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neospora caninum infection and congenital transmission: serological and parasitological study of cows up to the fourth gestation.in this paper, a parasitological and serological study performed in three cows up to the fourth gestation is reported in order to clarify the extent of vertical propagation and, secondly, in which period of gestation the recrudescence of previous infection occurs. the cows selected for the study delivered healthy but congenitally infected calves in first pregnancy. the parasite was found, by biological tests in swiss mice, in all the placentas of the three cows examined, during the three subsequ ...200314633211
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
neospora caninum in sheep: a herd case report.neospora caninum was detected by means of pcr in the brain of 4 out of 20 aborted fetuses in a flock of 117 sheep exhibiting a persistent abortion problem, and n. caninum tissue cysts were furthermore found in encephalitic lesions in one of the pcr-positive fetuses. toxoplasma gondii was detected as aborting agent in another 3 out of 20 fetuses. antibodies to n. caninum (by indirect fluorescence antibody test (ifat)) were found in 10.3% of 117 ewes and antibodies for t. gondii were found in 97.4 ...200314630429
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
detection of hammondia heydorni-like organisms and their differentiation from neospora caninum using random-amplified polymorphic dna-polymerase chain reaction.neospora caninum and hammondia heydorni are morphologically and phylogenetically related coccidians that are found in dogs. new diagnostic genetic loci, based on random-amplified polymorphic dna-polymerase chain reaction (rapd-pcr), were developed to aid in the detection of h. heydorni-like parasites and to discriminate them from n. caninum and other related coccidians of dogs. on the basis of the data obtained from 5 random decamers, h. heydorni (manhattan-1) and n. caninum (nc1) were character ...200314627168
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
seroprevalence of neospora caninum and toxoplasma gondii in captive and free-ranging nondomestic felids in the united states.seven serum samples of 101 samples from nondomestic, captive and free-ranging felids from the united states were indirect fluorescent antibody positive for antibodies to neospora caninum, whereas 44 samples were positive for antibodies to t. gondii. although none of the captive animals displayed clinical signs of disease, nondomestic felids in the united states have been exposed to, and are likely infected with, n. caninum and t. gondii. this may have serious implications for zoological gardens ...200314582785
toxoplasma gondii, neospora caninum, sarcocystis neurona, and sarcocystis canis-like infections in marine mammals.toxoplasma gondii, neospora caninum, sarcocystis neurona, and s. canis are related protozoans that can cause mortality in many species of domestic and wild animals. recently, t. gondii and s. neurona were recognized to cause encephalitis in marine mammals. as yet, there is no report of natural exposure of n. caninum in marine mammals. in the present study, antibodies to t. gondii and n. caninum were assayed in sera of several species of marine mammals. for t. gondii, sera were diluted 1:25, 1:50 ...200314580799
a role for balance of interferon-gamma and interleukin-4 production in protective immunity against neospora caninum infection.a suitable balance in the production of th1/th2-type cytokines has a crucial role in the control of microbial infections. we investigated cytokine production patterns and effects during neospora caninum infection, based on two mouse models and an in vitro system. in the acute infection of n. caninum, balb/c-background ifn-gamma-deficient mice that were sensitive to the n. caninum infection showed high levels of il-10 production, whereas significant levels of interferon-gamma (ifn-gamma) and inte ...200314559161
neospora caninum and toxoplasma gondii: a novel adhesion/invasion assay reveals distinct differences in tachyzoite-host cell interactions.this paper describes an adhesion/invasion assay, based on combined pyrrolidine dithiocarbamate (pdtc) and antibody treatment of parasites followed by quantitative real-time pcr. this pdtc-pcr assay can be used to comparatively assess the participation of host cell- and parasite-associated components during host cell adhesion and entry by neospora caninum and toxoplasma gondii tachyzoites, respectively, and is potentially applicable to any other apicomplexan parasite. the assay allows to determin ...200314552862
isolation of neospora caninum from a blind calf in paraná, southern brazil. 200314533770
seroprevalence of neospora caninum and toxoplasma gondii antibodies in the south american opossum (didelphis marsupialis) from the city of são paulo, brazil.antibodies to neospora caninum and toxoplasma gondii were assayed in sera of 396 opossums (didelphis marsupialis) from the city of são paulo, brazil. antibodies to n. caninum were assayed using the indirect immunofluorescent antibody test (ifat). antibodies (ifat, approximately 1:25) to n. caninum were found in 84 opossums (d. marsupialis) in titers of 1:25 in 46, 1:50 in 20, 1:100 in 17, and 1:400 in 1. antibodies to t. gondii were assayed with the modified agglutination test (mat) and the ifat ...200314533710
autofluorescence of toxoplasma gondii and related coccidian oocysts.this is the first report of blue autofluorescence as a useful characteristic in the microscopic detection of toxoplasma gondii, hammondia hammondi, hammondia heydorni, neospora caninum, besnoitia darlingi, and sarcocystis neurona oocysts or sporocysts. this autofluorescence is of sufficient intensity and duration to allow identification of these oocysts from complex microscopic sample backgrounds. as with the autofluorescence of related coccidia, the oocysts glow pale blue when illuminated with ...200314533708
meningoencephalitis associated with an unidentified apicomplexan protozoan in a pacific harbor seal.a pacific harbor seal (phoca vitulina richardsii) was found on the central california coast with neurologic signs and labored breathing, which were unresponsive to treatment. necropsy revealed a nonsuppurative necrotizing meningoencephalitis, a multilocular thymic cyst, and nonsuppurative cystitis and renal pyelitis. microscopic examination revealed protozoans in the brain, thymic cyst, and bladder mucosa. ultrastructurally, the protozoal tachyzoites were different from those of neospora caninum ...200314533706
prevalence of antibodies to neospora caninum, sarcocystis neurona, and toxoplasma gondii in wild horses from central wyoming.sarcocystis neurona, neospora caninum, n. hughesi, and toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. the source of infection for n. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for s. neurona, n. caninum, and t. gondii, respectively. seroprevalence of these coccidians in 276 wild horses from central wyoming outside the known range of the opossum (didelphis virginiana) was determined. antibodies to t. gond ...200314533680
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
dermatitis in a dog associated with an unidentified toxoplasma gondii-like parasite.protozoal dermatitis was diagnosed in a 6-year-old female great dane dog from rio de janeiro, brazil. the dog died because of a chronic illness with an ehrlichia-like organism. numerous apicomplexan parasites were identified histologically in the section of dermal lesions. the protozoan reacted with toxoplasma gondii polyclonal rabbit serum but not with neospora caninum or sarcocystis neurona antibodies. ultrastructurally, the protozoa was not t. gondii because it had schizont-like structures wi ...200314519327
anti-protozoal efficacy of medicinal herb extracts against toxoplasma gondii and neospora caninum.the purpose of this study was to determine whether alcohol extracts of herbs (sophora flavescens aiton, sinomenium acutum (thunb.) rehder and e.h. wilson, pulsatilla koreana (yabe ex nakai) nakai ex t. mori, ulmus macrocarpa hance and torilis japonica (houtt.) dc.) from south korea, possess in vitro anti-protozoal activity against cultures of toxoplasma gondii and neospora caninum. these herbs have been used as human anti-parasitics in asian countries for many years. alcohol extracts of these he ...200314519322
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
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
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
laboratory passage and characterization of an isolate of toxoplasma gondii from an ocular patient in korea.toxoplasma gondii tachyzoites were isolated from the blood of an ocular patient, and have been successfully passaged in the laboratory, for over a year, by peritoneal inoculation in mice. the isolated parasite was designated the korean isolate-1 (ki-1) and its characteristics were compared with those of the rh strain, a wellknown virulent strain originating from a child who suffered from encephalitis. the morphology, pathogenicity, infectivity and cell culture characteristics of the ki-1 were si ...200312972728
development and evaluation of a seminested pcr for detection and differentiation of babesia gibsoni (asian genotype) and b. canis dna in canine blood samples.canine babesiosis has recently been recognized as an emerging infectious disease of dogs in north america. we sought to develop a seminested pcr to detect and differentiate babesia gibsoni (asian genotype), b. canis subsp. vogeli, b. canis subsp. canis, and b. canis subsp. rossi dna in canine blood samples. an outer primer pair was designed to amplify an approximately 340-bp fragment of the 18s rrna genes from b. gibsoni (asian genotype), b. canis subsp. vogeli, b. canis subsp. rossi, and b. can ...200312958243
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
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
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
hammondia heydorni from the arabian mountain gazelle and red fox in saudi arabia.unsporulated oocysts were detected in the feces of an arabian red fox (vulpes vulpes arabica) between 6 and 8 days after it had been fed meat from arabian mountain gazelles (gazella gazella) known to contain sarcocysts. no oocysts were discovered in the feces of other experimental cubs, although sporocysts of sarcocystis spp. were passed subsequently by all cubs that were fed gazelle meat, including those fed with reem (g. subgutturosa marica). the oocysts sporulated in 3 days at room temperatur ...200312880254
immunization of mice with plasmid dna coding for ncgra7 or ncshsp33 confers partial protection against vertical transmission of neospora caninum.the purpose of the present study was to use direct plasmid deoxyribonucleic acid (dna) injection to identify specific antigens that confer protection against congenital transfer of neospora caninum. inbred balb/c mice were vaccinated before pregnancy with a recombinant plasmid containing sequences encoding n. caninum antigen ncgra7 or ncshsp33. the mice were challenged with n. caninum tachyzoites at 10-12 days of gestation. whereas 100% of pups born from dams immunized with control plasmid conta ...200312880248
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
characterization of an alpha tubulin gene sequence from neospora caninum and hammondia heydorni, and their comparison to homologous genes from apicomplexa.the gene coding for a tubulin has been isolated by the polymerase chain reaction and sequenced from 2 isolates of neospora caninum (nc-liverpool and nc-sweb1). the data show that the gene, as in toxoplasma gondii, is single copy and contains 3 exons and 2 introns and is identical in sequence in the 2 isolates studied. comparison of the predicted protein sequence shows it to be identical to the a tubulin protein encoded by the t. gondii gene. the majority of the nucleotide substitutions that have ...200312866794
antibodies to neospora caninum in european brown hare (lepus europaeus).neospora caninum antibodies in european brown hares (lepus europaeus) were reported for the first time in sera collected from hares imported in italy from east europe. sera from 93 hares coming from hungary and 44 hares coming from slovakia were tested using a direct agglutination test (dat). seroprevalence was 8.0% at the 1:40 dilution and 1.5% at 1:320 dilution. seroprevalence in females and males and in different countries of origin did not differ significantly. our results indicate that euro ...200312860071
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
electron microscopic study of in vitro cultures of hammondia heydorni (berlin 1996) tachyzoites after passages through dogs, mice, rats, guinea pigs and jirds.this study describes the fine structure and reproduction of tachyzoites of hammondia heydorni (isolate berlin 1996) after in vitro cultivation of stages isolated from serial passages between dogs and various intermediate hosts such as mice, rats, guinea pigs, jirds, knock-out mice, goats and sheep. the tachyzoites are identical with respect to their ultrastructural features to the corresponding stages of the nc-1-strain of neospora caninum. this fact conforms with other already published data an ...200312838414
analysis of the sarcocystis neurona microneme protein snmic10: protein characteristics and expression during intracellular development.sarcocystis neurona, an apicomplexan parasite, is the primary causative agent of equine protozoal myeloencephalitis. like other members of the apicomplexa, s. neurona zoites possess secretory organelles that contain proteins necessary for host cell invasion and intracellular survival. from a collection of s. neurona expressed sequence tags, we identified a sequence encoding a putative microneme protein based on similarity to toxoplasma gondii mic10 (tgmic10). pairwise sequence alignments of snmi ...200312814647
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
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
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
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
vaccination of mice against experimental neospora caninum infection using ncsag1- and ncsrs2-based recombinant antigens and dna vaccines.ncsag1 and ncsrs2, the two major immunodominant tachyzoite surface antigens of the apicomplexan parasite neospora caninum, were investigated for their potential as vaccine candidates in mice. recombinant recncsrs2 and recncsag1 were expressed in escherichia coli as poly-histidine-tagged fusion proteins. separate groups of mice were immunized with purified recncsag1, recncsrs2, or a combination of both, and were then challenged with n. caninum tachyzoites. subsequent experiments included intramus ...200312741509
first pcr-confirmed report of a neospora caninum-associated bovine abortion in austria. 200312723631
vaccination of ewes for prevention of vertical transmission of neospora caninum.to evaluate the immunologic response of a killed tachyzoite vaccine against neospora caninum and its effectiveness in preventing vertical transmission of n caninum in sheep.200312693535
susceptibility of djungarian hamsters (phodopus sungorus) to neospora caninum infection.djungarian hamsters were examined for the susceptibility to neospora caninum infection. after 29 djungarian hamsters were intraperitoneally inoculated with 5 x 10(6) n. caninum tachyzoites of jpa1 strain, some animals showed symptoms such as ataxia, and many tissue cysts were detected in the brain and a cyst in the muscular tunics of stomach. especially, more than 100 cysts per head were observed after 5 weeks post inoculation. it is suggested that the djungarian hamster is a model useful to exa ...200312679575
[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
[abortion in small ruminants in switzerland: investigations during two lambing seasons (1996-1998) with special regard to chlamydial abortions].abortion cases of 144 goats und 86 sheep were investigated etiologically during 2 lambing seasons (1996/1997, 1997/1998). macroscopic inspection of fetus and placenta was completed by histopathology and bacteriological isolation of agents. in addition, immunohistologically the following antigens were labeled in formalin-fixed and paraffin-embedded tissue sections: toxoplasma gondii, neospora caninum, chlamydophila abortus (formerly chlamydia psittaci serovar 1) and border disease virus. from far ...200212677687
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
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
reduced cerebral infection of neospora caninum-infected mice after vaccination with recombinant microneme protein ncmic3 and ribi adjuvant.c57bl/6 mice were vaccinated with a bacterially expressed and purified polyhistidine-tagged full-length version of the microneme protein ncmic3 (recncmic3) emulsified in ribi adjuvant system (ras). subsequently, they were challenged by intraperitoneal inoculation of 2 x 10(6) live neospora caninum tachyzoites. as controls, groups of mice received phosphate-buffered saline (pbs)-ras alone (adjuvant control) or were treated with pbs before infection (infection control). the protective effect of va ...200312659301
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
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
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
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
gene discovery in the apicomplexa as revealed by est sequencing and assembly of a comparative gene database.large-scale est sequencing projects for several important parasites within the phylum apicomplexa were undertaken for the purpose of gene discovery. included were several parasites of medical importance (plasmodium falciparum, toxoplasma gondii) and others of veterinary importance (eimeria tenella, sarcocystis neurona, and neospora caninum). a total of 55192 ests, deposited into dbest/genbank, were included in the analyses. the resulting sequences have been clustered into nonredundant gene assem ...200312618375
survey of neospora caninum antibodies in dairy and beef cattle from five regions of the united states.serum samples from 4,907 cows from 93 dairy and five beef herds were analyzed for antibodies to neospora caninum by commercially available elisa. the herds were recruited from 20 states and the territory of puerto rico. a questionnaire assessed the herd's abortion history and exposure risks to n. caninum. results showed that 788 (16%) cows tested positive for antibodies to n. caninum. at least one positive animal was detected in 90% of the herds tested. the prevalence of cows seropositive to n. ...200212584676
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
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
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
[progress in the research on the tachyzoite-bradyzoite conversion of toxoplasma gondii]. 200012567672
seroprevalence of antibodies to neospora caninum in dogs from spain.the prevalence of neospora caninum antibodies was determined in sera of 139 dogs from catalonia (northeastern spain) using the indirect immunofluorescence antibody test (ifat). antibodies in the ifat were found in 17 of 139 dogs (12.2%) with titers ranging from 1:50 to 1: 1,600. seroprevalence was higher in dogs over 1 yr old compared with dogs younger than 1 yr (p < 0.05). no statistical difference was observed when sex, breed, purpose, or modus vivendi was compared with seropositivity. most do ...200212537126
prevalence of antibodies to neospora caninum and sarcocystis neurona in sera of domestic cats from brazil.parasite biology, epidemiology and systematics laboratory, animal and natural resources institute, agricultural research service, united states department of agriculture, building 1001, beltsville, maryland 20705-2350 antibodies to neospora caninum and sarcocystis neurona were determined in serum samples of 502 domestic cats from brazil using direct agglutination tests with the respective antigens. antibodies to s. neurona were not found in 1:50 dilution of any serum in the s. neurona agglutinat ...200212537122
isolation of viable toxoplasma gondii from naturally infected aborted bovine fetuses.neospora caninum and toxoplasma gondii are related parasites. the former is a common cause of abortion in dairy cattle. the latter has not been conclusively demonstrated in bovine fetuses. during the course of attempts to isolate n. caninum from aborted fetuses, t. gondii was isolated from 2 aborted fetuses, 1 from portugal and 1 from the united states. both isolates were made by bioassay of fetal brains in mice. the fetus from portugal was about 5 mo in gestational age, and the fetus from the u ...200212537120
improved production of neospora caninum oocysts, cyclical oral transmission between dogs and cattle, and in vitro isolation from oocysts.scarce information is available about neospora caninum oocysts and sporozoites, in part because only small numbers of oocysts have typically been produced by experimentally infected dogs. we hypothesized that i reason for low experimental production of oocysts is that dogs have been fed tissues from experimentally infected mice instead of tissues from cattle (which are natural intermediate hosts of n. caninum). in this study, 9 dogs were fed tissues from n. caninum-infected calves, and oocyst pr ...200212537111
experimental infection of sheep with neospora caninum oocysts.the purpose of the present study was to investigate the potential of neospora caninum oocysts to infect sheep and determine whether n. caninum dna could be detected by polymerase chain reaction (pcr) assay in blood and brain of sheep after oocyst inoculation. six ewes were inoculated per os with 10(4) n. caninum oocysts, whereas 2 ewes served as uninoculated controls. all sheep were bled weekly for 7 wk after inoculation. blood was analyzed for the presence of n. caninum dna by 2 different pcr a ...200212537104
characterization of neospora caninum protease, ncsub1 (nc-p65), with rabbit anti-n54.ncsub1 (formerly known as nc-p65) is the first molecularly described proteolytic enzyme of the intracellular protozoan parasite neospora caninum. this report describes the characterization of a rabbit anti-n54, which is an antiserum generated against an internal fragment of ncsub1 (amino acids 649-783). in immunofluorescence studies rabbit and-n54 labeled the apical end of the fixed parasite. by immuno-gold electron microscopy, the antibody bound primarily to the microneme organelles of the para ...200212537103
neospora caninum in vitro: evidence that the destiny of a parasitophorous vacuole depends on the phenotype of the progenitor zoite.we previously reported that neospora caninum can be induced to express bagi, a bradyzoite antigen, within 3 days of culture under stress conditions. the main goals of the present experiment were to increase the expression of bagi in vitro (in part by extending cultures for 9 days), to observe parasitophorous vacuoles at various points of stage differentiation, and to test the ability of organisms produced in vitro to function like mature bradyzoites. expression of bag1 and of a tachyzoite antige ...200212537100
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
diagnostic survey of bovine abortion in korea: with special emphasis on neospora caninum.causes of bovine abortion were surveyed in korea within a designated period from the cases submitted to the department of veterinary pathology, college of veterinary medicine, seoul national university. one hundred and eighty aborted fetuses and maternal sera were evaluated by necropsy, histopathology, bacteriology, virology, pcr, and serologic tests. the causes of abortion were identified in 108 (60%) cases, of which 38 (21.1%) were due to the infection with neospora caninum. none of the 38 cas ...200212520105
the influence of feeding and maintenance system on occurrence of toxoplasma gondii infections in dogs.serum samples of 113 dogs visiting "outpatient clinics", 52 dogs kept in shelters and 35 animals from a military dog training centre were examined for toxoplasma gondii specific antibodies using a latex agglutination test. significant differences in seroprevalences were found between dogs from the training centre (8.6% of positive results) and the other populations examined (40.7% of positive seroreagents in animals visiting outpatient clinics and 44.2% in the group from shelters, respectively). ...200212512556
risk of abortion associated with neospora caninum during different lactations and evidence of congenital transmission in dairy cows.to examine the relationship between exposure to neospora caninum and abortion in dairy cows during their first, second, third, and fourth or later lactations and to establish the main mode of transmission in female calves from birth until their first pregnancy was terminated by abortion or parturition.200212494973
neospora caninum: pregnancy, parasites and prolactin. 200312488220
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
the comparative pathogenesis of neosporosis.since its first description in dogs in 1984, the protozoan parasite neospora caninum has been found to infect a wide range of animals, worldwide. in cattle, n. caninum has particular significance as a cause of abortion in which persistence of infection in the mother, recrudescence of the parasite during pregnancy, and the vulnerability of the placenta and foetus to invasion are important features. this article discusses how neospora invades cells, how it infects and causes disease in several ani ...200212482540
immune responses to neospora caninum and prospects for vaccination.developing an effective vaccine against neosporosis presents several interesting challenges. the parasite is spread efficiently from mother to foetus over several generations, and naturally infected cattle do not appear to develop adequate protective immunity. modulation of the immune response during pregnancy favours parasite survival and multiplication. however, induction of pro-inflammatory responses that are thought to be protective against neospora caninum would be detrimental to the pregna ...200212473366
characterisation of the first australian isolate of neospora caninum from cattle.to isolate neospora caninum from a congenitally infected calf.200212465814
transplacental toxoplasmosis in a reindeer (rangifer tarandus) fetus.toxoplasma gondii infection was diagnosed in a full term stillborn reindeer (rangifer tarandus) fetus. the fetus had encephalitis and placentitis associated with t. gondii. tissue cysts were identified histologically in sections of brain and tachyzoites were present in placenta and the myocardium. protozoa in the brain, heart, and placenta stained positively with t. gondii antibodies, but not with neospora caninum antibodies in an immunohistochemical test. the dam of the fetus had a 1:12,800 tit ...200212446098
use of bulk milk for detection of neospora caninum infection in dairy herds in thailand.the relationship between the level of neospora caninum antibodies in bulk milk and the seroprevalence in lactating cows was investigated. bulk milk was also used to estimate the prevalence of n. caninum infection in dairy herds in the northeast and north thailand. bulk milk and individual serum from all lactating cows in 11 herds as well as 220 bulk milk samples from nine milk collection centres were analysed for presence of n. caninum antibodies using an iscom elisa. in the 11 herds the bulk mi ...200212446088
seroprevalence of neospora caninum infection in dairy and beef cattle in paraguay.seroprevalence of neospora caninum in 879 beef and dairy cattle in different locations of paraguay was determined by an elisa. in the survey, 262 (29.8%) cattle were positive to n. caninum, and animals with anti-neospora antibody titre were observed in all the locations tested in the country. serum samples taken from a herd that exhibited persistent abortion had the highest percentage of animals being positive to the parasite (17/30, 56.7%). in the same herd, abortion was significantly more like ...200212446086
first portuguese isolate of neospora caninum from an aborted fetus from a dairy herd with endemic neosporosis.neospora caninum was isolated from the brain of an aborted 4-month-old fetus from a dairy cow herd with endemic neosporosis in porto, portugal. the fetal brain homogenate was inoculated interperitoneally first into outbred swiss webster mice given dexamethasone and then the peritoneal exudates from these mice was co-inoculated with mouse sarcoma cells in the peritoneal cavity of mice given dexamethasone. n. caninum tachyzoites were seen in peritoneal exudate of the second passage. tachyzoites fr ...200212446085
an explorative study to assess the efficacy of toltrazuril-sulfone (ponazuril) in calves experimentally infected with neospora caninum.neospora caninum is an important cause of infectious abortion and stillbirth in cattle world-wide. infection is common and may frequently be passed from mother to calf (vertical transmission) with no signs of disease. based on our previous observation that n. caninum-infection can be efficiently controlled with toltrazuril-sulfone (ponazuril) in experimentally infected mice, we addressed the question if efficacy could also be obtained in experimentally infected calves.200212437777
a high rate of seroconversion for neospora caninum in a dairy herd without an obvious increased incidence of abortions.the purpose of this paper is to investigate the high rate of seroconversion for neospora caninum in a dairy herd. forty-five of 95 (47%) of the seronegative animals seroconverted within a period of 6 months. seropositive animals were not equally distributed among age-groups. a high seroprevalence age-group of 8-30 months was housed together during a period of 4 months, indicating a point source infection within this period. a lack of association between the serological status of daughters and mo ...200212423933
neospora caninum ncsrs2 is a transmembrane protein that contains a glycosylphosphatidylinositol anchor in insect cells.we investigated the terminal location of ncsrs2, a surface antigen of neospora caninum that has potential use for diagnosis, and demonstrated its importance as a vaccine component against neosporosis, in an insect-baculovirus expression system. to examine the role of the hydrophobic c-terminal tail in ncsrs2, four types of recombinant baculoviruses were constructed. immunoblotting and n-terminal amino acid analysis revealed cleavage of a 6 kda of the n-terminal signal peptide in the mature ncsrs ...200212423932
dog shedding oocysts of neospora caninum: pcr diagnosis and molecular phylogenetic approach.results of molecular determination of a dog isolate of neospora caninum in the czech republic are presented. colorless bisporocystic oocysts measuring 10-13 micro m x 10-11 micro m were recovered from feces and used for dna isolation. a diagnostic pcr procedure using previously described molecular methods was performed to determine the species. the n. caninum species-specific primers based on the nc 5 region produced a positive result, while primers specific for hammondia heydorni rdna internal ...200212423929
prevalence of antibodies to neospora caninum in korean native beef cattle.a total of 438 sera from korean native beef cattle in 9 provinces were tested for neospora caninum antibodies using an immunofluorescent antibody test (ifat). eighteen (4.1%) cattle were positive by ifat. the titers ranged from 1:200 (10 animals), 1:400 (5 animals), 1:800 (2 animals) to 1:1,600 (1 animal). although the seroprevalence was slightly higher in chungnam (8.9%), this was not significantly different from those noted in kyunggi, kangwon, kyungbuk, kyungnam, and cheju provinces. sera obt ...200212419873
validation of 2 commercial neospora caninum antibody enzyme linked immunosorbent assays.this is a validation study of 2 commercially available enzyme linked immunosorbent assays (elisa) for the detection of antibodies against neospora caninum in bovine serum. the results of the reference sera (n = 30) and field sera from an infected beef herd (n = 150) were tested by both elisas and the results were compared statistically. when the immunoblotting results of the reference bovine sera were compared to the elisa results, the same identity score (96.67%) and kappa values (k) (0.93) wer ...200212418782
steroid hormones do not reactivate neospora caninum in ovariectomized mice.the direct effects of three steroid hormones (progesterone, estradiol-17beta and corticosterone) on the growth of neospora caninum (n. caninum) tachyzoite were examined in vero cells. subsequently, ovariectomized balb/c mice infected with n. caninum were treated with physiological concentrations of the steroid hormones for 1 or 2 weeks. these hormones had no direct effect on the parasite growth in vitro. in the infected mice, there was no significant difference in the parasite distribution and h ...200212399600
neospora caninum serostatus and culling of holstein cattle.to determine whether time until culling or risk of culling was associated with neospora caninum serostatus among holstein cattle in dairy herds in ontario.200212387388
neospora caninum serostatus and milk production of holstein cattle.to determine whether neospora caninum serostatus was associated with milk production among holstein cattle in ontario.200212387387
neospora caninum: oocyst challenge of pregnant cows.three pregnant cows were each orally challenged at 10 weeks of gestation with 600 sporulated oocysts of neospora caninum. the number of oocysts was limited by those available. in concurrent bioassays, one oocyst per os infected each of two gerbils. challenged cattle developed neospora-specific antibody, cell proliferation and gamma-interferon responses. n. caninum specific pcr demonstrated persisting infection in the brains of cows 4 months after calving. abortion was not induced and there was n ...200212383634
neospora caninum: a cause of immune-mediated failure of pregnancy?resistance to many intracellular protozoan parasites is dependent on t helper cell 1 cytokine responses. this has important repercussions for pregnant females because strong t helper cell 1 cytokine responses are incompatible with successful pregnancy. thus, there are two possible consequences of infection with protozoans such as leishmania major, plasmodium falciparum and toxoplasma gondii during pregnancy: (1) pregnancy is compromised; or (2) resistance to the parasite is compromised. the apic ...200212377255
direct production losses and treatment costs from bovine viral diarrhoea virus, bovine leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum.our purpose was to determine direct production losses (milk loss, premature voluntary culling and reduced slaughter value, mortaliy loss, and abortion and reproductive loss) and treatmetn costs (veterinary services, medication cost, and extra farm labour cost) due to four infectious diseases in the maritime provinces of canada: bovine viral diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis. we used a partial-budget model, and incorporated risk and sensitivity ...200212350317
management factors related to seroprevalences to bovine viral-diarrhoea virus, bovine-leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum in dairy herds in the canadian maritimes.bovine viral-diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis lower on-farm productivity, reduce export competitiveness, and increase consumer concerns regarding safety. our purpose was to examine the relationship between 27 control practices and the estimated true seroprevalences for these four diseases for 2604 cattle in 90 dairy herds in the maritimes provinces of canada. overall, 37.8, 20.4, 3.4, and 19.2% of all sampled cattle were truly exposed to the ...200212324207
confirmation of the prevention of vertical transmission of neospora caninum in cattle by the use of embryo transfer. 200212224621
cutaneous neosporosis during treatment of pemphigus foliaceus in a dog.a 4-year-old, intact male rottweiler was presented with a 10-day history of papulonodular dermatitis. at the time of presentation, the dog was receiving prednisone and azathioprine to treat pemphigus foliaceus. cutaneous neosporosis was diagnosed by immunohistochemistry on skin biopsy specimens and a high serum antibody titer to neospora caninum by neospora agglutination test. electron microscopy examination of skin specimens further supported the diagnosis. clindamycin therapy, together with wi ...200212220024
fetal infection with neospora caninum in dairy and beef cattle in belgium.neospora caninum is a protozoan parasite, which causes fetal and neonatal mortality in livestock and companion animals. in 224 abortions in belgian cattle, different diagnostic methods were used to demonstrate infection, and the presence of n. caninum. an indirect fluorescent antibody test (ifat) was used to analyze fetal and maternal sera and immunohistochemistry (ihc) was performed when lesions consistent with neosporosis were observed in the brain, heart or liver. twenty dairy cattle sera out ...200212212893
serological investigation of aborted sheep and pigs for infection by neospora caninum.serology for neospora caninum was undertaken using direct elisas on sera from 660 aborted sheep and 454 breeding sows, which had aborted or were considered infertile. all ovine sera were further tested by indirect fluorescent antibody test (ifat) for n. caninum, and a latex agglutination test (lat) for toxoplasma gondii was performed on 423 of the samples, including all those positive by elisa. elisa-positive porcine sera were tested by ifat and an inhibition elisa for antibodies to n. caninum a ...200212204640
exogenous nitric oxide triggers neospora caninum tachyzoite-to-bradyzoite stage conversion in murine epidermal keratinocyte cell cultures.neospora caninum, like toxoplasma gondii, undergoes stage conversion in chronically infected animals, and forms tissue cysts which contain the slowly proliferating bradyzoite stage. these tissue cysts are delineated by a cyst wall, protect the parasite from physiological and immunological reactions on part of the host, and bradyzoites remain viable within an infected host for many years. however, unlike t. gondii, n. caninum bradyzoites have been difficult to obtain using in vitro culture techni ...200212204225
characterization of an outbred pregnant mouse model of neospora caninum infection.fetal loss and vertical transmission of neospora caninum were evaluated in outbred quackenbush (qs) mice with respect to dose of parasites, n. caninum isolate, and route of injection. mice were infected with nc-liverpool or nc-sweb1 at day 5 or 8 of pregnancy with doses of 10(4), 10(6), or 10(7) parasites, through either a subcutaneous or intraperitoneal injection. polymerase chain reaction was used to detect n. caninum in the brains of offspring, and enzyme-linked immunosorbent assay was used t ...200212197115
mechanisms of apoptosis in murine fibroblasts by two intracellular protozoan parasites, toxoplasma gondii and neospora caninum.studies to clarify the mechanisms of apoptosis in host cells, a31 (balb/3t3 clone a31 fibroblasts), caused by two intracellular protozoan parasites, toxoplasma gondii and neospora caninum, were carried out in an in vitro system. the viability of n. caninum-infected cells was significantly reduced following treatment with mouse interferon (ifn)-gamma. by contrast, mouse ifn-gamma treatment had no significant effect on the induction of apoptosis in t. gondii-infected cells. apoptosis of n. caninum ...200212164820
seroepidemiology of beef and dairy herds and fetal study of neospora caninum in argentina.the purpose of the present work was to study the epidemiology of neospora caninum in beef and dairy herds in the humid pampas of argentina. the seroprevalence of n. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. an indirect fluorescent antibody test (ifat) was used to determine specific antibodies. the sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. cows without history of reprod ...200212163242
red foxes (vulpes vulpes) are a natural intermediate host of neospora caninum.the present study was undertaken to determine if red foxes are natural intermediate and/or definitive host for neospora caninum and to study the importance of infection of n. caninum in this species in north-eastern spain. faecal samples and brain tissues were obtained from 122 foxes from 21 rural areas of catalonia. faeces collected were examined for parasite eggs and coccidian oocysts using sucrose flotation. for pcr-based diagnosis of n. caninum in brain tissues, the specific genomic nc5 regi ...200212163240
an analysis of the performance characteristics of serological tests for the diagnosis of neospora caninum infection in cattle.to analyse the performance characteristics (sensitivity/specificity) of two enzyme-linked immunosorbent assays (elisa) against the indirect fluorescent antibody test (ifat).200212127250
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