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 analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums.
Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. drejmanek@ucdavis.edu
Daniel
D
Rejmanek
Melissa A
MA
Miller
Michael E
ME
Grigg
Paul R
PR
Crosbie
Patricia A
PA
Conrad
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D002140:California / Q000453:epidemiology; D003247:Conservation of Natural Resources; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D009893:Opossums / Q000469:parasitology*; D010041:Otters / Q000469:parasitology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011110:Polymorphism, Genetic / Q000235:genetics*; D012522:Sarcocystis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012523:Sarcocystosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D021903:DNA, Ribosomal Spacer