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description of a new neospora species (protozoa: apicomplexa: sarcocystidae).neospora hughesi n. sp. was isolated from the central nervous system tissue of an adult equine (equus caballus) from california. the tachyzoites are crescent-shaped, approximately 2 x 5 microm (1.8-3.0 x 4.0-7.0 microm), with characteristic apical complex structures consisting of an anterior polar ring, conoid, numerous rhoptries filled with a uniform electron-dense material, and 22 microtubules extending posteriorly from the polar ring. comparison of n. hughesi to canine and bovine neospora can ...19989794642
differentiation of neospora hughesi from neospora caninum based on their immunodominant surface antigen, sag1 and srs2.neospora hughesi is a newly recognised parasite that is closely related to neospora caninum, and is a cause of equine protozoal myeloencephalitis. we have characterised two n. hughesi immunodominant tachyzoite antigens which exhibit antigenic and molecular differences from the homologous tachyzoite antigens on n. caninum. these antigens on n. hughesi are referred to as nhsag1 and nhsrs2, using the same mnemonics as used for the n. caninum antigens (ncsag1 and ncsrs2), and are homologous to toxop ...199910608444
neospora hughesi: experimental infections in mice, gerbils, and dogs.neospora hughesi is a recently described cause of equine protozoal myeloencephalitis (epm). a rodent model for pathogenicity would facilitate development of therapies to be used in horses. in the present study, we examined the susceptibility of balb/c gamma-interferon gene knockout (gamma-infko), balb/c, cd-1, and c57bl/6 strains of mice and gerbils to infection with tachyzoites of the nh-a1 strain of n. hughesi isolated from a horse from al, usa. only the gamma-ifnko mice developed severe clini ...200010946135
a random amplified polymorphic dna polymerase chain reaction technique that differentiates between neospora species.neospora caninum is a recently described coccidial parasite that was first isolated from a dog in 1988 and has subsequently been shown to infect a wide range of mammals. neospora hughesi, a new species of this genus, has recently been isolated from the spinal cord of horses showing clinical signs of equine protozoal myeloencephalitis. the random amplified polymorphic dna polymerase chain reaction technique is capable of differentiating between n. caninum and n. hughesi.200011191920
prevalence of neospora hughesi and sarcocystis neurona antibodies in horses from various geographical locations.parasite-specific antibody responses to neospora antigens were detected using the immunofluorescent antibody test (ifat) and immunoblot analysis in select equine populations. for comparison, a naturally infected neospora hughesi horse and an experimentally inoculated neospora caninum horse were used. in addition, all samples were tested for antibodies to sarcocystis neurona by immunoblot analysis. a total of 208 samples was evaluated. the equine populations were derived from five distinct geogra ...200111223207
molecular comparison of the dense granule proteins gra6 and gra7 of neospora hughesi and neospora caninum.neospora hughesi is a recently described apicomplexan parasite that has been associated with several cases of equine protozoal myeloencephalitis. the biology of this new parasite is just beginning to be defined. towards this understanding, we report important differences between the nucleotide and deduced amino acid sequences of the dense granule proteins gra6 and gra7 of n. hughesi and neospora caninum. this information can be used to differentiate the two species and contribute to further unde ...200111226451
characterization of the oregon isolate of neospora hughesi from a horse.neospora hughesi was isolated in cell cultures inoculated with homogenate of spinal cord from a horse in oregon. tachyzoites of this oregon isolate of n. hughesi were maintained continuously by cell culture passage and tachyzoites were infective to immunosuppressed mice. gamma interferon gene knockout (ko) mice injected with tachyzoites developed fatal myocarditis and numerous tachyzoites were seen in lesions. gerbils (meriones unguiculatus) inoculated with tachyzoites developed antibodies (> or ...200111318565
seroprevalence of neospora, toxoplasma gondii and sarcocystis neurona antibodies in horses from jeju island, south korea.parasite-specific antibody responses to neospora spp. and toxoplasma gondii, antigens were detected using the indirect fluorescent antibody test (ifat) and immunoblot analysis in a korean equine population located on jeju island, south korea (126 degrees 12' e and 33 degrees 34' n). for comparison, a naturally infected neospora hughesi horse and an experimentally inoculated t. gondii equid (pony) were used. in addition, all samples were tested for antibodies to sarcocystis neurona by immunoblot ...200212062508
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
qualitative evaluation of selective tests for detection of neospora hughesi antibodies in serum and cerebrospinal fluid of experimentally infected horses.neospora hughesi is a newly recognized protozoan pathogen in horses that causes a myeloencephalitis similar to sarcocystis neurona. there are no validated serologic tests using the gold standard sera that are currently available to detect specific n. hughesi antibodies and, thus, no tests available to detect antemortem exposure or estimate seroprevalence in the horse. the objectives of the present study were to establish a bank of gold standard equine sera through experimental infections with n. ...200212537119
risk of postnatal exposure to sarcocystis neurona and neospora hughesi in horses.to estimate risk of exposure and age at first exposure to sarcocystis neurona and neospora hughesi and time to maternal antibody decay in foals.200415334837
risk of transplacental transmission of sarcocystis neurona and neospora hughesi in california horses.the study objective was to assess the risk of transplacental transmission of sarcocystis neurona and neospora hughesi in foals from 4 california farms during 3 foaling seasons. serum of presuckle foals and serum and colostrum of periparturient mares were tested using indirect fluorescent antibody tests for s. neurona and n. hughesi. serum antibody titers were < or =10 in 366 presuckle foals tested. there was no serologic or histologic evidence of either parasite in aborted fetuses or placentas e ...200415715226
recombinant nhsag1 elisa: a sensitive and specific assay for detecting antibodies against neospora hughesi in equine serum.neospora hughesi is a recently identified cause of equine protozoal myeloencephalitis. however, the significance of this parasite is poorly understood. an enzyme-linked immunosorbent assay (elisa) with a recombinant form of the n. hughesi 29-kda surface antigen (rnhsag1) was developed for serodiagnosis of equine n. hughesi infections. parallel elisa analysis showed that animals immunized or infected with n. hughesi exhibited greater antibody reactivity with rnhsag1 than with the neospora caninum ...200515986623
enzyme-linked immunosorbent assays for detection of equine antibodies specific to sarcocystis neurona surface antigens.sarcocystis neurona is the primary causative agent of equine protozoal myeloencephalitis (epm), a common neurologic disease of horses in the americas. we have developed a set of enzyme-linked immunosorbent assays (elisas) based on the four major surface antigens of s. neurona (snsags) to analyze the equine antibody response to s. neurona. the snsag elisas were optimized and standardized with a sample set of 36 equine sera that had been characterized by western blotting against total s. neurona p ...200516148170
prevalence of sarcocystis neurona and neospora spp. infection in horses from brazil based on presence of serum antibodies to parasite surface antigen.sera from 961 horses from brazil were tested for antibodies against the major surface antigens snsag4 and nhsag1 to determine the seroprevalence of sarcocystis neurona and neospora hughesi, respectively. antibodies against snsag4 were detected in 669 (69.6%) of the horses, while antibodies against nhsag1 were detected in only 24 (2.5%) of the horses. these serologic results suggest that there is a high concentration of s. neurona in the environment of brazil, which results in marked exposure of ...200616310955
cytokine gene signatures in neural tissue of horses with equine protozoal myeloencephalitis or equine herpes type 1 myeloencephalopathy.this study was designed to determine the relative levels of gene transcription of selected pathogens and cytokines in the brain and spinal cord of 12 horses with equine protozoal myeloencephalitis (epm), 11 with equine herpesvirus type 1 (ehv-1) myeloencephalopathy, and 12 healthy control horses by applying a real time pcr to the formalin-fixed and paraffin-embedded tissues. total rna was extracted from each tissue, transcribed to complementary dna (cdna) and assayed for sarcocystis neurona, neo ...200616963713
effects of blood contamination of cerebrospinal fluid on results of indirect fluorescent antibody tests for detection of antibodies against sarcocystis neurona and neospora hughesi.the purpose of this study was to determine the effect of blood contamination of cerebrospinal fluid (csf) on the results of indirect fluorescent antibody tests (ifats) for sarcocystis neurona and neospora hughesi. the in vitro study used antibody-negative csf collected from non-neurologic horses immediately after euthanasia and blood samples from 40 healthy horses that had a range of ifat antibody titers against s. neurona and n. hughesi. serial dilutions of whole blood were made in seronegative ...200717459859
molecular phylogenetic analysis in hammondia-like organisms based on partial hsp70 coding sequences.the 70 kda heat-shock protein (hsp70) sequences are considered one of the most conserved proteins in all domains of life from archaea to eukaryotes. hammondia heydorni, h. hammondi, toxoplasma gondii, neospora hughesi and n. caninum (hammondia-like organisms) are closely related tissue cyst-forming coccidians that belong to the subfamily toxoplasmatinae. the phylogenetic reconstruction using cytoplasmic hsp70 coding genes of hammondia-like organisms revealed the genetic sequences of t. gondii, n ...200717462122
canine and bovine neospora caninum control sera examined for cross-reactivity using neospora caninum and neospora hughesi indirect fluorescent antibody tests.neospora caninum is a well known protozoan parasite of domestic and wild animals. neospora hughesi is a closely related protozoan with an unknown life cycle, host range, and infection prevalence. many serologic surveys of n. caninum have been performed without consideration of potential cross-reactions with n. hughesi, which could confound results. the aim of this study was to investigate whether postexposure sera from animals experimentally infected with n. caninum exhibit significant reactivit ...200918613752
sarcocystis neurona: molecular characterization of enolase domain i region and a comparison to other protozoa.sarcocystis neurona causes protozoal myeloencephalitis and has the ability to infect a wide host range in contrast to other sarcocystis species. in the current study, five s. neurona isolates from a variety of sources, three sarcocystis falcatula, one sarcocystis dasypi/s. neurona-like isolate, and one besnoitia darlingi isolate were used to compare the enolase 2 gene segment containing the domain i region to previously sequenced enolase genes from neospora caninum, neospora hughesi, toxoplasma ...200818625501
a second generation multiplex pcr for typing strains of neospora caninum using six dna targets.genetic diversity of neospora caninum was investigated through a study of repetitive sequences found in the genome of this species. twenty different loci were studied, and three were identified that varied in repeat content amongst isolates. no relationship was found between the copy number of repetitive sequences present and host type or geographical location from which the isolates were derived. a multiplex pcr assay was developed for multilocus-strain typing using three microsatellites and th ...201019683051
equine protozoal myeloencephalitis caused by neospora hughesi in an adult horse in saskatchewan.a protozoal parasite identified as neospora hughesi was found in inflammatory lesions in the central nervous system of a canadian-born adult horse presented with neurological signs. this is believed to be the first case of equine protozoal myeloencephalitis (epm) caused by neospora hughesi in a horse outside of the united states.200919881924
equine protozoal myeloencephalitis due to neospora hughesi and equine motor neuron disease in a mule.a 23-year-old female mule was presented for bilateral ocular abnormalities and an abnormal pelvic limb gait.201020618805
identification of hammondia heydorni oocysts by a heminested-pcr (hnpcr-ap10) based on the h. heydorni rapd fragment ap10.toxoplasma gondii, hammondia hammondi, neospora caninum, neospora hughesi and hammondia heydorni are members of the toxoplasmatinae sub-family. they are closely related coccidians with similarly sized oocysts. molecular diagnostic techniques, especially those based on polymerase chain reaction (pcr), can be successfully applied for the differentiation of hammondia-like oocysts. in this paper, we describe a rapid and simple method for the identification of h. heydorni oocysts among other members ...201021030154
endogenous transplacental transmission of neospora hughesi in naturally infected horses.abstract over a 2-yr study period, we investigated possible endogenous transplacental transmission of neospora hughesi in 74 mare and foal pairs following the diagnosis of neuronal neosporosis in a weanling foal. presuckle and postsuckle serum of each foal, serum and colostrum of each periparturient mare, and serum of each mare and foal pair, collected at 3-mo intervals thereafter, were tested for n. hughesi using an indirect fluorescent antibody test (ifat). furthermore, whole blood and colostr ...201121506870
molecular phylogeny of toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences.phylogenies within toxoplasmatinae have been widely investigated with different molecular markers. here, we studied molecular phylogenies of the toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. partial sequences of apicoplast genes coding for caseinolytic protease (clpc) and beta subunit of rna polymerase (rpob), and mitochondrial gene coding for cytochrome b (cytb) were analyzed. laboratory-adapted strains of the closely related parasites sarcocystis falcatula and sarcocys ...201627007245
brazilian donkeys (equus asinus) have a low exposure to neospora spp.donkeys (equus asinus) are closely related to horses and are known to be infected by several equine pathogens. neospora caninum and neospora hughesi are protozoan parasites that infect horses, but they were not confirmed in donkeys up to this date. the aim of this study was to evaluate the exposure of donkeys (equus asinus) to neospora spp. using tachyzoites of n. caninum as antigen and employing two common serologic methods, ifat and immunoblot. sera from 500 donkeys were obtained from 30 munic ...201526444065
therapeutics for equine protozoal myeloencephalitis.equine protozoal myeloencephalitis is an infectious disease of the central nervous system caused by sarcocystis neurona or neospora hughesi. affected horses routinely present with progressive and asymmetrical neurologic deficits. the diagnosis relies on the presence of neurologic signs, ruling out other neurologic disorders, and the detection of intrathecally derived antibodies to either s neurona and/or n hughesi. recommended treatment is use of an fda-approved anticoccidial drug formulation. m ...201728161037
prevalence of antibodies against neospora spp. and sarcocystis neurona in donkeys from northeastern brazil.sarcocystis neurona and neospora hughesi are coccidian protozoa that can cause neurological illness in horses in america. in this study we report seroprevalence of neospora spp. ands. neurona in sera of 333 donkeys from the northeastern region of brazil. antibodies to neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (ifat) with a cut-off dilution of 1:40. antibodies to s. neurona were found in 3% (10 donkeys) of the samples tested by ifat ...201626982557
equine protozoal myeloencephalitis: an updated consensus statement with a focus on parasite biology, diagnosis, treatment, and prevention.equine protozoal myeloencephalitis (epm) remains an important neurologic disease of horses. there are no pathognomonic clinical signs for the disease. affected horses can have focal or multifocal central nervous system (cns) disease. epm can be difficult to diagnose antemortem. it is caused by either of 2 parasites, sarcocystis neurona and neospora hughesi, with much less known about n. hughesi. although risk factors such as transport stress and breed and age correlations have been identified, b ...201726857902
equine protozoal myeloencephalitis.equine protozoal myeloencephalitis (epm) can be caused by either of 2 related protozoan parasites, sarcocystis neurona and neospora hughesi, although s. neurona is the most frequent etiologic pathogen. horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. risk factors for the development of epm include the presence of opossums and prior stressful health-related events. attempts to reproduce epm experimentally h ...201425441115
serological investigation of transplacental infection with neospora hughesi and sarcocystis neurona in broodmares.the aim of the present study was to investigate the likelihood of transplacental transmission of neospora hughesi and sarcocystis neurona in foals, born from seropositive mares. three broodmares with persistent n. hughesi infection gave birth to eight healthy foals over a period of 7 years. these foals were seropositive to n. hughesi prior to colostrum ingestion, with titers ranging between 640 and 20,480, measured by indirect fluorescence antibody test (ifat). of 174 foals born at another farm ...201425438732
comparison of prevalence factors in horses with and without seropositivity to neospora hughesi and/or sarcocystis neurona.equine protozoal myeloencephalitis is a commonly diagnosed neurological disease of horses in north america and is caused by infection with sarcocystis neurona or neospora hughesi. the aim of this study was to compare prevalence factors among horses seropositive or seronegative to n. hughesi and/or s. neurona. a total of 3123 submissions were included in the study, with horses originating from 49 states. thirty-eight animals from 21 states tested seropositive for n. hughesi only, 840 horses from ...201424703324
prevalence of antibodies to sarcocystis neurona and neospora hughesi in horses from mexico.equine protozoal myeloencephalitis (epm) is a debilitating disease of horses caused by sarcocystis neurona and neospora hughesi. sera from 495 horses in durango state, mexico were tested for anti-protozoal antibodies using enzyme-linked immunosorbent assays (elisas) based on major surface antigens of these two parasites. antibodies to s. neurona were detected in 240 (48.5%) of the 495 horse sera tested with the rsnsag2/4/3 trivalent elisa. multivariate analysis showed that exposure to s. neurona ...201324016396
a serosurvey of selected cystogenic coccidia in spanish equids: first detection of anti-besnoitia spp. specific antibodies in europe.equine besnoitiosis, caused by besnoitia bennetti, and equine protozoal myeloencephalitis (epm), caused by sarcocystis neurona and neospora hughesi are relevant equine diseases in the americas that have been scarcely studied in europe. thus, a serosurvey of these cystogenic coccidia was carried out in southern spain. a cross-sectional study was performed and serum samples from horses (n = 553), donkeys (n = 85) and mules (n = 83) were included. an in-house enzyme-linked immunosorbent assay (elis ...201728490374
seroepidemiology of sarcocystis neurona and neospora hughesi infections in domestic donkeys (equus asinus) in durango, mexico.there is currently no information regarding sarcocystis neurona and neospora hughesi infections in donkeys in mexico. here, we determined the presence of antibodies against s. neurona and n. hughesi in donkeys in the northern mexican state of durango. serum samples of 239 domestic donkeys (equus asinus) were assayed for s. neurona and n. hughesi antibodies using home-made enzyme-linked immunoassays; six (2.5%) of the 239 donkeys tested seropositive for s. neurona. the seroprevalence of s. neuron ...201728730993
toxoplasma gondii seroprevalence and association with equine protozoal myeloencephalitis: a case-control study of californian horses.while toxoplasmosis is not commonly considered a clinical disease of equines, previous seroprevalence studies have reported differing background rates of toxoplasma gondii infection in horses globally. the objective of this study was to evaluate possible associations between t. gondii seroprevalence and clinical signs of equine protozoal myeloencephalitis (epm) in horses. using a case-control study design, 720 californian horses with neurologic signs compatible with epm were compared to healthy, ...201728697873
seroprevalences of anti-sarcocystis neurona and anti-neospora hughesi antibodies among healthy equids in the united states.objective to describe the general seroprevalence of anti-sarcocystis neurona and anti-neospora hughesi antibodies among healthy equids by use of indirect fluorescent antibody tests and determine potential risk factors for seropositivity. design cross-sectional study. sample whole blood samples collected from 5,250 equids (1 sample/animal) across 18 states in the united states during october 2013. procedures information regarding potential risk factors (geographic region, breed, primary use, sex, ...201728509641
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