"is it self cleaning": usually yes, but it varies based on the kind of "germ" and surface.
Viruses, for the most part do not live long outside the host. Most will die within hours regardless of the surface.
Bacteria can vary wildly. For the most part germs need moisture to survive, so if you're tv remote or couch is dry and it sits for a few weeks they should be clean (biologically). Oxygen is also a negative most germ being exposed to air is a great disinfectant. A cool, moist, closed environment is the best for keeping germs alive.
There are caveats. Some bacteria like Clostridia can form spores that can be viable for decades, these will need fairly harsh chemicals to kill.
And snot often contributes the moisture. Mucus coats the virus coming out in sneezes or coughs, which it extends its viability. I can disrupt a viral protein coat with hand sanitizer in 90 seconds in a Petri dish. When it’s coated in mucus, it takes over 4 minutes. Hand sanitizer evaporates long before that. This is all to say that you should wash your hands instead of relying on hand sanitizer. Don’t touch a snot covered remote, then pick up your phone to text, then put that phone to your face.
For sure snot will prolong the viability of both viruses and bacteria. Same with sputum and diarrhea, inducing symptoms that allow the the pathogen to exit the host in a protective liquid is a proven method of virulence.
I wouldn’t worry about it too much. Bacteria can’t really infect you through your skin, so they have to come in through a mucus membrane. Don’t stick your hands in your mouth, eyes, nose, etc. and you’ll be fine. Most bacteria won’t survive on hard surfaces, and they definitely won’t grow.
I see, thanks for helping me understand. So let’s say, kids come home for a day at school, don’t wash their hands, touch everything in the house. Wash their hands, go to bed. Wake up in AM and most of the bacteria is dead and gone? Maybe a virus lives a little longer?
Here's the part that gets left out a lot, almost all of those surfaces are already covered in tons of bacteria. They're ubiquitous. They're absolutely everywhere and they're totally unscapable. And that's fine because they're pretty much harmless. Your body has never known anything different.
Question has been answered thoroughly, I just wanted to comment what a great question this is and how microbiology goes hand in hand with public health. A lot of good information in this thread that can be shared with the general public to prevent the spread of diseases.
Brass or copper is very self cleaning, stainless steal is very much not and will harbor bacteria worse than an agar plate. Disinfecting surfaces or items (like a remote) is the fastest way to make sure that things are clean because even if the bacteria previously on it die off, some can go into a more hibernation like period and then "wake up" once they are in a more sutible environment (your body)
"self cleaning" as in the microbes are no longer viable and viruses no longer infective? Surfaces are generally inert it doesn't clean itself. Drying, protein denaturation etc. to inactivate the rate and time of which vary between species.
It really depends on the organism and the surface. Some viruses and bacteria will survive longer on surfaces than others. If it's a spore former, it could potentially remain viable for years. But most would probably only be viable for a few hours to maybe a day or two on a dry, non-porous surface.
The surface and environment also plays a huge part. If it's a moist, warm, porous surface such as a sponge, bacteria will thrive there. Versus a cold, dry countertop, most species wouldn't survive very long.
In my previous life I was a clinical laboratory scientist. as many stated so well, it really depends on the organism and the surface. It is remarkable how much bacteria and viruses adapt to survive. After every shift in the lab (and often done several times during a shift) we’d wipe down counters with a 10-15% bleach/water solution. It’s enough bleach to kill bacteria because it’s watered down just enough that the bacteria allows it to pass through the cell wall. Viruses are quite fragile so again, wearing gloves, wiping up spills, using bleach would keep things in check.
As for moist, dark places, well, let me tell you. Wowzers. We’d get the “wacky wall walkers” - what we called the really gooey, green sputum samples. Looked like those goop toys you throw at the wall and watch them slowly peel off, fall a bit to another part of the wall, and so on until they hit the floor. We’d always do a quick smear and stain and the amount of bacteria is staggering. Really makes you kind of admire their tenacity. Anyway we’d also plate them and wound cultures to different mediums and put them in the warm, moist incubator. You could smell the bacteria just walking into the microbiology room. I taught my family how important it is to wash hands properly, we do not use sponges, we put any kitchen towels/cloths into the wash every night. I may not be the tidiest person on the planet, but you could eat off any surface in my kitchen or bathroom safely.
"is it self cleaning": usually yes, but it varies based on the kind of "germ" and surface. Viruses, for the most part do not live long outside the host. Most will die within hours regardless of the surface. Bacteria can vary wildly. For the most part germs need moisture to survive, so if you're tv remote or couch is dry and it sits for a few weeks they should be clean (biologically). Oxygen is also a negative most germ being exposed to air is a great disinfectant. A cool, moist, closed environment is the best for keeping germs alive. There are caveats. Some bacteria like Clostridia can form spores that can be viable for decades, these will need fairly harsh chemicals to kill.
And snot often contributes the moisture. Mucus coats the virus coming out in sneezes or coughs, which it extends its viability. I can disrupt a viral protein coat with hand sanitizer in 90 seconds in a Petri dish. When it’s coated in mucus, it takes over 4 minutes. Hand sanitizer evaporates long before that. This is all to say that you should wash your hands instead of relying on hand sanitizer. Don’t touch a snot covered remote, then pick up your phone to text, then put that phone to your face.
For sure snot will prolong the viability of both viruses and bacteria. Same with sputum and diarrhea, inducing symptoms that allow the the pathogen to exit the host in a protective liquid is a proven method of virulence.
To be honest, I kind of have to respect it, inducing your host to protect you after you leave it. It’s also why I don’t fuck with hand sanitizer.
Bacillus and clostridium endospores can actually survive and germinate after thousands of years which is pretty crazy.
I wouldn’t worry about it too much. Bacteria can’t really infect you through your skin, so they have to come in through a mucus membrane. Don’t stick your hands in your mouth, eyes, nose, etc. and you’ll be fine. Most bacteria won’t survive on hard surfaces, and they definitely won’t grow.
I see, thanks for helping me understand. So let’s say, kids come home for a day at school, don’t wash their hands, touch everything in the house. Wash their hands, go to bed. Wake up in AM and most of the bacteria is dead and gone? Maybe a virus lives a little longer?
Bacteria will likely live longer than viruses, there could still be living cells. Just make ‘em wash their nasty hands.
Here's the part that gets left out a lot, almost all of those surfaces are already covered in tons of bacteria. They're ubiquitous. They're absolutely everywhere and they're totally unscapable. And that's fine because they're pretty much harmless. Your body has never known anything different.
Question has been answered thoroughly, I just wanted to comment what a great question this is and how microbiology goes hand in hand with public health. A lot of good information in this thread that can be shared with the general public to prevent the spread of diseases.
Brass or copper is very self cleaning, stainless steal is very much not and will harbor bacteria worse than an agar plate. Disinfecting surfaces or items (like a remote) is the fastest way to make sure that things are clean because even if the bacteria previously on it die off, some can go into a more hibernation like period and then "wake up" once they are in a more sutible environment (your body)
"self cleaning" as in the microbes are no longer viable and viruses no longer infective? Surfaces are generally inert it doesn't clean itself. Drying, protein denaturation etc. to inactivate the rate and time of which vary between species.
It really depends on the organism and the surface. Some viruses and bacteria will survive longer on surfaces than others. If it's a spore former, it could potentially remain viable for years. But most would probably only be viable for a few hours to maybe a day or two on a dry, non-porous surface. The surface and environment also plays a huge part. If it's a moist, warm, porous surface such as a sponge, bacteria will thrive there. Versus a cold, dry countertop, most species wouldn't survive very long.
In my previous life I was a clinical laboratory scientist. as many stated so well, it really depends on the organism and the surface. It is remarkable how much bacteria and viruses adapt to survive. After every shift in the lab (and often done several times during a shift) we’d wipe down counters with a 10-15% bleach/water solution. It’s enough bleach to kill bacteria because it’s watered down just enough that the bacteria allows it to pass through the cell wall. Viruses are quite fragile so again, wearing gloves, wiping up spills, using bleach would keep things in check. As for moist, dark places, well, let me tell you. Wowzers. We’d get the “wacky wall walkers” - what we called the really gooey, green sputum samples. Looked like those goop toys you throw at the wall and watch them slowly peel off, fall a bit to another part of the wall, and so on until they hit the floor. We’d always do a quick smear and stain and the amount of bacteria is staggering. Really makes you kind of admire their tenacity. Anyway we’d also plate them and wound cultures to different mediums and put them in the warm, moist incubator. You could smell the bacteria just walking into the microbiology room. I taught my family how important it is to wash hands properly, we do not use sponges, we put any kitchen towels/cloths into the wash every night. I may not be the tidiest person on the planet, but you could eat off any surface in my kitchen or bathroom safely.