E. Coli and sickness

SEGAL, DAVID JAY djs1539 at cc.utah.edu
Mon Feb 1 18:05:00 EST 1993

In article <1993Jan27.213929.1300 at mala.bc.ca>, apland at mala.bc.ca writes...
{Hi. I'm a grade 12 biology student.  I am wondering about the effects of E. 
{Coli bacteria injested through uncooked meat. Recently a young child died and 
{tens of others have became ill in Washington State after eating uncooked 
{hamburgers.  The news attributed the illness to E. Coli, but my biology text 
{says that E.Coli is a harmless bacteria found in the colon.  Does this have 
{something to do with the high pH in the colon as apposed to the low pH in the 
{Thanks, Shannon

If you think about human development, we all start out as a single
cell with no stomach or colon.  These things come later.  It 
therefore follows that the E. coli must enter the colon later,
most likely passing through the stomach on the way.  A long 
winded way to say:  I don't think the pH in the stomach has
much to do with the pathogeneisis.  
And actually, I don't know why some E. coli are harmful.
But I think it has to do with differential gene expression.
This could result in different types of surface molocules, 
so that the body mounts a response against it.  It could
also result in toxins being secreted by these E. coli.
This may be due in part to the fact that the E.coli on 
the meat probably come from somewhere not near you, so 
that the bacteria are slightly genetically different, 
and/or it could be due to the aerobic living conditions
it "enjoys" on the the outside of the meat, as opposed
to the anaerobic conditions inside your colon.

But remember, this is only my yack.
I really don't know.

- Dave Segal
- Biochemistry, U. of Utah

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