The striped skunk (Mephitis mephitis) is an intermediate host for Sarcocystis neurona

Striped skunks, initially negative for antibodies to Sarcocystis neurona, f ormed sarcocysts in skeletal muscles after inoculation with S. neurona spor ocysts collected from a naturally infected Virginia opossum (Didelphis virg iniana). Skunks developed antibodies to S, neurona by immunoblot and muscle s containing sarcocysts were fed to laboratory-reared opossums which then s hed sporulated Sarcocystis sporocysts in their faeces. Mean dimensions for sporocysts were 11.0 x 7.5 mum and each contained four sporozoites and a re siduum. Sarcocysts from skunks and sporocysts from opossums fed infected sk unk muscle were identified as S. neurona using PCR and DNA sequence analysi s. A 2-month-old. S, neurona-naive pony foal was orally inoculated with 5 x 10(5) sporocysts. Commercial immunoblot for antibodies to S. neurona perfo rmed using CSF collected from the inoculated pony was low positive at 4 wee ks p.i.. positive at 6 weeks p.i., and strong positive at 8 weeks p.i. Gamm a-interferon gene knockout mice inoculated with skunk/opossum derived sporo cysts developed serum antibodies to S. neurona and clinical neurologic dise ase. Merozoites of S. neurona present in the lung, cerebrum, and cerebellum of mice were detected by immunohistochemistry using polyclonal antibodies to S. neurona. Based on the results of this study, the striped skunk is an intermediate host of S. neurona. (C) 2001 Australian Society for Parasitolo gy Inc. Published by Elsevier Science Ltd. All rights reserved.