biological characterisation of sarcocystis neurona isolated from a southern sea otter (enhydra lutris nereis). | sarcocystis neurona was isolated from the brain of a juvenile, male southern sea otter (enhydra lutris nereis) suffering from cns disease. schizonts and merozoites in tissue sections of the otter's brain reacted with anti-s. neurona antiserum immunohistochemically. development in cell culture was by endopolyogeny and mature schizonts were first observed at 3 days postinoculation. pcr of merozoite dna using primer pairs jnb33/jnb54 and restriction enzyme digestion of the 1100 bp product with dra ... | 2000 | 10779575 |
a review of sarcocystis neurona and equine protozoal myeloencephalitis (epm). | equine protozoal myeloencephalitis (epm) is a serious neurological disease of horses in the americas. the protozoan most commonly associated with epm is sarcocystis neurona. the complete life cycle of s. neurona is unknown, including its natural intermediate host that harbors its sarcocyst. opossums (didelphis virginiana, didelphis albiventris) are its definitive hosts. horses are considered its aberrant hosts because only schizonts and merozoites (no sarcocysts) are found in horses. epm-like di ... | 2001 | 11223193 |
myocarditis and encephalitis associated with sarcocystis neurona infection in raccoons (procyon lotor). | sarcocystis neurona associated granulomatous encephalitis was found in 2 of 84 adult raccoons. both raccoons also had an extensive nonsuppurative myocarditis and one had s. neurona schizonts and merozoites in the myocardium. only the asexual stages (schizonts and merozoites) of s. neurona are found in tissues of naturally infected animals (horse, mink, raccoons, cats, skunk, pony, seals, sea otters) and since these have not been reported outside the central nervous system, the presence of concur ... | 2001 | 11223214 |
dual sarcocystis neurona and toxoplasma gondii infection in a northern sea otter from washington state, usa. | dual sarcocystis neurona and toxoplasma gondii infection was observed in a northern sea otter from washington, usa. the animal was found stranded, convulsed, and died shortly thereafter. encephalitis caused by both s. neurona and t. gondii was demonstrated in histological sections of brain. immunohistochemical examination of sections with s. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. pcr of brain tissue from the sea ... | 2001 | 11390085 |
sarcocystis neurona infections in sea otter (enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (didelphis virginiana). | although sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. here, sarcocysts from 2 naturally infected sea otters (enhydra lutris) were characterized biologically, ultrastructurally, and genetically. dna was extracted from frozen muscle of the first of these sea otters and was characterized as s. neurona by polymerase chain reation (pcr) amplification followed by restriction fragment length p ... | 2001 | 11780826 |
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 |
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 |
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 |
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 |
strains of sarcocystis neurona exhibit differences in their surface antigens, including the absence of the major surface antigen snsag1. | a gene family of surface antigens is expressed by merozoites of sarcocystis neurona, the primary cause of equine protozoal myeloencephalitis (epm). these surface proteins, designated snsags, are immunodominant and therefore excellent candidates for development of epm diagnostics or vaccines. prior work had identified an epm isolate lacking the major surface antigen snsag1, thus suggesting there may be some diversity in the snsags expressed by different s. neurona isolates. therefore, a bioinform ... | 2008 | 17980881 |
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 |
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 |
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 |
prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system. | the processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. by combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (enhydra lutris nereis) population growth: disease and resource limitation. this threatened population has struggled to recover despite protection, so we followed radio-tagged se ... | 2009 | 19164513 |
enteric bacterial pathogen detection in southern sea otters (enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff. | although protected for nearly a century, california's sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like toxoplasma gondii and sarcocystis neurona. however, potential impacts from exposure to fecal bacteria have not been systematically explored. using selective media, we examined feces from live and dead sea otters from california for specific enteric bacterial pathogens (campylobacter, salmonella, clostridium perfringens, c. difficile an ... | 2010 | 19720009 |
limited genetic diversity among sarcocystis neurona strains infecting southern sea otters precludes distinction between marine and terrestrial isolates. | sarcocystis neurona is an apicomplexan parasite identified as a cause of fatal neurological disease in the threatened southern sea otter (enhydra lutris nereis). in an effort to characterize virulent s. neurona strains circulating in the marine ecosystem, this study developed a range of markers relevant for molecular genotyping. highly conserved sequences within the 18s ribosomal gene array, the plastid-encoded rna polymerase (rpob) and the cytochrome c oxidase subunit 1 mitochondrial gene (co1) ... | 2010 | 20071081 |
molecular characterization of sarcocystis neurona strains from opossums (didelphis virginiana) and intermediate hosts from central california. | sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened southern sea otter (enhydra lutris nereis). opossums (didelphis virginiana), the only known definitive hosts for s. neurona in north america, are an introduced species in california. s. neurona dna isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 southern sea otters, and 1 harbor porpoise (phocoena phocoena) with natural infections was analy ... | 2010 | 20226596 |
self-mating in the definitive host potentiates clonal outbreaks of the apicomplexan parasites sarcocystis neurona and toxoplasma gondii. | tissue-encysting coccidia, including toxoplasma gondii and sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. during its sexual life stage, t. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. ... | 2010 | 21203443 |
sarcocystis neurona retinochoroiditis in a sea otter (enhydra lutris kenyoni). | sarcocystis neurona is an important cause of fatal disease in sea otters in the usa. encephalitis is the predominant lesion and parasites are confined to the central nervous system and muscles. here we report retinochoroiditis in a sea otter (enhydra lutris kenyoni) found dead on copalis beach, wa, usa. salient lesions were confined to the brain and eye. multifocal nonsuppurative meningoencephalitis was present in the cerebrum and cerebellum associated with s. neurona schizonts. the retina of on ... | 2011 | 21782345 |
assessment of clinical pathology and pathogen exposure in sea otters (enhydra lutris) bordering the threatened population in alaska. | northern sea otter (enhydra lutris kenyoni) abundance has decreased dramatically over portions of southwest alaska, usa, since the mid-1980s, and this stock is currently listed as threatened under the endangered species act. in contrast, adjacent populations in south central alaska, usa, and russia have been stable to increasing during the same period. sea otters bordering the area classified in the recent decline were live-captured during 2004-2006 at bering island, russia, and the kodiak archi ... | 2011 | 21719822 |
a protozoal-associated epizootic impacting marine wildlife: mass-mortality of southern sea otters (enhydra lutris nereis) due to sarcocystis neurona infection. | during april 2004, 40 sick and dead southern sea otters (enhydra lutris nereis) were recovered over 18km of coastline near morro bay, california. this event represented the single largest monthly spike in mortality ever recorded during 30 years of southern sea otter stranding data collection. because of the point-source nature of the event and clinical signs consistent with severe, acute neurological disease, exposure to a chemical or marine toxin was initially considered. however, detailed post ... | 2010 | 20615616 |
pathogen exposure and blood chemistry in the washington, usa population of northern sea otters (enhydra lutris kenyoni). | northern sea otters (enhydra lutris kenyoni) from washington state, united states were evaluated in 2011 to determine health status and pathogen exposure. antibodies to brucella spp. (10%) and influenza a virus (23%) were detected for the first time in this population in 2011. changes in clinical pathology values (serum chemistries), exposure to pathogens, and overall health of the population over the last decade were assessed by comparing 2011 data to the data collected on this population in 20 ... | 2013 | 24502716 |
detection and characterization of diverse coccidian protozoa shed by california sea lions. | tissue-cyst forming coccidia in the family sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed southern sea otter (enhydra lutris). california sea lions (zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named coccidia a, b and c. while coccidia a and b have unknown clinical effects on aquatic wildlife hosts, coccidia c is associated with severe protozoal dis ... | 2016 | 27141438 |
california mussels (mytilus californianus) as sentinels for marine contamination with sarcocystis neurona. | sarcocystis neurona is a terrestrial parasite that can cause fatal encephalitis in the endangered southern sea otter (enhydra lutris nereis). to date, neither risk factors associated with marine contamination nor the route of s. neurona infection to marine mammals has been described. this study evaluated coastal s. neurona contamination using california mussels (mytilus californianus) as sentinels for pathogen pollution. a field investigation was designed to test the hypotheses that (1) mussels ... | 2016 | 27003262 |
dual congenital transmission of toxoplasma gondii and sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (enhydra lutris nereis). | toxoplasma gondii and sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. close monitoring of threatened southern sea otters (enhydra lutris nereis) in california allowed for the diagnosis of dual transplacental transmission of t. gondii and s. neurona in a wild female otter that was chronically infected with both parasites. congenital infection resulted in late-term abortion due to dissemina ... | 2016 | 26494610 |
sarcocyst development in raccoons (procyon lotor) inoculated with different strains of sarcocystis neurona culture-derived merozoites. | sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (epm), a neurological disease in horses. raccoon ( procyon lotor ) is considered the most important intermediate host in the life cycle of s. neurona in the united states; s. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating epm. the focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different ... | 2015 | 25811893 |
an update on sarcocystis neurona infections in animals and equine protozoal myeloencephalitis (epm). | equine protozoal myeloencephalitis (epm) is a serious disease of horses, and its management continues to be a challenge for veterinarians. the protozoan sarcocystis neurona is most commonly associated with epm. s. neurona has emerged as a common cause of mortality in marine mammals, especially sea otters (enhydra lutris). epm-like illness has also been recorded in several other mammals, including domestic dogs and cats. this paper updates s. neurona and epm information from the last 15 years on ... | 2015 | 25737052 |
sarcocystis neurona infection in gamma interferon gene knockout (ko) mice: comparative infectivity of sporocysts in two strains of ko mice, effect of trypsin digestion on merozoite viability, and infectivity of bradyzoites to ko mice and cell culture. | the protozoan sarcocystis neurona is the primary cause of equine protozoal myeloencephalitis (epm). epm or epm-like illness has been reported in horses, sea otters, and several other mammals. the gamma interferon gene knockout (ko) mouse is often used as a model to study biology and discovery of new therapies against s. neurona because it is difficult to induce clinical epm in other hosts, including horses. in the present study, infectivity of three life cycle stages (merozoites, bradyzoites, sp ... | 2013 | 23375195 |
temporal association between land-based runoff events and california sea otter (enhydra lutris nereis) protozoal mortalities. | toxoplasma gondii and sarcocystis neurona have caused significant morbidity and mortality in threatened southern sea otters (enhydra lutris nereis) along the central california coast. because only terrestrial animals are known to serve as definitive hosts for t. gondii and s. neurona, infections in otters suggest a land to sea flow of these protozoan pathogens. to better characterize the role of overland runoff in delivery of terrestrially derived fecal pathogens to the near shore, we assessed t ... | 2012 | 22493114 |
prevalence and risk factors associated with sarcocystis neurona infections in opossums (didelphis virginiana) from central california. | sarcocystis neurona, a protozoal parasite shed by opossums (didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. over the course of 3 years (fall 2005-summer 2008), opossums from central california were tested for infection with s. neurona. of 288 opossums sampled, 17 (5.9%) were infected with s. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. risk factors evaluated fo ... | 2009 | 19735983 |
ultrastructural and molecular confirmation of the development of sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (enhydra lutris nereis). | in 2004, three wild sea otters were diagnosed with putative sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. tissue cysts walls from sea otter 1 (so1) stained positively using anti-s. neurona polyclonal antiserum. however, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. two ... | 2009 | 19527725 |
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 |
encephalomyelitis associated with a sarcocystis neurona-like organism in a sea otter. | an adult female sea otter housed for 5 years in an outdoor habitat in an aquarium developed signs of neurologic disease. bilateral caudal paresis was evident initially and other neurologic signs consistent with cns disease developed rapidly. diagnostic work-up included cbc, serum biochemical analyses, determination of serum antibody titers, radiography of the vertebral column, csf analysis, muscle biopsy, computed tomography of the brain, and assays for mercury, lead, and thiamine. a tentative d ... | 1999 | 10613219 |