Can bacteria develop a resistance to alcohol swabs? Alcohol dissolves bacterial lipids as it is soluble with them and it denatures proteins, is there a possible defense against this?
In MIT not too long ago an engineer discovered a new antibiotic technique. He built microscopic stakes out of carbon chains and made them positively charged. These positively charged stakes attracted negatively charged bacteria and impaled them, making the surfaces of anything coated with these nanospikes mostly sterile. The stakes are too small to harm human cells though. Could bacteria ever develop resistance to being impaled or punctured? In 50+ years nanotechnology may use battering ram-esqe technology to fight infections (ie nanobots which ram into and puncture bacteria or viruses), can bacteria develop defenses against this?
What about using soap and water, can resistance to this be built so large numbers of bacteria have the capacity to remains on the hands after you wash?
Well, sure, bacteria can develop more resistance than they already have to pretty much any threat - even heat. All animals can. Hell, bacteria even come in forms that like versus dislike oxygen. That’s a pretty fundamental tweak.
One key to developing resistance would be that some bacteria would survive the initial damage. Evolution doesn’t accomplish anything when all the critters die.
There seems to be something about antibiotics that makes them very effective unless you breed specially resistant bacteria, in which case they get very ineffective. That is, for some reason antibiotics are especially strongly leveraged in their killing power. I don’t think there’s any difference of kind at work here, but rather that it’s just that antibiotics are touchier than soaps and teeny tiny arrows.
There is another reason to favor soaps over antibiotics at your kitchen sink. If you keep selectively breeding antibiotic resistant bacteria when you wash your hands, you create the opportunity to infect your body with them - and when they’re throughout your system, antibiotics are the only one of these tools you can apply. I’d rather need treatment for a lungfull of soap-resistant bugs than a lungfull of drug-resistant ones.
Ordinary soap and water washing physically removes dirt, some of the germs, etc. from your skin, regardless of whether it kills them. After all, you don’t really care if the Salmonella is dead or alive once it’s on its way to the sewer, do you? OTOH, antibiotics, sloshing around in the environment, are helping the antibiotic-resistant critters to survive and thrive.
In addition, antibiotic stuff also kills certain beneficial bacteria. In their absence, stronger and more harmful ones, as well as fungi, live long and prosper.
IMHO, I’d prefer that unless they’re performing surgery people stick to the proper and appropriately frequent use of good ol’ soap and hot water.
I hate to hijack here, but I had a vague memory recently that’s been bugging me. I seem to recall that 70% isopropyl alcohol is better at killing bacteria than 91%. This seems contrary to common sense.
Have I been smoking dope or is there any truth to this?
WAG: No. It would be like trying to evolve a human who is resistant to gunshot wounds or being dipped in acid. Even if you could, it would lose it’s effectiveness at being a bacteria.
The best evidence that bacteria can’t develop resistance to alcohol is simple: they haven’t. Alcohol has been used to kill bacteria for a lot longer than even penicillin has been around. Bacteria have evolved resistance to antibiotics that have been developed far more recently than penicillin, so if they could get resistant to alcohol, they would have.
Alcohol is a lot more destructive than antibiotics. Many antibiotics don’t even kill bacteria, they just stop them from multiplying. Alcohol dissolves some cell compounds, coagulates others and generally makes a mess of living things. This is why alcohol, unlike antibiotics, can be acutely poisonous to humans as well as bacteria.
Bacteria aren’t so much killed by soap as physically removed by the washing process. They may be able to develop resistance to specific antibacterial soap ingredients, like triclosan.
Developing resistance to puncture, as Shalmanese noted, is like humans developing resistance to being shot or stabbed. Tain’t likely.
I wonder if it is actually possible to build spikes for bacteria to “impale” themselves on? Understanding how the mechanics of our world translates to the nanoscale is a big challenge, the relative importance of the various forces at work changes as you change scale from kg to g to ng. (Maybe its not a big challenge to understand the theory, but its certainly a big challenge to harness these considerations into the design of nanodevices).
Going from memory of a lecture I saw recently, viscosity force dominates inertia forces on the nanoscale. If a nanofoot were to kick a nanofootball, the football would stick to the foot, rather than be sent flying. Random thermal energy also becomes extremely important when trying to control the mechanical movement of very tiny devices. Macroscopic devices, like spikes and battering rams, may not have a direct analogue on the nanoscale.
Breaking bacterial cell walls is such an effective strategy because of the very high internal pressures found in some bacteria, up to 50atm. The hypothetical nanospike would act like a pin on a balloon, very little force needed to explode the bacterium. It doesn’t seem beyond the bounds of credibility that bacteria with thicker cell walls would be selected by evolutionary pressure in such a system.
Alcohol that is too strong can lead bacteria to develop spores which means they can repopulate the area afterwards, so weaker alcohol in the 50-70% range is used. I think it is due to the water content of the alcohol.