Escherichia coli Good Bacteria Gone Bad

e.coli Good Bacteria Gone Bad

E. coli has become a growing public health problem in recent years. The bacteria doesn't usually cause any trouble, says University of Minnesota microbiology professor Michael Sadowski. "E. coli is a normal inhabitant of the intestinal tract of warm-blooded animals."

That means you, me, our livestock and even wild animals are all carrying strains of E. coli around in our guts. The types that cause disease are rare, Sadowski says.

"The majority of E. coli are in fact considered to be harmless. And they carry out various biochemical processes in your intestine and they help you digest food."

And most are relatively harmless until recently, says the University of Minnesota food safety professor Francisco Diez. "We have not had this type of system before 1982."

That was when the first deadly strain of E. coli appeared in the hamburger meat in the United States. Before that, says Diez, E. coli was not even considered a germ that causes the disease.

According to Diez, it is unclear exactly how this new virulence developed. There may have been changes in the bacteria, or changes in the way of producing food or distributed. Whatever the cause, E. coli is becoming a growing number of fruits and vegetables like apples, lettuce and spinach.

By a germ that first met in the flesh, it seems a long way to the produce aisle. However, Diez said that there is a connection.

We've seen an increase in cases of produce-associated outbreaks, but ultimately the source is cattle."

He says cattle-manure fertilizer that has not been well composted may still carry live bacteria from the animals’ gut. Or manure may contaminate irrigation water. It could also be on the hands of someone picking or sorting the produce. Add storage, transportation, and preparation as other places between the farm and the fork where food can become contaminated with the bacteria.

That's part of why tracing an outbreak to its source is so difficult. In Europe, officials originally blamed Spanish-grown cucumbers, but now they are not so sure. Other suspects include tomatoes and lettuce.

The problem is, those are all common salad ingredients.

"It's hard to find enough people that only ate one, and only ate one once in the time period before their infection," says Christopher Braden, head of the foodborne disease section at the U.S. Centers for Disease Control and Prevention." They're commonly eaten. They're commonly eaten together. So to try to tease one apart as to which one is the culprit can be difficult."

Spain maintains that its cucumbers have been falsely accused. Spanish farmers are losing huge amounts of money, and they are furious.

The CDC was in a similar position in 2008 when it blamed tomatoes for a salmonella outbreak that ultimately was pinned on peppers.

Braden says it can be a difficult decision to make when you have preliminary information points to a suspect. "And meanwhile, people are getting sick and possibly dying in large numbers. Sometimes there is a real balance between being fast and being right. Many times it is very difficult to do both."

It adds that if his initial suspicions are right, it could also be criticized if they do not act.

There are still many unknowns about the current European outbreak, and probably will be some time before they are all resolved.

Meanwhile, the advice remains the same: Wash your hands after going to the toilet and before preparing food and eating and washing counters and utensils that come into contact with raw meat.

And if you are concerned about the cleanliness of raw vegetables, cooked well.