I think that’s got it all in the title.
Evolution on a grand scale simply does not work that fast and it would be scary if it did. Hundreds of thousands of years is considered fast and changes below that are considered lightening speed.
Humans are good at inventing stuff but we aren’t that good at making the entire microbial world adapt its DNA structure around a topical cream that has been around for a few decades.
Of course there are some strains that have become resistant. The vast majority have nave not and that is why it remains useful for most purposes. We are but a small part of the world regardless of what we may feel and creams tend not to alter whole worlds that have been and will be long after we are all gone.
No. Mainly because it’s not to the bug’s advantage to keep producing the counter to each antibiotic in Neosporin (I think it’s Bacitracin and Polymyxin B and Neomycin maybe). While strict human pathogens probably want to keep those genes around and expressing for continual infection, bacteria that is surviving out in the environment that doesn’t have to commit extra energy to anti-antibiotics will fare better (divide faster, save energy) than those bacteria that keep the genes around.
I use Neosporin but I’m not sure why really, my immune system likely kills all of that stuff anyhow. I guess better safe than sorry.
Unless someone is running around rubbing Neosporin on bugs, how would bugs become immune to it? I would think that a human that uses it on an almost daily basis could develop some immunity and it could become less effective when used to treat bug bites and stings.
Humans don’t develop immunity to antibiotics (or, more accurately, they normally already are immune in the sense that the antibiotics don’t cause them problems); micro-organisms develop immunity to antibiotics.
Do what? People do not become immune to antibiotics, it is bacteria that become resistant(cite). From that page:
This is not evolution in action, it’s adaptation and it can take place very quickly. Again, from the above cite:
“Decades” would be plenty of time for a particular strain of bacteria to become resistant. As a matter of fact, it’s a big worry in the medical field. See this WebMD article for example: Super Bugs Pose Bigger Threat than SARS
Ringo, the links above are very good articles on antibiotic immunity, though they don’t answer the Neosporin question specifically. My WAG would be that, since Neosporin is a “cocktail” of antibiotics, it defeats multiple resistance mechanisims commonly present in bacteria. Beond that, I got nothin’.
It’s when they develop a resistance to isopropyl that I’ll start worrying.
Developing antibiotic resistance in bacteria in vivo (vs. in a test tube) is much more complicated than it seems. Quite often, it’s really a combination of selection of already resistant strains/species through preferential growth, and transduction of genetic material between strains and very different species (it’d be like us absorbing lobster genes)
Even disrgarding the details of exposure frequency/duration, mechanisms of action, etc., it’s useful to remember that the concentration of antibiotics in a topical ointment can safely be MUCH higher than the serum/tissue concentrations of antibiotics taken internally. Resistance is rarely absolute. It can be overcome if the concentration is high enough
Neosporin and similar topical anti-biotics kill the bacteria at the site of a wound to prevent/miniize risk of infection.
No bacteria should survie to procreate offspring with increased resistance.
It is when patients refuse to finish a course of Rx medication that bugs go on the loose to infect others and procreate more reisistant offspring.
And bleach. Fortunately 70% ethanol pretty much unfolds every protein, and I don’t see how anything could counter bleach chemical modification, it’s so reactive. Of course the mold growing in my shower seems to survive it just fine 