Tuesday, November 29, 2011

Save the World! Boycott Antibiotic Soaps

I try not to use this blog as a soap box, but this issue is too important to ignore. I'm currently studying microbiology, and I want to take a moment to educate you about a real problem you may not be aware of or may not understand fully. Consider this a Public Service Announcement.

More and more we're encountering antibiotic-resistant bacteria (e.g. MRSA and VRE). 

There are a lot of problems in the world today, and it can often seem that there is little that you, the conscientious individual, can do about it. Well, this is an issue that you CAN do something about. STOP USING ANTIBIOTIC SOAPS! Seriously, we should all be boycotting soaps and cleaners that contain antibiotics. If a soap or cleaner claims on the label "Kills 99.9% of bacteria" or something similar, don't buy it. I'll tell you why.

For one, it's a marketing scam. The truth is, soaps kill bacteria just fine by themselves! The detergent action of soaps break down bacterial cell membranes, killing them. This means, if you wash your hands properly, then the bacteria will be killed. There's no need to use antibiotics.

But, you may ask, what's wrong with having a little extra protection? Maybe I can't be bothered to spend 30 seconds scrubbing like I'm supposed to, or maybe I just want a little extra insurance. Antibiotics are a case where "too much of a good thing" is bad. I'll explain why.

Bacteria reproduce really quickly. To give you an idea, E. coli divide once every 20 minutes. As you may remember from your basic genetics, every time a cell divides, there's a chance for random genetic mutation. Since bacteria divide so quickly, these mutations actually crop up pretty often. Besides that, bacteria have mechanisms that cause them to mutate more often because it's advantageous for them to do so. 

Consider a population of bacteria. They're all reproducing like mad, because that's what bacteria do. Every so often, there's a random mutation. Again, these mutations are random, so most of them are either harmful or have no discernible effect. However, due to the very large numbers of bacteria, divisions, and mutations, there are some that will have a beneficial mutation, for example a resistance to an antibiotic. 

Now, you expose that population of bacteria to an antibiotic. Most of the bacteria are killed by it, but there are a few that have a mutation that makes them resistant. They aren't harmed by the antibiotic, so they keep growing and dividing. Before long you have a population of bacteria that are ALL resistant to the antibiotic, because each parent cell passes its genes (including the beneficial mutation) to all its daughter cells. Any cells that mutate to the wild form without the antibiotic resistance (called back mutation) will be killed by the antibiotic.

So, when you expose bacteria to antibiotics that aren't needed, you're doing a disservice to not only yourself, but everyone else. The more bacteria are exposed to antibiotics, the more antibiotic-resistant bacteria we'll have. 

Every dollar you spend is a vote, my friends. Right now the companies who make these antibacterial products are capitalizing on your ignorance. What they're doing is at best misguided, at worst unethical. Let's save the antibiotics for people who are sick, who really need them. If we continue this madness, before too long most bacteria will be antibiotic-resistant.

People love to blame doctors for this, saying they're too quick to prescribe antibiotics. There is some truth to that. But each and every one of us can do something about this problem: boycott antibiotic soaps. They're unnecessary and ultimately harmful. 


  1. So very true.

    Using antibacterial/antibiotic soaps today leads to real problems in the future.

    Soap works, soap has always worked. We can't let unethical corporate interests play us for chumps.

    In fact, those corporate marketers pushing antibacterial cleaning products ought to have their mouths washed out....with soap.

    Thanks for the heads up, Lex.


  2. I think another point that needs to be mentioned is the fact that not all bacteria are bad for our health. Quite a few of them help us NOT to get sick because they feed on other microbes and such that are dangerous to us.

  3. So, what you're saying is that by using anti-biotics, we're killing the bacteria that the anti-biotics are meant to kill. But leaving alive the ones that it can't kill already. And that is the reason for anti-biotic resistant bacteria?

    If I understand the way that bacteria multiply, using/not using antibiotic soap will have zero impact on the number of antibiotic resistant bacteria. It will only have an impact on the number of NON-antibiotic resistant bacteria. Because they'll be dead.

    Or does the soap somehow make the antibiotic resistant bacteria multiply faster, or exclusively?

  4. The key thing to understand here is what's called "reproductive advantage". Condiser a bacterial population living in an environment where no antibiotics are present. There may be bacteria in that population that gives them a resistance to antibiotics, but since there are no antibiotics present, the mutation doesn't give them a reproductive advantage over the other bacteria. It wouldn't give them a disadvantage either, so they would grow, reproduce, and pass the gene with the antibiotic resistance on to their offspring. However, the bacteria with resistance would be a minority in the entire population.

    Now, take the same population of bacteria into an environment where antibiotics are present. You're right, the antibiotics will kill all the "normal" (or wild type) bacteria that don't have the gene for antibiotic resistance. However, those few bacteria with the antibiotic resistance mutation now have a mutation that gives them a reproductive advantage. While all the other bacteria die, those with the resistance will survive, and they will continue to reproduce. All of their offspring will have the mutation, and all their offspring's offspring will have the mutation, and on down the line as long as the antibiotic is present. Fast forward a bit, and instead of a population of bacteria with a few antibiotic resistant mutants present, you now have a population where almost all the bacteria are antibiotic resistant (and the few that aren't won't live long enough to reproduce as long as antibiotics are present).

    Once you took the antibiotics away in this scenario, the resistant bacteria would still dominate the population (because there would be a lot more of them) unless something in the environment selected AGAINST antibiotic resistance.

    This is exactly what's happening in hospitals today. Numerous strains of antibiotic resistant bacteria have evolved, and they're very diffictult to kill. MRSA and VRE are two examples of these new "super bugs". It gets worse, now there are bacteria who have evolved the ability to EAT antibiotics. Not only won't the drugs used for treatment not kill them, they'll actually feed them and make them stronger.

    This can be hard to wrap our heads around. Our experience is limited in that it's hard for us as humans to see natural selection at work in our day-to-day lives, namely because our generations are too long. It's because bacteria have such short generations that they're used so often for biological research. However, this also gives them the ability to adapt with a speed that boggles the mind.

    Beyond that, there are bacteria that are able to pass on genes (located on plasmid DNA) to other bacteria. This is often the case with antibiotic-resistant genes. So not only can one bacterium pass on its resistance to all its progeny, but to all its neighbors as well.

  5. Little late to the party, but I have been busy.

    I have refused to have 'anti-bacterial' anything in my house for a long time.

    I come from a generation when Doctors prescribed antibiotics for a viral infection to prevent secondary infections and now thanks to this my mother contracted MRSA during a heart bypass which is all probability she will have for the rest of her life.

    I was always told that plain soup and water is good enough for most situations and in fact I know an ER doctor that tells me that she just uses soap and hot water before treating patients.

    Anyhow, great post.