Spiroplasma as a candidate agent for the transmissible spongiform encephalopathies.

The recovery of a novel Spiroplasma sp. from brain tissues from sheep with scrapie, cervids with chronic wasting disease, and from patients with Creutzfeldt-Jakob disease through passage through embryonated eggs has raised the issue of the role of Spiroplasma in the transmissible spongiform encephalopathies (TSE). In this review, we have inserted into an epidemiologic infection model evidence accumulated over the past 30 years showing involvement of Spiroplasma infection in TSE. These data support our hypothesis that a Spiroplasma sp. is the causal agent of TSE, although Koch's postulates must be fulfilled to definitively answer that question.