We’ve all heard about antibiotic resistance, but is it also possible for bacteria to develop resistance to common disinfectants, like bleach, alcohol and soap?
I was reading this story and was sort of confused as to what was going on
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Based on my rudimentary understanding of this stuff from being in the middle of a trade school sterile technician program, what this sounds like to me is that they are discovering that bleach is not working on spores of antibiotic resistant bacteria, but not that it used to work and now it doesnt, they just assumed that disinfectants were sufficient.
What I am being taught right now is that bacterial spores, being in essence a mechanism to protect the bacteria by going dormant and forming a shell around itself, can only be properly and acceptably dealt with by flat out sterilization, this means either a process like subjecting them to
90c degree heat inan autoclave or similar for instruments, or some really fucked up strong chemicals to sterilize larger surfaces.For context, the acceptable perimeters that I have been taught for disinfection vs sterilization is that for every 1000 things you disinfect, its acceptable to find 1 microorganism in these 1000. For sterilization this becomes 1 in 1,000,000.
Im not gonna be dealing with any fabrics to my knowledge, but the guidance Ive received on my work attire is that it only has to be subjected to regular 60c degree washes, same as underwear. I would have to go back and look at more material but patient gowns and such might just fall into a category of better safe than sorry and just make them single use if this is a concern? Unless the gowns can hold up to sterilization procedures.
Edit: Looked through my material Ive received so far and theres nothing about fabrics but plastics like gloves or plastic gowns are just flat out single use then recycle or burn. Googled a bit and I found some US studies about autoclaving single use gowns that were not visibly dirty or contaminated, but this was in the context of pandemic supply line issues so as to maintain some degree of operations.
I would assume that gowns made out of fabric are more tolerant of that but being stuck in an autoclave is gonna be rough either way.
Edit2: also disregard my 90c comment, Im mixing up procedures cause its past my bedtime, thats for disinfection in a washer-disinfector that we’re currently being taught about, autoclaves are way hotter than that, above the boiling point of water(cause its steam, duh.)
Also to give my just gut feeling answer to the question, the spore stage already is a form of resistance to disinfectants for bacteria, we just have fairly reliable ways to deal with that anyways. The big problem with antibiotics resistance is that antibiotics are what we use to kill bacteria in living things, living things that cannot just be blasted with hot steam, radiation or fucked up chemicals until nothing lives there anymore.
https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.001418
Found the actual study as well for anyone interested, and they do bring up the use of >100c degree moist heat to deactivate these spores, but note that it can destroy the hydrophobic properties of PPE fabrics, which instead would make them a transmission risk for future contaminants that stick to the gowns.
Making a third reply to also say that in terms of what needs to be sterile and what needs to be disinfected, the only things that are held to the standard of sterile are things that are involved when something is entering the body, like for surgery, needles going inside you, open wounds etc.
For most everything else disinfected or even just clean to the naked eye is considered up to standard, the big issue here was that they were apparently disinfecting surgical gowns and not sterilizing them or treating them as single use.
my understanding is that disinfectants generally work by physically destroying undesirable organisms.
but Life Finds a Way™ and I guess not all bacterial spores are damaged by bleach. there are critters that can live in all kinds of hopelessly inhospitable environments, so why not bleach? it’s a bummer that this one is really medically problematic though.
Yeah, bacterial spores are basically a specific defense and survival stage for bacteria that are resilient to pretty much everything, you gotta go for sterilization procedures to reliably get rid of them.
Pretty sure they can yes, QAC (quaternary ammonium compound) resistance. I will look in more detail later.
edit: read the paper, as Huldra pointed out well, spores are really tough in general, and are highly resistant to chemical and physical attack. This does seem to be a new finding though otherwise it would probably not have been published in this manner.
QAC’s are compounds similar to bleach but not the same, and are used in those cleaning sprays and wipes that are labelled as antimicrobial or antibacterial. They are a wide class of chemicals with a lot of different effects. What I was referring to earlier was that QAC tolerance and resistance to clinically relevant concentrations of QACs has been found in several genus of bacteria, and they have been isolated directly from hospitals. This paper is a recent review on the topic. Resistance to these compounds can arise in a few different ways, many of the same ways that resistance to antibiotics works:
- Efflux pumps (actively pumps out the compounds from the bacteria)
- enzyme deactivation
- outer membrane changes What I found most scary from that paper was that they apparently have isolated bacteria living inside the disinfectant buckets used to clean hospitals.
seems like for now the bacteria are not resistant in this same way to things like bleach, soap and alcohol, but I’m sure there are certain species that have higher tolerance for them. I’ve read, due to how persistant and potentially harmful the QACs are, it’s best to avoid using products including them and to just use regular soap. (eg, avoid the "Kills 99.99% of bacteria antimicrobial soap) https://asm.org/Articles/2017/February/antibiotic-resistance-soap-and-false-advertising
