title: California mussels (Mytilus californianus) as sentinels for marine contamination with Sarcocystis neurona.
abstract: 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 can serve as sentinels for S. neurona contamination, and (2) S. neurona contamination in mussels would be highest during the rainy season and in mussels collected near freshwater. Initial validation of molecular assays through sporocyst spiking experiments revealed the ITS-1500 assay to be most sensitive for detection of S. neurona, consistently yielding parasite amplification at concentrations ⩾5 sporocysts/1 mL mussel haemolymph. Assays were then applied on 959 wild-caught mussels, with detection of S. neurona confirmed using sequence analysis in three mussels. Validated molecular assays for S. neurona detection in mussels provide a novel toolset for investigating marine contamination with this parasite, while confirmation of S. neurona in wild mussels suggests that uptake by invertebrates may serve as a route of transmission to susceptible marine animals.
authors.affiliation: Pathology, Microbiology and Immunology Department,School of Veterinary Medicine, University of California Davis,One Shields Avenue,Davis, CA 95616,USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Michaels
authors.affiliation: Center for Animal Health and Food Safety,School of Veterinary Medicine, University of California Davis,One Shields Avenue,Davis, CA 95616,USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rejmanek
authors.affiliation: Pathology, Microbiology and Immunology Department,School of Veterinary Medicine, University of California Davis,One Shields Avenue,Davis, CA 95616,USA.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Aguilar
authors.affiliation: Pathology, Microbiology and Immunology Department,School of Veterinary Medicine, University of California Davis,One Shields Avenue,Davis, CA 95616,USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Conrad
authors.affiliation: Pathology, Microbiology and Immunology Department,School of Veterinary Medicine, University of California Davis,One Shields Avenue,Davis, CA 95616,USA.
authors.forename: Karen
authors.identifier: 0000-0003-2678-3851
authors.initials: K
authors.lastname: Shapiro
mesh_terms: D000818:Animals; D002140:California; D004784:Environmental Monitoring / Q000379:methods*; D049878:Mytilus / Q000469:parasitology*; D015203:Reproducibility of Results; D012522:Sarcocystis / Q000502:physiology*; D012621:Seasons; D012680:Sensitivity and Specificity; D000072739:Sentinel Species / Q000469:parasitology*
keywords: California mussels (Mytilus californianus); Detection; Haemolymph; Marine; Sarcocystis neurona; Sea otters (Enhydra lutris nereis); Sporocysts