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characterization of neospora caninum surface protein ncsrs2 based on baculovirus expression system and its application for serodiagnosis of neospora infection.the baculovirus expression system has proved to be a useful tool for the production of recombinant proteins. here we have characterized the neospora caninum surface protein ncsrs2 produced by two types of the recombinant virus and also have developed an enzyme-linked immunosorbent assay (elisa) using recombinant ncsrs2 for the serologic diagnosis of neospora infection. western blot analysis showed two major protein bands that were detectable in insect cells infected with each recombinant baculov ...200111682519
small-subunit rdna sequencing of the italian bovine neospora caninum isolate (nc-pv1 strain).the small-subunit (ssu) rdna of the neospora sp. nc-pv1 strain isolated in italy from cattle has been sequenced and compared to the other five n. caninum strains ssu rdna sequences deposited in the data bases. the nc-pv1 strain sequence is identical to three published sequences. minor differences, respectively four nucleotide bases and one nucleotide base, have been found when comparing the nc-pv1 sequence with two other available sequences of n. caninum. according to these results, the neospora ...200011686077
neospora caninum in persistently infected, pregnant cows: spontaneous transplacental infection is associated with an acute increase in maternal antibody.nine cows which were naturally and persistently infected with neospora caninum were housed and observed intensively throughout pregnancy. no recrudescence of a latent infection was detected by pcr tests on maternal blood but fetal infection, implying a recrudescence of maternal parasitosis, was associated with a marked increase in maternal antibody. the increase occurred in the second half of pregnancy in five cows which infected their calves, and before mid-pregnancy in one cow which aborted. t ...200111688746
hammondia heydorni-like oocysts shed by a naturally infected dog and neospora caninum nc-1 cannot be distinguished.this study describes transmission experiments using hammondia heydorni-like oocysts isolated in 1996 from a naturally infected dog. the isolate was designated as h. heydorni-berlin-1996. examination of sera from infected intermediate hosts showed immunoblot reactions that resembled patterns observed after neospora caninum nc-1 infection. furthermore, n. caninum dna could be demonstrated in tissue samples (e.g. heart, brain) of experimentally infected intermediate hosts and in oocyst preparations ...200111688886
immune responses in pregnant cattle and bovine fetuses following experimental infection with neospora caninum.humoral and cell-mediated immune (cmi) responses [i.e. proliferative responses and gamma interferon (ifn-gamma) production], were elicited in five cows infected between 159 and 169 days of gestation by a combined intravenous-intramuscular inoculation of neospora caninum tachyzoites. analysis of antigen-specific immunoglobulin (igg) subclasses revealed a predominant igg2 response in two cows, a mixed igg1-igg2 response in two other cows and a predominant igg1 response in one cow. no correlation w ...200111688887
cyclic transmission of neospora caninum: serological findings in dogs shedding oocysts.in a previous paper we demonstrated that hammondia heydorni-like oocysts isolated in 1996 from a naturally infected dog could not be distinguished from the isolate neospora caninum nc-1. the isolate, designated as h. heydorni-berlin-1996, was cyclically transmitted using dogs as the final hosts. the present study provides information on the antibody responses of the dogs used for the cyclical transmission of this isolate. the majority of dogs that had shed oocysts showed no sero-conversion with ...200111688895
comparative molecular investigation of nc5-pcr amplicons from neospora caninum nc-1 and hammondia heydorni-berlin-1996.the clinical relevance of neospora caninum as a cyst-forming coccidian parasite is increasingly acknowledged within veterinary medicine, although the pathways of transmission are far from being solved. the parasite is well known for causing diaplacental infections in cows associated with abortion and/or severe damage of the fetus. in addition, it may cause neuromuscular disease in dogs, which thus apparently act as intermediate hosts as well as final hosts. in our previous studies, we have demon ...200111688897
prevalence of agglutinating antibodies to neospora caninum in raccoons, procyon lotor.neospora caninum is an apicomplexan parasite that causes neonatal neuromuscular disease in dogs and abortions in cattle. dogs are the only proven definitive host. little is known about the prevalence of antibodies to this parasite in wildlife. sera from 99 raccoons (procyon lotor) were examined for agglutinating antibodies to n. caninum using the modified agglutination test employing formalin-fixed tachyzoites as antigen. raccoons originated in florida (n = 24, collected in 1996), new jersey (n ...200111695399
association of serologic status for neospora caninum and postweaning feed efficiency in beef steers.to determine the effects of serologic status for neospora caninum on short-term weight gain, feed intake, and feed efficiency (feed intake/gain).200111697371
a swiss case-control study to assess neospora caninum-associated bovine abortions by pcr, histopathology and serology.neospora caninum is one of the most frequent infectious organisms causing abortion in cattle worldwide. the present case-control study was designed to assess the importance of bovine neosporosis for causing abortion in swiss cattle and to identify selected risk factors. infection was primarily diagnosed by a n. caninum-specific pcr and serology, complemented with histopathology and immunohistochemistry. a total of 113 case and 113 corresponding control-farms were studied for 1.5 year. during thi ...200111705647
serodiagnosis of toxoplasma gondii infection in cats by enzyme-linked immunosorbent assay using recombinant sag1.the gene encoding surface antigen 1 (sag1, p30) of toxoplasma gondii (t. gondii) was cloned into the plasmid pgex-4t-3 and subsequently expressed in escherichia coli (e. coli) as a glutathione-s-transferase (gst) fusion protein. the recombinant sag1 (rsag1) was refolded using 8m urea solution followed by dialysis and thereafter evaluated in an enzyme-linked immunosorbent assay (elisa) for serological diagnosis of toxoplasmosis. the test sera were adsorbed with gst to block non-specific reactivit ...200111705650
seroprevalences of toxoplasma gondii and neospora caninum in swedish red foxes (vulpes vulpes).the prevalences of antibodies to the protozoan parasites toxoplasma gondii and neospora caninum were investigated by the direct agglutination test (dat) and elisa, respectively, in 221 red foxes (vulpes vulpes) from different parts of sweden. a total of 84 (38%) of the analysed sera had antibodies to t. gondii, but none of the foxes had antibodies to n. caninum. the results indicate that t. gondii infection is fairly common in swedish red foxes and that the infection is present in most parts of ...200111705663
neosporosis in bovine dairy herds from the west of france: detection of neospora caninum dna in aborted fetuses, seroepidemiology of n. caninum in cattle and dogs.neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. in this study, the role of n. caninum was investigated in groups of aborted cattle and dairy herds from the west of france. good correlation was found between parasite dna detection in fetuses and serologic statuses of dams. in groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropositive for n. caninum, and significant relationship b ...200111731070
bovine neosporosis: immunoblot improves foetal serology.the purpose of the study is the comparative evaluation of the immunofluorescent antibody test (ifat) and an immunoblot (ib) test for the examination of foetal fluids for specific antibodies against neospora caninum. peritoneal and pleural fluids as well as abomasal contents were analysed. the results of the serological examinations were compared to those obtained by histological, immunohistochemical, and pcr analysis of foetal tissues as well as to the results of maternal serological examination ...200111731071
neosporosis as a cause of abortion in dairy cattle in rio grande do sul, southern brazil.forty-six aborted bovine fetuses submitted to the faculty of veterinary, department of clinical pathology, universidade federal do rio grande do sul, were examined histopathologically. non-suppurative inflammation was observed mainly in the brain and heart of 22 fetuses. brain lesions consisted primarily of mononuclear inflammatory cell infiltrates with occasional foci of necrosis. protozoa that reacted with neospora caninum antisera were seen in 18 of the 22 (81.8%) brain specimens from fetuses ...200211750112
in vitro antiprotozoal effects of artemisinin on neospora caninum.neospora caninum is an intracellular apicomplexan parasite that infects a wide range of mammals and has been associated with abortion in cattle worldwide. artemisinin is an effective antimalarial compound derived from a traditional chinese herbal remedy, qinghao or artemisia annua l. in the study reported, the cultured host cells (vero cells or mouse peritoneal macrophages) infected with n. caninum tachyzoites were incubated with alpha-mem (minimal essential medium) 10%hs supplemented with vario ...200211751000
placentophagia--an alternative way for horizontal transmission of neospora caninum in cattle? 200111756037
application of real-time fluorescent pcr for quantitative assessment of neospora caninum infections in organotypic slice cultures of rat central nervous system tissue.the previously described nc5-specific pcr test for the diagnosis of neospora caninum infections was used to develop a quantitative pcr assay which allows the determination of infection intensities within different experimental and diagnostic sample groups. the quantitative pcr was performed by using a dual fluorescent hybridization probe system and the lightcycler instrument for online detection of amplified dna. this assay was successfully applied for demonstrating the parasite proliferation ki ...200211773124
isolation of neospora caninum from the brain of a pregnant sheep.neospora caninum was isolated from the brain of a naturally infected pregnant sheep by inoculation of immunodeficient mice with a homogenate of the brain tissue. the ewe showed no clinical signs. tachyzoites were observed in the tissues of the nu/nu mice injected with the brain tissue homogenate and the diagnosis was confirmed by immunohistochemical staining with anti-n. caninum antibodies and by detecting n. caninum-specific dna by polymerase chain reaction.200111780846
serological diagnosis of neosporosis in a herd of dairy cattle in southern brazil.neospora caninum-specific antibodies were detected in 60 of 172 (34.8%) dairy cattle by enzyme-linked immunosorbent assay (elisa) in a herd from parana state, brazil. the seropositive animals included 47 of 126 (37.3%) adult cows, 7 of 29 (24%) heifers (1-2 yr), 4 of 15 (27%) heifers (5 mo-1 yr), and 2 precolostral samples. data collected over a 9-yr follow-up period revealed that the proportion of pregnancies ending in abortion was 20% (31/154) among elisa seropositive cows and 8% (15/193) amon ...200111780849
red foxes (vulpes vulpes) in ireland as hosts for parasites of potential zoonotic and veterinary significance.intestinal washes, faecal flotations and serological examinations for antibodies to toxoplasma gondii and neospora caninum were used to assess the prevalence of parasites in carcases of foxes killed on roads or shot in the dublin area and surrounding counties. the ascarids uncinaria stenocephala and toxocara canis were prevalent, as was the trematode alaria alata. taenia species, eggs of capillaria species and sporocysts of sarcocystis species were also found. only one fox out of 70 examined was ...200111808662
in contrast to dogs, red foxes (vulpes vulpes) did not shed neospora caninum upon feeding of intermediate host tissues.to clarify whether red foxes (vulpes vulpes) can be final hosts of neospora caninum, foxes and dogs were fed in parallel on tissues of a sheep and a goat experimentally infected with n. caninum. the faeces of at least two of five dogs contained n. caninum oocysts, as determined by bioassay. in the faeces of all six foxes fed in parallel, oocysts were detected that were larger in size (length 12.6 +/- 0.5 microm, width 11.8 +/- 0.4 microm) than the oocysts shed by the dogs. ribosomal rna sequence ...200211822736
neospora caninum and hammondia heydorni are separate species/organisms.neospora caninum and hammondia heydorni are two coccidian parasites with morphologically similar oocysts in canine feces. it was recently proposed that they are one species. in this paper, we review the biology and morphology of these parasites and present evidence that n. caninum and h. heydorni are separate species.200211832296
neospora 2001.infection with the protozoan parasite neospora caninum is emerging as a major cause of reproductive loss in cattle worldwide. recent advances in research with the ultimate goal of devising effective and sustainable control measures were discussed at neospora 2001. neospora 2001 was held, 13-15 september 2001, at the moredun research institute, edinburgh, uk. the international meeting covered many aspects of bovine neosporosis including diagnosis, epidemiology and immunology.200211850000
neospora caninum and waddlia chondrophila strain 2032/99 in a septic stillborn calf.characteristics of an intracellularly growing micro-organism isolated from an aborted bovine foetus are described. the organism replicated within cytoplasmic vacuoles, was resistant to penicillin and exhibited structural characteristics compatible with waddlia chondrophila. an elisa specific for chlamydia spp., immunofluorescence tests using antibodies directed against chlamydia spp. or simkania negevensis, and pcr using chlamydia-specific primers showed that the agent was distinct from chlamydi ...200211852195
vaccine development against neospora caninum infection.neospora caninum is a recognized protozoan parasite of a wide range of mammalian hosts, and was reported for the first time in 1988. the isolation of its oocysts in dog's faeces in 1998 led to its establishment as a parasitic species undergoing typical coccidian life cycle. infection with n. caninum causes paralysis and death in young livestock and companion animals, and is associated with abortions and stillbirth in cattle, and neurologic disease in calves. considering the economic and agricult ...200211853138
neosporosis with cerebellar involvement in an adult dog.a case of an adult dog with multifocal, progressive neurological signs caused by neospora caninum is reported. pathological studies showed cerebellar lesions due to the parasite, which was also present in other parts of the nervous system and muscle. cerebellar atrophy related to neospora infection has been rarely reported in veterinary medicine, and has been shown to affect ruminants and dogs. the cerebellar involvement and the age of the present dog make this case uncommon.200211873953
point source exposure of cattle to neospora caninum consistent with periods of common housing and feeding and related to the introduction of a dog.eight dairy herds with evidence of post-natal transmission of neospora caninum were used to test the hypothesis of a point source exposure by a retrospective analysis of the housing and feeding of infected age-groups. the first n. caninum-associated abortion or birth of n. caninum-seropositive offspring from the post-natally infected age-group was considered as the first indication of the infection. in seven of the eight dairy herds, a point source exposure to n. caninum of the infected age-grou ...200211900922
natural transmission routes of neospora caninum between farm dogs and cattle.twelve dairy herds with evidence of post-natal infection with neospora caninum were compared with 21 control herds with no evidence of post-natal infection. on the former farms, dogs consumed placenta or licked uterine discharge in 75 and 67% of the farms, respectively, while on control farms these activities occurred in 38 and 24% of the farms, respectively. on all control farms and all but three post-natally infected farms the dogs were fed colostrum or milk. defecation of dogs on the feeding ...200211900923
a method of probability diagnostic assignment that applies bayes theorem for use in serologic diagnostics, using an example of neospora caninum infection in cattle.to develop a method of probability diagnostic assignment (pda) that uses continuous serologic measures and infection prevalence to estimate the probability of an animal being infected, using neospora caninum as an example.200211911564
studies on serological cross-reaction of neospora caninum with toxoplasma gondii and hammondia heydorni.the enzyme-linked immunosorbent assay (elisa) was used to examine cross-reactivity of neospora caninum with toxoplasma gondii and hammondia heydorni. anti-t. gondii mouse and cat sera cross-reacted with n. caninum soluble antigen (nla), but not with the recombinant surface antigen (ncsrs2). anti-h. heydorni dog sera showed no cross-reactivity with either the nla antigen or the ncsrs2. lack of cross-reactivity between anti-h. heydorni sera and n. caninum antigens, and the cross-reactivity of anti ...200211913555
effect of neospora caninum on in vitro development of preimplantation stage bovine embryos and adherence to the zona pellucida. 200211913589
necrotizing cerebellitis due to neospora caninum infection in an old dog.a severe, necrotizing, non-suppurative inflammation of the cerebellum associated with neospora caninum infection was identified in a 14-year-old male labrador retriever. on presentation, clinical signs included mild depression and head tremor, marked ataxia of both thoracic and pelvic limbs, and abnormal postural reactions. in the central nervous system, inflammatory lesions were mainly restricted to the cerebellar leptomeninges and cerebellar cortex, which appeared necrotic and atrophic. protoz ...200211913826
quantitative detection of neospora caninum in bovine aborted fetuses and experimentally infected mice by real-time pcr.we report the development of a real-time pcr assay for the quantitative detection of neospora caninum in infected host tissues. the assay uses the double-stranded dna-binding dye sybr green i to continuously monitor product formation. oligonucleotide primers were designed to amplify a 76-bp dna fragment corresponding to the nc5 sequence of n. caninum. a similar method was developed to quantify the 28s rrna host gene in order to compare the parasite load of different samples and to correct for th ...200211923330
first confirmed case of neospora caninum-associated abortion outbreak in portugal.in a dairy herd experiencing an abortion outbreak, 49% of the 119 cows were positive for neospora caninum antibodies and the remaining 51% were seronegative. using immunohistochemical analysis of foetal brain tissue, neospora cysts and bradyzoite clusters were identified in two of the 15 aborted foetuses submitted for testing. other agents that commonly cause abortions were not found. these results, coupled with neurological clinical symptoms in new-born calves, implicated n. caninum as the majo ...200111928926
seroprevalence of antibodies against neospora caninum in diagnostic equine serum samples and their possible association with fetal loss.a case-control study of the association between the presence of serum antibodies against neospora spp. and fetal loss was performed on serum samples submitted to a veterinary diagnostic laboratory in northwestern united states. control sera were randomly selected from those submitted from healthy horses for routine equine infectious anemia testing required for regulatory health certification. case sera were randomly selected from those submitted from aborting mares for diagnostic workup. based o ...200211934465
neospora caninum is an invalid species name: an evaluation of facts and statements.an evaluation of both the formal requirements of the international rules of zoological nomenclature and the scientific reasons for the description of new genera and species shows that the name neospora caninum is a nomen nudum. the only characteristic criteria for discriminating between the previously described species hammondia heydorni and the proposed new species n. caninum (i.e. the lack of a parasitophorous vacuole) has been shown to be wrong in many publications. furthermore, absolutely no ...200211936509
factors associated with neospora caninum serostatus in cattle of 20 specialised costa rican dairy herds.twenty-five specialised costa rican dairy farms (located in the poás area) were used to determine neosporosis seroprevalence and the association of seropositivity with environmental and management factors. the farms involved were selected intentionally and all of them use vampp 5.1 (veterinary automated management and production control programme) as management-information system. holstein-friesian, jersey and crosses between them were the most-frequent breeds in these herds. the number of femal ...200211937233
infection of organotypic slice cultures from rat central nervous tissue with neospora caninum: an alternative approach to study host-parasite interactions.neospora caninum is an apicomplexan parasite which has emerged as an important cause of bovine abortion worldwide. abortion is usually triggered by reactivation of dormant bradyzoites during pregnancy and subsequent congenital infection of the foetus, where the central nervous system appears to be most frequently affected. we here report on an organotypic tissue culture model for neospora infection which can be used to study certain aspects of the cerebral phase of neosporosis within the context ...200211943226
companion animal parasitology: a clinical perspective.in recent years there have been many changes to the ways that clinical veterinary science is conducted and nowhere is this more evident than in companion animal practice. veterinarians working with pet dogs and cats are facing new challenges associated with the emergence and re-emergence of parasitic diseases. some, such as neospora caninum, have been recently recognised; others like giardia and cryptosporidium have been reported with increasing frequency, in part as a result of laboratory tests ...200211943231
diagnosis and seroepidemiology of neospora caninum-associated bovine abortion.a round table was conducted at the viiith international coccidiosis conference on neospora diagnosis with particular emphasis on strategies to diagnose bovine abortion. the strength and weakness of different assays for neospora caninum infection and whether these methods have resulted in the overdiagnosis of neosporosis was discussed. it was evident that each diagnostic method, namely histology, immunohistochemistry, molecular detection and serological assays were, under certain circumstances, v ...200211943234
use of a serum-free medium to produce in vitro neospora caninum and toxoplasma gondii tachyzoites on vero cells.neospora caninum and toxoplasma gondii are cyst-forming coccidian parasites of human and veterinary clinical relevance. in vitro cultivation of the protozoans using vero cells is usually performed in order to produce antigenic materials. quantitative and qualitative comparisons of vero cells grown in rpmi medium supplemented either with foetal calf serum (fcs), horse serum (hs) or a specific serum-free additive (defcell) were performed. a serum-free cell culture system used to propagate n. canin ...200211944805
sensitive and specific identification of neospora caninum infection of cattle based on detection of serum antibodies to recombinant ncp29.neosporosis is an economically important disease of dairy cattle caused by the protozoan neospora caninum. diagnostic tests for neosporosis are complicated by the potential for cross-reaction of antibodies to antigens that are similar between n. caninum and closely related parasites toxoplasma gondii and sarcocystis cruzi. to provide a sensitive and specific assay for detecting antibodies to n. caninum in the serum of infected animals, we have investigated a recombinant form of the antigen known ...200211986268
immunological relationship between neospora caninum and besnoitia besnoiti.neospora caninum is a coccidian parasite identified as a major cause of abortion in cattle. a combined infection of n. caninum with another taxonomically related parasite of cattle, besnoitia besnoiti can occur in geographical areas endemic for both species. both infections are routinely diagnosed serologically, and incorrect diagnosis could occur if immunological cross-reactivity exists between the two parasites. to investigate the possible degree of cross-reactivity, we compared results obtain ...200211992709
identification of a neospora caninum microneme protein (ncmic1) which interacts with sulfated host cell surface glycosaminoglycans.the invasive stages of apicomplexan parasites enter their host cells through mechanisms which are largely conserved throughout the phylum. host cell invasion is divided into two distinct events, namely, adhesion onto the host cell surface and the actual host cell entry process. the former is mediated largely through microneme proteins which are secreted at the onset of establishing contact with the host cell surface. many of the microneme proteins identified so far contain adhesive domains. we h ...200212011014
epidemiological investigations of abortions due to neospora caninum on swiss dairy farms.abortions apparently due to neospora caninum in two swiss dairy herds were investigated by means of a pcr and elisa, and other potential causes were eliminated. in addition, a case-control study of 24 case herds and 24 control herds indicated that n caninum-associated abortions were more likely to occur in herds with antibodies to coxiella burnetii (with an odds ratio [or] of 3.38 with a 95 per cent confidence interval [ci] of 1.82 to 6.22), whereas the likelihood was less in herds with antibodi ...200212019533
trigeminal neuropathy in dogs: a retrospective study of 29 cases (1991-2000).the medical records of 29 dogs unable to close their mouths due to flaccid paralysis or paresis of the muscles innervated by the mandibular branch of the trigeminal nerve, were reviewed. idiopathic trigeminal neuropathy was diagnosed in 26 dogs based on complete resolution of clinical signs and lack of any long-term neurological disease. of these dogs, golden retrievers were overrepresented. no age, sex, or seasonal predispositions were identified. trigeminal sensory innervation deficits were ob ...200212022413
serological survey of neospora caninum infection in dairy cattle herds in aguascalientes, mexico.a serological survey for antibody activity to neospora caninum was carried out in aguascalientes, a state in the central part of mexico. one-hundred and eighty-seven serum samples from 13 dairy herds were tested by the elisa test. the herd prevalence was 100% and the overall prevalence was 59% (n=110). seventy-six of 97 seropositive cows had previous records of abortion. there was a statistically significant difference between the groups (p<0.05). however, the odds ratio was 1.4, suggesting an a ...200212031815
occurrence of neospora caninum antibodies in sera from dogs of the city of são paulo, brazil.neospora caninum is an important cause of abortion in dairy cattle worldwide. dogs are important in the epidemiology of this parasite because they are the only hosts known to excrete n. caninum oocysts. in order to understand the prevalence of n. caninum in dogs, sera from 500 owned dogs and from over 600 feral street dogs from the city of são paulo, brazil were assayed for antibodies to n. caninum. sera were examined by the neospora agglutination test (nat) using mouse-derived tachyzoites. anti ...200212031819
hepatic sarcocystosis in a striped dolphin (stenella coeruleoalba) from the spanish mediterranean coast.fatal hepatic sarcocystosis was diagnosed in a striped dolphin (stenella coeruleoalba) from the northeastern spanish mediterranean coast based on pathologic findings and the microscopic and ultrastructural characteristics of the intralesional parasite. main gross lesions were icterus, subcutaneous hemorrhages, and hepatic congestion. the most prominent microscopic lesions consisted of severe acute multifocal to coalescing necrotizing hepatitis with cholestasis and intralesional protozoa. there w ...200212053971
immune factors influencing the course of infection with neospora caninum in the murine host.this paper investigates the role of specific immune factors on the course of infection in genetic knockout (gko) mice infected with 3 different strains of neospora caninum. survival time and parasite persistence were examined in interferon-gamma (ifn-gamma), tumor necrosis factor receptor-2 (tnfr2), interleukin 10 (il-10), beta 2 microglobulin (beta2m), and inducible nitric oxide synthase (inos2) gko or wild-type (wt) mice following infection with either pathogenic (nc-1 or nc-2) or attenuated ( ...200212053997
susceptibility of psammomys obesus and meriones tristrami to tachyzoites of neospora caninum.the susceptibility of psammomys obesus (sand rat) and meriones tristrami (tristram's jird) to neospora caninum was investigated by subcutaneous (s.c.) and intraperitoneal (i.p.) inoculation of 10-fold doses of culture-derived tachyzoites. groups of 5 animals were inoculated with doses of 10-10(7) parasites via each route of inoculation. all but 2 of the sand rats inoculated with doses of 10-10(4) parasites succumbed to the infection by 7-18 days postinfection. all jirds inoculated with 10(7) tac ...200212054004
prevalence of neospora caninum antibodies in dogs from dairy cattle farms in parana, brazil.serum samples from 134 dogs from 22 cattle dairy farms in the northern region of parana state, brazil, were tested for antibodies to neospora caninum in an indirect fluorescent antibody test. antibodies (> or = 1:50) to n. caninum were found in 29 (21.6%) of the 134 dogs, and seropositive dogs were found on 14 (63.6%) of the 22 dairy cattle farrms. the antibody titers of dogs were 1:50 (3 dogs), 1:100 (7 dogs), 1:200 (7 dogs), 1:400 (6 dogs), and > or = 1:800 (6 dogs). the low prevalence (9%) in ...200212054023
prevalence of antibodies to neospora caninum in white-tailed deer, odocoileus virginianus, from the southeastern united states.serum samples from 305 white-tailed deer (odocoileus virginianus) from 14 states in the southeastern united states were examined for antibodies to neospora caninum using a direct agglutination test. positive agglutination titers were found in 145 (48%) of the white-tailed deer examined: 21 (7%) had titers of 1:25, 92 (30%) had titers of 1:50, and 32 (10%) had titers of > or = 1:500. these findings that antibodies to n. caninum are common in white-tailed deer support the concept that a sylvatic c ...200212054027
vero cell surface proteoglycan interaction with the microneme protein ncmic(3) mediates adhesion of neospora caninum tachyzoites to host cells unlike that in toxoplasma gondii.neospora caninum and toxoplasma gondii are characterised by a very low host cell specificity, thus they are able to infect a wide range of different cells in vivo and in vitro. infection of the host cell by tachyzoites is a process which is preceded by adhesion onto the host cell surface. the receptors on the host cell surface which would allow n. caninum to establish a physical interaction have not been investigated so far. here we report the role of host cell surface proteoglycans as receptors ...200212062488
a longitudinal study of neospora caninum infection on a dairy farm in new zealand.a 600-cow new zealand dairy herd experienced an abortion storm in 1997 and was monitored (blood sampling at about 3-month intervals) from may 1997 until january 1999. abortion risk reached 9% in 1997 and was highest in heifers at 19%. the abortion risk decreased in 1998 to 3.2% (still somewhat higher than during the years prior to the outbreak). the serological reaction pattern for neospora caninum showed an association with abortion risk only around the time of the 1997 outbreak when seropositi ...200212062516
immunisation of mice against neosporosis.in the present study a murine encephalitis model was used to investigate if protection against neosporosis could be achieved by immunisation. groups of 10 mice were immunised with a sublethal dose of live neospora caninum tachyzoites, n. caninum antigens incorporated into iscoms, n. caninum lysate mixed with quil a, or n. caninum lysate in pbs. control mice were given quil a only. challenge infection with 2.5x10(6) n. caninum tachyzoites resulted in clinical symptoms that remained until the end ...200212062558
pattern of recognition of neospora caninum tachyzoite antigens by naturally infected pregnant cattle and aborted foetuses.different aspects of neospora tachyzoite antigen recognition by neospora-infected heifers and cows and aborted foetuses were studied. the pattern of antigen recognition and the relationship between ifat titres and number of neospora antigens detected, were evaluated. in addition, the tachyzoite antigens involved in the humoral immune response developed against infection in normal cows and cows that aborted were also characterised throughout pregnancy. comparison of tachyzoite antigen recognition ...200212072210
redescription of neospora caninum and its differentiation from related coccidia.neospora caninum is a protozoan parasite of animals, which before 1984 was misidentified as toxoplasma gondii. infection by this parasite is a major cause of abortion in cattle and causes paralysis in dogs. since the original description of n. caninum in 1988, considerable progress has been made in the understanding of its life cycle, biology, genetics and diagnosis. in this article, the authors redescribe the parasite, distinguish it from related coccidia, and provide accession numbers to its t ...200212076623
p38-avidity-elisa: examination of herds experiencing epidemic or endemic neospora caninum-associated bovine abortion.an enzyme-linked immunosorbent assay (elisa) was established to measure the avidity of bovine igg directed against p38, a surface antigen (ncsrs2) of neospora caninum tachyzoites. in the sera of dams intravenously infected with n. caninum nc-1, the p38-specific avidity increased from initially below 40% up to avidity indices between 50 and 80% after days 23 and 91 p.i. the p38-avidity-elisa was used to examine various herds that had experienced endemic and epidemic n. caninum-associated bovine a ...200212079735
serological survey of neospora caninum and leishmania infantum co-infection in dogs.a seroprevalence survey and risk analysis of neospora caninum and leishmania infantum was conducted in dogs from an area of the campania region of southern italy, in order to investigate the co-infection of these two protozoa. blood samples were collected from 1058 asymptomatic dogs over a 18 months period. serum samples were tested for antibodies to n. caninum and to l. infantum using the indirect fluorescent antibody test. epidemiological data (breed, age, sex, and utilization) were collected ...200212079736
neosporosis in a white rhinoceros (ceratotherium simum) calf.a 16-day-old white rhinoceros calf died suddenly while in excellent condition and showing no obvious previous clinical signs. it was the 9th calf of a mature female kept free-ranging with 11 other rhinoceros as well as various other game species on a 2000 hectare game breeding centre adjacent to the town of lichtenburg and outlying cattle farmlands in the northern province. at post mortem examination, death was ascribed to heart failure. there was marked multifocal to coalescing subacute parasit ...200212088073
coprodiagnosis of hammondia heydorni in dogs by pcr based amplification of its 1 rrna: differentiation from morphologically indistinguishable oocysts of neospora caninum.hammondia heydorni is thought to be a non-pathogenic coccidian parasite of dogs that is closely related to neospora caninum, an important parasite of cattle and dogs. oocysts of these two species are morphologically indistinguishable from each other. a population of 2240 dogs in the czech republic was screened for the presence of h. heydorni/n. caninum oocysts and five (0.22%), represented by five of 3135 faecal samples (0.16%), were positive. the internal transcribed spacer 1 region of the rrna ...200212093189
responses of adipose and muscle lipoprotein lipase to chronic infection and subsequent acute lipopolysaccharide challenge.infection of male swiss webster mice with toxoplasma gondii or neospora caninum leads to long-term alterations in energy balance. following an initial 20 to 30% weight loss in all t. gondii-infected mice, half of the animals regain most of the lost weight (gainers), whereas the others maintain their low body weight (nongainers). infection with n. caninum does not elicit weight loss. lipoprotein lipase (lpl), the enzyme responsible for plasma triglyceride (tg) clearance and partitioning among tis ...200212093671
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
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
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
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
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
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
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
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
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
confirmation of the prevention of vertical transmission of neospora caninum in cattle by the use of embryo transfer. 200212224621
management factors related to seroprevalences to bovine viral-diarrhoea virus, bovine-leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum in dairy herds in the canadian maritimes.bovine viral-diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis lower on-farm productivity, reduce export competitiveness, and increase consumer concerns regarding safety. our purpose was to examine the relationship between 27 control practices and the estimated true seroprevalences for these four diseases for 2604 cattle in 90 dairy herds in the maritimes provinces of canada. overall, 37.8, 20.4, 3.4, and 19.2% of all sampled cattle were truly exposed to the ...200212324207
direct production losses and treatment costs from bovine viral diarrhoea virus, bovine leukosis virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum.our purpose was to determine direct production losses (milk loss, premature voluntary culling and reduced slaughter value, mortaliy loss, and abortion and reproductive loss) and treatmetn costs (veterinary services, medication cost, and extra farm labour cost) due to four infectious diseases in the maritime provinces of canada: bovine viral diarrhoea (bvd), enzootic bovine leukosis (ebl), johne's disease (jd), and neosporosis. we used a partial-budget model, and incorporated risk and sensitivity ...200212350317
neospora caninum: 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
neospora caninum: oocyst challenge of pregnant cows.three pregnant cows were each orally challenged at 10 weeks of gestation with 600 sporulated oocysts of neospora caninum. the number of oocysts was limited by those available. in concurrent bioassays, one oocyst per os infected each of two gerbils. challenged cattle developed neospora-specific antibody, cell proliferation and gamma-interferon responses. n. caninum specific pcr demonstrated persisting infection in the brains of cows 4 months after calving. abortion was not induced and there was n ...200212383634
neospora caninum serostatus and milk production of holstein cattle.to determine whether neospora caninum serostatus was associated with milk production among holstein cattle in ontario.200212387387
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
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
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
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
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
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
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
an explorative study to assess the efficacy of toltrazuril-sulfone (ponazuril) in calves experimentally infected with neospora caninum.neospora caninum is an important cause of infectious abortion and stillbirth in cattle world-wide. infection is common and may frequently be passed from mother to calf (vertical transmission) with no signs of disease. based on our previous observation that n. caninum-infection can be efficiently controlled with toltrazuril-sulfone (ponazuril) in experimentally infected mice, we addressed the question if efficacy could also be obtained in experimentally infected calves.200212437777
first portuguese isolate of neospora caninum from an aborted fetus from a dairy herd with endemic neosporosis.neospora caninum was isolated from the brain of an aborted 4-month-old fetus from a dairy cow herd with endemic neosporosis in porto, portugal. the fetal brain homogenate was inoculated interperitoneally first into outbred swiss webster mice given dexamethasone and then the peritoneal exudates from these mice was co-inoculated with mouse sarcoma cells in the peritoneal cavity of mice given dexamethasone. n. caninum tachyzoites were seen in peritoneal exudate of the second passage. tachyzoites fr ...200212446085
seroprevalence of neospora caninum infection in dairy and beef cattle in paraguay.seroprevalence of neospora caninum in 879 beef and dairy cattle in different locations of paraguay was determined by an elisa. in the survey, 262 (29.8%) cattle were positive to n. caninum, and animals with anti-neospora antibody titre were observed in all the locations tested in the country. serum samples taken from a herd that exhibited persistent abortion had the highest percentage of animals being positive to the parasite (17/30, 56.7%). in the same herd, abortion was significantly more like ...200212446086
use of bulk milk for detection of neospora caninum infection in dairy herds in thailand.the relationship between the level of neospora caninum antibodies in bulk milk and the seroprevalence in lactating cows was investigated. bulk milk was also used to estimate the prevalence of n. caninum infection in dairy herds in the northeast and north thailand. bulk milk and individual serum from all lactating cows in 11 herds as well as 220 bulk milk samples from nine milk collection centres were analysed for presence of n. caninum antibodies using an iscom elisa. in the 11 herds the bulk mi ...200212446088
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
characterisation of the first australian isolate of neospora caninum from cattle.to isolate neospora caninum from a congenitally infected calf.200212465814
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
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
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
neospora caninum: pregnancy, parasites and prolactin. 200312488220
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
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
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
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
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