Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| modest genetic differentiation among north american populations of sarcocystis neurona may reflect expansion in its geographic range. | sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, epm) and sea otters in the united states. in addition, epm-like disease has been diagnosed in several other land and marine mammals. opossums are its only definitive hosts. little genetic diversity among isolates of s. neurona from different hosts has been reported. here, we used 11 microsatellites to characterize s. neurona dna isolated from natural infections in 22 sea otters (enhyd ... | 2008 | 18243561 |
| investigation of snspr1, a novel and abundant surface protein of sarcocystis neurona merozoites. | an expressed sequence tag (est) sequencing project has produced over 15,000 partial cdna sequences from the equine pathogen sarcocystis neurona. while many of the sequences are clear homologues of previously characterized genes, a significant number of the s. neurona ests do not exhibit similarity to anything in the extensive sequence databases that have been generated. in an effort to characterize parasite proteins that are novel to s. neurona, a seemingly unique gene was selected for further i ... | 2008 | 18291589 |
| transplacental toxoplasmosis in a wild southern sea otter (enhydra lutris nereis). | in september 2004, a neonatal sea otter pup was found alive on the beach in northern monterey bay, ca. efforts to locate the mother were unsuccessful. due to a poor prognosis for successful rehabilitation, the pup was euthanized. postmortem examination revealed emaciation, systemic lymphadenopathy and a malformation of the left cerebral temporal lobe. on histopathology, free tachyzoites and tissue cysts compatible with toxoplasma gondii were observed in the brain, heart, thymus, liver, lymph nod ... | 2008 | 18304737 |
| effect of intermittent oral administration of ponazuril on experimental sarcocystis neurona infection of horses. | to evaluate the effect of intermittent oral administration of ponazuril on immunoconversion against sarcocystis neurona in horses inoculated intragastrically with s neurona sporocysts. | 2008 | 18312139 |
| antibody index and specific antibody quotient in horses after intragastric administration of sarcocystis neurona sporocysts. | to investigate the use of a specific antibody index (ai) that relates sarcocystis neurona-specific igg quotient (q(sn)) to total igg quotient (q(igg)) for the detection of the anti-s neurona antibody fraction of cns origin in csf samples obtained from horses after intragastric administration of s neurona sporocysts. | 2008 | 18312140 |
| brown-headed cowbirds (molothrus ater) harbor sarcocystis neurona and act as intermediate hosts. | we tested the hypothesis that brown-headed cowbirds (molothrus ater) harbor sarcocystis neurona, the agent of equine protozoal myeloencephalitis (epm), and act as intermediate hosts for this parasite. in summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with sarcocystis spp. by macroscopic inspection. seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. histopathology revealed two classes of sa ... | 2008 | 18342449 |
| 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 ... | 2008 | 18625501 |
| snsag5 is an alternative surface antigen of sarcocystis neurona strains that is mutually exclusive to snsag1. | sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (epm). previous work has identified a gene family of paralogous surface antigens in s. neurona called snsags. these surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. however, snsag diversity exists in strains of s. neurona, including the absence of the major surface antigen gene snsag1. instead, sequence ... | 2008 | 18829171 |
| horses experimentally infected with sarcocystis neurona develop altered immune responses in vitro. | equine protozoal myeloencephalitis (epm) due to sarcocystis neurona infection is 1 of the most common neurologic diseases in horses in the united states. the mechanisms by which most horses resist disease, as well as the possible mechanisms by which the immune system may be suppressed in horses that develop epm, are not known. therefore, the objectives of this study were to determine whether horses experimentally infected with s. neurona developed suppressed immune responses. thirteen horses tha ... | 2008 | 18973416 |
| seroprevalence of toxoplasma gondii, sarcocystis neurona, and encephalitozoon cuniculi in three species of lemurs from st. catherines island, ga, usa. | in the current study, we determined the seroprevalence of toxoplasma gondii, sarcocystis neurona, and encephalitozoon cuniculi in three species of lemurs from st. catherines island, georgia. serum samples were tested from 52 ring-tailed lemurs (lemur catta), six blue-eyed black lemurs (eulemur macaco flavifrons), and four black and white ruffed lemurs (varecia variegata variegata) using an agglutination assay. three ring-tailed lemurs (5.8%) were positive for t. gondii (titer of 1:50); one ring- ... | 2007 | 17052854 |
| does human proximity affect antibody prevalence in marine-foraging river otters (lontra canadensis)? | the investigation of diseases of free-ranging river otters (lontra canadensis) is a primary conservation priority for this species; however, very little is known about diseases of river otters that forage in marine environments. to identify and better understand pathogens that could be important to marine-foraging river otters, other wildlife species, domestic animals, and humans and to determine if proximity to human population could be a factor in disease exposure, serum samples from 55 free-r ... | 2007 | 17347401 |
| 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 ... | 2007 | 17459859 |
| protozoal meningoencephalitis in sea otters (enhydra lutris): a histopathological and immunohistochemical study of naturally occurring cases. | protozoal meningoencephalitis is considered to be an important cause of mortality in the california sea otter (enhydra lutris). thirty nine of 344 (11.3%) california (ca) and washington state (wa) sea otters examined from 1985 to 2004 had histopathological evidence of significant protozoal meningoencephalitis. the aetiological agents and histopathological changes associated with these protozoal infections are described. the morphology of the actively multiplicative life stages of the organisms ( ... | 2007 | 17692867 |
| molecular typing of sarcocystis neurona: current status and future trends. | sarcocystis neurona is an important protozoal pathogen because it causes the serious neurological disease equine protozoal myeloencephalitis (epm). the capacity of this organism to cause a wide spectrum of neurological signs in horses and the broad geographic distribution of observed cases in the americas drive the need for sensitive, reliable and rapid typing methods to characterize strains. various molecular methods have been developed and used to diagnose epm due to s. neurona, to identify s. ... | 2007 | 17706872 |
| sarcocystis sp.-associated meningoencephalitis in a bald eagle (haliaeetus leucocephalus). | protozoal meningoencephalitis is uncommon in raptors. an adult female bald eagle (haliaeetus leucocephalus) was euthanized after several months of treatment for progressive neurologic signs. the predominant histologic lesion was lymphoplasmacytic and histiocytic meningoencephalitis involving the cerebrum and cerebellum. there was a marked segmental loss of granular cells and purkinje cells, as well as segmental atrophy of the molecular layer in the cerebellum. protozoal merozoites and schizonts ... | 2007 | 17823405 |
| chronic polymyositis associated with disseminated sarcocystosis in a captive-born rhesus macaque. | a 2-year-old, captive-born, clinically healthy male, rhesus macaque, was euthanatized as part of an experimental study. at necropsy, diffuse pale streaking of the trunk, lumbar, and limb muscles were noted macroscopically. on histology, numerous elongated cysts that contained crescent-shaped basophilic spores were found in the fibers of skeletal muscles. scattered affected myofibers were degenerate and accompanied by eosinophilic-to-granulomatous inflammation. sarcocysts had prominent villus-lik ... | 2007 | 17846244 |
| sarcocystis neurona encephalitis in a dog. | a 1.5-year-old male feist dog was presented to a veterinarian for reluctance to stand on the hind legs. treatment included dexamethasone and resulted in a favorable initial response, but posterior paresis returned and progressed to recumbency, hyperesthesia, and attempts to bite the owner. the dog was euthanized. the brain was negative for rabies by fluorescent antibody analysis. multiple foci of encephalitis were found in the cerebrum and particularly in the cerebellum. protozoa morphologically ... | 2007 | 18039914 |
| early migration of sarcocystis neurona in ponies fed sporocysts. | sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (epm), a neurologic disease of the horse. in the present work, the kinetics of s. neurona invasion is determined in the equine model. six ponies were orally inoculated with 250 x 10(6) s. neurona sporocysts via nasogastric intubation and killed on days 1, 2, 3, 5, 7, and 9 postinoculation (pi). at necropsy, tissue samples were examined for s. neurona infection. the parasite was isolated from the mesenteric lymp ... | 2007 | 18163363 |
| survey of the large-animal diplomates of the american college of veterinary internal medicine regarding knowledge and clinical use of polymerase chain reaction: implications for veterinary education. | a questionnaire was developed to document the knowledge base of large-animal diplomates of the american college of veterinary internal medicine (acvim) regarding polymerase chain reaction (pcr) technology and to identify the common use of this technology in equine practice. ninety-three of the 278 mailed questionnaires were returned, for an overall response rate of 33.4%. ninety respondents (99%) reported being familiar with the general principles of nucleic acid probe technology; however, only ... | 2006 | 17220506 |
| generally applicable methods to purify intracellular coccidia from cell cultures and to quantify purification efficacy using quantitative pcr. | the objective of this study was to evaluate the utility of a simple, efficient, and rapid method for the isolation of sarcocystis neurona merozoites and besnoitia darlingi tachyzoites from cultured cells. the efficacy of this purification method was assessed by microscopy, sds-page, western blotting, immuno-fluorescence, and three novel quantitative pcr assays. culture medium containing host cell debris and parasites was eluted through pd-10 desalting columns. this purification method was compar ... | 2006 | 16280197 |
| 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 ... | 2006 | 16310955 |
| lack of sarcocystis neurona antibody response in virginia opossums (didelphis virginiana) fed sarcocystis neurona-infected muscle tissue. | serum was collected from laboratory-reared virginia opossums (didelphis virginiana) to determine whether experimentally infected opossums shedding sarcocystis neurona sporocysts develop serum antibodies to s. neurona merozoite antigens. three opossums were fed muscles from nine-banded armadillos (dasypus novemcinctus), and 5 were fed muscles from striped skunks (mephitis mephitis). serum was also collected from 26 automobile-killed opossums to determine whether antibodies to s. neurona were pres ... | 2006 | 16884017 |
| clinical sarcocystis neurona, sarcocystis canis, toxoplasma gondii, and neospora caninum infections in dogs. | sarcocystis neurona, sarcocystis canis, toxoplasma gondii, and neospora caninum are related apicomplexans that can cause systemic illness in many species of animals, including dogs. we investigated one breeder's 25 basset hounds for these infections. in addition, tissues from dogs and other non-canine hosts previously reported as s. canis infections were studied retrospectively. schizonts resembling those of s. neurona, and recognized by polyclonal rabbit anti-s. neurona antibodies, were found i ... | 2006 | 16458431 |
| a genetically diverse but distinct north american population of sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles. | the population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian toxoplasma gondii despite opportunities for sexual recombination. in order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus sarcocystis, we chara ... | 2006 | 16488197 |
| penetration of equine leukocytes by merozoites of sarcocystis neurona. | horses are considered accidental hosts for sarcocystis neurona and they often develop severe neurological disease when infected with this parasite. schizont stages develop in the central nervous system (cns) and cause the neurological lesions associated with equine protozoal myeloencephalitis. the present study was done to examine the ability of s. neurona merozoites to penetrate and develop in equine peripheral blood leukocytes. these infected host cells might serve as a possible transport mech ... | 2006 | 16517080 |
| immune response to sarcocystis neurona infection in naturally infected horses with equine protozoal myeloencephalitis. | equine protozoal myeloencephalitis (epm) is one of the most common neurologic diseases of horses in the united states. the primary etiologic agent is sarcocystis neurona. currently, there is limited knowledge regarding the protective or pathophysiologic immune response to s. neurona infection or the subsequent development of epm. the objectives of this study were to determine whether s. neurona infected horses with clinical signs of epm had altered or suppressed immune responses compared to neur ... | 2006 | 16563631 |
| development and evaluation of a sarcocystis neurona-specific igm capture enzyme-linked immunosorbent assay. | equine protozoal myeloencephalitis (epm) is a serious neurologic disease of horses caused primarily by the protozoal parasite sarcocystis neurona. currently available antemortem diagnostic testing has low specificity. the hypothesis of this study was that serum and cerebrospinal fluid (csf) of horses experimentally challenged with s neurona would have an increased s neurona-specific igm (sn-igm) concentration after infection, as determined by an igm capture enzyme linked immunoassay (elisa). the ... | 2006 | 16594589 |
| indirect fluorescent antibody testing of cerebrospinal fluid for diagnosis of equine protozoal myeloencephalitis. | to assess the use of csf testing with an indirect fluorescent antibody test (ifat) for diagnosis of equine protozoal myeloencephalitis (epm) caused by sarcocystis neurona. | 2006 | 16649923 |
| genetic variation among isolates of sarcocystis neurona, the agent of protozoal myeloencephalitis, as revealed by amplified fragment length polymorphism markers. | sarcocystis neurona causes serious neurological disease in horses and other vertebrates in the americas. based on epidemiological data, this parasite has recently emerged. here, the genetic diversity of sarcocystis neurona was evaluated using the amplified fragment length polymorphism (aflp) method. fifteen s. neurona taxa from different regions collected over the last 10 years were used; six isolates were from clinically diseased horses, eight isolates were from wild-caught opossums (didelphis ... | 2006 | 16714575 |
| neospora caninum associated with septic peritonitis in an adult dog. | a 7-year-old, male neutered rhodesian ridgeback dog was referred to the university of california-davis veterinary medical teaching hospital with a 4-month history of peritonitis and episodic abdominal discomfort, lethargy, and weakness. marked abdominal distension with a prominent fluid wave was noted on physical examination. cytologic analysis of the abdominal fluid indicated a septic exudate with mixed bacteria and many protozoal zoites. differentials for the identity of the protozoal zoites i ... | 2006 | 16783720 |
| identification of a dithiol-dependent nucleoside triphosphate hydrolase in sarcocystis neurona. | a putative nucleoside triphosphate hydrolase (ntpase) gene was identified in a database of expressed sequence tags (ests) from the apicomplexan parasite sarcocystis neurona. analysis of culture-derived s. neurona merozoites demonstrated a dithiol-dependent ntpase activity, consistent with the presence of a homologue to the tgntpases of toxoplasma gondii. a complete cdna was obtained for the s. neurona gene and the predicted amino acid sequence shared 38% identity with the two tgntpase isoforms f ... | 2006 | 16790243 |
| molecular genetic transfection of the coccidian parasite sarcocystis neurona. | sarcocystis neurona is an apicomplexan parasite that is the major cause of equine protozoal myeloencephalitis (epm). the biology of this pathogen remains poorly understood in part due to unavailability of molecular genetic tools. hence, with an objective to develop dna transfection capabilities for s. neurona, the 5' flanking region of the snsag1 gene was isolated from a genomic library and used to construct expression plasmids. in transient assays, the reporter molecules beta-galactosidase (bet ... | 2006 | 16844242 |
| prophylactic administration of ponazuril reduces clinical signs and delays seroconversion in horses challenged with sarcocystis neurona. | the ability of ponazuril to prevent or limit clinical signs of equine protozoal myeloencephalitis (epm) after infection with sarcocystis neurona was evaluated. eighteen horses were assigned to 1 of 3 groups: no treatment, 2.5 mg/kg ponazuril, or 5.0 mg/kg ponazuril. horses were administered ponazuril, once per day, beginning 7 days before infection (study day 0) and continuing for 28 days postinfection. on day 0, horses were stressed by transport and challenged with 1 million s. neurona sporocys ... | 2006 | 16884012 |
| molecular and microscopic techniques for detection of sarcocystis neurona sporocysts in fecal samples. | diagnosis of sarcocystis sp. in the definitive host is generally by microscopic detection of the sporocysts in feces. this method is insensitive and cannot differentiate between species because sporocysts lack specific staining criteria. the hypothesis suggested that molecular techniques provide better alternatives to classical detection of sarcocystis sporocysts. the sensitivity of two pcr assays was compared to one another and to microscopic examination by conventional fecal flotation and diam ... | 2006 | 16927879 |
| persistence of serum antibodies to sarcocystis neurona in horses moved from north america to india. | the study reported here was undertaken to assess the presence of antibodies to sarcocystis neurona in the serum of horses of north american origin that had been relocated for 1 year or more to india (ie, outside of the known endemic areas for s. neurona). | 2006 | 16955828 |
| 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 ... | 2006 | 16963713 |
| fatal hepatic sarcocystosis in a puppy with eosinophilia and eosinophilic peritoneal effusion. | a 3-month-old male golden retriever puppy was evaluated for lethargy and fever of 2-days duration. results of a cbc and biochemical profile revealed marked eosinophilia (6.3 x 10(3)/microl; reference interval 0.1-1.2 x 10(3)/microl), moderate thrombocytopenia, and increased activities of alanine aminotransferase, aspartate aminotransferase, and creatine kinase. hepatomegaly and peritoneal effusion were found using abdominal ultrasound. peritoneal fluid analysis revealed eosinophilic inflammation ... | 2006 | 16967426 |
| increased presence of t lymphocytes in central nervous system of epm affected horses. | equine protozoal myeloencephalitis (epm), caused by sarcocystis neurona infection in the central nervous system (cns), affects up to 1% of all horses during their lifetimes. neither the protective immune response nor the immunopathology associated with the disease is well understood. to begin to clarify the pathogenesis of the disease, immunohistochemical staining for b and t lymphocytes was performed on spinal cord sections obtained from 17 horses, all of which were all positive for s. neurona ... | 2005 | 16539042 |
| sarcocystis neurona merozoites express a family of immunogenic surface antigens that are orthologues of the toxoplasma gondii surface antigens (sags) and sag-related sequences. | sarcocystis neurona is a member of the apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. analysis of an s. neurona expressed sequence tag (est) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (sags) and sag-related sequences of toxoplasma gondii. the primary peptide sequences of the s. neurona proteins are consistent with the two-domain structure that has been described f ... | 2005 | 15664946 |
| parasitemia in an immunocompetent horse experimentally challenged with sarcocystis neurona sporocysts. | equine protozoal myeloencephalitis (epm) is a serious neurological disease of horses in americans. most cases are attributed to infection of the central nervous system with sarcocystis neurona. parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. the objective of this study was to isolate viable s. neurona from the blood of immunocompetent horses. horses used in this study received orally administered s. neurona sporocysts (strai ... | 2005 | 15619368 |
| cutaneous manifestations of disseminated toxoplasmosis in an immunosuppressed dog. | a 3.5-year-old, castrated male, giant schnauzer was presented with alopecic pustular dermatitis. immune-mediated hemolytic anemia had been diagnosed 45 days previously. at the time of presentation, the dog was receiving prednisone, azathioprine, and cyclosporine. cutaneous protozoosis was diagnosed, and postmortem examination revealed protozoa within cutaneous, cardiac, pancreatic, and pulmonary tissues. the protozoa divided by endodyogeny, had the morphology of toxoplasma gondii (t. gondii) tac ... | 2005 | 15870255 |
| cytokine gene expression in response to snsag1 in horses with equine protozoal myeloencephalitis. | equine protozoal myeloencephalitis (epm) is a neurologic syndrome seen in horses from the americas and is mainly caused by sarcocystis neurona. recently, a 29-kda surface antigen from s. neurona merozoites was identified as being highly immunodominant on a western blot. this antigen has been sequenced and cloned, and the expressed protein has been named snsag1. in a previous study, cell-mediated immune responses to snsag1 were shown to be statistically significantly reduced in horses with epm in ... | 2005 | 15879026 |
| the effects of ponazuril on development of apicomplexans in vitro. | we examined the effects of 5 microg/ml ponazuril treatment on developing tachyzoites of neospora caninum and merozoites of sarcocystis neurona to better determine the mode of action of this anticoccidial drug. both parasites develop asexually by endogenesis. neospora caninum was selected for study because it develops by endodyogeny, which results in two tachyzoites being produced internally, and s. neurona was selected because it develops by endopolygeny which results in many merozoites being pr ... | 2005 | 15926999 |
| effect of daily administration of pyrantel tartrate in preventing infection in horses experimentally challenged with sarcocystis neurona. | to determine whether daily administration of pyrantel tartrate can prevent infection in horses experimentally challenged with sarcocystis neurona. | 2005 | 15934612 |
| evidence to support horses as natural intermediate hosts for sarcocystis neurona. | opossums (didelphis spp.) are the definitive host for the protozoan parasite sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis (epm). opossums shed sporocysts in feces that can be ingested by true intermediate hosts (cats, raccoons, skunks, armadillos and sea otters). horses acquire the parasite by ingestion of feed or water contaminated by opossum feces. however, horses have been classified as aberrant intermediate hosts because the terminal asexual sarcocyst stage ... | 2005 | 15970386 |
| naturally occurring sarcocystis neurona-like infection in a dog with myositis. | tissue stages similar to those of sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis, were identified in skeletal muscles of a dog. the dog, a 6-year-old labrador retriever, was seropositive for toxoplasma gondii infection and euthanized due to a history of polymyositis and progressive muscular atrophy. histologically, 30, variably sized, microscopic, intracellular sarcocysts were observed in 60 sections of skeletal muscles taken from the neck, fore limbs and hind lim ... | 2005 | 16005151 |
| phylogenetic congruence of sarcocystis neurona dubey et al., 1991 (apicomplexa: sarcocystidae) in the united states based on sequence analysis and restriction fragment length polymorphism (rflp). | the objectives of the present study were to assess the genetic diversity, phylogeny and phylogeographical relationships of available sarcocystis neurona isolates from different localities in the united states. all 13 sarcocystis isolates from different hosts were subjected to polymerase chain reaction restriction fragment length polymorphism (pcr-rflp) analyses using two published dna markers (25/396 and 33/54). the 334 bp sequence of the 25/396 marker of these isolates and besnoitia darlingi, b ... | 2005 | 16025209 |
| plastid segregation and cell division in the apicomplexan parasite sarcocystis neurona. | apicomplexan parasites harbor a secondary plastid that is essential to their survival. several metabolic pathways confined to this organelle have emerged as promising parasite-specific drug targets. the maintenance of the organelle and its genome is an equally valuable target. we have studied the replication and segregation of this important organelle using the parasite sarcocystis neurona as a cell biological model. this model system makes it possible to differentiate and dissect organellar gro ... | 2005 | 16079283 |
| phylogenetic relationships of sarcocystis neurona of horses and opossums to other cyst-forming coccidia deduced from ssu rrna gene sequences. | phylogenetic analyses based on sequences of the nuclear-encoded small subunit rrna (ssurrna) gene were performed to examine the origin, phylogeny, and biogeographic relationships of sarcocystis neurona isolates from opossums and horses from the state of michigan, usa, in relation to other cyst-forming coccidia. a total of 31 taxa representing all recognized subfamilies and genera of sarcocystidae were included in the analyses with clonal isolates of two opossum and two horse s. neurona. phylogen ... | 2005 | 16133298 |
| 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 ... | 2005 | 16148170 |
| inhibitory activities of epidermal growth factor receptor tyrosine kinase-targeted dihydroxyisoflavone and trihydroxydeoxybenzoin derivatives on sarcocystis neurona, neospora caninum, and cryptosporidium parvum development. | several gene sequences of parasitic protozoa belonging to protein kinase gene families and epidermal growth factor (egf)-like peptides, which act via binding to receptor tyrosine kinases of the egf receptor (egfr) family, appear to mediate host-protozoan interactions. as a clue to egfr protein tyrosine kinase (ptk) mediation and a novel approach for identifying anticoccidial agents, activities against sarcocystis neurona, neospora caninum, and cryptosporidium parvum grown in bm and hct-8 cell cu ... | 2005 | 16251305 |
| sarcocystis neurona-associated meningoencephalitis and description of intramuscular sarcocysts in a fisher (martes pennanti). | a free-ranging juvenile fisher (martes pennanti) with ataxia, lethargy, stupor, and intermittent, whole-body tremors was examined postmortem. microscopically, the fisher had protozoal meningoencephalitis caused by sarcocystis neurona, which was confirmed by immunohistochemistry, polymerase chain reaction (pcr) and restriction fragment length polymorphism testing, and genetic sequencing. sarcocysts found in the skeletal muscle of the fisher were negative for s. neurona by pcr, but were morphologi ... | 2005 | 15827227 |
| evaluation of cardiac lesions and risk factors associated with myocarditis and dilated cardiomyopathy in southern sea otters (enhydra lutris nereis). | to describe cardiac lesions and identify risk factors associated with myocarditis and dilated cardiomyopathy (dcm) in beach-cast southern sea otters. | 2005 | 15757130 |
| prevalence of agglutinating antibodies to toxoplasma gondii and sarcocystis neurona in beavers (castor canadensis) from massachusetts. | the present study examined the seroprevalence of toxoplasma gondii and sarcocystis neurona in a population of beavers (castor canadensis) from massachusetts. sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. blood was collected onto filter paper and shipped to the department of biomedical sciences, virginia tech, blacksburg, virginia, for parasite testing. the samples were tested at dilutions of 1:25, 1:50, and 1:100 against each par ... | 2005 | 16419776 |
| humoral immunity is not critical for protection against experimental infection with sarcocystis neurona in b-cell-deficient mice. | immunodeficient b-cell-deficient mice (mmumt) were infected with sarcocystis neurona merozoites to determine the role of b cells and the humoral immune response in protective immunity. as expected, the mice did not seroconvert based on a direct agglutination test. infected mice did not have significant changes in gross pathology at the time points examined. histologic changes included mild perivascular and peribronchial infiltrate in the lungs; perivascular infiltrate and mild inflammatory sinus ... | 2005 | 17089750 |
| sarcocystis neurona major surface antigen gene 1 (sag1) shows evidence of having evolved under positive selection pressure. | the major surface antigen gene 1 (sag1) is conserved among members of sarcocystidae and may play an important role in parasite pathogenesis. additionally, generation and selection of different antigenic variants of sag1 has the potential for inclusion in a subunit vaccine or in the development of a diagnostic assay. in this study, patterns of nucleotide polymorphism were used to test the hypothesis that natural selection promotes diversity in different parts of sag1 of sarcocystis neurona. nucle ... | 2004 | 15517384 |
| prevalence of and risk factors associated with the presence of sarcocystis neurona sporocysts in opossum (didelphis virginiana) from michigan: a retrospective study. | from april 1996 to december 2002 the prevalence of sarcocystis neurona sporocysts in north american opossum (didelphis virginiana) in southern michigan was estimated. sporocysts of s. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. the frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). also, prevalence of s. neurona sporocysts in opossums in relation to factors s ... | 2004 | 15482884 |
| viability of sarcocystis neurona sporocysts after long-term storage. | the effect of long-term storage on the viability and infectivity of sarcocystis neurona sporocysts was investigated. s. neurona sporocysts were harvested from the small intestine of virginia opossums from 1996 to 2002 and stored at 4 degrees c. viability of sporocysts was assessed by propidium iodide (pi) exclusion assay, in vitro excystation and development in tissue cultures, and bioassay in gamma-interferon gene knockout (gamma-ifn-ko) mice. the rate of excystation was apparently unaffected b ... | 2004 | 15325051 |
| prevention of meningo/encephalomyelitis due to sarcocystis neurona infection in mice is mediated by cd8 cells. | immunodeficient cd8 knockout mice were infected with sarcocystis neurona merozoites, in order to determine the role of cd8 cells in protective immunity. using a direct agglutination test, all infected mice seroconverted by selected time points. infected mice developed splenomegaly and bilateral lymphadenopathy. histological changes included marked follicular development in the spleen, endothelitis and moderate perivascular inflammation in the liver, and meningoencephalitis in the brain. infected ... | 2004 | 15619522 |
| 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 ... | 2004 | 15715226 |
| an equine protozoal myeloencephalitis challenge model testing a second transport after inoculation with sarcocystis neurona sporocysts. | previous challenge studies performed at ohio state university involved a transport-stress model where the study animals were dosed with sarcocystis neurona sporocysts on the day of arrival. this study was to test a second transportation of horses after oral inoculation with s. neurona sporocysts. horses were assigned randomly to groups: group 1, transported 4 days after inoculation (dai); group 2, at 11 dai; group 3, at 18 dai; and group 4, horses were not transported a second time (controls). a ... | 2004 | 15715237 |
| experimental infection of ponies with sarcocystis fayeri and differentiation from sarcocystis neurona infections in horses. | sarcocystis neurona and sarcocystis fayeri infections are common in horses in the americas. their antemortem diagnosis is important because the former causes a neurological disorder in horses, whereas the latter is considered nonpathogenic. there is a concern that equine antibodies to s. fayeri might react with s. neurona antigens in diagnostic tests. in this study, 4 ponies without demonstrable serum antibodies to s. neurona by western immunoblot were used. three ponies were fed 1 x 10(5) to 1 ... | 2004 | 15715250 |
| apiest-db: analyzing clustered est data of the apicomplexan parasites. | apiest-db (http://www.cbil.upenn.edu/paradbs-servlet/) provides integrated access to publicly available est data from protozoan parasites in the phylum apicomplexa. the database currently incorporates a total of nearly 100,000 ests from several parasite species of clinical and/or veterinary interest, including eimeria tenella, neospora caninum, plasmodium falciparum, sarcocystis neurona and toxoplasma gondii. to facilitate analysis of these data, est sequences were clustered and assembled to for ... | 2004 | 14681425 |
| sarcocystis neurona-specific immunoglobulin g in the serum and cerebrospinal fluid of horses administered s neurona vaccine. | a vaccine against sarcocystis neurona, which induces equine protozoal myeloencephalitis (epm), has received conditional licensure in the united states. a major concern is whether the immunoglobulin g (igg) response elicited by the vaccine will compromise the use of western blotting (wb) as a diagnostic tool in vaccinated horses with neurologic disease. our goals were to determine if vaccination (1) causes seroconversion: (2) causes at least a transient increase in s neurona-specific igg in the c ... | 2004 | 14765738 |
| evaluation of immune responses in horses immunized using a killed sarcocystis neurona vaccine. | clinically normal horses developed cellular immunity to sarcocystis neurona following im vaccination with a commercial killed s. neurona vaccine, as indicated by the development of measurable anti-s. neurona igg antibodies and additional intradermal skin testing. large-scale independent assessments of the vaccine's performance and safety are in progress under field conditions. the next step in the evaluation of this vaccine would be to attempt experimental challenge after a reproducible reliable ... | 2004 | 15150728 |
| evaluation and comparison of an indirect fluorescent antibody test for detection of antibodies to sarcocystis neurona, using serum and cerebrospinal fluid of naturally and experimentally infected, and vaccinated horses. | the objectives of this study were to evaluate the accuracy of the indirect fluorescent antibody test (ifat) using serum and cerebrospinal fluid (csf) of horses naturally and experimentally infected with sarcocystis neurona, to assess the correlation between serum and csf titers, and to determine the effect of s. neurona vaccination on the diagnosis of infection. using receiver-operating characteristic analysis, the areas under the curve for the ifat were 0.97 (serum) and 0.99 (csf). sensitivity ... | 2004 | 15165063 |
| cell-mediated immune responses in horses with equine protozoal myeloencephalitis. | equine protozoal myeloencephalitis (epm) is a neurologic syndrome seen in horses from the americas and is mainly caused by sarcocystis neurona. cell-mediated immune responses to mitogens have been shown to be reduced in horses with epm, although it is not known whether the parasite causes this immunosuppression or if the immunosuppression is required for disease manifestation. recently, a 29-kda surface antigen from s. neurona merozoites was identified as being highly immunodominant on western b ... | 2004 | 15165077 |
| sarcocystis neurona (protozoa: apicomplexa): description of oocysts, sporocysts, sporozoites, excystation, and early development. | equine protozoal myeloencephalitis is a major cause of neurological disease in horses from the americas. horses are considered accidental intermediate hosts. the structure of sporocysts of the causative agent, sarcocystis neurona, has never been described. sporocysts of s. neurona were obtained from the intestines of a laboratory-raised opossum fed skeletal muscles from a raccoon that had been fed sporocysts. sporocysts were 11.3 by 8.2 microm and contained 4 sporozoites. the appearance of the s ... | 2004 | 15272465 |
| concurrent presence of sarcocystis neurona sporocysts, besnoitia darlingi tissue cysts, and sarcocystis inghami sarcocysts in naturally infected opossums (didelphis virginiana). | opossums (didelphis virginiana) are exposed to a wide range of coccidia through feeding on a variety of foods, including, but not limited to, carrion, insects, and nestling birds. abundant d. virginiana populations in urban and suburban areas can be important reservoirs of parasitic infection because of their profuse and prolonged excretion of the sporocysts of several species of sarcocystis, their omnivorous diet, and their relatively long life span. this report describes 2 adult female opossum ... | 2004 | 15305752 |
| 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. | 2004 | 15334837 |
| depletion of natural killer cells does not result in neurologic disease due to sarcocystis neurona in mice with severe combined immunodeficiency. | sarcocystis neurona is an apicomplexan parasite that is the primary etiologic agent of equine protozoal myeloencephalitis in horses. protective immune responses in horses have not been determined, but interferon-gamma (ifn-gamma) is considered critical for protection from neurologic disease in mice. the role of adaptive and innate immune responses in control of parasites was explored by infecting balb/c, ifn-gamma knockout (gko), and severe combined immune deficient (scid) mice with s. neurona ( ... | 2004 | 15357069 |
| assessment of sarcocystis neurona sporocyst viability and differentiation between viable and nonviable sporocysts using propidium iodide stain. | sarcocystis neurona has become recognized as the major causative agent of equine protozoal myeloencephalitis (epm) in the americas. at least 3 pathogenic species of sarcocystis, including s. neurona, can be isolated from opossums. methods are needed to ascertain whether these isolates are viable and capable of causing infections. in this study, the nuclear stain propidium iodide (pi) was used to differentiate between live (viable) and heat-killed (nonviable) s. neurona sporocysts. pi was exclude ... | 2004 | 15357088 |
| prevalence of agglutinating antibodies to sarcocystis neurona in raccoons (procyon lotor) from an urban area of virginia. | equine protozoal myeloencephalitis is the most important protozoan disease of horses in north america and is usually caused by sarcocystis neurona. natural and experimentally induced cases of encephalitis caused by s. neurona have been reported in raccoons (procyon lotor) and raccoons are an intermediate host for this parasite. a 3-yr-long serological survey was conducted to determine the prevalence of agglutinating antibodies to s. neurona in raccoons collected from fairfax county, virginia, a ... | 2004 | 15357091 |
| infection of immunodeficient horses with sarcocystis neurona does not result in neurologic disease. | equine protozoal myeloencephalitis is a progressive neurologic disease of horses most commonly caused by infection with the apicomplexan parasite sarcocystis neurona. factors affecting neuroinvasion and neurovirulence have not been determined. we investigated the pathogenesis of infection with s. neurona in horses with severe combined immune deficiency (scid). two immunocompetent (ic) arabian horses and two arabian horses with scid were infected orally with 5 x 10(5) sporocysts of s. neurona. fo ... | 2004 | 15539518 |
| the identification of a sequence related to apicomplexan enolase from sarcocystis neurona. | equine protozoal myeloencephalitis (epm) is a neurological disease caused by sarcocystis neurona, an apicomplexan parasite. s. neurona is also associated with epm-like diseases in marine and small mammals. the mechanisms of transmission and ability to infect a wide host range remain obscure; therefore, characterization of essential proteins may provide evolutionary information allowing the development of novel chemotherapeutics that target non-mammalian biochemical pathways. in the current study ... | 2004 | 15549383 |
| antigenic evaluation of a recombinant baculovirus-expressed sarcocystis neurona sag1 antigen. | sarcocystis neurona is the primary parasite associated with equine protozoal myeloencephalitis (epm). this is a commonly diagnosed neurological disorder in the americas that infects the central nervous system of horses. current serologic assays utilize culture-derived parasites as antigen. this method requires large numbers of parasites to be grown in culture, which is labor intensive and time consuming. also, a culture-derived whole-parasite preparation contains conserved antigens that could cr ... | 2004 | 15562602 |
| a herd-level analysis of risk factors for antibodies to sarcocystis neurona in michigan equids. | equine protozoal myeloencephalitis (epm) is a neurological disease of horses and ponies caused by infection of the central nervous system with the protozoan parasite sarcocystis neurona. a herd-level analysis of a cross-sectional study of serum antibodies to s. neurona in michigan equids was conducted, using data collected in 1997 for study that included 1121 equids from 98 michigan horse farms. our objective was to identify specific herd-level risk factors associated with seropositivity. we tes ... | 2003 | 12547171 |
| comparison of a serum indirect fluorescent antibody test with two western blot tests for the diagnosis of equine protozoal myeloencephalitis. | a serum indirect fluorescent antibody test (ifat) was compared with a western blot (wb) and a modified western blot (mwb) for diagnosis of equine protozoal myeloencephalitis (epm). using receiver-operating characteristic (roc) analysis, the area under the curve of the ifat was greater than the areaunder the curves of the wb and the mwb (p = 0.025 and p = 0.044, respectively). there was no statistically significant difference between the areas under the curves of the wbs (p > 0.05). on the basis ... | 2003 | 12580288 |
| sequence comparison of sarcocystis neurona surface antigen from multiple isolates. | sarcocystis neurona is responsible for equine protozoal myeloencephalitis (epm) and is phylogenetically closely related to toxoplasma gondii and neospora spp. there has been major progress in evaluating immunodominant and surface proteins of t. gondii and neospora spp.; however, there is a paucity of data on the proteins or genes from s. neurona and s. neurona-like parasites. in this study, using reverse transcription-pcr (rt-pcr) and restriction fragment length polymorphism (rflp) methods, the ... | 2003 | 12581581 |
| gene discovery in the apicomplexa as revealed by est sequencing and assembly of a comparative gene database. | large-scale est sequencing projects for several important parasites within the phylum apicomplexa were undertaken for the purpose of gene discovery. included were several parasites of medical importance (plasmodium falciparum, toxoplasma gondii) and others of veterinary importance (eimeria tenella, sarcocystis neurona, and neospora caninum). a total of 55192 ests, deposited into dbest/genbank, were included in the analyses. the resulting sequences have been clustered into nonredundant gene assem ... | 2003 | 12618375 |
| clinical sarcocystis neurona encephalomyelitis in a domestic cat following routine surgery. | sarcocystis neurona is an important cause of equine protozoal myeloencephalitis (epm) in horses in the americas. an epm-like neurological disease also has been reported from other mammals but it is difficult to induce this disease in the laboratory. a 4-month-old male domestic cat developed neurological signs 3 days following castration. the cat was euthanized 12 days later because of paralysis. encephalomyelitis was the only lesion and was associated with numerous sarcocystis schizonts and mero ... | 2003 | 12623205 |
| characterization of a serine protease activity in sarcocystis neurona merozoites. | sarcocystis neurona merozoites were examined for their ability to invade and divide in bovine turbinate (bt) cell cultures after treatment with cysteine (iodoacetamide), aspartic (pepstatin a), metallo-(1,10-phenanthroline and ethylene glycol-bis(aminoethylether)-tetraacetic acid [egta]), or serine (4-[2-aminoethyl]-benzenesulfonyl fluoride hydrochloride [aebsf], phenylmethane sulphonyl fluoride [pmsf], and tosyl lysyl chloramethyl ketone [tlck]) protease inhibitors. significant (p < 0.01) inhib ... | 2003 | 12760660 |
| effect of a single dose of ponazuril on neural infection and clinical disease in sarcocystis neurona-challenged interferon-gamma knockout mice. | interferon gamma-knockout mice were challenged with 5000 sarcocystis neurona sporocysts acquired from a naturally infected opossum. ponazuril was administered once, by gavage, at day 1, 3, 7, 10, or 14 post-infection (pi). ponazuril was given at either 20 or 200mg/kg. mice that survived to day 30 pi were euthanized. severity of cns infection was quantified as schizont density in the cerebellum. unchallenged mice in treatment and non-treatment groups remained free of disease and gained weight thr ... | 2003 | 12781474 |
| analysis of the sarcocystis neurona microneme protein snmic10: protein characteristics and expression during intracellular development. | sarcocystis neurona, an apicomplexan parasite, is the primary causative agent of equine protozoal myeloencephalitis. like other members of the apicomplexa, s. neurona zoites possess secretory organelles that contain proteins necessary for host cell invasion and intracellular survival. from a collection of s. neurona expressed sequence tags, we identified a sequence encoding a putative microneme protein based on similarity to toxoplasma gondii mic10 (tgmic10). pairwise sequence alignments of snmi ... | 2003 | 12814647 |
| naturally occurring sarcocystis infection in domestic cats (felis catus). | equine protozoal myeloencephalitis is an important neurological disease of horses in the united states. consequently, there is an active research effort to identify hosts associated with the primary causative agent, sarcocystis neurona. the purpose of this study was to determine whether the domestic cat (felis catus) is a natural host for s. neurona. muscle sections from 50 primarily free-roaming domestic cats were examined for the presence of sarcocysts. serum from cats in this group and anothe ... | 2003 | 12865087 |
| first case report of sarcocystis neurona-induced equine protozoal myeloencephalitis in japan. | equine protozoal myeloencephalitis developed in a three-year-old male thoroughbred racehorse imported from the united states. the animal showed astasia five days after the onset of ataxia. histopathologically, focal nonpurulent myelitis accompanied by hemorrhage and perivascular infiltration was observed in the fourth and fifth cervical spinal cord. immunohistochemically, shizonts were occasionally observed and were positive for anti-sarcocystis neurona (s. neurona) antiserum. s. neurona-specifi ... | 2003 | 12867742 |
| assessing the agreement of western blot test results for paired serum and cerebrospinal fluid samples from horses tested for antibodies to sarcocystis neuronaf. | equine protozoal myeloencephalitis (epm) is a neurological disease of equids that is caused by infection of the central nervous system with sarcocystis neurona. veterinarians diagnose epm by performing a neurological examination and by ordering western blot tests for antibodies to s. neurona in the blood and/or cerebrospinal fluid (csf). the negative predictive value of the western blot test is generally accepted to be high for both serum and csf. if the agreement between serum and csf test resu ... | 2003 | 12935738 |
| dermatitis in a dog associated with an unidentified toxoplasma gondii-like parasite. | protozoal dermatitis was diagnosed in a 6-year-old female great dane dog from rio de janeiro, brazil. the dog died because of a chronic illness with an ehrlichia-like organism. numerous apicomplexan parasites were identified histologically in the section of dermal lesions. the protozoan reacted with toxoplasma gondii polyclonal rabbit serum but not with neospora caninum or sarcocystis neurona antibodies. ultrastructurally, the protozoa was not t. gondii because it had schizont-like structures wi ... | 2003 | 14519327 |
| prevalence of antibodies to neospora caninum, sarcocystis neurona, and toxoplasma gondii in wild horses from central wyoming. | sarcocystis neurona, neospora caninum, n. hughesi, and toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. the source of infection for n. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for s. neurona, n. caninum, and t. gondii, respectively. seroprevalence of these coccidians in 276 wild horses from central wyoming outside the known range of the opossum (didelphis virginiana) was determined. antibodies to t. gond ... | 2003 | 14533680 |
| meningoencephalitis associated with an unidentified apicomplexan protozoan in a pacific harbor seal. | a pacific harbor seal (phoca vitulina richardsii) was found on the central california coast with neurologic signs and labored breathing, which were unresponsive to treatment. necropsy revealed a nonsuppurative necrotizing meningoencephalitis, a multilocular thymic cyst, and nonsuppurative cystitis and renal pyelitis. microscopic examination revealed protozoans in the brain, thymic cyst, and bladder mucosa. ultrastructurally, the protozoal tachyzoites were different from those of neospora caninum ... | 2003 | 14533706 |
| autofluorescence of toxoplasma gondii and related coccidian oocysts. | this is the first report of blue autofluorescence as a useful characteristic in the microscopic detection of toxoplasma gondii, hammondia hammondi, hammondia heydorni, neospora caninum, besnoitia darlingi, and sarcocystis neurona oocysts or sporocysts. this autofluorescence is of sufficient intensity and duration to allow identification of these oocysts from complex microscopic sample backgrounds. as with the autofluorescence of related coccidia, the oocysts glow pale blue when illuminated with ... | 2003 | 14533708 |
| toxoplasma gondii, neospora caninum, sarcocystis neurona, and sarcocystis canis-like infections in marine mammals. | toxoplasma gondii, neospora caninum, sarcocystis neurona, and s. canis are related protozoans that can cause mortality in many species of domestic and wild animals. recently, t. gondii and s. neurona were recognized to cause encephalitis in marine mammals. as yet, there is no report of natural exposure of n. caninum in marine mammals. in the present study, antibodies to t. gondii and n. caninum were assayed in sera of several species of marine mammals. for t. gondii, sera were diluted 1:25, 1:50 ... | 2003 | 14580799 |
| protective immune response to experimental infection with sarcocystis neurona in 57bl/6 mice. | immunocompetent c57bl/6 mice were infected with sarcocystis neurona merozoites to assess the protective immune response to active infection. using a direct agglutination test, all infected mice seroconverted to s. neurona merozoite antigens by day 14 postinfection (pi). further, mice developed splenomegaly and bilateral symmetrical lymphadenopathy by day 14 pi, which appeared to be resolving by day 28 pi. histologic analysis revealed a marked increase in germinal center formation in the spleen a ... | 2003 | 14627139 |
| epidemiology of sarcocystis neurona infections in domestic cats (felis domesticus) and its association with equine protozoal myeloencephalitis (epm) case farms and feral cats from a mobile spay and neuter clinic. | equine protozoal myeloencephalitis (epm) is a serious neurologic disease in the horse most commonly caused by sarcocystis neurona. the domestic cat (felis domesticus) is an intermediate host for s. neurona. in the present study, nine farms, known to have prior clinically diagnosed cases of epm and a resident cat population were identified and sampled accordingly. in addition to the farm cats sampled, samples were also collected from a mobile spay and neuter clinic. overall, serum samples were co ... | 2003 | 14637026 |
| seroprevalence of antibodies to sarcocystis neurona in equids residing in oklahoma. | a sampling of equids from the state of oklahoma produced an estimate of seroprevalence of antibody to sarcocystis neurona to be about 89.2%. this figure represents the highest currently reported regional seroprevalence of antibody to this organism. regional differences in seroprevalence were found in the western quadrants of the state relative to the eastern quadrants of the state, with a significantly higher seroprevalence in the eastern regions. thoroughbreds were found to exhibit a statistica ... | 2003 | 14667028 |
| reactivity against sarcocystis neurona and neospora by serum antibodies in healthy french horses from two farms with previous equine protozoal myeloencephalitis-like cases. | sarcocystis neurona is considered a leading cause of equine protozoal myeloencephalitis (epm), a common infectious neurological disease in horses in the americas. epm-like cases associated with s. neurona peptide reactive antibodies in western blots were recently described in normandy, france. in this report, antibodies reacting with s. neurona merozoites were detected using an agglutination assay at titers ranging from 50 to 500 in sera from 18/50 healthy horses from two farms with a previous e ... | 2003 | 12523974 |
| immunopathologic effects associated with sarcocystis neurona-infected interferon-gamma knockout mice. | interferon-gamma knockout (ifn-gamma ko) mice were infected with sarcocystis neurona merozoites to characterize the immunopathology associated with infection. by day 14 postinfection (pi), mice developed splenomegaly and lymphadenopathy, characterized by marked lymphoid hyperplasia with increased numbers of germinal centers. additional histopathologic changes included increased extramedullary hematopoiesis, multifocal mixed inflammatory infiltrates in the liver, perivascular infiltrate of the li ... | 2003 | 14627140 |
| purification of sarcocystis neurona sporocysts from opossum (didelphis virginiana) using potassium bromide discontinuous density gradient centrifugation. | this report describes a new, inexpensive procedure for the rapid and efficient purification of sarcocystis neurona sporocysts from opossum small intestine. s. neurona sporocysts were purified using a discontinuous potassium bromide density gradient. the procedure provides a source of sporocyst wall and sporozoites required for reliable biochemical characterization and for immunological studies directed at characterizing antigens responsible for immunological responses by the host. the examined i ... | 2003 | 12756543 |
| pathology of sarcocystis neurona in interferon-gamma gene knockout mice. | pathologic changes were studied in 27 interferon-gamma gene knockout mice 34-54 days after being fed graded doses of sarcocystis neurona sporocysts derived from a naturally infected opossum. the target tissue for s. neurona infection was the central nervous system. characteristic histopathologic changes present in all mice consisted of an inflammatory infiltrate consisting of mostly neutrophils and macrophages, fewer eosinophils, and rare multinucleated giant cells. intralesional protozoa and sc ... | 2002 | 12102206 |
| life cycle of sarcocystis neurona in its natural intermediate host, the raccoon, procyon lotor. | sarcocystis neurona causes encephalomyelitis in many species of mammals and is the most important cause of neurologic disease in the horse. its complete life cycle is unknown, particularly its development and localization in the intermediate host. recently, the raccoon (procyon lotor) was recognized as a natural intermediate host of s. neurona. in the present study, migration and development of s. neurona was studied in 10 raccoons that were fed s. neurona sporocysts from experimentally infected ... | 2002 | 12537110 |