That's fine. Some bacteria is actually good for you. Even trace amounts of "bad" bacteria will help build your immune system so you don't need to kill all bacteria.
There's actually pretty good evidence now that childhood sanitation is correlated with the incidence of Acute Lymphoblastic Leukemia (ALL). Edit: accidentally wrote inversely
That's true, but when it comes to hospitals, you want to try and minimize all bacteria. Your skin may be a very protective organ, however if you get those same bacteria in a wound, it could lead to dangerous infection.
Bacterial growth is essentially logarithmic / exponential - so all it takes is a few bacterial cells to have a chance mutation which affords the resistance to $THING, and the population is back to growing fine in the presence of $THING, and is ready to spread those beneficial mutations with other bacteria (in a hospital drain system for instance [1,2]).
$THING could be antibiotics, hand sanitizer - etc.
This basic principle is taught by example in every intro to microbiology / molecular bio laboratory course.
(^) Edit after downvotes: My only point was that the underlying mechanism is somewhat irrelevant - bacteria will always find a way to break down things humans put in their environment, even Nylon or radiation.
People that had that mutation were better able to fight off malarial infections in those environments where it was prevalent - and those genes now are passed on specifically in certain ethnicities, etc.
It’s probably more like humans evolving to drink alcohol, which not all primates tolerate well. Admitedly here is a difference between drinking it at 10% strength and bathing in 60%.
That's what I thought as well. When I took a biology class in college we asked why hand sanitizer that kills 99.9 percent of germs is fine, but excessive use of antibiotics breeds super germs. The professor told us that it just destroys it at a molecular level, so there's nothing to resist, it'd be like trying to develop a resistance to being torn apart by a black hole.
That's my understanding as well. Bacteria cannot survive in alcohol because the lipid structure in their cell membranes are disrupted and their proteins become denatured
It's known that some bacteria can survive just fine in moderate concentrations (the paper points out lactic acid bacteria in sake, surviving at more than 18%) by means of membrane transporters.
The authors suggest that insufficient concentrations could allow tolerant bacteria to survive.
> As alcohol tolerance increases, we hypothesize that there will be skin surfaces in contact with alcohol-based hand rubs or inanimate surfaces in contact with other alcohol-based cleaning agents that do not receive the maximum biocide concentration or contact time required for effective bacterial killing.
Hand sanitisers in offices etc. should be outlawed. There's simply no reason for their existence and using them probably weakens your immune system anyway. They are useful for situations like camping but that is all.
They should be outlawed for camping too... the importance of keeping bacteria from growing immune outweighs the small risk of getting a stomach bug while camping
Sanitizer should ONLY be legal for use in hospitals
I’m guessing this is sarcasm but soap works through a mechanical process of helping to push the bacteria off your skin, rather than a chemical process of killing them.
Alcohol-based hand sanitizers aren't effective against noroviruses, etc. viral gastroenteritis anyway. Campers should be using soap if they actually want their hands clean (and wash for at least 10 seconds).
It is not a small risk. Being stuck in the backcountry while losing fluids and nutrients to a GI infection can be a life-threatening situation. Hygiene is in short supply out there to begin with, so it’s very important to have clean hands when handling food and water.
Comments full of woo should be outlawed first. The next time you want to comment, consider your argument critically. Yes, there are plenty of reasons for them to exist. No, saying "well, it's probably, like, dumb and stuff, regardless," is not a valid argument.
Simply because you think it, you believe your opinion is worth typing out.
> Hand sanitisers in offices etc. should be outlawed. There's simply no reason for their existence and using them probably weakens your immune system anyway. They are useful for situations like camping but that is all.
That, or we could just make sure we use sanitizers that have high concentrations of alcohol in these settings.
The bacteria referred to here require lower concentrations of alcohol to survive. They're not able to survive 100% alcohol (or close to 100%), and it's very unlikely that they could evolve to tolerate alcohol levels that high. The reason we don't commonly use high concentrations of alcohol is that it's more irritating to the skin (for the same reason that it kills bacteria). But in settings where killing bacteria is necessary, dehydrating the skin is an acceptable tradeoff.
> They're not able to survive 100% alcohol (or close to 100%)
IIRC, there's something of a peak in the effectiveness curve below the close-to 100% [1] point for ethanol, having something to do with too high a concentration not actually penetrating cell membranes fast enough when there isn't enough water in solution already. It's been a while since I read up on it. The papers are out there, for the curious.
That said, I also recall the European standard of 85% (w/w?) being far better as a disinfectant, as supported by the evidence, than the US minimum of 62% w/w (or 70% v/v). Perhaps instead of a ban, merely increasing the minimum percentage to something that doesn't encourage resistance would be enough.
[1] 96.5% or thereabouts is the highest distillation concentration, above which it would be hygroscopic and come down to that if left open to air.
That was actually another detail I discovere, although with much less data behind it, that mixtures of ethanol and isopropanol [1] could be more effective than just one alone.
Mixing the two works well for liquid formulations, where the dispenser is a fine mist sprayer, but I'd be concerned that anything gelled or with additives for a foaming dispenser might not mix evenly enough.
[1] The usual alcohol in "rubbing alcohol" and, of course, for the previously-mentioned reason, ethanol is excluded if it's 99%
Oddly enough I'm less worried about germs while camping, then when I'm in civilization. Maybe I'm misguided, but I don't expect to encounter human pathogens in the wilderness.
E. coli, Shigella, Giardia, Cryptosporidium and Salmonella can all very happily live in the wilderness, infect multiple species, and can be carried by other campers and their pets.
Combine that with poor refrigeration of food, generally less hand-washing overall (due to the absence of plumbing) and the potentially more serious consequences of those infections (dehydration due to a GI pathogen is a much bigger deal two days from anywhere in the Colorado Rockies than it is curled up on your couch), it's definitely a thing.
When camping I like having hand sanitizer with the toilet paper. At other times it seems unnecessary, but the toilet paper is probably a bit less sanitary than what you typically experience in a city since there's water near the fine hole in the ground and you have to handle the toilet paper the next person is going to use more than if it was in a bathroom.
Don’t you think banning an extremely common product in response to one study is an overreaction? From the article:
>"To our knowledge this was the first time anyone had shown hospital bacteria becoming tolerant to alcohols," says Timothy Stinear, a coauthor of the study and a researcher at the University of Melbourne's Doherty Institute for Infection and Immunity.
Not really, I think there's a broad consensus that excessive disinfecting across society now has negative rather than positive effects.
Bacteria can plausibly develop resistance to just about anything so gratuitously adding antibacterials to the environment is pretty inherently bad - use them when and only when needed (antibiotics in meat being another problem example).
Also, it seems there's a threshold below which a lack-of-exposure to bacteria and other immune-vectors is actually bad for a person - by preventing the immune system from acting normally.
It's funny, because I remember have arguments with biology majors. And them explaining how alcohol is different and bacteria will never be able to evolve immunity to it unlike anti-biotics. Something I couldn't understand. And they kept trying to describe how it's different, and something about how any bacterium that evolved to survive in an high alcohol environment would no longer be able to survive in a non-alcohol environment. So they would die, just laying on the ground or any surface.
I still never got it.
Bio majors, is thete any truth to that? This article seems to say no. What phenomena could they have been referring to?
There's understanding what has been experimentally determined so-far about bacteria and organisms and there's understanding that the realm of things we haven't so-far discovered about organisms and their potential evolutions may larger than what we have discovered.
All this talk makes me think of the 'unkillable' T1 phage. Just a tidbit copied from the internet[1]:
'T1 is not easy to get rid off. The best solution of all is to not use T1-sensitive strains. You’ll need to bleach the hell out of everything as well as UV irradiate if possible. And I mean everything, water baths, glassware, specs, pipets, your wife and kids (the latter is probably deserving of a good bleaching anyways). This is serious business T1 can exist in aerosol form for up to a few months, so it’s going to take regular cleaning and testing intervals. In a previous lab it took about six months to a year of solid effort to eradicate our T1 infection.'
> The researchers used different strengths of alcohol concentrations to combat the bacteria, starting with 23 percent. Eventually, at a 70-percent alcohol mixture, the bacteria were conquered. Typically, hand sanitizers are 60 percent alcohol.
Is it simply a matter of using higher concentrations of alcohol? Or is it possible that bacteria could evolve resistance right up to 100%?
One of the problems with alcohol-based hand sanitizers is that there's a war between "Kills Bacteria" and "Demolishes Your Hands" - one of the major problems in hospitals is compliance, and the harsher the alcohol concentration, the harder it is to get people to use it.
A 70% solution is considered the most effective. Higher concentrations of alcohol (over 90% especially) evaporate more quickly, reducing contact time. Also, they work too quickly. By coagulating the outer proteins of bacteria instantly, they form a protective layer that actually stops the alcohol from penetrating further.
Although I agree that over 90% is less effective (and your explanation is clearer than mine [1]), do you have a reference for 70% (and is it w/w or v/v?) is the most effective?
Last I read up on it, I found the number to be closer to the European hospital standard of 85%, although I don't have the reference in my bookmarks, nor do I recall if it was reflect of scientific consensus, if one even exists on the topic.
"have hard shells that make it difficult for alcohol to kill them"
It is likely that such adaptation has a cost. Is alcohol resistant bacteria more benign inside the human body?
Also, with only my rudimentary understanding of microbiology, wouldn't just scrubbing your hands together vigorously, which is already recommended, overcome that?
Biofilms and sporulation are enough of a benefit in hospital environments that I doubt it confers much of a fitness detriment, and there's no promise that even if it does, that that comes in the form of decreased virulence.
Those shells are temporary; They talk about endospore forming bacteria. They are very hardy and "dormant", but can reactivate given the right conditions. Bacillus cereus for example can survive rice cooking in the spore form, then reactivate and poison you if you leave the cooked rice out of the fridge long enough.
I wish this article had provides a link to a comparison between the different hand sanitizing methods.
OK, so alcohol-based sanitizer isn't great. How does it compare to plain old soap and water? What about foaming liquid soap? How does the big gun of Hibiclens work out nowadays?
Soap and water doesn't directly kill the bacteria, it dissolves the oils and lipids that that they live in and washes them away. Some die, but if bacteria was humans, using soap and water is the equivalent of causing a landslide and just clearing the entire surface of the area of anything but dirt/skin and dumping the people/bacteria off the cliff and down the drain.
The key to all adaptive mechanisms is that they have to not kill the bacteria as well.
The mechanism of action for hand sanitizers is to disrupt the lipid membrane - it's possible no adaptation exists to make a lipid membrane resistance to high concentrations of alcohol (or other surfactants) that also still renders it a workable membrane.
The current resistance mechanisms in the study are mostly efflux pumps, which again, may not be expressible to save a bacteria when alcohol is present at volume. Even most antibiotic resistance mechanisms are not actually a binary "Works/Doesn't Work" but rather can fight off the antibiotics at the concentration they're delivered in.
As someone with compulsive skin picking who gets LOTS of staph infections, Hibiclens combined with tubes of muciprocin left over from the occasional infection I couldn't knock out myself has saved me easily hundreds in copays (and lots of sunburns from doxycycline). That stuff is miracles in a bottle, I will not travel without it, every household should have some on hand. As soon as something starts getting red and hard and painful, I Hibiclens those sins away before it can even THINK about getting streaky, and within hours it looks and feels SO much better. Plus, it doesn't burn or sting like other antiseptics!
Most people don't use it correctly anyway. You're supposed to soak your hands so they're dripping, rub together and let it evaporate. You see most people just using a small dot on their palms.
I've also read about a certain rare bacteria that thrives on a food additive. I cant recall what it was but I remember it was really expensive to make the suddenly a new methods made it cheap. The bacteria rose as the cost of the additive went down.
I was on mobile and it was tedious to look. But now I did a search and the article I linked below mentions "virulent strains of the bacterium Clostridium difficile".
A brief snippet
>Trehalose is an extremely stable sugar, resistant both to high temperatures and to acid hydrolysis thanks to the glycosidic bond linking its two glucose units. This makes it valuable for high temperature food processing, since it doesn’t lead to browning as part of the Maillard reaction.
Speaking of Clostridium difficile.
>...they can grow on this sugar while others cannot.’
we need a new "manhattan" project to tackle the problem of bacterial resistance. Seriously we should be investing hundreds of billions of dollars into research into more effective means of controlling infectious diseases. We're on the brink of reverting to the times before antibiotics where common infections that are now easily treatable will be deadly and debilitating again. It's terrifying.
But sadly, this is not new news. Unfortunately, it's not sexy in a political and/or mainstream media sense. No one seems interested in owning the problem. Perhaps, again sadly, the only hope is this becoming a national security issue and the DoD throwing its budget weight at it. But if obesity is any indication, that's not going to be enough.
It’s concerning, but shouldn’t be terrifying (although the media prefers it to be).
Even with highly resistant strains, current antibiotics works in nearly all cases. Physicians are quite careful about reserving the “big guns” for last. In addition, anti-resistance techniques have been effective with some resistant strains actually decreasing in prevalence over the past few years.
Do we need to keep researching new antibiotics? Of course. Is it doomsday? No.
Links to whatever you're reading that gives you that confidence/understanding? The media has me pretty convinced that we're on the brink of a modern medicine failure
Three out of the six tracked antibiotic have decreasing resistance rates (aminopenicillins, amoxicillin, piperacillin). The last two are front-line antibiotics that have been around for decades. They still work for most infections.
It's not evident from these graphs, but prior predictions were rates were going to drastically increase over the past decade. That hasn't born out.
Not saying this isn't a public health concern, but it's also not antibiotic armageddon.
If anything, the Armageddon scenarios that the media like to play out (which are utterly terrifying - an end to routine surgery, cutting yourself gardening potentially being fatal etc.) could have caused a shift in the "I'm ill, give me antibiotics", so in that way, has been just as useful as other controls put in place.
Antibiotic resistance is a major threat, but this one was talking about resistance to cleaning products such as alcohol.
Developing a resistance to them is like developing a resistance against being burned alive. A thicker skin might help you somewhat with mild concentrations, but at the end of the day, basic biology says you can't build alcohol-proof bacteria.
Would it be too much just to install little hand washing sinks in front buildings? I don’t need the germs to die. They can live in the sewer all day long. I just want them off my hands.
The study is looking in hospitals, where the volume of hand sanitization needs are much higher than the average setting. And where, interestingly, germs living in the sewer are causing problems - biofilms in plumbing can easily recontaminate sink surfaces.
I for one would like to know what happens to the cellulose carrier. It always seemed creepy to me to slather that over your hands, leaving a nice food source for new bacteria once the alcohol evaporates.
I sometimes wonder, if we couldn't make some sort of tailored grave-digger bacterium- hell bent on eating toxins, encapsulating them and get burried with them.
Thats how nature does it after all- no matter what spills and kills, something eats something, gets sick and not devoured- falling to the floor, becoming another strange bark layer for the geologists to marvel about.
104 comments
[ 4.7 ms ] story [ 167 ms ] threadHere is a pretty good overview:
https://www.medscape.com/viewarticle/897242
Note that this is a little different than the usual interpretation of the hygiene hypothesis.
Bacterial growth is essentially logarithmic / exponential - so all it takes is a few bacterial cells to have a chance mutation which affords the resistance to $THING, and the population is back to growing fine in the presence of $THING, and is ready to spread those beneficial mutations with other bacteria (in a hospital drain system for instance [1,2]).
$THING could be antibiotics, hand sanitizer - etc.
This basic principle is taught by example in every intro to microbiology / molecular bio laboratory course.
1. https://en.wikipedia.org/wiki/Horizontal_gene_transfer
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4117541/
(^) Edit after downvotes: My only point was that the underlying mechanism is somewhat irrelevant - bacteria will always find a way to break down things humans put in their environment, even Nylon or radiation.
For instance Sickle Cell anemia is hypothesized to actually be a defense we evolved against malaria:
https://en.wikipedia.org/wiki/Human_genetic_resistance_to_ma...
People that had that mutation were better able to fight off malarial infections in those environments where it was prevalent - and those genes now are passed on specifically in certain ethnicities, etc.
Or those bacteria that feed on bi-products of Nylon manufacture - because their environment is rife with wastewater from it:
https://en.wikipedia.org/wiki/Nylon-eating_bacteria
https://www.scientificamerican.com/article/origins-of-human-...
http://www.sciencemag.org/news/2014/12/ability-consume-alcoh...
Looks like we need to start washing with Everclear now.
The authors suggest that insufficient concentrations could allow tolerant bacteria to survive.
> As alcohol tolerance increases, we hypothesize that there will be skin surfaces in contact with alcohol-based hand rubs or inanimate surfaces in contact with other alcohol-based cleaning agents that do not receive the maximum biocide concentration or contact time required for effective bacterial killing.
http://ubertoolcomic.com/?comic=no-138
It's actually backwards from that. Adding some water to alcohol kills more bacteria than pure alcohol.
See here: https://blog.gotopac.com/2017/05/15/why-is-70-isopropyl-alco...
Sanitizer should ONLY be legal for use in hospitals
http://sitn.hms.harvard.edu/flash/2017/say-goodbye-antibacte...
https://www.cdc.gov/norovirus/about/prevention.html
Simply because you think it, you believe your opinion is worth typing out.
Fuck off.
That, or we could just make sure we use sanitizers that have high concentrations of alcohol in these settings.
The bacteria referred to here require lower concentrations of alcohol to survive. They're not able to survive 100% alcohol (or close to 100%), and it's very unlikely that they could evolve to tolerate alcohol levels that high. The reason we don't commonly use high concentrations of alcohol is that it's more irritating to the skin (for the same reason that it kills bacteria). But in settings where killing bacteria is necessary, dehydrating the skin is an acceptable tradeoff.
IIRC, there's something of a peak in the effectiveness curve below the close-to 100% [1] point for ethanol, having something to do with too high a concentration not actually penetrating cell membranes fast enough when there isn't enough water in solution already. It's been a while since I read up on it. The papers are out there, for the curious.
That said, I also recall the European standard of 85% (w/w?) being far better as a disinfectant, as supported by the evidence, than the US minimum of 62% w/w (or 70% v/v). Perhaps instead of a ban, merely increasing the minimum percentage to something that doesn't encourage resistance would be enough.
[1] 96.5% or thereabouts is the highest distillation concentration, above which it would be hygroscopic and come down to that if left open to air.
Mixing the two works well for liquid formulations, where the dispenser is a fine mist sprayer, but I'd be concerned that anything gelled or with additives for a foaming dispenser might not mix evenly enough.
[1] The usual alcohol in "rubbing alcohol" and, of course, for the previously-mentioned reason, ethanol is excluded if it's 99%
A better solution would probably be to mandate 70% alcohol concentration in all sanitize containers.
E. coli, Shigella, Giardia, Cryptosporidium and Salmonella can all very happily live in the wilderness, infect multiple species, and can be carried by other campers and their pets.
Combine that with poor refrigeration of food, generally less hand-washing overall (due to the absence of plumbing) and the potentially more serious consequences of those infections (dehydration due to a GI pathogen is a much bigger deal two days from anywhere in the Colorado Rockies than it is curled up on your couch), it's definitely a thing.
https://www.avma.org/public/Health/Pages/Outdoor-Enthusiasts...
https://www.cdc.gov/family/camping/index.htm
>"To our knowledge this was the first time anyone had shown hospital bacteria becoming tolerant to alcohols," says Timothy Stinear, a coauthor of the study and a researcher at the University of Melbourne's Doherty Institute for Infection and Immunity.
Bacteria can plausibly develop resistance to just about anything so gratuitously adding antibacterials to the environment is pretty inherently bad - use them when and only when needed (antibiotics in meat being another problem example).
Also, it seems there's a threshold below which a lack-of-exposure to bacteria and other immune-vectors is actually bad for a person - by preventing the immune system from acting normally.
I still never got it.
Bio majors, is thete any truth to that? This article seems to say no. What phenomena could they have been referring to?
There's understanding what has been experimentally determined so-far about bacteria and organisms and there's understanding that the realm of things we haven't so-far discovered about organisms and their potential evolutions may larger than what we have discovered.
'T1 is not easy to get rid off. The best solution of all is to not use T1-sensitive strains. You’ll need to bleach the hell out of everything as well as UV irradiate if possible. And I mean everything, water baths, glassware, specs, pipets, your wife and kids (the latter is probably deserving of a good bleaching anyways). This is serious business T1 can exist in aerosol form for up to a few months, so it’s going to take regular cleaning and testing intervals. In a previous lab it took about six months to a year of solid effort to eradicate our T1 infection.'
[1]http://genrepair.scientopia.org/2011/01/11/do-we-have-a-t1-p...
Is it simply a matter of using higher concentrations of alcohol? Or is it possible that bacteria could evolve resistance right up to 100%?
Last I read up on it, I found the number to be closer to the European hospital standard of 85%, although I don't have the reference in my bookmarks, nor do I recall if it was reflect of scientific consensus, if one even exists on the topic.
[1] https://news.ycombinator.com/item?id=17684070
Adding some water to alcohol kills more bacteria than pure alcohol.
See here: https://blog.gotopac.com/2017/05/15/why-is-70-isopropyl-alco...
OK, so alcohol-based sanitizer isn't great. How does it compare to plain old soap and water? What about foaming liquid soap? How does the big gun of Hibiclens work out nowadays?
And out of which bacteria membranes are made.
We know these organisms adapt, just as they did to (oral) antibiotics. Is there any biological reason why hand sanitizers would be any different?
The mechanism of action for hand sanitizers is to disrupt the lipid membrane - it's possible no adaptation exists to make a lipid membrane resistance to high concentrations of alcohol (or other surfactants) that also still renders it a workable membrane.
The current resistance mechanisms in the study are mostly efflux pumps, which again, may not be expressible to save a bacteria when alcohol is present at volume. Even most antibiotic resistance mechanisms are not actually a binary "Works/Doesn't Work" but rather can fight off the antibiotics at the concentration they're delivered in.
I've also read about a certain rare bacteria that thrives on a food additive. I cant recall what it was but I remember it was really expensive to make the suddenly a new methods made it cheap. The bacteria rose as the cost of the additive went down.
I was on mobile and it was tedious to look. But now I did a search and the article I linked below mentions "virulent strains of the bacterium Clostridium difficile".
A brief snippet >Trehalose is an extremely stable sugar, resistant both to high temperatures and to acid hydrolysis thanks to the glycosidic bond linking its two glucose units. This makes it valuable for high temperature food processing, since it doesn’t lead to browning as part of the Maillard reaction.
Speaking of Clostridium difficile. >...they can grow on this sugar while others cannot.’
https://www.chemistryworld.com/news/food-additive-may-have-g...
https://text.npr.org/s.php?sId=635017716
Even with highly resistant strains, current antibiotics works in nearly all cases. Physicians are quite careful about reserving the “big guns” for last. In addition, anti-resistance techniques have been effective with some resistant strains actually decreasing in prevalence over the past few years.
Do we need to keep researching new antibiotics? Of course. Is it doomsday? No.
Three out of the six tracked antibiotic have decreasing resistance rates (aminopenicillins, amoxicillin, piperacillin). The last two are front-line antibiotics that have been around for decades. They still work for most infections.
It's not evident from these graphs, but prior predictions were rates were going to drastically increase over the past decade. That hasn't born out.
Not saying this isn't a public health concern, but it's also not antibiotic armageddon.
Developing a resistance to them is like developing a resistance against being burned alive. A thicker skin might help you somewhat with mild concentrations, but at the end of the day, basic biology says you can't build alcohol-proof bacteria.