title: Spiroplasma found in the eyes of scrapie affected sheep.
abstract: OBJECTIVE
  Scrapie, a transmissible spongiform encephalopathy (TSE) occurring naturally in sheep, characteristically shows a severe retinopathy that is well developed in the terminal phases of the disease. In this study, we set out to demonstrate similar retinal changes in our ruminant spiroplasmosis TSE model.
  
  
  METHODS
  The eyes from deer, sheep, and goats that were inoculated intracranially with the laboratory strain of spiroplasma (suckling mouse cataract [SMCA] strain of Spiroplasma mirum) or with Spiroplasma sp. isolated from the brains affected with scrapie or with chronic wasting disease were examined by light microscopy for pathologic changes and by immunocytochemistry for distribution of spiroplasma antigen. The eyes were also obtained from a research flock of sheep with terminal scrapie, from which the intraocular tissues were submitted aseptically for culture assay in M1D broth or as explants on bovine corneal endothelia (BCE).
  
  
  RESULTS
  The eyes from the spiroplasmosis ruminant models showed retinopathy remarkably similar to eye lesions seen in sheep with scrapie. The spiroplasma antigen accrued in the ruminant model eye tissues, particularly in the retina, the vitreous humor, and the corneal endothelia. A Spiroplasma sp. grew out of the scrapie-affected eyes both in the M1D broth and in the BCE cultures but did not expand. These new spiroplasma isolates differed immunologically from SMCA.
  
  
  CONCLUSIONS
  These data showed a clear association of spiroplasma with scrapie suggesting that these bacteria have a role in the pathogenesis of TSE and that the eye should be a research focus for future studies of TSE.
authors.affiliation: Department of Veterinary Science, Louisiana State University Agricultural Center, Baton Rouge, LA, USA. fbastian@agcenter.lsu.edu
authors.forename: Frank O
authors.initials: FO
authors.lastname: Bastian
authors.forename: Charles M
authors.initials: CM
authors.lastname: Boudreaux
authors.forename: Sue D
authors.initials: SD
authors.lastname: Hagius
authors.forename: Marie S
authors.initials: MS
authors.lastname: Bulgin
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Sorensen-Melson
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Enright
authors.forename: Philip H
authors.initials: PH
authors.lastname: Elzer
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005123:Eye / Q000382:microbiology / Q000473:pathology; D019085:Fluorescent Antibody Technique, Direct / Q000662:veterinary; D016905:Gram-Negative Bacterial Infections / Q000150:complications / Q000382:microbiology / Q000662:veterinary*; D008854:Microscopy, Electron / Q000662:veterinary; D012160:Retina / Q000382:microbiology / Q000473:pathology; D012164:Retinal Diseases / Q000150:complications / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D012608:Scrapie / Q000150:complications* / Q000382:microbiology; D012756:Sheep; D013149:Spiroplasma