[extropy-chat] magic johnson, aids, longevity ...

[Robert Bradbury]

Related to the discussion of resistance is an article in the NY Times today
[1] discussing the development of Salmonella infections in humans which may
be antibiotic resistant.  These bacteria are theorized to be the product of
fish farm overuse of antibiotics in SE Asia leading to resistant salmonella
in aquarium fish leading to human transfer.  They may have 5 resistance
genes to various types of antibiotics.  A more general information source is
[2].

This raises one point that should be made with respect to antibacterial
cocktails vs. viral cocktails.  Viruses, for the most part, have extremely
compact genomes.  They do not easily add genes to bypass or eliminate drugs
being used to prevent their replication.  Bacteria on the other hand are
quite comfortable adding genes because they don't have the genome size
constraints that viruses do.  So evolving resistance in viruses generally
means that you have to mutate the existing genome (and not break anything in
the process) while evolving resistance in bacteria simply means that you
have to incorporate resistance genes that may have evolved long ago in the
environment.  Mind you bacteria tend to have defenses against incorporating
foreign DNA (as defenses against bacteriophages) but once those have been
worked around there is little selection pressure for bacteria to lose genes
which may be useful in some particular environment.  So the long term
evolutionary path for bacteria is to develop and spread antibiotic
resistance at a much higher rate than viruses will be able to manage.

Robert

1. "Nemo Beware: Fish Tank Can Be a Haven for Salmonella"
http://www.nytimes.com/2006/04/18/health/18cons.html
2. Alliance for the Prudent Use of Antibiotics
http://www.tufts.edu/med/apua/
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