Hello, my name is Scott and I am a graduate student at the
University of North Dakota. Our current seminar topic of the semester is
emerging infectious diseases, and a few things have caught my attention.
The topics chosen have been on (and will in some way deal with)
treatment, specifically chemotheraputic control (e.g., antibiotics,
metabolic structural analogues, etc.). I am hoping that those reading
this post can give me some information or point me in the right
direction.
In a nutshell I'm am interested in the incorporation of
Darwinian ideals into current medical thinking (an idea presented in the
Quaterly Review of Biology, vol 66 no.1 by Williams and Nesse). So far
two of the presentaions have dealt with antibiotic resistance. For example,
Enterococcus
is showing widespread resistance to vanomycin. One of my questions is
this: If a population of vancomycin resistant cells were selected for by
vancomycin treatment, and then the selective pressure of vancomycin was
removed, would it be resonable to believe that a population of vancomycin
sensitive cells would eventually outcompete and re-establish itself? As
I understand vancomycin resistance is encoded by about 6 genes. There
must be an energy cost in maintaining these genes (paid for in ATP,
etc.). A cost that sensitive cells do not have to pay. This may be a
bad example since (if I understood the presenter correctly) vancomycin
can be inserted stably onto the chromosome through transposition, and
more importantly that this set of genes is inducible (less energy
maintainence). But there are other antibiotic resistance examples that
are not so dramatic. Do these type of reversions usually occur? If the
medical community were to completely "black out" the use of certain
antibiotics in predetermined areas for a period of time could it be
possible to re-establish non-resistant strains? I know that this is a
bit simplistic, and there are probably a million inherent problems.
World travel doesn't lend itself well either, the spread of disease and
antibiotic resistance is a factor. But I could see the possible benefits
to nocosomial infections.
Are there other ways to incorporate evolutionary thought into
medical microbiology? If anyone could please send me your thoughts but
more importantly the names and locations of articles with experiments and
data that might be helpful from the evolutionary standpoint. My
presentaion will be on a virus (a big leap from bacteria I know)
and any information there would be appreciated. Please e-mail me at
schoffma at badlands.nodak.edu or feel free to post answers at this site.
Thanks in advance.
