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endogenous and exogenous transplacental infection in neospora caninum and toxoplasma gondii.it is clear from researching the vertical transmission of neospora caninum in cattle that the terms 'vertical', 'congenital' and, indeed, 'transplacental' are inadequate for describing two extremely different situations that have fundamentally different immunological, epidemiological and control implications. a similar situation pertains to toxoplasma gondii in different hosts. we advocate the use of the terms 'endogenous transplacental infection (tpi)' to define foetal infection from a recrudes ...200516223599
association between neospora caninum antibodies and blue tongue vaccination in dairy cows. 200516244963
inhibitory activities of epidermal growth factor receptor tyrosine kinase-targeted dihydroxyisoflavone and trihydroxydeoxybenzoin derivatives on sarcocystis neurona, neospora caninum, and cryptosporidium parvum development.several gene sequences of parasitic protozoa belonging to protein kinase gene families and epidermal growth factor (egf)-like peptides, which act via binding to receptor tyrosine kinases of the egf receptor (egfr) family, appear to mediate host-protozoan interactions. as a clue to egfr protein tyrosine kinase (ptk) mediation and a novel approach for identifying anticoccidial agents, activities against sarcocystis neurona, neospora caninum, and cryptosporidium parvum grown in bm and hct-8 cell cu ...200516251305
identification and characterization of neospora caninum cyclophilin that elicits gamma interferon production.gamma interferon (ifn-gamma) response is essential to the development of a host protective immunity in response to infections by intracellular parasites. neosporosis, an infection caused by the intracellular protozoan parasite neospora caninum, is fatal when there is a complete lack of ifn-gamma in the infected host. however, the mechanism by which ifn-gamma is elicited by the invading parasite is unclear. this study has identified a microbial protein in the n. caninum tachyzoite n. caninum cycl ...200516041025
the host-parasite relationship in bovine neosporosis.infection with the protozoan parasite neospora caninum is thought to be a major cause of reproductive failure in cattle worldwide. cattle infected with the parasite are three to seven times more likely to abort compared to uninfected cattle. the parasite may be transmitted to cattle through the ingestion of oocysts that are shed in the faeces of acutely infected dogs (definitive host of n. caninum) or by congenital infection from mother to foetus via the placenta. interestingly, transplacental t ...200516098610
comparison of proteome and antigenic proteome between two neospora caninum isolates.this study was conducted to explore the relationship between two isolates of neospora caninum (n. caninum) (kba-2 and vmdl-1) using proteomics. to achieve the goal, proteins of n. caninum tachyzoite lysates of kba-2 and vmdl-1 were separated by two-dimensional gel electrophoresis (2-de), stained with silver-nitrate and analyzed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (maldi-tof ms) to compare protein profiles. in addition, proteins separated by 2-de wer ...200516098674
neospora caninum seropositivity and association with abortions in dairy cows in mexico.the seroprevalence of neospora caninum infection was estimated from a sample of 813 cattle from 20 dairy herds in five regions in mexico. the true prevalence of infection was estimated to be 42% (95% ci: 39, 46). seropositivity was associated with abortion (odds ratio (or)=2.0) and was higher among cows raised on-farm (41%), than among replacement cattle purchased outside the farm (28%). the ors relating abortion to seropositivity in individual herds ranged from 1.3 to 10. overall, 26% of the ab ...200516098675
the sylvatic cycle of neospora caninum: where do we go from here?bovine abortions due to neospora caninum infection are a major cattle-production problem worldwide. the parasite is readily maintained in cattle populations by vertical transmission. the domestic dog excretes oocysts in its feces and, after sporulation, these oocysts are infectious to cattle. current control measures are aimed at culling infected cows and limiting the access of cattle to infective oocysts. the recent revelations that coyotes (canis latrans) can excrete n. caninum oocysts in thei ...200516098812
adaptation of neospora caninum isolates to cell-culture changes: an argument in favor of its clonal population structure.neospora caninum, a recently recognized protozoan parasite of animals, is considered to be a major cause of bovine abortion worldwide. although its life cycle is not completely known, recent studies suggest that the sexual stage occurs in dogs. the prevalence of sexual reproduction in n. caninum, however, is unknown. we investigated the ability of 3 n. caninum isolates (nc-1, nc-sweb1, and nc-liverpool) to propagate asexually for approximately 250 parasite generations in a cell line in which the ...200516108539
neospora caninum antigens defined by antigen-dependent bovine cd4+ t cells.neosporosis is an important cause of pregnancy loss in cattle worldwide. the objective of the present study was to identify neospora caninum antigens as vaccine candidates using antigen-specific, short-term cd4+ t cells established from n. caninum-immunized and -challenged cows. whole n. caninum tachyzoite lysate was separated into 6 fractions by deae anion-exchange chromatography using high-pressure liquid chromatography (hplc). the cd4+ t-cell proliferation assay results indicated that antigen ...200516108548
environmental effect on the occurrence of anti-neospora caninum antibodies in pampas-deer (ozotoceros bezoarticus).sera obtained from pampas-deer (ozotoceros bezoarticus) captured in two different brazilian environments were analyzed for the presence of anti-neospora caninum antibodies by the indirect fluorescent antibody test (ifat). samples were collected from 23 animals from a savanna area in the national park of emas, in the state of goiás, brazil. this area is surrounded by cultivated lands and allows very little contact between wild and domestic animals. another batch of samples was collected from 16 a ...200516112811
[bovine neosporosis: general concepts, immunity and perspectives for vaccination].neospora caninum causes abortions in cattle worldwide. the neospora-cycle of life is heteroxenous. dogs (canis familiaris) and coyotes (canis latrans) are the definitive hosts known at present. although, transplacental infection is an efficiently mode of transmission in cattle; there are also experimental and field data that prove horizontal transmission. several techniques are available for diagnosis since neosporosis is recognized as a disease that causes economic losses in cattle. the mechani ...200516502644
use of avidity enzyme-linked immunosorbent assay and avidity western blot to discriminate between acute and chronic neospora caninum infection in cattle.avidity serological tests (avidity enzyme-linked immunosorbent assay [elisa] and avidity western blot) were developed and used to differentiate between acute (primary infection, reinfection, and recrudescence) and chronic neospora caninum infection in cattle. in addition, the pattern of immunoglobulin g (igg) avidity maturation against different specific antigens of n. caninum tachyzoites was studied. sequential serum samples were collected from cattle naturally and experimentally infected with ...200516312235
persistence of neospora caninum-specific immunoglobulin g antibodies in bovine blood and lung tissue stored at room temperature.blood and tissue samples obtained at necropsy from carcasses showing varying degrees of postmortem decomposition are sometimes used as sources of antibodies for serological tests, primarily in studies involving wild animals or in examination of aborted fetuses. to test the persistence of antibodies in blood and lung tissue kept at room temperature (approximately 20degreesc) for up to 48 and 118 days, respectively, serum and lung fluid from neospora caninum-infected and uninfected cattle were tes ...200516312237
[survey of neospora caninum in cattle in some provinces in the eastern anatolian region.]this study was carried out in order to investigate the presence of neospora caninum in cattle in the elaziğ, malatya, muş and bingöl provinces from january 2003- may 2004. blood samples were collected from 513 cattle and 32 aborting cows that were of various breeds and ages in all provinces. sera were obtained from these animals and antibodies against n. caninum were investigated using the enzyme-linked immunosorbent assay (elisa). a commercially available competitive elisa (celisa) kit (vmrd, i ...200517167738
prevalence of antibodies to neospora caninum in local and imported cattle breeds in the kars province of turkey.this study investigates the seroprevalence of neospora caninum in cattle in the province of kars in north-eastern turkey. a total of 301 serum samples, 228 from local breeds of cows with a history of recent abortion and the remaining 73 collected at random from simmental cows imported from germany or their offspring, were tested for anti-neospora antibodies by elisa. all the serum samples from local breeds were negative for n. caninum antibodies, apart from one which tested inconclusive. in cont ...200515563918
gerbil model of acute neosporosis.experimental infections with the nc-1 strain of neospora caninum were conducted in gerbils (meriones unguiculatus) to determine their acute responses to experimental intraperitoneal infection. five groups of five female gerbils were used and they were intraperitoneally infected with 1x10(6), 2x10(6), 3x10(6), 4x10(6) or 5x10(6) tachyzoites. gerbils in all groups developed clinical signs of neosporosis which consisted of inactivity 4-5 days post-inoculation. morbidity and mortality were observed ...200515631903
adaptation of a surface antigen-based elisa for the detection of antibodies against neospora caninum in bovine milk.the aim of the present study was to determine whether an elisa based on a 38-kda surface antigen (ncsrs2) of neospora caninum tachyzoites could be used to examine bovine milk for antibodies against n. caninum. a total of 797 undiluted milk samples from n. caninum-infected herds were examined in the p38-elisa. milk results of individual animals were compared with those obtained by the same elisa for the corresponding serum samples. the linear correlation between milk and serum antibody results of ...200515703000
neospora caninum infection does not affect the fertility of dairy cows in herds with high incidence of neospora-associated abortions.this present study, was designed to establish whether neospora caninum infection affects the fertility of high-producing dairy cows, and was based on yearly serological screening for neosporosis and on the confirmation of n. caninum infection in aborted foetuses. assessment was made of 7518 artificial inseminations (ai) (applied to parous cows) performed in three herds. of these inseminations, 2540 (33.8%) resulted in pregnancy; 34% of which corresponded to seronegative cows (2226 of 6556 ai per ...200515703002
risk factors associated with neospora caninum abortion in ontario holstein dairy herds.the objective of this epidemiological study was to identify risk factors for neospora caninum-related abortions in ontario holstein dairy herds. a total of 88 herds, consisting of 5080 cattle, and utilizing dairy herd improvement (dhi) services, were divided into three groups. case (n = 30) and first control (n = 31) herds were selected from 1998 and 1999 fetal abortion submissions to the animal health laboratory, university of guelph, that were histopathologically positive or negative, respecti ...200515710518
transmission of neospora caninum between wild and domestic animals.to determine whether deer can transmit neospora caninum, brains of naturally infected white-tailed deer (odocoileus virginianus) were fed to 4 dogs; 2 of these dogs shed oocysts. oocysts from 1 of the dogs were tested by polymerase chain reaction and found to be positive for n. caninum and negative for hammondia heydorni. the internal transcribed spacer 1 sequence of the new strain (designated nc-deer1) was identical to n. caninum from domestic animals, indicating that n. caninum is transmitted ...200415715229
transplacental transmission and abortion in cows administered neospora caninum oocysts.neospora caninum infection is a common cause of bovine abortion. one method by which cattle can acquire infection is through ingestion of oocysts; however, this has not yet been proved to cause transplacental infection or abortion. in this study, 19 cows, pregnant between 70 and 176 days, were administered 1500 to 115,000 oocysts through an esophageal tube. seventeen of the cows became seropositive, indicating acquisition of infection, whereas 8 negative control cows remained seronegative (p < 0 ...200415715235
an interlaboratory comparison of immunohistochemistry and pcr methods for detection of neospora caninum in bovine foetal tissues.seven european laboratories contributed to a multi-centre evaluation of detection techniques for neospora caninum in bovine foetuses. six laboratories participated in immunohistochemistry (ihc) testing. all seven laboratories participated in pcr testing, but the results from one laboratory were not included in the analysis, because of contamination problems in the preparation of the samples. a coded panel of tissue sections from 36 infected and non-infected foetuses was used to evaluate the ihc ...200415567040
elaboration of a crude antigen elisa for serodiagnosis of caprine neosporosis: validation of the test by detection of neospora caninum-specific antibodies in goats from sri lanka.the protozoan parasite n. caninum is a major pathogen in cattle and dogs. however, clinical symptoms are occasionally described for other potential hosts. natural abortion in goats due to n. caninum has been rarely reported and only little data is available on the seroprevalence of n. caninum in this species. in the present study, 486 goats from sri lanka were tested in a crude antigen elisa for the presence of serum antibodies against n. caninum. additionally, the sera were analysed by n. canin ...200415567589
isolation of neospora caninum from a calf in malaysia.in order to attempt isolate the protozoan parasite neospora caninum, an n. caninum seropositive pregnant sahiwal friesian cross heifer from a large-scale dairy farm in malaysia was kept for observation until parturition at the veterinary research institute, ipoh. the heifer gave birth to a female calf that was weak, underweight and unable to rise. precolostral serum from the calf had an n. caninum indirect fluorescent antibody test titre of 1:3200. it died 12 h after birth and necropsy was perfo ...200415567590
potential risk factors for bovine neospora caninum infection in germany are not under the control of the farmers.in the german state of rhineland-palatinate, herds were identified that were likely to have a neospora caninum sero-prevalence > or = 10% by using a bulk milk elisa. individual herd data were obtained by a questionnaire. univariate logistic regression showed that bulk milk positive farms had a significantly higher chance to report an increased abortion rate than negative farms (p(wald)<0.1). the chance to have a bulk milk positive herd increased with the minimum number of years a farm had report ...200415471005
genetic susceptibility to neospora caninum infection in holstein cattle in ontario.neospora caninum has been reported to be an important cause of endemic fetal loss and occasional abortion epidemics in cattle around the world. this study examined 12,016 sera collected from 9723 holstein cows on 125 herds across ontario in 1998, 1999, and 2000. an enzyme-linked immunosorbent assay was used to examine the sera for antibodies to n. caninum. the overall prevalence of n. caninum antibodies in the cattle was 11.2% and the prevalence in individual herds varied from 0 to 70.4%. among ...200415483182
meningoencephalomyelitis caused by neospora caninum in a juvenile fallow deer (dama dama).neosporosis, caused by the protozoan parasite neospora caninum, is a serious cause of bovine abortion, stillbirth and perinatal death. this paper reports a clinical neosporosis in a 3-week-old fallow deer (dama dama). the fawn was full term and appeared normal at birth. histological lesions consisted of a multifocal necrotizing and granulomatous meningoencephalomyelitis, with intralesional protozoal cysts. positive immunohistochemical staining and characteristic pcr products confirmed the diagno ...200415485563
establishment of neospora caninum antigen-specific t cell lines of primarily cd4 t cells.neosporosis is an important cause of pregnancy loss in cattle worldwide. protective immunity against neospora caninum infection may include both cell-mediated (cmi) and humoral immune responses. this study was to establish short-term antigen-specific t cell lines composed of primarily cd4(+)t cells from peripheral blood lymphocytes (pbl) of infected cows, which may be used to identify immunodominant antigens for the development of n. caninum vaccines. crude n. caninum tachyzoite antigen was prep ...200415491474
detection of the protozoan neospora caninum using in situ polymerase chain reaction.a new method to detect the protozoan neospora caninum using indirect in situ polymerase chain reaction (pcr) is described. in situ pcr combines the advantages of the extraordinarily high sensitivity and specificity of pcr and the in situ representation of immunohistochemical methods. we describe an indirect in situ pcr, whereby the amplified products were detected using a primed in situ (prins) reaction with hapten-labeled nucleotides and visualized using fluorochrome-labeled antibodies. this te ...200415513712
neospora-associated abortion episode over a 1-year period in a dairy herd in north-east spain.this report describes a retrospective study based on serological screening, performed on a neospora-associated abortion episode over a 12-month period in a dairy herd in north-east spain. during the 1-year study period, the overall abortion rate for the herd was 23.2% (38 abortions of 164 diagnosed pregnancies). the data analysed were those derived from blood samples collected from the whole herd (n = 237) and from diagnosed pregnancies. antibodies to neospora caninum were found in 35.4% of the ...200415525363
tissue culture and explant approaches to studying and visualizing neospora caninum and its interactions with the host cell.neospora caninum is an apicomplexan parasite first mentioned in 1984 as a causative agent of neuromuscular disease in dogs. it is closely related to toxoplasma gondii and hammondia heydorni, and its subsequent description in 1988 has been, and still is, accompanied by discussions on the true phylogenetical status of the genus neospora. n. caninum exhibits features that clearly distinguish this parasite from other members of the apicomplexa, including distinct ultrastructural properties, genetic ...200415525434
alternative mechanism of eimeria bovis sporozoites to invade cells in vitro by breaching the plasma membrane.in vitro eimeria bovis sporozoites invade a wide range of cell types, and in the case of bovine cells, they may develop to first-generation schizonts. often, however, they subsequently leave their host cell to invade a new one, which seems contrary to the classical way of infecting a cell by forming a parasitophorous vacuole. using a standard, "cell wound assay," we show that e. bovis can invade bovine endothelial cells by breaching the plasma membrane and may again leave the surviving cell. eim ...200415562619
the cell-mediated immune response to neospora caninum during pregnancy in the mouse is associated with a bias towards production of interleukin-4.neospora caninum is an obligate intracellular protozoan parasite which is efficiently transmitted transplacentally in cattle where it may cause abortion. a pregnant mouse model was used to characterise the immune response following n. caninum infection; the response in non-pregnant and pregnant mice was compared. spleen cells from both infected/non-pregnant and infected/pregnant mice produced interferon-gamma, interleukin-12 and tumour necrosis factor alpha; however, the levels of these th1 cyto ...200415111094
an abortion storm in cattle associated with neosporosis in taiwan.an abortion storm associated with acute neosporosis involving 18 cattle was observed in a dairy farm in taiwan. aborted fetus age ranged from 3 to 8 months. of the 38 cattle in that farm examined during the abortion storm, 52.6% (20/38), 13.2% (5/38) and 10.5% (4/38) contained both igg and igm, only igg and only igm antibodies to neospora caninum, respectively. no antibody to n. caninum was detected prior to the abortion storm. follow-up study conducted a year later showed that 23 out of 28 catt ...200415133282
neospora caninum seroprevalence in dairy cattle in central thailand.the seroprevalence, in dairy cattle, of antibodies to neospora caninum, the relationship between seropositivity and age (heifer versus cow), the relationship of herd infection with herd size and the relationship of herd infection with the presence of dogs on the farm were studied. the study involved 549 cows and 82 dogs in 59 dairy herds in nakhon pathom, thailand. a competitive enzyme-linked immunosorbent assay (celisa) with nc-specific monoclonal antibody was used to detect the nc antibodies i ...200415135865
economic considerations for diagnostic and control options for neospora caninum-induced abortions in endemically infected herds of beef cattle.to compare economic outcome for herds not exposed to neospora caninum with that for herds with various seroprevalences of n caninum infection and evaluate 3 control strategies.200415154728
finding of neospora caninum in the wild brown rat (rattus norvegicus).nine rats (16.4%) out of 55 (rattus norvegicus) from cattle farms were seropositive to neospora caninum. two of the seropositive rats were also pcr positive but all were negative by immunohistochemistry and pas staining. the brains of all the captured rats were homogenized and initially inoculated intraperitoneally into nude mice or into spf icr mice, which had been immunosuppressed with prednisolone. one mouse that was inoculated with brain material from a seropositive rat became infected with ...200415210077
[stillbirth/perinatal weak calf syndrome in dairy heifers: results of a pilot study].a pilot study of 10 dutch dairy herds was performed to investigate possible causes of stillbirth/perinatal weak calf syndrome in heifers. possible causes and advice for further investigations on farms affected by this syndrome are discussed based on the results of investigations of blood and urine from pregnant young stock, postmortem examination of still-born calves, and a questionnaire held among farmers. infections with neospora caninum, salmonella spp. or leptospira hardjo, or a deficiency o ...200415211907
neospora caninum infection does not affect early pregnancy in dairy cattle.this study was designed to evaluate the relationship between neospora caninum infection prior to pregnancy, as determined through maternal serology, and the subsequent occurrence of abortion in dairy cattle. special emphasis was placed on pregnancy losses in the first trimester of pregnancy. neospora caninum antibodies were analyzed by commercial elisa in 2773 pregnant animals (2022 parous cows and 751 heifers) from six herds. the mean seroprevalence of antibodies to n. caninum in the herds was ...200415226015
the use of pcr to detect neospora caninum dna in the blood of naturally infected cows.twelve 2-year old heifers in their fifth month of gestation when pregnancy tested were used in this study. six heifers aborted at approximately 4 months of gestation and had blood samples drawn less than 6 weeks after the abortions were identified. blood samples were also drawn from three sero-positive pregnant and three sero-negative pregnant heifers. dna was isolated from the samples and a 350 bp fragment of the nc-5 gene was pcr amplified using primer pair np21+ and np6+. also, the internal t ...200415262009
comparison of three techniques for the serological diagnosis of neospora caninum in the dog and their use for epidemiological studies.an enzyme-linked immunosorbent assay (elisa) was developed in our laboratory and used to determine the seroprevalence of neospora caninum in three different dog populations in belgium: healthy dogs from cattle farms and urban dogs with or without various neurological disorders. the test was validated and compared with two other tests: an indirect fluorescent antibody test (ifat) and a commercially available competitive enzyme-linked immunosorbent assay (c-elisa). the study showed a good correlat ...200415265568
comparative analysis of stress agents in a simplified in vitro system of neospora caninum bradyzoite production.neospora caninum is an apicomplexan parasite identified as a major cause of abortion in cattle and neurological disease in various animal species. it is closely related to toxoplasma gondii, sharing the ability to persist indefinitely in latent stage within the host as a tissue cyst containing slow-dividing bradyzoites. in this study, we compared different stress methods to induce in vitro bradyzoite conversion, using marc-145 cells infected with nc-liverpool isolate. the tachyzoite-to-bradyzoit ...200415270086
localization of a 56-kda antigen that is present in multiple developmental stages of neospora caninum.the purpose of the present study was to characterize the intracellular distribution of a native neospora caninum 56-kda protein that is recognized by sera from n. caninum-infected dairy cattle. the complementary dna coding for this protein was expressed in escherichia coli as a polyhis fusion protein to which antiserum was prepared and used to localize the antigen in n. caninum tachyzoites and bradyzoites. by sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting, antirecomb ...200415270121
placental pathology associated with fetal death in cattle inoculated with neospora caninum by two different routes in early pregnancy.pregnant cattle were inoculated with n. caninum strain nc-1 tachyzoites intravenously (iv) (group 1, n = 8) or subcutaneously (sc) (group 2, n = 8) at 70 days' gestation. control animals (group 3; n = 8) received uninfected vero cells iv. two animals from each group were killed at 14, 28, 42 and 56 days post-inoculation (dpi). fetal mortality was 100% and 50%, respectively, in groups 1 and 2 from 28 dpi. in group 1 foci of degenerative fetal placental villi were observed at 14 dpi, with clusters ...200415276854
the role of b- and t-cell immunity in toltrazuril-treated c57bl/6 wt, micromt and nude mice experimentally infected with neospora caninum.neospora caninum is a protozoan parasite predominantly known for causing abortion in cattle and neuromuscular disease in dogs. so far, no efficient metaphylactic chemotherapy has been developed. in preliminary studies, toltrazuril had been successfully used against experimental neosporosis in mice and calves. in the present study, we used immunocompetent and immunodeficient mouse strains to address the role of immunity in supporting the chemotherapy of experimental n. caninum infection. wt, micr ...200415290254
agreement between three serological tests for neospora caninum in beef cattle.during 1999, serum samples were collected from beef cows on pastures in western canada. some of the herds had a history of confirmed abortions associated with neospora caninum infection. all these samples were initially analyzed using a single application of 1 common commercial enzyme-linked immunosorbent assay (elisa) for antibodies to n. caninum. from these initial results, 239 positive and 250 negative samples were randomly selected for further testing. this group of samples was retested usin ...200415305742
effect of a killed whole neospora caninum tachyzoite vaccine on the crude abortion rate of costa rican dairy cows under field conditions.a standard field trial was carried out to assess the effect of a commercial neospora-vaccine based on whole killed tachyzoites (bovilis-neoguard, intervet) on the abortion rate. eight hundred and seventy-six cows, over 2.5 months pregnant, belonging to 25 costa rican dairy herds, were used in the analysis. for each cow vaccinated, a cow of the same herd, breed and age category, was selected as control. the period of administration of treatments extended from june to november of 2000. the treatme ...200415325041
detection of neospora caninum in an aborted goat foetus.in italy neospora caninum has been reported in cattle, in buffaloes and in dogs. no data are available about the infection in sheep and goats. in this paper, the authors report the detection of protozoan cysts, identified as n. caninum by pcr, in the brain of an aborted goat foetus.200415325053
detection of antibodies to neospora caninum in two species of wild canids, lycalopex gymnocercus and cerdocyon thous from brazil.domestic dog (canis domesticus) and the coyote (canis latrans) are the only known definitive hosts for the protozoan neospora caninum that causes abortion in dairy cattle. in the present study, antibodies to n. caninum were sought in three species of wild canids, cerdocyon thous, lycalopex gymnocercus and dusicyon vetulus from brazil. antibodies to n. caninum were assayed by the indirect fluorescent antibody test (ifat) and the neospora agglutination test (nat). n. caninum antibodies were found ...200415325054
prevalence of neospora caninum infection in dairy cows and its consequences for reproductive management.this study was carried out to determine the prevalence of neosporosis in an area of intensive dairy production, in portugal. sera samples were obtained in a random basis from 114 cows in 49 herds (group a), and from 1237 cows in 36 herds with a history of abortion outbreaks (group b). all sera samples were tested for neosporosis by direct agglutination test (dat). additionally, attempts to isolate neospora caninum in 42 aborted bovine fetuses from 38 dairy herds (group c) were carried out, utili ...200415325549
occasional detection of neospora caninum dna in frozen extended semen from naturally infected bulls.recently, the presence of neospora caninum dna in semen from naturally infected bulls was reported. in the present work, the presence and quantification of n. caninum by pcr techniques in frozen extended semen straws from naturally infected bulls was investigated. a total of 20 seropositive and five seronegative bulls raised for reproductive purposes in an ai centre were used. ten extended semen straws from each bull obtained at different time-points during the previous 2 years were selected for ...200415325558
udder health in dairy cattle infected with neospora caninum.blood samples were collected from 3449 cows on 57 representative ontario dairy herds during the summer of 1998 and analysed for antibody to neospora caninum using an elisa. forty-eight herds (2742 cattle) contained at least one n. caninum-seropositive animal. two composite milk samples were collected from all cattle: the first on the day of blood collection and the second 68 to 365 days later. all milk samples were submitted for bacteriological culture. ontario dairy herd improvement corporation ...200415325765
prevalence of neospora caninum antibodies and factors associated with their presence in dairy cattle of the north of paraná state, brazil.to determine the prevalence of neospora caninum antibodies and associated factors, blood sera from 623 female dairy cattle from 23 farms in the north of the state of paraná, brazil, were analyzed by means of the indirect immunofluorescent-antibody test (ifat > or = 25). serum samples from 134 dogs living on the same farms also were tested for n. caninum antibodies (ifat > or = 50), and the presence of dogs was associated with the prevalence of n. caninum antibodies in cattle. the overall seropre ...200415350656
neospora caninum infection in breeder bulls: seroprevalence and comparison of serological methods used for diagnosis.to investigate the seroprevalence of neospora caninum infection in breeder bulls. in addition, the level of agreement of serological methods used was evaluated.200415350658
first isolation of neospora caninum from an aborted bovine fetus in spain.neospora caninum was isolated from the brain of a 6-mo-old aborted bovine fetus from galicia, spain. the fetal brain homogenate was inoculated intraperitoneally into cortisonized mice. the peritoneal exudate from the infected mice, along with mouse sarcoma cells (tg180), was inoculated into a second group of mice, and parasites were harvested from the peritoneal exudate. the parasites were adapted to in vitro growth in vero monolayers. the tachyzoites from the peritoneal exudate reacted positive ...200415357083
recognition patterns of neospora caninum tachyzoite antigens by bovine igg at different ifat titres.this study describes qualitative and quantitative antibody response in cows naturally infected with neospora caninum. the study was carried out with 269 serum samples obtained from 24 cows over a period of 15 weeks. prior to sample collection, the cows were tested with elisa. the 269 samples were screened with ifat and categorized into seven ifat titre groups (< 1 : 80, 1 : 80, 1 : 200, 1 : 600, 1 : 1000, 1 : 2000, > 1 : 2000). the samples were finally analysed by western blotting. seven immunod ...200415367295
serological prevalence of neospora caninum in healthy and aborted dairy cattle in mashhad, iran.a total of 810 dairy cattle were blood sampled and used to evaluate serological screening for neospora caninum infection in dairy cattle herds in mashhad (khorasan province, iran). in 4 herds, of the 810 cattle, 123 (15.18%) were seropositive by ifa test (vmrd inc., pullman, wa 99163, usa) with titer 1:200 and range of prevalence per herd from 9.92 to 19.60%. seroprevalence was not significantly different between holstein breed (14.88%) and brown swiss breed (19.60%). comparison of n. caninum se ...200415381300
identification of antigenic proteins from neospora caninum recognized by bovine immunoglobulins m, e, a and g using immunoproteomics.antigenic proteins of neospora caninum (n. caninum) against bovine immunoglobulins m, e, a, and g were investigated by using immunoproteomics. proteins of n. caninum (kba-2) tachyzoite lysates separated by two-dimensional gel electrophoresis were transferred to polyvinylidene difluoride (pvdf) membranes, probed with different bovine immunoglobulin class and classified. antigenic spots recognized were also identified by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry ...200415449377
infection by neospora caninum associated with bovine herpesvirus 1 and bovine viral diarrhea virus in cattle from minas gerais state, brazil.neospora caninum is a canine parasite which is considered a significant cause of bovine abortion. two cattle herd groups were serologically studied with the objective of studying the prevalence of infection by n. caninum associated with bhv1 and bvdv infections. in group i, 15 dairy herds (476 samples) naturally infected by the three infectious agents were analyzed,. in group ii, three dairy herds (100 samples) of cows vaccinated for two viruses were analyzed, in order to determine the infection ...200414746970
maternal and fetal immune responses of cattle inoculated with neospora caninum at mid-gestation.the humoral and cell-mediated immune responses of pregnant cattle and their fetuses were examined at intervals after infection with neospora caninum tachyzoites at mid-gestation (day 140). all cattle seroconverted and interferon gamma was detected in supernatants of peripheral blood mononuclear cells stimulated with specific antigen. at day 14 post-inoculation (pi), specific cell proliferation responses were detected in the lymph node draining the site of inoculation and in the uterine lymph nod ...200415003463
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
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
effect of bovine viral diarrhea virus infection on fertility of dairy heifers.a prospective field study in heifers from birth to first breeding was undertaken on two commercial dairies to assess the effect of bovine viral diarrhea virus (bvdv) congenital and post-natal infection (pni) on fertility. a high bvdv type 2 antibody titer (1:4096) at 10 months of age was associated with 32 more days to conceive, compared with a low titer (1:128). conversely, infection with bvdv by 5-6 months of age and high bvdv type 2 titers 1 month before conception or breeding was associated ...200415036997
coyotes (canis latrans) are definitive hosts of neospora caninum.four captive-raised coyote pups consumed tissues from neospora caninum-infected calves. faeces were examined from 4 days before to 28 days after infection. one pup shed n. caninum-like oocysts, which tested positive for n. caninum and negative for hammondia heydorni using pcr tests. coyotes are the second discovered definitive host of n. caninum, after dogs. in north america, the expanding coyote ranges and population increase the probability of contact with domestic livestock. to reduce the ris ...200415037103
determination of the seroprevalence of neospora caninum in feedlot steers in alberta.a study was conducted in alberta to determine the seroprevalence of neospora caninum in feedlot calves purchased from various auction markets throughout western canada. four feedlots (1 feedlot from each of the airdrie and high river areas and 2 feedlots from the strathmore area) were selected for sampling. at each feedlot, a random 10% sample of feedlot steer and bull calves entering the feedlot from september 2001 to december 2001 were enrolled in the study until there were a maximum of 500 an ...200415072193
incidence of abortion and association with putative causes in dairy herds in new zealand.to estimate the distribution and causes of abortion in dairy herds across new zealand during the 2001/2002 breeding season.200415768103
isolation and molecular characterisation of neospora caninum in cattle in new zealand.to isolate neospora caninum from the brains of naturally infected cattle and use molecular techniques to characterise the isolates.200415768137
antibodies to neospora caninum in the blood of european bison (bison bonasus bonasus l.) living in poland.the prevalence of antibodies to neospora caninum was examined in european bison (bison bonasus bonasus l.) living in free and fenced areas in poland. sera of 320 european bison, different ages and sexes, from breeding areas in poland were tested for n. caninum antibodies using elisa test. positive antibody responses were found in 23 bison (prevalence 7.3%). additionally, all positive sera were tested by western blot to verify the elisa results. the western blot results confirmed the presence of ...200415725547
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
prevalence of antibodies to neospora caninum in dogs of rural or urban origin in central new zealand.to investigate the seroprevalence of neospora caninum infection in populations of dogs from dairy farms, sheep/beef farms and urban areas in the central part of new zealand. it was postulated seroprevalence would be higher for farm dogs than urban dogs if the life-cycle of this parasite involves transmission between dogs and cattle.200316032332
prevalence of antibodies to neospora caninum within central queensland beef cattle. 200315080432
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
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
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
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
evaluation of an inactivated neospora caninum vaccine in beef feedlot steers.to 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
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
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
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
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
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 importance of bovine neosporosis for abortion in switzerland].the protozoan parasite neospora caninum is one of the most important infectious abortion causes in cattle worldwide. in a swiss case-control-study we investigated 113 abortion problem farms and 113 control farms. it was possible to detect n. caninum in 21% of 242 investigated aborted fetuses by pcr upon brain samples. eighty-four % of mothers aborting n. caninum positive fetuses were serologically positive for this parasite. the seroprevalence for n. caninum of all aborting mothers was 44%. with ...200312677771
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
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
the effect of the dam-calf relationship on serostatus to neospora caninum on 20 costa rican dairy farms.an 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
serological evidence of neospora caninum infections in beef bulls in six counties of the corrientes province, argentina.the purpose of the present work was to identify neospora caninum infections in beef bulls belonging to 19 herds from six counties located in the corrientes province, argentina. the presence of antibodies to n. caninum was evaluated in 305 serum samples of bulls (bos taurus and bos indicus). age and breed were recorded. an indirect fluorescent antibody test was used to determine specific antibodies. the number of bulls with natural neospora-infection was 15 of 305 (4.9%). no association between s ...200312809751
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
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
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 pathogenesis of neosporosis in pregnant cattle: inoculation at mid-gestation.to 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
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
elisa detection of igg antibody against a recombinant major surface antigen (nc-p43) fragment of neospora caninum in bovine sera.an 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
first demonstration of protective immunity against foetopathy in cattle with latent neospora caninum infection.the parasite neospora caninum is an important cause of abortion in cattle world-wide. chronically infected dams transmit the parasite transplacentally and infected foetuses may be aborted or born chronically infected but clinically normal. chronically infected cows repeatedly transmit the parasite to foetuses in several pregnancies and some may abort more than once suggesting that the immune response in these cattle is compromised during pregnancy. to investigate the nature of the immune respons ...200313129528
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
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
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
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
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