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Patricia A. Conrad - One of the best experts on this subject based on the ideXlab platform.
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seroprevalences of anti sarcocystis neurona and anti Neospora hughesi antibodies among healthy equids in the united states
Javma-journal of The American Veterinary Medical Association, 2017Co-Authors: Kaitlyn James, Andrea E. Packham, Patricia A. Conrad, Woutrina A Smith, Leopoldo Guerrero, Mitchell Ng, Nicola PusterlaAbstract: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, and age) was collected along with the blood samples. For each equid, an indirect fluorescent antibody test was used to determine serum titers of antibody against each of the 2 protozoal parasites. Mixed-effects logistic regression models were created to determine ORs for seropositivity. RESULTS The overall seroprevalence of anti-S neurona and anti-N hughesi antibodies in the tested equids was 78% and 34%, respectively. Of the equids, 31% were seropositive and 18% were seronegative for antibodies against both paras...
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diagnosis of equine protozoal myeloencephalitis using indirect fluorescent antibody testing and enzyme linked immunosorbent assay titer ratios for sarcocystis neurona and Neospora hughesi
Journal of Equine Veterinary Science, 2016Co-Authors: Anna C Renier, Andrea E. Packham, Carrie J. Finno, Patricia A. Conrad, Daniel K Howe, Eva Tameztrevino, Jennifer K Morrow, Amy Graves, Sean D Owens, Nicola PusterlaAbstract:The aim of this study was to compare two serologic tests used to support a diagnosis of equine protozoal myeloencephalitis (EPM). Serum and cerebrospinal fluid (CSF) samples were analyzed for antibodies to Sarcocystis neurona and Neospora hughesi by indirect fluorescent antibody testing (IFAT) and surface antigens of S. neurona and N. hughesi by enzyme-linked immunosorbent assay (ELISA). The samples originated from neurologic horses with confirmed and suspected EPM (nine S. neurona, three N. hughesi), from neurologic horses with confirmed neurologic diseases other than EPM (16 horses) and from healthy horses (10). The IFAT on CSF and ELISA titer ratios showed equal sensitivity in diagnosing EPM caused by S. neurona. The ELISA titer ratios showed slightly greater specificity in diagnosing EPM than the IFAT on CSF. Overall agreement between the IFAT on CSF and ELISA titer ratio was 90.9%. The IFAT on CSF and ELISA serum/CSF ratio are indicated to help support a laboratory diagnosis of EPM.
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serological investigation of transplacental infection with Neospora hughesi and sarcocystis neurona in broodmares
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Sarah Mackie, Patricia A. ConradAbstract: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 to mares with a high seroprevalence to S. neurona, only one (with a pre-colostrum antibody titer of 80) tested seropositive. Transplacental transmission of N. hughesi seems to occur from latently infected mares to their foals, while this route of transmission does not seem to occur commonly for S. neurona.
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comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and or sarcocystis neurona
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Patricia A. Conrad, Eva Tameztrevino, A White, Joshua Vangeem, Philip H KassAbstract: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 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status.
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Comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and/or Sarcocystis neurona.
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Patricia A. Conrad, A White, Joshua Vangeem, Eva Tamez-trevino, Philip H KassAbstract: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 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status.
Nicola Pusterla - One of the best experts on this subject based on the ideXlab platform.
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seroprevalences of anti sarcocystis neurona and anti Neospora hughesi antibodies among healthy equids in the united states
Javma-journal of The American Veterinary Medical Association, 2017Co-Authors: Kaitlyn James, Andrea E. Packham, Patricia A. Conrad, Woutrina A Smith, Leopoldo Guerrero, Mitchell Ng, Nicola PusterlaAbstract: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, and age) was collected along with the blood samples. For each equid, an indirect fluorescent antibody test was used to determine serum titers of antibody against each of the 2 protozoal parasites. Mixed-effects logistic regression models were created to determine ORs for seropositivity. RESULTS The overall seroprevalence of anti-S neurona and anti-N hughesi antibodies in the tested equids was 78% and 34%, respectively. Of the equids, 31% were seropositive and 18% were seronegative for antibodies against both paras...
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Therapeutics for Equine Protozoal Myeloencephalitis
Veterinary Clinics of North America-equine Practice, 2017Co-Authors: Nicola Pusterla, Thomas TobinAbstract: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. Medical and supportive treatment is provided based on the severity of neurologic deficits and complications. This article focuses on recent data related to diagnosis, pharmacologic treatment, and prevention.
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Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention
Journal of Veterinary Internal Medicine, 2016Co-Authors: Stephen M. Reed, Nicola Pusterla, Daniel K Howe, Jennifer K Morrow, Martin Furr, Amy L. Johnson, Robert J. Mackay, Sharon G. WitonskyAbstract: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, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement update presents current published knowledge of the parasite biology, host immune response, disease pathogenesis, epidemiology, and risk factors. Importantly, the statement provides recommendations for EPM diagnosis, treatment, and prevention.
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diagnosis of equine protozoal myeloencephalitis using indirect fluorescent antibody testing and enzyme linked immunosorbent assay titer ratios for sarcocystis neurona and Neospora hughesi
Journal of Equine Veterinary Science, 2016Co-Authors: Anna C Renier, Andrea E. Packham, Carrie J. Finno, Patricia A. Conrad, Daniel K Howe, Eva Tameztrevino, Jennifer K Morrow, Amy Graves, Sean D Owens, Nicola PusterlaAbstract:The aim of this study was to compare two serologic tests used to support a diagnosis of equine protozoal myeloencephalitis (EPM). Serum and cerebrospinal fluid (CSF) samples were analyzed for antibodies to Sarcocystis neurona and Neospora hughesi by indirect fluorescent antibody testing (IFAT) and surface antigens of S. neurona and N. hughesi by enzyme-linked immunosorbent assay (ELISA). The samples originated from neurologic horses with confirmed and suspected EPM (nine S. neurona, three N. hughesi), from neurologic horses with confirmed neurologic diseases other than EPM (16 horses) and from healthy horses (10). The IFAT on CSF and ELISA titer ratios showed equal sensitivity in diagnosing EPM caused by S. neurona. The ELISA titer ratios showed slightly greater specificity in diagnosing EPM than the IFAT on CSF. Overall agreement between the IFAT on CSF and ELISA titer ratio was 90.9%. The IFAT on CSF and ELISA serum/CSF ratio are indicated to help support a laboratory diagnosis of EPM.
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serological investigation of transplacental infection with Neospora hughesi and sarcocystis neurona in broodmares
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Sarah Mackie, Patricia A. ConradAbstract: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 to mares with a high seroprevalence to S. neurona, only one (with a pre-colostrum antibody titer of 80) tested seropositive. Transplacental transmission of N. hughesi seems to occur from latently infected mares to their foals, while this route of transmission does not seem to occur commonly for S. neurona.
Daniel K Howe - One of the best experts on this subject based on the ideXlab platform.
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Histologically, immunohistochemically, ultrastructurally, and molecularly confirmed neosporosis abortion in an aborted equine fetus.
Veterinary Parasitology, 2019Co-Authors: Joseph A. Anderson, Daniel K Howe, Derron A. Alves, Camila K. Cerqueira-cézar, Andressa F. Da Silva, Fernando Henrique Antunes Murata, Jamie K. Norris, Jitender P. DubeyAbstract:Abstract Neosporosis is a common cause of abortion in cattle worldwide but is rare in horses. Here, the first case of histologically, ultrastructurally, immunohistochemically, and molecularly confirmed equine abortion caused by neosporosis is reported. Samples of lung, heart, liver, skeletal muscle, tongue, brain, and the placenta from a female fetus aborted at 280 days of gestation were fixed in formalin and submitted for diagnosis. Histologically, there was disseminated neosporosis with severe lesions in lungs, liver and the heart. Protozoal tachyzoites in all tissues reacted with polyclonal anti-Neospora caninum rabbit antibodies. Transmission electron microscopic observation on lung tissue revealed tachyzoites consistent with Neospora, including many rhoptries. Polymerase-chain reaction (PCR) using primers designed to amplify the rRNA gene internal transcribed spacer 1 (ITS1) of the Sarcocystidae was performed on DNA extracted from fetal tissues. Comparison of the ITS1 amplified from the foal tissue to sequences available in GenBank revealed 100% sequence identity to the ITS1 from three isolates of Neospora hughesi.
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Protozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States.
Journal of Veterinary Internal Medicine, 2018Co-Authors: Sarah Schale, Michelle R Yeargan, Daniel K Howe, Jennifer K Morrow, Amy Graves, Amy L. JohnsonAbstract:BACKGROUND: Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. HYPOTHESIS/OBJECTIVES: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. ANIMALS: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. METHODS: Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii, as well as serum and CSF for N. hughesi. RESULTS: Horses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P
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Antibodies Against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii in Horses and Mules From the Northern Pantanal Wetland of Brazil
Journal of Equine Veterinary Science, 2017Co-Authors: Alice M.c.m. Borges, Michelle R Yeargan, Daniel K Howe, Lucas Gaíva E Silva, Isis Indaiara Gonçalves Granjeiro Taques, Daniel Moura De AguiarAbstract:Abstract The present study evaluated the prevalence of antibodies against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii in 547 equids (500 horses and 47 mules) from 25 ranches in the Brazilian Pantanal wetlands. The indirect fluorescent antibody test (IFAT) using the appropriate parasite antigens was used as a screening test, and all positive samples for Sarcocystis spp. and Neospora spp. were subsequently evaluated by the rSnSAG2/4/3 and rNhp29 enzyme-linked immunosorbent assays (ELISAs) for S. neurona and Neospora hughesi , respectively. According to the IFAT, 112 of 547 (20.4%) samples were positive for Sarcocystis spp., 65 (11.8%) were positive for Neospora spp., and 138 (25.2%) for T. gondii . In the follow-up analyses, 33 of 112 Sarcocystis spp. IFAT-positive samples were positive by rSnSAG2/4/3 ELISA, and 5 of 65 Neospora spp. IFAT-positive samples were rNhp29 ELISA positive. Western blot (WB) analysis of a subset of samples confirmed the Sarcocystis rSnSAG2/4/3 ELISA results. In contrast, WB analysis using Neospora antigen did not confirm the rNhp29 ELISA results, and further revealed that only two samples were true positives. Interestingly, the two samples seroreacted against immunodominant antigens of N. hughesi but showed stronger reaction to the same antigens of Neospora caninum in the WB. Our results demonstrate that equids from the Brazilian Pantanal wetlands have antibodies to S. neurona and T. gondii , but antibodies to Neospora spp. are uncommon in these animals.
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a serosurvey of selected cystogenic coccidia in spanish equids first detection of anti besnoitia spp specific antibodies in europe
BMC Veterinary Research, 2017Co-Authors: D Gutierrezexposito, Michelle R Yeargan, Daniel K Howe, Ignacio Garciabocanegra, Antonio Arenasmontes, Sallyanne L Ness, Luis Miguel Ortegamora, Gema AlvarezgarciaAbstract: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 (ELISA) was employed to identify a Besnoitia spp. infection and positive results were confirmed by an a posteriori western blot. For Neospora spp. and Sarcocystis spp., infections were detected using in-house ELISAs based on the parasite surface antigens N. hughesi rNhSAG1 and S. neurona rSnSAG2/3/4. Risk factors associated with these protozoan infections were also investigated. Antibodies against Besnoitia spp., Neospora spp. and Sarcocystis spp. infections were detected in 51 (7.1%), 46 (6.4%) and 20 (2.8%) of 721 equids, respectively. The principal risk factors associated with a higher seroprevalence of Besnoitia spp. were the host species (mule or donkey), the absence of shelter and the absence of a rodent control programme. The presence of rodents was the only risk factor for Neospora spp. infection. This study was the first extensive serosurvey of Besnoitia spp. infection in European equids accomplished by two complementary tests and gives evidence of the presence of specific antibodies in these populations. However, the origin of the infection is still unclear. Further parasite detection and molecular genotyping are needed to identify the causative Besnoitia and Neospora species. Finally, cross-reactions with antibodies directed against other species of Sarcocystis might explain the positive reactions against the S. neurona antigens.
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A serosurvey of selected cystogenic coccidia in Spanish equids: first detection of anti-Besnoitia spp. specific antibodies in Europe
BMC Veterinary Research, 2017Co-Authors: Daniel Gutiérrez-expósito, Michelle R Yeargan, Daniel K Howe, Sallyanne L Ness, Ignacio García-bocanegra, Antonio Arenas-montes, Luis M. Ortega-mora, G. Álvarez-garcíaAbstract:Background 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 (ELISA) was employed to identify a Besnoitia spp. infection and positive results were confirmed by an a posteriori western blot. For Neospora spp. and Sarcocystis spp., infections were detected using in-house ELISAs based on the parasite surface antigens N. hughesi rNhSAG1 and S. neurona rSnSAG2/3/4. Risk factors associated with these protozoan infections were also investigated. Results Antibodies against Besnoitia spp., Neospora spp. and Sarcocystis spp. infections were detected in 51 (7.1%), 46 (6.4%) and 20 (2.8%) of 721 equids, respectively. The principal risk factors associated with a higher seroprevalence of Besnoitia spp. were the host species (mule or donkey), the absence of shelter and the absence of a rodent control programme. The presence of rodents was the only risk factor for Neospora spp. infection. Conclusions This study was the first extensive serosurvey of Besnoitia spp. infection in European equids accomplished by two complementary tests and gives evidence of the presence of specific antibodies in these populations. However, the origin of the infection is still unclear. Further parasite detection and molecular genotyping are needed to identify the causative Besnoitia and Neospora species. Finally, cross-reactions with antibodies directed against other species of Sarcocystis might explain the positive reactions against the S. neurona antigens.
Antoinette E Marsh - One of the best experts on this subject based on the ideXlab platform.
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Sarcocystis neurona: molecular characterization of enolase domain I region and a comparison to other protozoa.
Experimental Parasitology, 2008Co-Authors: K. E. Bolten, Antoinette E Marsh, Jitender P. Dubey, Stephen M. Reed, Ramiro E. Toribio, William J. SavilleAbstract: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 gondii, Plasmodium falciparum, and Trypanosoma cruzi; enolase 2 segment containing domain I region is highly conserved amongst these parasites of veterinary and medical importance. Immunohistochemistry results indicates reactivity of T. gondii enolase 1 and 2 antibodies to S. neurona merozoites and metrocytes, but no reactivity of anti-enolase 1 to the S. neurona bradyzoite stage despite reactivity to T. gondii bradyzoites, suggesting expression differences between organisms.
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qualitative evaluation of selective tests for detection of Neospora hughesi antibodies in serum and cerebrospinal fluid of experimentally infected horses
Journal of Parasitology, 2002Co-Authors: Andrea E. Packham, Patricia A. Conrad, Ian A. Gardner, David W Wilson, Antoinette E Marsh, Lisa V Jeanes, Karen W Sverlow, B M Daft, Byron L BlagburnAbstract: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. hughesi and to assess several serologic tests for the detection of related protozoan antibodies. Seven horses were inoculated with N. hughesi tachyzoites, and 7 horses received uninfected cell culture material. The horses were monitored, and blood and cerebrospinal fluid were collected repeatedly over a 4-mo period. With the sera, 4 different serologic techniques were evaluated, including a whole-parasite lysate enzyme-linked immunosorbent assay (ELISA), a recombinant protein ELISA, a modified direct agglutination test, and an indirect fluorescent antibody test. Qualitative and quantitative evaluation of the results showed that the N. hughesi indirect fluorescent antibody test (IFAT) consistently discriminated between experimentally infected and noninfected horses, using a cutoff of 1:640. Sera from 3 naturally infected horses had titers >1:640. Cerebrospinal fluid in all but 1 infected horse had very low N. hughesi IFAT titers (<1:160), starting at postinoculation day 30.
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Seroprevalence of Neospora, Toxoplasma gondii and Sarcocystis neurona antibodies in horses from Jeju island, South Korea
Veterinary Parasitology, 2002Co-Authors: G.d Gupta, Jeffrey Lakritz, Antoinette E MarshAbstract:Abstract 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°12′ E and 33°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 analysis. A total of 191 serum samples from clinically normal horses were evaluated. Only 2% (4 out of 191) and 2.6% (5 out of 191) of the samples had showed reactivity at 1:100 using the IFAT for Neospora spp. and T. gondii, respectively. For T. gondii, two samples matched the antigen banding pattern of the positive control by immunoblot analysis. No sample was positive for N. hughesi by immunoblot analysis in this study. Overall, there was a 1% seroprevalence for T. gondii antibodies in the horses tested based on immunoblot analysis. The seroprevalence for S. neurona and N. hughesi antibodies was 0%. We concluded that these horses are either not routinely exposed to these parasites or antibody titers are not sufficiently elevated to be detectable. It is most likely the former explanation since Jeju island equine farms are isolated from the main land, and the horses were all less than 3 years of age. This naive population of horses could be useful when evaluating S. neurona serodiagnostic tests or evaluating potential S. neurona vaccines since exposure risks to S. neurona and closely related parasites are negligible.
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prevalence of Neospora hughesi and sarcocystis neurona antibodies in horses from various geographical locations
Veterinary Parasitology, 2001Co-Authors: D Vardeleon, Antoinette E Marsh, J G Thorne, W Loch, R Young, P J JohnsonAbstract:Abstract 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 geographic regions. Locations were selected based on distribution of Didelphis virginiana , the native North American opossum which serves as the definitive host for S. neurona . Only 11% of the samples that had positive titers of 1:100 using the IFAT were also positive for antibodies by immunoblot analysis in this study. Overall, there was a 2% seroprevalence for Neospora antibodies in all horses tested based on immunoblot analysis described. The seroprevalence for S. neurona antibodies varied from 0% (New Zealand and Montana) to 54% (Missouri). We concluded that, in testing for antibodies against Neospora antigens using either IFAT or immunoblot analysis, as described, positive results should not be attributed to the presence of antibodies to S. neurona .
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differentiation of Neospora hughesi from Neospora caninum based on their immunodominant surface antigen sag1 and srs2
International Journal for Parasitology, 1999Co-Authors: Antoinette E Marsh, Bradd C Barr, Daniel K Howe, G Wang, N Cannon, Patricia A. ConradAbstract:Abstract 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 Toxoplasma gondii surface antigen 1 (SAG1) and SAG1-related sequence 2 (SRS2). The NcSAG1 and NcSRS2 were antigenically conserved in six different N. caninum isolates from cattle and dogs. The two equine-derived Neospora isolates, one designated as N. hughesi , were similar to each other but different from N. caninum . There was 6% difference in amino acid identity between NcSAG1 and NhSAG1, whereas there was a 9% difference when NcSRS2 and NhSRS2 were compared. The polymorphism of these genes and their corresponding proteins provide additional markers which can be used to distinguish N. caninum from N. hughesi .
Andrea E. Packham - One of the best experts on this subject based on the ideXlab platform.
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seroprevalences of anti sarcocystis neurona and anti Neospora hughesi antibodies among healthy equids in the united states
Javma-journal of The American Veterinary Medical Association, 2017Co-Authors: Kaitlyn James, Andrea E. Packham, Patricia A. Conrad, Woutrina A Smith, Leopoldo Guerrero, Mitchell Ng, Nicola PusterlaAbstract: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, and age) was collected along with the blood samples. For each equid, an indirect fluorescent antibody test was used to determine serum titers of antibody against each of the 2 protozoal parasites. Mixed-effects logistic regression models were created to determine ORs for seropositivity. RESULTS The overall seroprevalence of anti-S neurona and anti-N hughesi antibodies in the tested equids was 78% and 34%, respectively. Of the equids, 31% were seropositive and 18% were seronegative for antibodies against both paras...
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diagnosis of equine protozoal myeloencephalitis using indirect fluorescent antibody testing and enzyme linked immunosorbent assay titer ratios for sarcocystis neurona and Neospora hughesi
Journal of Equine Veterinary Science, 2016Co-Authors: Anna C Renier, Andrea E. Packham, Carrie J. Finno, Patricia A. Conrad, Daniel K Howe, Eva Tameztrevino, Jennifer K Morrow, Amy Graves, Sean D Owens, Nicola PusterlaAbstract:The aim of this study was to compare two serologic tests used to support a diagnosis of equine protozoal myeloencephalitis (EPM). Serum and cerebrospinal fluid (CSF) samples were analyzed for antibodies to Sarcocystis neurona and Neospora hughesi by indirect fluorescent antibody testing (IFAT) and surface antigens of S. neurona and N. hughesi by enzyme-linked immunosorbent assay (ELISA). The samples originated from neurologic horses with confirmed and suspected EPM (nine S. neurona, three N. hughesi), from neurologic horses with confirmed neurologic diseases other than EPM (16 horses) and from healthy horses (10). The IFAT on CSF and ELISA titer ratios showed equal sensitivity in diagnosing EPM caused by S. neurona. The ELISA titer ratios showed slightly greater specificity in diagnosing EPM than the IFAT on CSF. Overall agreement between the IFAT on CSF and ELISA titer ratio was 90.9%. The IFAT on CSF and ELISA serum/CSF ratio are indicated to help support a laboratory diagnosis of EPM.
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serological investigation of transplacental infection with Neospora hughesi and sarcocystis neurona in broodmares
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Sarah Mackie, Patricia A. ConradAbstract: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 to mares with a high seroprevalence to S. neurona, only one (with a pre-colostrum antibody titer of 80) tested seropositive. Transplacental transmission of N. hughesi seems to occur from latently infected mares to their foals, while this route of transmission does not seem to occur commonly for S. neurona.
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comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and or sarcocystis neurona
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Patricia A. Conrad, Eva Tameztrevino, A White, Joshua Vangeem, Philip H KassAbstract: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 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status.
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Comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and/or Sarcocystis neurona.
Veterinary Journal, 2014Co-Authors: Nicola Pusterla, Andrea E. Packham, Patricia A. Conrad, A White, Joshua Vangeem, Eva Tamez-trevino, Philip H KassAbstract: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 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status.