I've thought this same thing for a long time. These different bacterias harm humans so much, but leave dogs, cats, etc. relatively unharmed, and all because we've sterilized our food to the point of intolerence.

One set of my grandparents made their living from their large farm.  My cousin and I spent part of our summers visiting them (I lived many states away) and no family member ever got ill while visiting, nor were either of my grandparents ever sick.  They didn't even have a refridgerator!  They had an "icebox."  Otherwise food was stored in a root cellar, home canned, or in the case of beef, there was the meat locker "in town."  Neighbors were spread far and wide, but they had frequent picnics.  The family hosting would provide usually the meat to be cooked out, while others brought dishes prepared at home.  I don't recall even one instance of anybody being sick from food served at those gatherings, and believe me, with all the work to be done on a farm daily, if anyone was ill, we'd have known it.  There was the occasional childbbirth or accident, and immediately neighbors would see to it that livestock were tended, and if crops needed anything, that would be handled as well.  But no food bourne illness that I can ever recall!  The soaps were simple.  None of today's "disinfect your kitchen surface" spray on products.  BTW, that grandfather lived to be a healthy 103 yr old.  So at the age of 103, he fell, broke his hip, was hospitalized for a couple of days.  Decided he wanted out of there and talked an orderly into helping him into a corset.  Then he put on his clothes, boots and all and walked out of that hospital on his own.  He passed on quickly, peacefully on his way to his pickup truck parked in the hospital parking lot!  (He had somehow managed to get to his truck and drive himself into town after that fall.  I don't think they make 'em, meaning grandfathers, like they used to!)  Never got ill at either grandparents' home.  We ate differently in those days but lived without the modern conveneinces of freezers and food storage containers, disinfectants.  Food was never irradiated, etc. 

We managed quite well without genetically engineered crops, too.  Check out the latest on corn and our aquatic ecosystems.  (sorry, bit off topic)
http://www.sciencedaily.com/releases/2007/10/071008171030.htm

db is back!!

All is right with the world again.......except for all the poisonous cr*p from afar