande do sul, were examined histopathologically. non-suppurative inflammation was observed mainly in the brain and heart of 22 fetuses. brain lesions consisted primarily of mononuclear inflammatory cell infiltrates with occasional foci of necrosis. protozoa that reacted with neospora caninum antisera were seen in 18 of the 22 (81.8%) brain specimens from fetuses ...200211750112
infection of organotypic slice cultures from rat central nervous tissue with neospora caninum: an alternative approach to study host-parasite interactions.neospora caninum is an apicomplexan parasite which has emerged as an important cause of bovine abortion worldwide. abortion is usually triggered by reactivation of dormant bradyzoites during pregnancy and subsequent congenital infection of the foetus, where the central nervous system appears to be most frequently affected. we here report on an organotypic tissue culture model for neospora infection which can be used to study certain aspects of the cerebral phase of neosporosis within the context ...200211943226
diagnosis and seroepidemiology of neospora caninum-associated bovine abortion.a round table was conducted at the viiith international coccidiosis conference on neospora diagnosis with particular emphasis on strategies to diagnose bovine abortion. the strength and weakness of different assays for neospora caninum infection and whether these methods have resulted in the overdiagnosis of neosporosis was discussed. it was evident that each diagnostic method, namely histology, immunohistochemistry, molecular detection and serological assays were, under certain circumstances, v ...200211943234
epidemiological investigations of abortions due to neospora caninum on swiss dairy farms.abortions apparently due to neospora caninum in two swiss dairy herds were investigated by means of a pcr and elisa, and other potential causes were eliminated. in addition, a case-control study of 24 case herds and 24 control herds indicated that n caninum-associated abortions were more likely to occur in herds with antibodies to coxiella burnetii (with an odds ratio [or] of 3.38 with a 95 per cent confidence interval [ci] of 1.82 to 6.22), whereas the likelihood was less in herds with antibodi ...200212019533
neosporosis in bovine dairy herds from the west of france: detection of neospora caninum dna in aborted fetuses, seroepidemiology of n. caninum in cattle and dogs.neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. in this study, the role of n. caninum was investigated in groups of aborted cattle and dairy herds from the west of france. good correlation was found between parasite dna detection in fetuses and serologic statuses of dams. in groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropositive for n. caninum, and significant relationship b ...200111731070
first confirmed case of neospora caninum-associated abortion outbreak in a dairy herd experiencing an abortion outbreak, 49% of the 119 cows were positive for neospora caninum antibodies and the remaining 51% were seronegative. using immunohistochemical analysis of foetal brain tissue, neospora cysts and bradyzoite clusters were identified in two of the 15 aborted foetuses submitted for testing. other agents that commonly cause abortions were not found. these results, coupled with neurological clinical symptoms in new-born calves, implicated n. caninum as the majo ...200111928926
a method of probability diagnostic assignment that applies bayes theorem for use in serologic diagnostics, using an example of neospora caninum infection in develop a method of probability diagnostic assignment (pda) that uses continuous serologic measures and infection prevalence to estimate the probability of an animal being infected, using neospora caninum as an example.200211911564
quantitative detection of neospora caninum in bovine aborted fetuses and experimentally infected mice by real-time pcr.we report the development of a real-time pcr assay for the quantitative detection of neospora caninum in infected host tissues. the assay uses the double-stranded dna-binding dye sybr green i to continuously monitor product formation. oligonucleotide primers were designed to amplify a 76-bp dna fragment corresponding to the nc5 sequence of n. caninum. a similar method was developed to quantify the 28s rrna host gene in order to compare the parasite load of different samples and to correct for th ...200211923330
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
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
sensitive and specific identification of neospora caninum infection of cattle based on detection of serum antibodies to recombinant ncp29.neosporosis is an economically important disease of dairy cattle caused by the protozoan neospora caninum. diagnostic tests for neosporosis are complicated by the potential for cross-reaction of antibodies to antigens that are similar between n. caninum and closely related parasites toxoplasma gondii and sarcocystis cruzi. to provide a sensitive and specific assay for detecting antibodies to n. caninum in the serum of infected animals, we have investigated a recombinant form of the antigen known ...200211986268
neosporosis in a white rhinoceros (ceratotherium simum) calf.a 16-day-old white rhinoceros calf died suddenly while in excellent condition and showing no obvious previous clinical signs. it was the 9th calf of a mature female kept free-ranging with 11 other rhinoceros as well as various other game species on a 2000 hectare game breeding centre adjacent to the town of lichtenburg and outlying cattle farmlands in the northern province. at post mortem examination, death was ascribed to heart failure. there was marked multifocal to coalescing subacute parasit ...200212088073
factors associated with neospora caninum serostatus in cattle of 20 specialised costa rican dairy herds.twenty-five specialised costa rican dairy farms (located in the poás area) were used to determine neosporosis seroprevalence and the association of seropositivity with environmental and management factors. the farms involved were selected intentionally and all of them use vampp 5.1 (veterinary automated management and production control programme) as management-information system. holstein-friesian, jersey and crosses between them were the most-frequent breeds in these herds. the number of femal ...200211937233
p38-avidity-elisa: examination of herds experiencing epidemic or endemic neospora caninum-associated bovine enzyme-linked immunosorbent assay (elisa) was established to measure the avidity of bovine igg directed against p38, a surface antigen (ncsrs2) of neospora caninum tachyzoites. in the sera of dams intravenously infected with n. caninum nc-1, the p38-specific avidity increased from initially below 40% up to avidity indices between 50 and 80% after days 23 and 91 p.i. the p38-avidity-elisa was used to examine various herds that had experienced endemic and epidemic n. caninum-associated bovine a ...200212079735
an analysis of the performance characteristics of serological tests for the diagnosis of neospora caninum infection in analyse the performance characteristics (sensitivity/specificity) of two enzyme-linked immunosorbent assays (elisa) against the indirect fluorescent antibody test (ifat).200212127250
prevalence of neospora caninum antibodies in dogs from dairy cattle farms in parana, brazil.serum samples from 134 dogs from 22 cattle dairy farms in the northern region of parana state, brazil, were tested for antibodies to neospora caninum in an indirect fluorescent antibody test. antibodies (> or = 1:50) to n. caninum were found in 29 (21.6%) of the 134 dogs, and seropositive dogs were found on 14 (63.6%) of the 22 dairy cattle farrms. the antibody titers of dogs were 1:50 (3 dogs), 1:100 (7 dogs), 1:200 (7 dogs), 1:400 (6 dogs), and > or = 1:800 (6 dogs). the low prevalence (9%) in ...200212054023
prevalence of antibodies to neospora caninum in white-tailed deer, odocoileus virginianus, from the southeastern united states.serum samples from 305 white-tailed deer (odocoileus virginianus) from 14 states in the southeastern united states were examined for antibodies to neospora caninum using a direct agglutination test. positive agglutination titers were found in 145 (48%) of the white-tailed deer examined: 21 (7%) had titers of 1:25, 92 (30%) had titers of 1:50, and 32 (10%) had titers of > or = 1:500. these findings that antibodies to n. caninum are common in white-tailed deer support the concept that a sylvatic c ...200212054027
a longitudinal study of neospora caninum infection on a dairy farm in new zealand.a 600-cow new zealand dairy herd experienced an abortion storm in 1997 and was monitored (blood sampling at about 3-month intervals) from may 1997 until january 1999. abortion risk reached 9% in 1997 and was highest in heifers at 19%. the abortion risk decreased in 1998 to 3.2% (still somewhat higher than during the years prior to the outbreak). the serological reaction pattern for neospora caninum showed an association with abortion risk only around the time of the 1997 outbreak when seropositi ...200212062516
direct production losses and treatment costs from bovine viral diarrhoea virus, bovine leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum.our purpose was to determine direct production losses (milk loss, premature voluntary culling and reduced slaughter value, mortaliy loss, and abortion and reproductive loss) and treatmetn costs (veterinary services, medication cost, and extra farm labour cost) due to four infectious diseases in the maritime provinces of canada: bovine viral diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis. we used a partial-budget model, and incorporated risk and sensitivity ...200212350317
neospora caninum: oocyst challenge of pregnant cows.three pregnant cows were each orally challenged at 10 weeks of gestation with 600 sporulated oocysts of neospora caninum. the number of oocysts was limited by those available. in concurrent bioassays, one oocyst per os infected each of two gerbils. challenged cattle developed neospora-specific antibody, cell proliferation and gamma-interferon responses. n. caninum specific pcr demonstrated persisting infection in the brains of cows 4 months after calving. abortion was not induced and there was n ...200212383634
neospora caninum serostatus and milk production of holstein determine whether neospora caninum serostatus was associated with milk production among holstein cattle in ontario.200212387387
seroepidemiology of beef and dairy herds and fetal study of neospora caninum in argentina.the purpose of the present work was to study the epidemiology of neospora caninum in beef and dairy herds in the humid pampas of argentina. the seroprevalence of n. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. an indirect fluorescent antibody test (ifat) was used to determine specific antibodies. the sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. cows without history of reprod ...200212163242
redescription of neospora caninum and its differentiation from related coccidia.neospora caninum is a protozoan parasite of animals, which before 1984 was misidentified as toxoplasma gondii. infection by this parasite is a major cause of abortion in cattle and causes paralysis in dogs. since the original description of n. caninum in 1988, considerable progress has been made in the understanding of its life cycle, biology, genetics and diagnosis. in this article, the authors redescribe the parasite, distinguish it from related coccidia, and provide accession numbers to its t ...200212076623
confirmation of the prevention of vertical transmission of neospora caninum in cattle by the use of embryo transfer. 200212224621
management factors related to seroprevalences to bovine viral-diarrhoea virus, bovine-leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum in dairy herds in the canadian maritimes.bovine viral-diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis lower on-farm productivity, reduce export competitiveness, and increase consumer concerns regarding safety. our purpose was to examine the relationship between 27 control practices and the estimated true seroprevalences for these four diseases for 2604 cattle in 90 dairy herds in the maritimes provinces of canada. overall, 37.8, 20.4, 3.4, and 19.2% of all sampled cattle were truly exposed to the ...200212324207
validation of a neospora caninum iscom elisa without a gold standard.neospora caninum is an intracellular parasite which causes abortion in cattle worldwide. one problem in the validation of the different methods for demonstration of this parasite is the lack of an appropriate gold standard. to validate an immunostimulating complex (iscom) enzyme-linked immunoassay (elisa) used to detect antibodies to n. caninum, sera from 244 cattle in five swedish dairy herds infected with n. caninum were analysed. the sera also were analysed by a standard indirect-fluorescent ...200312581597
coprodiagnosis of hammondia heydorni in dogs by pcr based amplification of its 1 rrna: differentiation from morphologically indistinguishable oocysts of neospora caninum.hammondia heydorni is thought to be a non-pathogenic coccidian parasite of dogs that is closely related to neospora caninum, an important parasite of cattle and dogs. oocysts of these two species are morphologically indistinguishable from each other. a population of 2240 dogs in the czech republic was screened for the presence of h. heydorni/n. caninum oocysts and five (0.22%), represented by five of 3135 faecal samples (0.16%), were positive. the internal transcribed spacer 1 region of the rrna ...200212093189
neospora caninum serostatus and culling of holstein determine whether time until culling or risk of culling was associated with neospora caninum serostatus among holstein cattle in dairy herds in ontario.200212387388
prevalence of antibodies to neospora caninum in korean native beef cattle.a total of 438 sera from korean native beef cattle in 9 provinces were tested for neospora caninum antibodies using an immunofluorescent antibody test (ifat). eighteen (4.1%) cattle were positive by ifat. the titers ranged from 1:200 (10 animals), 1:400 (5 animals), 1:800 (2 animals) to 1:1,600 (1 animal). although the seroprevalence was slightly higher in chungnam (8.9%), this was not significantly different from those noted in kyunggi, kangwon, kyungbuk, kyungnam, and cheju provinces. sera obt ...200212419873
validation of 2 commercial neospora caninum antibody enzyme linked immunosorbent assays.this is a validation study of 2 commercially available enzyme linked immunosorbent assays (elisa) for the detection of antibodies against neospora caninum in bovine serum. the results of the reference sera (n = 30) and field sera from an infected beef herd (n = 150) were tested by both elisas and the results were compared statistically. when the immunoblotting results of the reference bovine sera were compared to the elisa results, the same identity score (96.67%) and kappa values (k) (0.93) wer ...200212418782
the comparative pathogenesis of neosporosis.since its first description in dogs in 1984, the protozoan parasite neospora caninum has been found to infect a wide range of animals, worldwide. in cattle, n. caninum has particular significance as a cause of abortion in which persistence of infection in the mother, recrudescence of the parasite during pregnancy, and the vulnerability of the placenta and foetus to invasion are important features. this article discusses how neospora invades cells, how it infects and causes disease in several ani ...200212482540
fetal infection with neospora caninum in dairy and beef cattle in belgium.neospora caninum is a protozoan parasite, which causes fetal and neonatal mortality in livestock and companion animals. in 224 abortions in belgian cattle, different diagnostic methods were used to demonstrate infection, and the presence of n. caninum. an indirect fluorescent antibody test (ifat) was used to analyze fetal and maternal sera and immunohistochemistry (ihc) was performed when lesions consistent with neosporosis were observed in the brain, heart or liver. twenty dairy cattle sera out ...200212212893
a high rate of seroconversion for neospora caninum in a dairy herd without an obvious increased incidence of abortions.the purpose of this paper is to investigate the high rate of seroconversion for neospora caninum in a dairy herd. forty-five of 95 (47%) of the seronegative animals seroconverted within a period of 6 months. seropositive animals were not equally distributed among age-groups. a high seroprevalence age-group of 8-30 months was housed together during a period of 4 months, indicating a point source infection within this period. a lack of association between the serological status of daughters and mo ...200212423933
neospora caninum: a cause of immune-mediated failure of pregnancy?resistance to many intracellular protozoan parasites is dependent on t helper cell 1 cytokine responses. this has important repercussions for pregnant females because strong t helper cell 1 cytokine responses are incompatible with successful pregnancy. thus, there are two possible consequences of infection with protozoans such as leishmania major, plasmodium falciparum and toxoplasma gondii during pregnancy: (1) pregnancy is compromised; or (2) resistance to the parasite is compromised. the apic ...200212377255
determination and correlation of anti-neospora caninum antibodies in dogs and cattle from mexico.the aim of the present study was to determine and to compare through an indirect enzyme linked immunosorbent assay (elisa) test, the presence of anti-neospora caninum antibodies in city and farm dogs, as well as in farm cows, and the relationship among them. the correlation between anti-n. caninum antibodies in farm dogs and cattle was also assessed. the research was conducted in the dairy region of tizayuca, hidalgo, mexico. the frequency of anti-n. caninum antibodies was significantly higher i ...200312760481
immunological relationship between neospora caninum and besnoitia besnoiti.neospora caninum is a coccidian parasite identified as a major cause of abortion in cattle. a combined infection of n. caninum with another taxonomically related parasite of cattle, besnoitia besnoiti can occur in geographical areas endemic for both species. both infections are routinely diagnosed serologically, and incorrect diagnosis could occur if immunological cross-reactivity exists between the two parasites. to investigate the possible degree of cross-reactivity, we compared results obtain ...200211992709
occurrence of neospora caninum antibodies in sera from dogs of the city of são paulo, brazil.neospora caninum is an important cause of abortion in dairy cattle worldwide. dogs are important in the epidemiology of this parasite because they are the only hosts known to excrete n. caninum oocysts. in order to understand the prevalence of n. caninum in dogs, sera from 500 owned dogs and from over 600 feral street dogs from the city of são paulo, brazil were assayed for antibodies to n. caninum. sera were examined by the neospora agglutination test (nat) using mouse-derived tachyzoites. anti ...200212031819
an explorative study to assess the efficacy of toltrazuril-sulfone (ponazuril) in calves experimentally infected with neospora caninum.neospora caninum is an important cause of infectious abortion and stillbirth in cattle world-wide. infection is common and may frequently be passed from mother to calf (vertical transmission) with no signs of disease. based on our previous observation that n. caninum-infection can be efficiently controlled with toltrazuril-sulfone (ponazuril) in experimentally infected mice, we addressed the question if efficacy could also be obtained in experimentally infected calves.200212437777
first portuguese isolate of neospora caninum from an aborted fetus from a dairy herd with endemic neosporosis.neospora caninum was isolated from the brain of an aborted 4-month-old fetus from a dairy cow herd with endemic neosporosis in porto, portugal. the fetal brain homogenate was inoculated interperitoneally first into outbred swiss webster mice given dexamethasone and then the peritoneal exudates from these mice was co-inoculated with mouse sarcoma cells in the peritoneal cavity of mice given dexamethasone. n. caninum tachyzoites were seen in peritoneal exudate of the second passage. tachyzoites fr ...200212446085
neospora caninum antigens recognized by mouse igg at different stages of infection including recrudescence.western blotting was performed to analyze neospora caninum tachyzoite antigens recognized by mouse igg at different stages of infection including recrudescence. at the early stage of infection, a 36-38 kda antigen was clearly recognized by the mouse antisera. after day 48 postinoculation, the signal of the 36-38 kda antigen gradually weakened. meanwhile, a 43 kda antigen was intensely and continuously recognized from 48 to 125 days postinoculation. this 43 kda antigen was clearly detectable with ...200312867739
seroprevalence of neospora caninum infection in dairy and beef cattle in paraguay.seroprevalence of neospora caninum in 879 beef and dairy cattle in different locations of paraguay was determined by an elisa. in the survey, 262 (29.8%) cattle were positive to n. caninum, and animals with anti-neospora antibody titre were observed in all the locations tested in the country. serum samples taken from a herd that exhibited persistent abortion had the highest percentage of animals being positive to the parasite (17/30, 56.7%). in the same herd, abortion was significantly more like ...200212446086
use of bulk milk for detection of neospora caninum infection in dairy herds in thailand.the relationship between the level of neospora caninum antibodies in bulk milk and the seroprevalence in lactating cows was investigated. bulk milk was also used to estimate the prevalence of n. caninum infection in dairy herds in the northeast and north thailand. bulk milk and individual serum from all lactating cows in 11 herds as well as 220 bulk milk samples from nine milk collection centres were analysed for presence of n. caninum antibodies using an iscom elisa. in the 11 herds the bulk mi ...200212446088
evaluation by different diagnostic techniques of bovine abortion associated with neospora caninum in spain.eighty foetuses from some of the main cattle-producing regions in spain were analysed to investigate the participation of neospora caninum in cases of bovine abortion. diagnosis of the infection was determined by histopathological analysis complemented with immunohistochemistry, serology (ifat and elisa) and pcr tests. a total of 38.8% of the bovine foetuses analysed were considered to be infected by at least one of the diagnostic techniques used. microscopic lesions consistent with neospora inf ...200312531290
neospora caninum in vitro: evidence that the destiny of a parasitophorous vacuole depends on the phenotype of the progenitor zoite.we previously reported that neospora caninum can be induced to express bagi, a bradyzoite antigen, within 3 days of culture under stress conditions. the main goals of the present experiment were to increase the expression of bagi in vitro (in part by extending cultures for 9 days), to observe parasitophorous vacuoles at various points of stage differentiation, and to test the ability of organisms produced in vitro to function like mature bradyzoites. expression of bag1 and of a tachyzoite antige ...200212537100
improved production of neospora caninum oocysts, cyclical oral transmission between dogs and cattle, and in vitro isolation from oocysts.scarce information is available about neospora caninum oocysts and sporozoites, in part because only small numbers of oocysts have typically been produced by experimentally infected dogs. we hypothesized that i reason for low experimental production of oocysts is that dogs have been fed tissues from experimentally infected mice instead of tissues from cattle (which are natural intermediate hosts of n. caninum). in this study, 9 dogs were fed tissues from n. caninum-infected calves, and oocyst pr ...200212537111
evaluation of a single serological screening of dairy herds for neospora caninum antibodies.twenty-one dairy herds with a history of neospora caninum-associated abortions were used for a longitudinal serological study. a total of 1,676 animals were blood sampled 3 times and used to evaluate a single serological screening for n. caninum antibodies. the results of the first serological screening were compared with the results based on three consecutive samples, whereby two or more positive or negative test results per animal were considered to determine its serological status as positive ...200312482645
isolation of viable toxoplasma gondii from naturally infected aborted bovine fetuses.neospora caninum and toxoplasma gondii are related parasites. the former is a common cause of abortion in dairy cattle. the latter has not been conclusively demonstrated in bovine fetuses. during the course of attempts to isolate n. caninum from aborted fetuses, t. gondii was isolated from 2 aborted fetuses, 1 from portugal and 1 from the united states. both isolates were made by bioassay of fetal brains in mice. the fetus from portugal was about 5 mo in gestational age, and the fetus from the u ...200212537120
pattern of recognition of neospora caninum tachyzoite antigens by naturally infected pregnant cattle and aborted foetuses.different aspects of neospora tachyzoite antigen recognition by neospora-infected heifers and cows and aborted foetuses were studied. the pattern of antigen recognition and the relationship between ifat titres and number of neospora antigens detected, were evaluated. in addition, the tachyzoite antigens involved in the humoral immune response developed against infection in normal cows and cows that aborted were also characterised throughout pregnancy. comparison of tachyzoite antigen recognition ...200212072210
survey of neospora caninum antibodies in dairy and beef cattle from five regions of the united states.serum samples from 4,907 cows from 93 dairy and five beef herds were analyzed for antibodies to neospora caninum by commercially available elisa. the herds were recruited from 20 states and the territory of puerto rico. a questionnaire assessed the herd's abortion history and exposure risks to n. caninum. results showed that 788 (16%) cows tested positive for antibodies to n. caninum. at least one positive animal was detected in 90% of the herds tested. the prevalence of cows seropositive to n. ...200212584676
serological survey of neospora caninum infection in dairy cattle herds in aguascalientes, mexico.a serological survey for antibody activity to neospora caninum was carried out in aguascalientes, a state in the central part of mexico. one-hundred and eighty-seven serum samples from 13 dairy herds were tested by the elisa test. the herd prevalence was 100% and the overall prevalence was 59% (n=110). seventy-six of 97 seropositive cows had previous records of abortion. there was a statistically significant difference between the groups (p<0.05). however, the odds ratio was 1.4, suggesting an a ...200212031815
risk of abortion associated with neospora caninum during different lactations and evidence of congenital transmission in dairy examine the relationship between exposure to neospora caninum and abortion in dairy cows during their first, second, third, and fourth or later lactations and to establish the main mode of transmission in female calves from birth until their first pregnancy was terminated by abortion or parturition.200212494973
abortion epidemic in a dairy herd associated with horizontally transmitted neospora caninum infection.a dairy herd experienced an abortion epidemic during which 43 per cent of the cows at risk aborted. neospora caninum infection was demonstrated in four of six fetuses suitable for examination and the group of at-risk cows that aborted had significantly higher n. caninum antibody concentrations than the at-risk cows that delivered a live calf at term (p<0.001). the antibody concentrations in the cow herd were significantly higher than in the youngstock (p<0.001), and the concentrations in the you ...200312620035
diagnostic survey of bovine abortion in korea: with special emphasis on neospora caninum.causes of bovine abortion were surveyed in korea within a designated period from the cases submitted to the department of veterinary pathology, college of veterinary medicine, seoul national university. one hundred and eighty aborted fetuses and maternal sera were evaluated by necropsy, histopathology, bacteriology, virology, pcr, and serologic tests. the causes of abortion were identified in 108 (60%) cases, of which 38 (21.1%) were due to the infection with neospora caninum. none of the 38 cas ...200212520105
characterisation of the first australian isolate of neospora caninum from isolate neospora caninum from a congenitally infected calf.200212465814
assessment of antibody avidity in aborting cattle by a somatic neospora caninum tachyzoite antigen igg avidity elisa.a neospora caninum igg avidity elisa was carried out on the basis of a somatic n. caninum tachyzoite antigen. the test was validated using experimentally infected calves, where a clear maturation of the igg avidity over time could be demonstrated. at a maximum of 82 days after infection (d.p.i.), all animals showed antibody avidities ranging above 35%, and respective sera were thus defined as highly avid. sera of 103 naturally infected seropositive cows with abortion (n. caninum association was ...200312581580
immune responses to neospora caninum and prospects for vaccination.developing an effective vaccine against neosporosis presents several interesting challenges. the parasite is spread efficiently from mother to foetus over several generations, and naturally infected cattle do not appear to develop adequate protective immunity. modulation of the immune response during pregnancy favours parasite survival and multiplication. however, induction of pro-inflammatory responses that are thought to be protective against neospora caninum would be detrimental to the pregna ...200212473366
protracted shedding of oocysts of neospora caninum by a naturally infected foxhound.feces from 15 dogs at 2 different foxhound kennels in the u.k. were examined microscopically for the presence of oocysts of neospora caninum. one sample containing approximately 400 candidate oocysts per gram was positive in a polymerase chain reaction (pcr) using n. caninum-specific primers. in a sample taken 4 mo later from the same hound. n. caninum oocysts were again detected visually and by pcr. this is the third reported case of a dog naturally excreting oocysts of n. caninum and suggests ...200312880273
the effect of the dam-calf relationship on serostatus to neospora caninum on 20 costa rican dairy epidemiological study was conducted on 20 dairy herds previously diagnosed as seropositive for neospora caninum. the number of females per farm varies from 41 to 296. all females present on the farms were bled once in the period of july and august 2000. a total of 3002 females were bled. an indirect elisa was used to determine the serostatus of the animals. the analysis of the data was performed in four steps: (1) descriptive statistics about the serological status and general characteristics ...200312788252
application of the neospora caninum igg avidity elisa in assessment of chronic reproductive losses after an outbreak of neosporosis in a herd of beef cattle.point-source infections are most likely the cause for neospora caninum-induced abortion outbreaks in cattle, whereas an increased annual abortion rate may be a consequence of vertical transmission. the aims of the present study were to examine the reproductive effects of neosporosis in a beef herd for 3 years, after a point-source outbreak and to use igg avidity serology to examine the chronicity of infections and patterns of transmission. during the study, 76-78% of animals were seropositive fo ...200312580287
review of neospora caninum and neosporosis in animals.neospora caninum is a coccidian parasite of animals. it is a major pathogen for cattle and dogs and it occasionally causes clinical infections in horses, goats, sheep, and deer. domestic dogs are the only known definitive hosts for n. caninum. it is one of the most efficiently transmitted parasite of cattle and up to 90% of cattle in some herds are infected. transplacental transmission is considered the major route of transmission of n. caninum in cattle. neospora caninum is a major cause of abo ...200312666725
neospora caninum-infected cattle develop parasite-specific cd4+ cytotoxic t lymphocytes.cattle infected with neospora caninum readily experience transplacental parasite transmission, presumably after maternal parasitemia, leading to abortion or birth of congenitally infected calves. cytotoxic t lymphocytes (ctl) are important mediators of protective immunity against toxoplasma gondii, an intracellular apicomplexan protozoan closely related to n. caninum. in this study, n. caninum-specific ctl expanded from peripheral blood mononuclear cells of two major histocompatibility complex-m ...200312761108
additional evaluation of undiagnosed bovine abortion cases may reveal fetal neosporosis.diagnosis of neospora caninum associated bovine abortion is often made by histological examination of fetal tissues, although this procedure is not very sensitive. one hundred and forty-four undiagnosed bovine abortion cases were evaluated for n. caninum associated bovine abortion using a revised diagnostic protocol. as a result, 12 (8.3%) of these previously undiagnosed bovine abortion cases were definitively diagnosed as n. caninum positive. the 12 new positive cases included 7 that had exhibi ...200312651213
seroprevalence of neospora caninum in aborting dairy cattle in the czech republic.a serological survey for antibodies against neospora caninum in aborting cattle was carried out in the czech republic. serum samples from 463 aborting dairy cows originated from 137 farms from different parts of the czech republic were tested for presence of n. caninum antibodies by use of an enzyme-linked immunosorbent assay (elisa) and an indirect fluorescent antibody test (ifat). antibodies (> or = 1:640) to n. caninum were found in 18 (3.9%) of 463 aborting cows. farm prevalence in aborting ...200312935739
a hammondia-like parasite from the european fox (vulpes vulpes) forms biologically viable tissue cysts in cell culture.tissue cysts of parasites of the genus hammondia are rarely described in naturally or experimentally infected intermediate hosts. however, ultrastructural examinations on tissue cyst stages of hammondia sp. are needed, e.g. to compare these stages with those of neospora caninum and other related parasites. we describe a cell culture system employed to examine the in vitro development of tissue cysts of a hammondia sp.-like parasite (isolate fox 2000/1) which uses the european fox as a definitive ...200312670509
the pathogenesis of neosporosis in pregnant cattle: inoculation at investigate the pathogenesis of bovine neosporosis, 14 pregnant cattle were each inoculated subcutaneously with either 10(7) or 5 x 10(8) neospora caninum (strain nc1) tachyzoites at 140 days' gestation. serial necropsies were then carried out over an 8-week period. in the placenta, neospora dna and histopathological changes were observed in samples taken 14 days post-inoculation (dpi), with focal necrosis of maternal caruncular septa and fetal placental villi, serum leakage, and a maternal a ...200312921725
evaluation of an inactivated neospora caninum vaccine in beef feedlot evaluate effects of vaccination of feedlot steers against bovine neosporosis on weight gain, feed intake and efficiency (feed intake per gain), and carcass characteristics.200312619843
prevalence of antibodies to neospora caninum in dogs from amazon, brazil.neospora caninum is an important cause of abortion in dairy cattle worldwide. dogs are important in the epidemiology of this parasite because they are the only hosts known to excrete n. caninum oocysts. antibodies to n. caninum were assayed in serum samples from 157 dogs from monte negro, rondônia, amazon, brazil using the indirect fluorescent antibody test. antibodies to n. caninum were found in 13 (8.3%) of dogs in titers of 1:50 in 1, 1:100 in 2, 1:200 in 5, 1:800 in 1, 1:1600 in 2, and 1:320 ...200312860070
humoral immune response to infectious agents in aborted bovine fetuses in argentina.the purpose of this study was to characterize the exposure of bovine aborted fetuses from beef and dairy herds of the humid pampas of argentina to different infectious agents by the evaluation of fetal fluid antibodies. presence of fetal antibodies to bovine viral diarrhea virus genotype 1 (bvdv-1), bovine herpes virus type 1 (bhv-1), leptospira interrogans, brucella abortus, and neospora caninum was determined. of the 95 fetuses processed, 66 came from 49 beef herds and 29 from 12 dairy herds. ...200314587376
aetiology of bovine abortion in argentina.necropsies were performed on 354 fetuses from dairy and beef herds submitted from 1994 to 2000 to the diagnostic laboratories at instituto nacional de tecnología agropecuaria, balcarce, argentina. samples from the fetuses were examined for pathogenic organisms and processed for microscopic examination. an aetiological diagnosis was made for 161 (45.5%) of the fetuses. no diagnosis was made for 193 (54.5%) fetuses. infectious agents were isolated from 122 (34.4%) of the fetuses, bacterial agents ...200314509450
cytokine gene expression in dams and foetuses after experimental neospora caninum infection of heifers at 110 days of gestation.neospora caninum is a major cause of abortion in cattle. an essential role for th1 cytokines, such as ifn-gamma and il-12 in protective immunity against n. caninum in murine models has been indicated. however, little is known about immunity to neospora in pregnant cattle where a considerable level of immunomodulation may exist. in this study, the immune response of heifers infected early in the second trimester of pregnancy by intravenous inoculation of n. caninum tachyzoites was compared with i ...200314521581
reproductive losses due to neospora caninum in a beef herd in argentina.reproductive losses in a beef herd of 857 heifers with a pregnancy rate of 86.3% are described. after pregnancy testing, 69 abortions were seen during a 3 month period. before calving season, three heifers had delivered pre-mature non-viable calves. serum samples from 58 of 69 aborted heifers were available for serological tests. in order to compare the seroprevalence in non-aborted vs. aborted heifers, 214 pregnant animals were bleed during the abortion storm. in addition, blood samples were co ...200314629003
seroprevalence of antibodies to neospora caninum in dogs and raccoon dogs in korea.neospora caninum is an important cause of abortion in cattle, and dogs are its only known definitive host. its seroprevalence among domestic urban and rural dogs and feral raccoon dogs (nyctereutes procyonoides koreensis) in korea was studied by indirect fluorescent antibody test (ifat) and by the neospora agglutination test (nat), respectively. antibodies to n. caninum were found in 8.3% of urban dogs and in 21.6% of dogs at dairy farms. antibody titers ranged from 1:50 to 1:400. antibodies to ...200314699266
a long-term study of neospora caninum infection in a swedish dairy herd.a longitudinal study was performed in a swedish dairy herd where neospora caninum had been isolated from a stillborn calf. starting in autumn 1994, blood samples from all female animals in the herd were collected once yearly until 1999. the sera were analysed for presence of igg1 antibodies to n. caninum by the iscom elisa, and by an avidity elisa to establish the timing of infection. in addition, data on reproductive performance were compiled. during the study the percentage of seropositive fem ...200314650545
regional distribution of bovine neospora caninum infection in the german state of rhineland-palatinate modelled by logistic obtain a rapid overview over the distribution of bovine neospora caninum-infections in the german state of rhineland-palatinate, an elisa to determine specific bovine antibodies against a p38 surface antigen of n. caninum tachyzoites was modified to examine bulk milk samples from cattle herds. experimental bulk milk samples were used to demonstrate that the seroprevalence in a group of animals can be estimated with this elisa. a cut-off was selected for the specific detection of herds having ...200314636679
anti-parasitic activity of depudecin on neospora caninum via the inhibition of histone deacetylase.neospora caninum is an apicomplexan parasite associated with abortion in cattle worldwide. apicidin, histone deacetylase (hdac) inhibitor, has shown a broad spectrum of anti-protozoal activity against apicomplexan parasites. cultured vero cells infected with n. caninum tachyzoites were treated with 0.5 microg/ml of depudecin, another known natural product isolated from altermaria brassiciicola with anti-histone deacetylase activity, to examine the efficacy of depudecin against intracellular mult ...200312623206
elisa detection of igg antibody against a recombinant major surface antigen (nc-p43) fragment of neospora caninum in bovine elisa was established to measure bovine igg directed against the recombinant antigenic determinant of nc-p43, a major surface antigen of neospora caninum. in a previous study, two thirds of the c-terminal of the molecule was expressed as a 6 x his tagged protein (ncp43p) for elisa using 2/3 of the n-terminal of sag1 from toxoplasma gondii as a control (tgsag1a). among 852 cattle sera collected from stock farms scattered nation-wide, 103 sera (12.1%) were found to react with ncp43p positively, ...200312972732
investigation of neospora sp. antibodies in aborted mares from normandy, france.neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle while limited information is presently available on association between equine neospora infections and abortions. the aim of the present study was to document prevalence of antibodies against neospora sp. in aborted mares as a clue to the role of n. caninum in mare reproductive failure in normandy, france. using an agglutination test, the number of animals with elevated (>80) anti-neospora ...200314651869
seroprevalence and associated risk factors of neosporosis in beef and dairy cattle in italy.a cross-sectional serological survey for neospora caninum was carried out on beef and dairy cattle in southern and northern italy. a total of 111 herds and 1140 animals were tested using an elisa assay (chekit-neospora) to detect anti-n. caninum antibodies. management and individual data were collected and analysed both by linear and logistic multiple-regression models in order to find good predictors of the cattle seroprevalence and anti-n. caninum antibody level. at least one seropositive anim ...200314651870
serological status and abortion rate in progeny obtained by natural service or embryo transfer from neospora caninum-seropositive cows.bovine neosporosis is an important disease in dairy herds in argentina. embryo transfer (et) technology offers the opportunity to minimize vertical transmission of neosporosis. the objective of this work was to compare the serological status and the incidence of abortion between heifers obtained via natural service and heifers obtained by et from neospora-infected cows. progeny from eight neospora-infected cows belonging to a commercial dairy farm where et was routinely performed were studied. b ...200314633201
adaptation of a commercial elisa for the detection of antibodies against neospora caninum in bovine milk.the aim of the present study was to determine whether a commercially available elisa could be used to examine bovine milk for antibodies against neospora caninum. in an initial titration experiment, a milk dilution of 1:2 was found optimal to obtain milk results that were linearly correlated to those obtained with corresponding sera. this dilution was then used to examine 791 milk samples from n. caninum infected herds in the commercial elisa. milk results of individual animals were compared wit ...200415019143
seroepidemiology of neosporosis in dairy cattle in uruguay.a seroepidemiological survey of neospora caninum was done in a dairy farm in uruguay employing indirect fluorescent antibody test (ifat). sera from 217 cattle (155 cows, 31 heifers and 31 calves) were tested for n. caninum antibodies in july 2000 and it was found that abortions were significantly associated with the seropositivity of the cows by chi(2)-test (p = 0.025). the cows with an ifat titre of 1:3200 were at a significantly higher risk of abortion than seronegative cows (p = 0.0013). neos ...200415019151
comparison and standardisation of serological methods for the diagnosis of neospora caninum infection in bovines.various existing serological tests were compared with a standard panel of 523 sera in a multicentred study across europe. well characterised sera from animals that were experimentally or naturally infected with neospora caninum as well as sera from cattle deemed uninfected with n. caninum were provided by the participants of the study and analysed in several commercial (chekit dr. bommeli/intervet, civtest bovis neospora hipra, cypress diagnostics c.v., herd check idexx, mastazyme mast diagnosti ...200415019139
detection of neospora caninum in semen of cattle, transplacental infection is the main route of neospora caninum transmission, but postnatal transmission by the oral uptake of sporozoite-containing oocysts shed by dogs may also be possible. other routes of horizontal transmission, such as the venereal route, have not been investigated. in this study, we evaluated the presence of n. caninum dna by a nested-pcr in fresh non-extended semen and frozen extended semen straws of five holstein-friesian bulls with naturally-acquired neosporos ...200314637032
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