Anecdotally, there have been many reports of small viral-like particles
among the protozoa, like Leishmania; the little I've seen about these
suggest that even these lacked complete or normal viral-type genomes; I
think attempts to identify such a virus at SF led to the first useful
parasitic protozoan ORI/transfection system (Beverley's). However, the
extrachromosomal DNA's of protists tend not to be of viral origin. Perhaps
because we can't plate a lawn of protists to see lytic plaques, detecting
viruses in protists including fungi, seems to be a repeatedly expected but
still absent finding. Viruses are common in the ocean and elsewhere, but
only the major viral pathogens of mammals and bacterial symbionts of mammals
have been sequenced, except for Baculovirus and other exceptions.
Bacterial endosymbionts are common, although to date, little analyzed. If
you're looking for a transfection system, perhaps bacteria can be made to
work. However, limited EST, uneven PCR, or genome sequencing could also
discover the necessary genetic features. In terms of viral killing of
protists as a therapy, I doubt putative viruses or endosymbiotic bacteria
could survive long enough to catch the protists in the mammalian host.
At 04:32 PM 4/7/98 -0400, David S. Lindsay wrote:
>>Are there any viruses that infect parasites and cause damage? I can't
>think of any that infect protozoan parasites.
>>David S. Lindsay
>>Gerald McLaughlin, Ph.D.
Dept Pathology & Laboratory Medicine
Indiana University School of Medicine
635 Barnhill Drive, MS A128
Indianapolis, IN 46202-5120
E-mail: gmclaugh at iupui.edu
Ph 317-274-2651; pager 275-5000, I.D. #2916