You probably already know something about E. Coli. You know that it can cause mass outbreaks of food poisoning, and you know that it can cause severe diarrhea.
But did you know E. coli bacteria also live harmlessly in your intestines? In fact, certain strains of E. Coli bacteria are vitally important for the function of your GI tract. So what is the deal? What is the difference between good and bad E. Coli bacteria, and how can certain strains make you sick?
All strains of E. coli come from the lower intestine of mammals. We have E. coli in our gut, so do dogs. You’re not going to want to hear this, but if you do suffer from an infection caused by a harmful strain of E. coli, that bacteria was pooped out of an organism, and you ingested it. Sorry.
Most strains of E. coli are completely harmless, but certain ones, such as E. coli #0157:H7 can actually kill you. This particular strain is often found in the intestinal track of cows. Most outbreaks have been linked to raw beef and contaminated leafy vegetables like spinach (here are some recorded outbreaks of E. coli documented by the CDC).
This strain (E. coli #0157:H7) is so destructive, because it produces what’s known as the shiga toxin, a substance that is actually capable of destroying red blood cells. While many harmful strains of E. coli will just produce bouts of diarrhea and possibly vomiting, this particular strain can be deadly.
How long can E. coli survive without nutrients?
There are differing viewpoints on this resulting from numerous studies. It seems clear, however, that E. coli can survive on a variety of surfaces for at least several days (see some evidence here). As a bacteria, E. coli does need nutrients to survive. In this way, it is less dangerous than a virus, which can potentially survive much longer in the right conditions.
How do you avoid E. coli infection?
There are a number of ways to prevent an E. coli infection.
- Wash your hands – washing your hands is possibly your best defense against an E. coli infection. It is especially important to wash your hands before eating and after using any toilet facilities. Keep in mind that communal spaces can harbor higher amounts of E. coli, and you should plan on washing your hands frequently regardless of what you are doing.
- Avoid undercooked meats – that steak cooked rare may be tempting, but just think about the potential time spent on the toilet afterwards. Better safe than sorry!
- Eat fresh fruits and vegetables – many people don’t realize that E. coli can show up in vegetables (this has happened repeatedly with bagged vegetables like spinach) and in fruit juices (avoid unpasteurized juices if you are buying them from the store). Go for what’s fresh, not what’s been sitting around or what’s been produced in questionable industrial settings.
The risk for E. coli infection certainly goes up in developing world countries, where infrastructure regulating hygienic practices may be lacking. If you are traveling, be conscious of the food you are eating, and plan to wash your hands often. Of course, we recommend traveling with hand sanitizer or alcohol based wipes – you don’t know if you will always have access to soap and water when using the bathroom or before eating a meal.