title: Concentration and retention of Toxoplasma gondii surrogates from seawater by red abalone (Haliotis rufescens).
abstract: Small marine snails and abalone have been identified as high- and low-risk prey items, respectively, for exposure of threatened southern sea otters to Toxoplasma gondii, a zoonotic parasite that can cause fatal encephalitis in animals and humans. While recent work has characterized snails as paratenic hosts for T. gondii, the ability of abalone to vector the parasite has not been evaluated. To further elucidate why abalone predation may be protective against T. gondii exposure, this study aimed to determine whether: (1) abalone are physiologically capable of acquiring T. gondii; and (2) abalone and snails differ in their ability to concentrate and retain the parasite. Abalone were exposed to T. gondii surrogate microspheres for 24 h, and fecal samples were examined for 2 weeks following exposure. Concentration of surrogates was 2-3 orders of magnitude greater in abalone feces than in the spiked seawater, and excretion of surrogates continued for 14 days post-exposure. These results indicate that, physiologically, abalone and snails can equally vector T. gondii as paratenic hosts. Reduced risk of T. gondii infection in abalone-specializing otters may therefore result from abalone's high nutritional value, which implies otters must consume fewer animals to meet their caloric needs.
authors: Department of Ecology and Evolutionary Biology,Princeton University,Princeton, NJ 08544,USA.
authors: Kristen C
authors: KC
authors: Schott
authors: Department of Pathology, Microbiology and Immunology,School of Veterinary Medicine, University of California-Davis,Davis, CA 95616,USA.
authors: Colin
authors: C
authors: Krusor
authors: Long Marine Laboratory,U.S. Geological Survey, Western Ecological Research Center,100 Shaffer Road,Santa Cruz,CA 95060,USA.
authors: M Tim
authors: MT
authors: Tinker
authors: California Department of Fish and Wildlife and UC Davis-Bodega Marine Laboratory,PO Box 247, Bodega Bay,CA 94923,USA.
authors: James
authors: J
authors: Moore
authors: Department of Pathology, Microbiology and Immunology,School of Veterinary Medicine, University of California-Davis,Davis, CA 95616,USA.
authors: Patricia A
authors: PA
authors: Conrad
authors: Department of Pathology, Microbiology and Immunology,School of Veterinary Medicine, University of California-Davis,Davis, CA 95616,USA.
authors: Karen
authors: 0000-0003-2678-3851
authors: K
authors: Shapiro
mesh_terms: D000818:Animals; D004199:Disease Vectors; D005243:Feces / Q000469:parasitology; D049851:Gastropoda / Q000469:parasitology*; D059208:Parasite Load; D012623:Seawater / Q000469:parasitology*; D012908:Snails / Q000469:parasitology; D014122:Toxoplasma / Q000254:growth & development* / Q000302:isolation & purification
keywords: 
                 Toxoplasma gondii
              ; abalone; marine snails; oocysts; sea otter; surrogates; transmission