Actually I have worked with mycoplasmas for years in conjunction with Dr.
Gail Cassell and do know alot about this and other work. (Although we are
not infallible, I think if you do a Medline search on our group and others
working with mycoplasmas at UAB that you'll find that we do know alot
about biology of mycoplasmas and pathogenesis of disease.) Personally, I
am involved in studies using Mycoplasma fermentans strain incognitus as
well as other strains of M. fermentans. I am also in contact with groups
that are addressing the potential of Mycoplasmas' role in Gulf War
Syndrome, AIDS and arthritis.
The suggestion that mycoplasmas are being genetically engineered as
biologic warfare agents seems very far-fetched. The fact is that
mycoplasmas cannot be genetically altered to any great extent. Alot of
time and money has be put forth to do this with limited success, by many
groups (and efforts are still being put forward). There was one group who
look like they were able to put genes back into mycoplasmas, but it turned
out (with independent confirmation and agreement with the original
authors) that they were not working with mycoplasmas but with a related
group of organisms, Acholeplasma. Acholeplasma has a normal genetic code
and can be readily be transformed which is in contrast with Mycoplasmas.
Some of the problems with genetic manipulation of mycoplasmas stems from
the mycoplasma's desire to delete and rearrange extrachromosomal and
chromosomal genetic material introduced into them. On the other hand,
deletion of genes in mycoplasma is possible through transposon mutagenesis
or possibly through homologous recombination using integrative plasmids.
Codon usage and altered genetic code is also a problem. The field of
genetic manipulation of mycoplasma is still in its infancy, and even with
unlimited funds, there are some fundamental technical hurdles that need to
be addressed.
It turns our that Mycoplasma incognitus is really a strain of Mycoplasma
fermentans. Mycoplasma incognitus was "discovered" by Dr. Shy Lo. If you
carefully read the literature on this organism, it was supposedly isolated
from a Kaposi's sarcoma and originally called a virus-like organism. Dr.
Lo extracted DNA from a Karposi's sarcoma and "transduced" another cell
line. He recovered from this cell line this virus-like organism which was
later characterized as Mycoplasma incognitus. Later studies by multiple
groups demonstrated that this organism was not a new mycoplasma but
Mycoplasma fermentans - this is the correct name of this organism.
Mycoplasma fermentans is a common cell culture contaminate. So, the most
likely explanation of the above results, unless you want to claim that
prokaryotic DNA can be transduced into eukaryotic cells to reproduce
itself, is that Mycoplasma fermentans strain incognitus was originally a
cell culture contaminant.
Dr. Lo did, however, demonstrate by using a probe against this organism
that this organism can be associated with systemic infection/disease in
man. In subsequent studies, Dr. Lo did take this organism and infected
monkeys, and they became sick. At the time, we found that these results
were promising. However, other groups, and I understand even Dr. Lo, have
tried to repeat those studies with no avail. The monkeys did not get sick.
The reasons for the failure to repeat those original studies are unclear,
but it is possible that the original group of monkeys may have had some
underlying condition that contributed to the effects seen. Presently, we
do not know. Earlier studies using murine (immunocompetent mice)
infections with M. fermentans do demonstrate that given high doses of
organisms intravenously results in effects in bone marrow and systemic
toxicity. So, it is possible that disease can result from this group of
organisms once the systemic compartment is reached. This effect is strain
and dose dependent, and the host's genetic background plays a role.
Although Mycoplasma fermentans may be associated with some illnesses in
some "normal" individuals, a cause-effect relationship and their incidence
has not yet been clearly demonstrated. One confusing aspect of this area
is that healthy individuals do carry this organism which is probably why
so many cell cultures do get contaminated with this organism (researchers
inadvertantly infect these cultures). So, if you don't consider what's in
the normal population, an association between the disease and this
organism is hard to demonstrate in the normal population. Work still needs
to be done on this area.
Most importantly for this current discussion, it is also known that
mycoplasmas can infect systemically in immunocompromised individuals (AIDS
and immunodeficiency patients) and animals. The effects from this appears
to range from nothing to arthritis to lesions in systemic organs.
Furthermore, my understanding via CNN (you can judge the reliability of
this source) is that, in all likelihood, troops did get exposed to
chemical or biologic agents - despite the official government line. I'll
admit that I'm not an expert in biologic or chemical warfare, but I'll bet
that the _known_ common toxins or chemicals used for these purposes have
an immunodepressive effect in exposed individuals and/or disrupt the
normal mucosal barrier. So if personnel in the Gulf War were exposed to
these agents, perhaps some of the symptoms could be explained by
infections secondary to the primary insult. Some individuals may develop
systemic infections due to mycoplasmas and other "normal" flora. The
symptoms resulting from these systemic infections would be real and should
be treatable. This is important, especially to those suffering from these
illnesses. Nevertheless, this explanation would not entail anyone using
Mycoplasma fermentans strain incognitus as a biological warfare agent and
would be consistent with known facts of the biology of mycoplasma,
pathogenesis of mycoplasma diseases and many, but not all, of the
observations in Gulf War Syndrome patients.
As I stated in my first posting, I believe that any claims of mycoplasmas
as _the_ cause of Gulf War Syndrome is premature. Other agents and effects
should be considered, including primary insult by toxins and other
infectious agents. Even other organisms from normal flora may contribute
to the Syndrome. In the meantime, if physicians can treat groups of
patients with GWS with antibiotics and they produce relief, that is
terrific whether this is due to effects on mycoplasmas or other infectious
or toxic agents. However, proof of mycoplasmas role in GWS may be a long
time coming.
Jerry W. Simecka
Department of Microbiology
University of Alabama at Birmingham