Mike the Mad Biologist

Consider this the post wherein I channel my Inner ERV. During the last week, I’ve come across a couple sensationalist article about E. coli and Staphylococcus aureus being found on common surfaces. Here’s one article about shopping carts and E. coli:

Researchers from the University of Arizona swabbed shopping cart handles in four states looking for bacterial contamination. Of the 85 carts examined, 72 percent turned out to have a marker for fecal bacteria.

The researchers took a closer look at the samples from 36 carts and discovered Escherichia coli, more commonly known as E. coli, on 50 percent of them — along with a host of other types of bacteria.

“That’s more than you find in a supermarket’s restroom,” said Charles Gerba, the lead researcher on the study and a professor of microbiology at the University of Arizona. “That’s because they use disinfecting cleaners in the restrooms. Nobody routinely cleans and disinfects shopping carts.”

AAIIIEEE!!!!! And here’s an article about Staphylococcus aureus (those S. aureus resistant to methicillin–and often other antibiotics–are known as MRSA):

The Bay Citizen commissioned Darleen Franklin, a supervisor at San Francisco State University’s biology lab, to analyze the bacterial content of a random BART seat. The results may make you want to stand during your trip.

Fecal and skin-borne bacteria resistant to antibiotics were found in a seat on a train headed from Daly City to Dublin/Pleasanton. Further testing on the skin-borne bacteria showed characteristics of methicillin-resistant staphylococcus aureus, or MRSA, the drug-resistant bacterium that causes potentially lethal infections, although Ms. Franklin cautioned that the MRSA findings were preliminary.

High concentrations of at least nine bacteria strains and several types of mold were found on the seat. Even after Ms. Franklin cleaned the cushion with an alcohol wipe, potentially harmful bacteria were found growing in the fabric.

ZOMG! Well, maybe (I’m not sure what these tests are or why they disagree):

In two separate tests, Ms. Franklin identified characteristics of the MRSA bacteria growing in the seat. The first test confirmed the presence of staphylococcus aureus, the skin-borne bacteria. A second confirmed that the bacteria, like MRSA, was resistant to the antibiotics methicillin and penicillin. But a third test intended to isolate the MRSA bacteria was negative.

Look, this is silly. Regarding the MRSA, about 1.5% of healthy people who haven’t been in the hospital recently have MRSA, and about 30% of healthy people carry S. aureus:

inurnoze

The numbers are higher for those who have been in the hospital system (including medical workers). If you wash your hands before picking your nose, you’ll be alright.

Moving along to E. coli. This is also silly. Do you keep your toothbrush in your bathroom? Do you want to know what’s growing on your toothbrush? (Probably not). Too bad, I’m gonna tell you: E. coli (among other things). To put it very crudely, when you wipe your ass, do you glove up or wear a biohazard suit? No. Just wash your hands? (Good).

How’s that working for you?

Not dead yet? (Glad to hear it).

MRSA is a problem in the clinical setting, and its increase in the healthy population is worrisome, since healthy people can serve as a reservoir of resistant organisms and resistance genes. Likewise, you don’t want to have an E. coli bloodstream infection. But both S. aureus and E. coli are commensal organisms: they live on and in us, and typically don’t cause disease–usually, only when they wind up where they don’t belong. If you come into contact with them–the aforementioned wiping your ass–you’ll be fine unless you’re severely immunocompromised or have an open wound.

This is scaremongering.

JUST WASH YOUR DAMN HANDS! (Haven’t said that in a while…)

Comments

  1. #1 Kevin
    March 9, 2011

    Oh good, I was going to do a post on this, but kept putting it off, because I feel like I’ve written about this before.

  2. #2 Paco
    March 9, 2011

    Well, yes, but…what about all those people that don’t wash their hands (and there are LOTS)? Fecal bacteria on a shopping cart handle? OK, the risk is minimal, but that’s GROZE! And if such things scare more people into washing their hands after a visit to the loo, so much the better.

  3. #3 Kate from Iowa
    March 9, 2011

    It may not be human fecal material either, Paco. Got a dog? Got a cat? Got a parakeet? Pet your pet before you go to the store? Guess what could end up all over your doorknobs, car, and on the food you handle while in the produce aisle? All kinds of poo!

    (don’t just wash your hands…wash everything else too!)

  4. #4 Paul Orwin
    March 9, 2011

    No. you miss the point. you can’t avoid touching bacteria – even icky gross fecal ones. Just wash your hands before you eat! Or whenever you feel like it. Or use purell (so far, at least, EtOH resistance isn’t an issue). Stop getting upset about it, because it’s pointless.

  5. #5 human
    March 9, 2011

    Has it not occurred to people that if this were actually a problem, people would be keeling over every time they went to the supermarket?

  6. #6 daedaalus2u
    March 9, 2011

    What I do when I have to touch things is fight fire with fire, or in this case, fight bacteria with bacteria.

    I enlist commensal bacteria to do chemical warfare against all the poopy bacteria.

    http://daedalus2u.blogspot.com/2008/06/suggestion-to-reduce-antibiotic.html

    Mostly this works by inhibiting quorum sensing so they can’t become resistant to it.

    I think this is the reason why people (and animals) have sweaty hands (paws), it is to provide substrate (ammonia) to a resident biofilm of ammonia oxidizing bacteria to suppress what ever potentially infectious bacteria those hands (paws) come in contact with.

  7. #7 BaldApe
    March 9, 2011

    human nailed it. I worked in a grocery store for 30 years. I never once washed my hands before eating something on my break. Guess how many times I got sick enough not to go to work? Maybe 5, including appendicitis.

  8. #8 Dean
    March 13, 2011

    I personally do not think that the E. coli problem is such a big deal. I agree that we should just wash our hands. Everybody has an immune system. As long as we are not licking the ground and eating raw meats and unwashed green veggies, I think we are okay. If we walk around being paranoid of everything we touch, all the fun of everything will be taken away. I do like the idea that some supermarkets have the hand wipes for the shopping carts. If we all wash our hands before we eat and when we get home, nobody will get sick. If you do get sick, it’s no big deal. It builds character as I always say. As BaldApe said, you won’t get sick that easily even if you don’t wash your hands before eating. I always urge people to wash their hands before eating, because it is an easy thing to do and it prevents a lot of bacteria or viruses entering your body (i.e. E. coli, Flu, Swine Flu, common cold, etc…)