HELP ! An obscure intracellular agent - a new bacterium ?

[Enevold.Falsen at alinks.se]

I have isolated an infectious agent  growing on different cell  
lines (from human fibroblasts to insect cell lines) with 
induction of a cytopathic effect visable as swollen and rounded 
cells before lysis. The cell culture medium is clear and looks 
not infected. The agent is possible to transfer to a new culture 
and a complete cytopathic effect appears within 5-7 days. Very 
few infectious particles are possible to identify in the cell 
culture medium and  they are trapped in a 200 nm big membrane 
filter. The agent grows at 16-50 centigrades. The growth is 
inhibited by ribavirin, foscarnet (antiviral drugs) and also 
acriflavine (an antibiotic for fungi infections). The 
infectiousity is abolished by chloroform treatment. In 
electronmicroscope on fixed  human fibroblasts I have been unable 
to identify any organism. In an infected cell culture I identify 
an extra  single stranded RNA band 2500 bases long when a RNA 
preparation was done. No extra DNA band was visible. Gen-ProbeR 
hybridization for Mycoplasma is negative.
I suspect an intracellular bacteria or fungi but a virus can 
not  be excluded completely.
My questions are:
Can anybody give a proposal how to distinguish between virus and 
bacteria ?
What different bacteria can you suspect?
What experiments can solve the problem? Antibiotics?
 
 Jan ]ke Liljeqvist
 Dept of Clinical Virology
 University of Goteborg
 Fax: +46.31.60 49 60
 E-mail: ccugef at ccug.gu.se (or as above)