title: A novel Sarcocystis neurona genotype XIII is associated with severe encephalitis in an unexpectedly broad range of marine mammals from the northeastern Pacific Ocean.
abstract: Sarcocystis neurona is an important cause of protozoal encephalitis among marine mammals in the northeastern Pacific Ocean. To characterise the genetic type of S. neurona in this region, samples from 227 stranded marine mammals, most with clinical or pathological evidence of protozoal disease, were tested for the presence of coccidian parasites using a nested PCR assay. The frequency of S. neurona infection was 60% (136/227) among pinnipeds and cetaceans, including seven marine mammal species not previously known to be susceptible to infection by this parasite. Eight S. neurona fetal infections identified this coccidian parasite as capable of being transmitted transplacentally. Thirty-seven S. neurona-positive samples were multilocus sequence genotyped using three genetic markers: SnSAG1-5-6, SnSAG3 and SnSAG4. A novel genotype, referred to as Type XIII within the S. neurona population genetic structure, has emerged recently in the northeastern Pacific Ocean and is significantly associated with an increased severity of protozoal encephalitis and mortality among multiple stranded marine mammal species.
authors.affiliation: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Barbosa
authors.affiliation: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Christine K
authors.initials: CK
authors.lastname: Johnson
authors.affiliation: Department of Fish and Wildlife, Olympia, WA 98501, USA.
authors.forename: Dyanna M
authors.initials: DM
authors.lastname: Lambourn
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA.
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Gibson
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA; University of British Columbia, Department of Zoology, Fisheries Centre, Marine Mammal Research Unit, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Katherine H
authors.initials: KH
authors.lastname: Haman
authors.affiliation: Cascadia Research Collective, Olympia, WA 98501, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Huggins
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Sweeny
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Sundar
authors.affiliation: University of British Columbia, Department of Zoology, Fisheries Centre, Marine Mammal Research Unit, Vancouver, British Columbia V6T 1Z4, Canada; Animal Health Center, Ministry of Agriculture, Abbotsford, British Columbia V3G 2M3, Canada.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Raverty
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD 20892, USA; University of British Columbia, Department of Zoology, Fisheries Centre, Marine Mammal Research Unit, Vancouver, British Columbia V6T 1Z4, Canada. Electronic address: griggm@niaid.nih.gov.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Grigg
mesh_terms: D000818:Animals; D010872:Caniformia; D002591:Cetacea; D004660:Encephalitis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D005838:Genotype; D010140:Pacific Ocean; D012522:Sarcocystis / Q000145:classification / Q000235:genetics*; D012523:Sarcocystosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*
keywords: Coccidia; Encephalitis; Genotype; Marine mammal; Parasite; Protozoal disease; Sarcocystis neurona; SnSAG