Some Harsh Facts About E. Coli
by Ridge Shinn

E. coli is a naturally occurring bacterium that lives in the lower intestines of mammals, and most strains are not harmful to people. However, there is a particularly virulent strain (E. coli O157:H7) that is dangerous to human health.

We all have heard about meat recalls and outbreaks that actually kill people, including the recent media reports concerning tainted spinach. Some people are theorizing that this spinach was infected with E. coli by exposure to animal manure or human manure (for example, feces from farm workers).

E. coli outbreaks are often linked to meats or meat products that are improperly cooked. Meat can be accidentally contaminated by E. coli in the slaughter process or by contamination of meat by manure from harvested animals that contains the E. coli.

What is the biology of this syndrome? Although E. coli naturally lives in the gut of all bovines, it needs an acidic environment to proliferate. The normal pH of a healthy rumen (digestive tract of the bovine) is basic in a range from 6.2 to 6.5.

However, most cattle in this country spend their final days in feedlots eating food that includes substantial amounts of grain. This diet causes an acid environment in the rumen called acidosis, which becomes a challenge to combat. Feedlots incorporate baking soda into cattle’s feed in an attempt to counteract the negative pH. In layman’s terms, the high grain diet causes indigestion and provides an environment in which E. coli proliferates. Is there any way to reduce this threat to human health and safety?

CORNELL RESEARCH
Cornell University suggests there are ways to curtail this problem. Although the research was reported in 1998, the findings are even more appropriate today: “A simple change in cattle diets in the days before slaughter may reduce the risk of Escherichia coli (E. coli) infections in humans, U.S. Department of Agriculture (USDA) and Cornell University microbiologists have discovered.”

As reported in the Sept. 11 issue of the journal Science, the research indicates that E. coli in the bovine digestive tract could be substantially reduced by removing the grain ration from finishing cattle and feeding them hay for about five days before slaughter. This allows the rumen to revert to its normal pH, which in turn makes a very unattractive environment for nasty strains of E. coli O157:H7 bacterium.

Here are the important points:

“In studies performed at Cornell, beef cattle fed grain-based rations typical of commercial feedlots had 1 million acid-resistant E. coli, per gram of feces, and dairy cattle fed only 60 percent grain also had high numbers of acid-resistant bacteria. In each case, the high counts could be explained by grain fermentation in the intestines. By comparison, cattle fed hay or grass had only acid-sensitive E. coli, and these bacteria were destroyed by an “acid shock” that mimicked the human stomach.”

“… acid-resistant strains of bacteria have evolved to overcome the protective barrier of the gastric stomach. The ongoing process of natural selection allows organisms with the appropriate genes to survive and multiply where others cannot. Because cattle have been fed high-grain, growth-promoting diets for more than 40 years, he says, there has been ample opportunity to select acid-resistant forms.”

• Follow this link for the whole story: http://http://www.news.cornell.edu/releases/Sept98/acid.relief.hrs.html

• Additional research on this topic is summarized at Jo Robinson’s EatWild.com site: http://www.eatwild.com/foodsafety.html

Once again we can see that changing how we raise cattle, moving them from their natural grass diet to a man-made diet of grain, has serious consequences for our food supply and our health. Raising 100% grass-fed and finished beef is just good sense.