Spongiform diseases - is the causative agent a spiroplasma?

[WasGross]

Thank you for your response. How are these  organisms identified? Are they
visible on special stains or only on electron microscopy?  I am familiar with
mycoplasms and ureoplasms .Are Spiroplasms in a spiral shape? Are these
organisms filterable? I have seen Ureoplasma s grow on routine media once. It
would not gram stain. It was from an amniotic fluid culture and did have
Ureoplasmas. Is it possible to grow Spiroplasms on routine media if held long
enough? Do these organisms produce or consume gas? Very interesting. Thank you,
again.
                                   Donna