Subject: Time:9:26 PM
OFFICE MEMO Re: Super-selected Flesh Eating .. Date:12/9/94
Just because a bacterium is resistant to antibiotics doesn't necesarily make
it more virulent. The metabolic energy spent in the production of
penicillinases and other mechanisms of resistance is energy that can't be used
for growth-so resistant strains tend to grow more slowly. Virulence is a
complicated subject-it depends not just on the bacterium itself (ie cell
surface proteins that aid in attachment to body sites) but also on the
immunological system of the host. It does seem possible that a resistant
strain could also mutate to a more virulent form. Finally, the new bacterium
also must compete with the established flora of host. Mode of transmission
changing...I dunno. Now we're talking at least three, probably many more
mutations occuring simultaneously. The probability of this is rather low,
though not impossible. Just antibiotic resistance is already a big problem!
These are just a few thoughts..walter may at merck.com
