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serodiagnosis of neospora caninum infection in cattle by enzyme-linked immunosorbent assay with recombinant truncated ncsag1.neospora caninum is a veterinary medically important pathogen capable of causing abortion in cattle and neuromuscular paralysis in dogs. the surface antigen 1 of n. caninum (ncsag1) is an important candidate for the development of a diagnostic reagent for neosporosis. in order to establish an effective diagnostic method, the gene encoding truncated ncsag1 (ncsag1t) lacking a signal peptide and c-terminal hydrophobic regions was cloned and expressed in escherichia coli as a fusion protein with gl ...200314729165
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
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
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
prevalence of antibodies to neospora caninum within central queensland beef cattle. 200315080432
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
neosporosis.neospora caninum is a recently recognized protozoan parasite of animals, which, until 1988, was misdiagnosed as toxoplasma gondii. neospora caninum or neospora-like parasites, here discussed by j.p. dubey and david lindsay, cause paralysis and death in dogs and neonatal mortality and abortion in cattle, sheep, goats and horses.199315463690
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
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
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
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
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
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
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
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
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
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
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
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
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
detection of neospora caninum in the semen and blood of naturally infected bulls.a prospective study was designed to investigate the presence of neospora caninum in semen and blood of eight bulls seropositive to n. caninum using nested-pcr procedures. positive semen and blood samples were bioassayed in a balb/c nu/nu mouse model. specific anti-n. caninum serological and interferon-gamma (ifn-gamma) responses were also studied. in parallel, five seronegative bulls acted as non-infected controls. all bulls were located in a collaborating ai centre and monitored for 22 weeks. s ...200515725454
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
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
prevalence and transmission of neospora caninum within infected swedish dairy herds.in this long-term study, the changes in within-herd neospora caninum seroprevalences and the relative importance of horizontal and vertical parasite transmission in swedish dairy herds were investigated. the within-herd prevalences varied between 5.8% and 65.0% when the herds were first sampled. comparing the prevalences of year 2000 with those found 2-3 years later, nine out of 14 investigated herds had a similar or lower within-herd prevalence while five herds had an increased portion of serop ...200515740858
igg avidity pattern in cattle after ingestion of neospora caninum oocysts.the avidity (functional affinity) of specific antibodies are being used to estimate duration of bovine neospora caninum infection. here, we report for the first time the avidity pattern in cattle orally inoculated with n. caninum oocysts. in all, 16 pregnant cows and 7 calves were administered n. caninum oocysts. in the cows, the avidity increased during the early course of infection. in all but one, the avidity was < or = 35 during the first 6 weeks after infection and no cow had an avidity val ...200515740856
neospora caninum in pastured cattle: determination of climatic, environmental, farm management and individual animal risk factors using remote sensing and geographical information systems.a cross-sectional serological survey was conducted on cattle pasturing in an area of the southern italian apennines to evaluate the seroprevalence to neospora caninum, and to investigate the climatic, environmental, farm management, and individual animal factors that influence the distribution of this protozoan. blood samples were collected from 864 pastured cattle raised on 81 farms. serum samples were tested for antibodies to n. caninum using an elisa assay (herdcheck), idexx). a geographical ...200515740859
neospora abortions in dairy cattle: diagnosis, mode of transmission and control.to determine the contribution of neospora caninum to abortions on a dairy farm in nsw (australia), determine the mode of transmission and develop and trial a control option for infection.200515740860
identification of vaccine candidate peptides in the ncsrs2 surface protein of neospora caninum by using cd4+ cytotoxic t lymphocytes and gamma interferon-secreting t lymphocytes of infected holstein cattle.previously, our laboratory showed that holstein cattle experimentally infected with neospora caninum develop parasite-specific cd4+ cytotoxic t lymphocytes (ctl) that lyse infected, autologous target cells through a perforin-granzyme pathway. to identify specific parasite antigens inducing bovine ctl and helper t-lymphocyte responses for vaccine development against bovine neosporosis, the tachyzoite major surface proteins ncsag1 and ncsrs2 were targeted. in whole tachyzoite antigen-expanded bovi ...200515731029
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
the use of beef bull semen reduced the risk of abortion in neospora-seropositive dairy cows.there is an evidence that the epidemiology of neosporosis differs in dairy and beef cattle, such that beef cattle carry a lower risk of abortion. the aim of the present study was to establish whether artificial insemination using semen from beef bulls could reduce the risk of abortion in dairy cows seropositive for the neospora caninum parasite. our study was based on yearly serological screening for neosporosis and on the confirmation of neospora infection in aborted fetuses in two high-produci ...200515752268
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
immunisation of mice against neosporosis with recombinant ncsrs2 iscoms.the coccidian parasite neospora caninum is an intracellular protozoan, causing abortion in cattle in many countries around the world. in this study, the protective potential of the major n. caninum surface antigen ncsrs2, expressed in escherichia coli and formulated into immunostimulating complexes (iscoms), was investigated in an experimental mouse model. the recombinant protein was specially designed for binding to iscoms via biotin-streptavidin interaction. two groups of 10 balb/c mice were i ...200515817199
serological responses to neospora caninum in experimentally and naturally infected water buffaloes (bubalus bubalis).the water buffalo (bubalus bubalis) is an important natural host for neospora caninum. serologic responses to n. caninum were studied in experimentally and naturally infected water buffaloes in brazil. antibodies were assayed by the indirect fluorescent antibody test (ifat) using a cut off value of 1:25. six buffaloes were each inoculated subcutaneously with 5 x 10(6) live culture-derived tachyzoites of the cattle illinois strain of n. caninum, and two calves were kept as uninoculated controls. ...200515817198
neospora caninum: quantification of dna in the blood of naturally infected aborted and pregnant cows using real-time pcr.this study quantified neospora caninum dna in the blood and brain of pregnant and aborted heifers by monitoring pcr product formation in real-time using sybr green i, a double-stranded dna-binding dye. primers were designed to amplify a 188 bp product specific to n. caninum from the nc-5 gene fragment of n. caninum. similarly, a 71 bp product was amplified from the 28s rrna gene of bovine genomic dna that served as a control. agarose gel electrophoresis and analysis of the melting curve for pcr ...200515804378
[first documentation of a neospora-induced "abortion storm" (exogenous transplacental transmission of neospora caninum) in a swiss dairy farm].in a swiss dairy farm (canton of geneva) consisting of 73 animals 8 abortions were observed within 2 weeks. serological and molecular biological analyses (pcr) on aborting dams, and abortion materials, respectively, revealed that the protozoan parasite neospora caninum was the causative agent. besides the 8 aborting animals, 12 other non-aborting heifers were found to be serologically positive for this parasite. all positive sera were further tested in an avidity-elisa to elucidate the recency o ...200515801622
immune responses during pregnancy in heifers naturally infected with neospora caninum with and without immunization.this study was designed to identify changes in parasite-specific immune responses that occur during vertical transmission of neospora caninum and can be used as indicators of parasite reactivation in naturally infected heifers. ten heifers were unimmunized and 11 immunized with killed tachyzoites. one unimmunized heifer, which aborted at week 19 of gestation, had an increase in parasite-specific antibodies, mainly igg(2), from week 15 to week 19 and a concomitant decline in parasite-specific cel ...200515841416
associations between pregnancy outcome and serological response to neospora caninum among a group of dairy heifers.to monitor pregnancy in a group of rising 2-year-old dairy heifers on a farm on which abortion due to neospora caninum was known to occur in previous years.200515846399
seroprevalence of antibodies against bovine leukemia virus, bovine viral diarrhea virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum in dairy cattle in saskatchewan.blood was drawn from 1530 dairy cows in 51 herds. for antibodies against bovine leukemia virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum, 37.4%, 2.7%, and 5.6% of cows were test positive, respectively, while 29.2% of herds had unvaccinated animals with > or = 1:64 for bovine viral diarrhea virus.200515759829
reduction in transplacental transmission of neospora caninum in outbred mice by vaccination.infection with the protozoan parasite neospora caninum is an important cause of abortion in cattle. a major source of infection is transplacental transfer of the parasite from mother to offspring during pregnancy. this study describes investigations on the immunisation of outbred qs mice before pregnancy with live or a crude lysate of n. caninum (nc-nowra isolate) to prevent transplacental transfer of a challenge infection administered during pregnancy. parasites present in the brains of pups fr ...200515885695
seroprevalence of neospora caninum in dairy and beef cattle with reproductive disorders in japan.serum samples from 145 dairy and 65 beef cattle with reproductive disorders and 54 normally calving dairy cattle (controls) in japan were tested for presence of neospora caninum antibodies by use of an indirect fluorescent antibody test (ifat, titer 1:200). overall, seroprevalence of n. caninum was significantly higher (p < 0.001) in dairy cattle (20.0%, 29/145) than in beef cattle (1.5%, 1/65). in cattle which aborted, seroprevalence of n. caninum was significantly higher (p = 0.041) in dairy c ...200515893065
serologic immunoreactivity to neospora caninum antigens in dogs determined by indirect immunofluorescence, western blotting and dot-elisa.neospora caninum, is a coccidian protozoan known as a major cause of bovine abortion and canine neuropathies. the aim of the present study was to develop a reliable and quick test to detect antibodies to n. caninum in dog sera. sixty-five serum samples from dogs, including 35 positive and 30 negative for n. caninum antibodies were used for standardization of the test. in parallel, immunoreactivity of the sera to toxoplasma gondii antigens was investigated using a passive agglutination test. a do ...200515893072
immune response to neospora caninum in naturally infected heifers and heifers vaccinated with inactivated antigen during the second trimester of gestation.the objective of this study was to compare the immune response to neospora caninum in naturally infected heifers and heifers inoculated with a killed whole n. caninum tachyzoite preparation during the second trimester of gestation. nine holstein heifers were used in this study; three naturally infected heifers were born from seropositive dams, and six seronegative heifers were born from seronegative dams. four seronegative heifers were subcutaneously vaccinated with a killed whole n. caninum tac ...200515893067
serological status for n. caninum, bovine viral diarrhea virus, and infectious bovine rhinotracheitis virus at pregnancy testing and reproductive performance in beef herds.neospora caninum, infectious bovine rhinotracheitis (ibr), and bovine viral diarrhea virus (bvdv) are important differentials for the diagnosis of infectious reproductive loss in beef herds. the objective of this study was to describe the serological status of both pregnant and non-pregnant beef cows from herds with varying levels of reproductive success. the study provided an opportunity to examine whether there were any associations between serological status for bvdv, ibr, and n. caninum and ...200515893892
detection of antibodies to neospora caninum in cattle by enzyme-linked immunosorbent assay with truncated ncsrs2 expressed in escherichia coli.the surface antigen 1-related sequence 2 of neospora caninum (ncsrs2) is considered as an immunodominant antigen. in this study, the gene encoding truncated ncsrs2 (ncsrs2t) lacking an n-terminal signal peptide and c-terminal hydrophobic regions was expressed in escherichia coli, and its diagnostic potential in an enzyme-linked immunosorbent assay (elisa) was evaluated. elisa could discriminate clearly between known n. caninum-positive and -negative sera from cattle. field serum samples collecte ...200515856900
development of neospora caninum cultured with human serum in vitro and in vivo.because there has been no report of symptomatic neospora caninum infection in humans, we examined the effect of human serum on the parasite's growth in either a bovine angioendothelial cell or caco-2 cell culture in vitro and in immunocompromised mice in vivo. there was no difference in intracellular parasite numbers between cells incubated with human serum at 24 hr after challenge and those incubated with fetal bovine serum (fbs), which has no titer for the anti-n. caninum agglutination antibod ...200515856911
relationship between rainfall and neospora caninum-associated abortion in two dairy herds in a dry environment.the possible direct relationship between climate variations and abortion in neospora caninum-infected cows has not been studied. the objective of this study was to determine whether climate changes could be a risk factor for abortion in n. caninum-infected cows, and was based on yearly serological screening for neosporosis and on the confirmation of n. caninum infection on aborted fetuses in two high-producing dairy herds with a mean 27% seroprevalence of n. caninum antibodies. the final populat ...200515876229
effect of neosporosis on productive and reproductive performance of dairy cattle in costa rica.a cross-sectional study was conducted to assess the effect of neosporosis on productive and reproductive parameters in dairy cows. cows (n=2743) from 94 farms located in the most important dairy areas in costa rica were used in the study. the size of the herds ranged from 32 to 379 females (mean=110, median=125). an indirect elisa was used to determine the serostatus of the cows towards neospora caninum. the effect of neosporosis on milk production was analysed by a mixed linear model. in additi ...200515936812
a review of neospora caninum in dairy and beef cattle--a canadian perspective.neospora caninum is one of the most important causes of abortion in cows. the occurrence of n. caninum infection in beef and dairy cattle has been reported worldwide, and in most provinces in canada. the objective of this review is to summarize our current understanding of n. caninum in dairy and beef cattle for canadian bovine practitioners. the review covers the life cycle of the agent, its mechanisms of transmission, clinical signs, and tests for diagnosing the infection. data on the prevalen ...200515884645
effects of host maturity and prior exposure history on the production of neospora caninum oocysts by dogs.to investigate whether dogs shed neospora caninum oocysts more than once, five dogs with a previous history of shedding oocysts were fed infected bovine tissues. two of three dogs shed oocysts when they were re-exposed 18-20 months after the first challenge; two other dogs re-exposed earlier, only 8 months after the primary exposure, did not produce oocysts. these results suggest that dogs may become refractory to shedding n. caninum oocysts for a period approximately between 8 and 18 months aft ...200516029931
influence of the stage of pregnancy on neospora caninum distribution, parasite loads and lesions in aborted bovine foetuses.in the present work we have studied in neospra caninum aborted bovine foetuses the influence of foetal age (first, second and third gestational periods) on parasite distribution by nested pcr, parasite loads by real-time pcr and n. caninum associated lesions. for this purpose, a total of 220 aborted foetuses were analysed and detection of n. caninum infection was accomplished by nested-pcr in brain, heart and liver, detecting the presence of the parasite in 72 (32.7%) bovine foetuses. when the d ...200616023188
exploration of immunoblot profiles of neospora caninum probed with different bovine immunoglobulin classes.the present study was attempted to compare the neospora caninum (n. caninum) antigenic bands recognized by different bovine immunoglobulin classes. a total 10, 5, 2, and 6 antigenic bands were exhibited on immunoblot profiles against bovine igm, ige, iga, and igg, respectively. a 46 kda band was probed as a common antigenic band except iga; 69 kda band was bovine igm and ige; 33, 37, 55, and 79 kda bands were bovine igm and igg; 72 kda band was found igm and iga profiles. based on the analysis, ...200515933437
hplc purification of recombinant ncgra6 antigen improves enzyme-linked immunosorbent assay for serodiagnosis of bovine neosporosis.the gene for a dense granule protein (ncgra6) of neospora caninum was expressed in escherichia coli as a his-tag fusion protein and purified by ninta affinity chromatography. in a preliminary study, high binding of antibodies from n. caninum-negative cows was observed in enzyme-linked immunosorbent assay (elisa) using ninta-purified ncgra6. analysis of ninta eluates revealed a significant number of e. coli proteins that co-purified with recombinant ncgra6. in an attempt to improve the relative s ...200515970387
effects of seropositivity for bovine leukemia virus, bovine viral diarrhoea virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum on culling in dairy cattle in four canadian provinces.the purpose of this research was to determine the effects of seropositivity for exposure to bovine leukemia virus (blv), bovine viral diarrhoea virus (bvdv), mycobacterium avium subspecies paratuberculosis (map) and neospora caninum (nc) on overall and reason-specific culling in canadian dairy cattle. serum samples from, approximately, 30 randomly selected cows from 134 herds were tested for antibodies against blv, map and nc using commercially available elisa test kits, while 5 unvaccinated cat ...200515970402
evaluation of three enzyme-linked immunosorbent assays for detection of antibodies to neospora caninum in bulk milk.three elisas for the detection of antibodies against neospora caninum in bulk milk were evaluated in 162 dutch dairy herds. the first elisa was the dutch animal health service (ahs) in-house elisa, developed from the routine in-house serum elisa. the other two elisas were commercial milk elisas from idexx and lsi. blood samples of all lactating cows in 162 dairy herds were tested using the ahs in-house serum elisa. based on previous studies in the netherlands a within-herd n. caninum seroprevale ...200515970385
seronegative conversion in four neospora caninum-infected cows, with a low rate of transplacental transmission.four neospora-seropositive pregnant cows (prebreeding indirect fluorescent antibody (ifa) titers between 1:400 and 1:1600) were confined and observed until parturition. all cows gave birth to normal calves. selected tissues were tested for nc by histopathology, immunohistochemical (ihc) and polymerase chain reaction (pcr). parasite isolation was attempted in vero cell cultures. at parturition, all cows were seronegative at 1:200 and two of four cows had a titer of 1:100 when further tested. thre ...200515939537
control options for neospora caninum infections in cattle--current state of knowledge.this article reviews control options for neospora caninum infection and abortion in cattle, drawing on published literature and the authors' own research in this field. apart from the successful use of embryo transfer to prevent congenital infection in calves born to infected cows, there are currently no accepted control methods for the prevention of abortions in cattle. the epidemiological data at hand suggest that concomitant infections with bovine pestivirus increase the risk of abortion sign ...200216032217
protozoal encephalomyelitis of dogs involving neospora caninum and toxoplasma gondii in new zealand.in a retrospective study of 15 cases of encephalomyelitis in dogs, three cases of neospora caninum and two cases of toxoplasma gondii infection were identified using immunohistochemical staining of central nervous system sections. all cases of neosporosis showed ataxia and progressive hind limb paralysis due to multifocal non-suppurative meningoencephalomyelitis which was most severe in the spinal cord and base of the brain stem. neospora tissue cysts could not be distinguished morphologically f ...199716031995
serology of a neospora abortion outbreak on a dairy farm in new zealand: a case study.to describe the kinetics of serological titres after an abortion outbreak in april-may 1995 due to neospora caninum affected 17 dairy cows in a herd of 320.199816032006
recent advances in understanding the epidemiology of neospora caninum in cattle.introduction: neospora caninum is the most frequently diagnosed cause of cattle abortion in new zealand and is an important pathogen worldwide. the parasite has been found in aborted bovine foetuses and in puppies with neurological disease. recent developments have provided new insights into the epidemiology of the disease that are reviewed in this article. transmission: transplacental infection is of major importance in the spread of n. caninum overseas. most congenital infections result in the ...200116032161
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
development of rapid immunochromatographic test with recombinant ncsag1 for detection of antibodies to neospora caninum in cattle.an immunochromatographic test (ict) with recombinant surface antigen 1 of neospora caninum (ncsag1) was developed for the rapid detection of antibodies to n. caninum in cattle. the ict was used to clearly discriminate between immunofluorescent-antibody test (ifat)-positive bovine sera and ifat-negative bovine sera. serum samples collected from cattle in yanbian, china, were examined by the ict. of the 96 serum samples, 23 (24.0%) were positive by the ict, and 19 (19.8%) samples were positive by ...200516002641
neospora abortion in new zealand cattle.protozoal abortion in cattle was retrospectively studied by examining material submitted to the batchelar animal health laboratory in the years 1987-90. only cases in which foetal brain had been submitted were examined. histologically, protozoal lesions were seen in the brains of 28% of 320 aborted foetuses. lesions were also seen in 10% of the hearts and 34% of the placentas examined, but these were not as characteristic as those in the brains. protozoa, confirmed immunohistochemically as being ...199116031639
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
prevalence of neospora antibodies in beef cattle in new zealand.to estimate the prevalence of neospora infection in a sample of new zealand beef cattle.200016032142
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
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