4 ms·

Note: > biocide-exposed spores were spiked onto surgical scrubs and patient gowns and recovery was determined by a plate transfer assay The article says nothi

by kpozin 3y ago

Note: > biocide-exposed spores were spiked onto surgical scrubs and patient gowns and recovery was determined by a plate transfer assay The article says nothing about washing scrubs and gowns. They put bleach-treated spores onto fabric, did not treat the fabric, and then collected samples from the fabric.

TeMPOraL 3y ago
I.e. this is less of a "spores on gowns surviving disinfection" case, and more of a "you bleached this surface, you thought it's enough, but your gown touched it too early and the fabric 'rescued' the spores" one, am I right?
- haldujai 3y ago
  Yes, the relevance is providers don’t change scrubs between patients (although do wear typically disposable gowns and gloves when entering a patient room with c. diff). Also relevant for things that travel between rooms and are disinfected in between, like ultrasound machines. Other studies have reported that spores can survive washing processes in use. https://pubmed.ncbi.nlm.nih.gov/30322417 https://pubmed.ncbi.nlm.nih.gov/30322417
vaidhy 3y ago
The fact the spores were treated with bleach and were still active means that you treating the fabric with the same biocide will not kill the spores. Spores alone survive the bleach. Spores + fabric will survive the bleach. Hence treated fabric cannot be considered safe.
- refulgentis 3y ago
  That doesn't necessarily follow -- it's tempting because it seems obvious. If X + Y = Z, X on surface + Y = Z _must_ follow, because "on surface" was just a hidden term in X + Y = Z anyway...right? But, both biology and fabrics have a lot of hidden surface (pun intended :P)
  - deleted 3y ago
    [deleted]
- chiefalchemist 3y ago
  Perhaps. But why not test that then? Why the special non-real life case? Because it got a result worth sensationalizing? For me, it makes me wonder what other study "gymnastics" they used. I hear ya. But to mitigate any doubt they should have covered all their bases, or at least the base most inline witb real life.
  - haldujai 3y ago
    This is a real life case. This article explores surface disinfection (commonly bleach in the hospital). Although provider gowns are removed after entering contaminated rooms, disinfected surfaces commonly come into contact with provider scrubs which are not laundered in between same day patient encounters as well as other patients (such as the table of a CT or MRI). I don’t see the gymnastics you’re referring to, other studies have looked at laundering processes which is not the focus of this study. https://pubmed.ncbi.nlm.nih.gov/30322417/ https://pubmed.ncbi.nlm.nih.gov/30322417/ https://academic.oup.com/lambio/article/75/6/1449/6989408 https://academic.oup.com/lambio/article/75/6/1449/6989408
- derefr 3y ago
  You don't just sterilize fabric with bleach. (How would that even work? Hang the gown, spray the bleach on it, and let it drip off?) You sterilize fabrics with bleach + water + detergent + heat + agitation — with the goal not being to lyse the spores/other germs, but rather to detach all the contaminants from the fabric and suspend them in the water — which then gets flushed away. In theory, bleach could help decrease the adhesion of the spore to a surface. A possible mechanism would be if it oxidized — and so weakened/destroyed — some spiky organic hooks that the spores were using to adhere to the fabric. Of course, agents other than bleach — things not normally considered biocides, in fact — would likely be a lot more effective at removing spores during fabric washing, since the goal is detachment, not lysing the spore. The obvious things (detergents themselves, and other soaps) would work, of course, to varying degrees. But also, less-obvious things could provide benefits here. For example, if spores tended to stay adhered to fabrics because they possessed a rough proteinous exosporium that acted sort of like nano-scale velcro, then conditioners (yes, like the kind you use in hair) might get that protein coat to relax and lay flatter, in a way that disrupts the velcro-like effect. Lubricants might also work, by "filling up" the rough valleys of the spore's surface. (Of course, you'd then need an extra wash cycle to remove the lubricants.)
  - exmadscientist 3y ago
    There are some really amazing detergents out there. My go-to for cleaning anything I don't have specific information about is Tergajet. It's gentle, extremely powerful, low-foaming (so machine compatible), oxidizing, bleach compatible, and contains a protein degradation enzyme potent enough to disrupt prions: https://technotes.alconox.com/detergents/tergazyme/do-enzyme-detergents-disinfect/ https://technotes.alconox.com/detergents/tergazyme/do-enzyme... The downside to this magic stuff is that it's fairly expensive ($45 for 4 pounds). So, not for wanton use. But well worth it to solve tough problems or when time is more important than money.
    - hinkley 3y ago
      oxidizing and bleach compatible is an unusual pairing is it not? There are a bunch of chemicals you can't mix with bleach because you create chemical weapon precursors if you do. Even the precursors can send you to the ER.

by kpozin 3y ago

TeMPOraL 3y ago

I.e. this is less of a "spores on gowns surviving disinfection" case, and more of a "you bleached this surface, you thought it's enough, but your gown touched it too early and the fabric 'rescued' the spores" one, am I right?

haldujai 3y ago
Yes, the relevance is providers don’t change scrubs between patients (although do wear typically disposable gowns and gloves when entering a patient room with c. diff). Also relevant for things that travel between rooms and are disinfected in between, like ultrasound machines. Other studies have reported that spores can survive washing processes in use. https://pubmed.ncbi.nlm.nih.gov/30322417 https://pubmed.ncbi.nlm.nih.gov/30322417

vaidhy 3y ago

The fact the spores were treated with bleach and were still active means that you treating the fabric with the same biocide will not kill the spores. Spores alone survive the bleach. Spores + fabric will survive the bleach. Hence treated fabric cannot be considered safe.

refulgentis 3y ago
That doesn't necessarily follow -- it's tempting because it seems obvious. If X + Y = Z, X on surface + Y = Z _must_ follow, because "on surface" was just a hidden term in X + Y = Z anyway...right? But, both biology and fabrics have a lot of hidden surface (pun intended :P)
- deleted 3y ago
  [deleted]
chiefalchemist 3y ago
Perhaps. But why not test that then? Why the special non-real life case? Because it got a result worth sensationalizing? For me, it makes me wonder what other study "gymnastics" they used. I hear ya. But to mitigate any doubt they should have covered all their bases, or at least the base most inline witb real life.
- haldujai 3y ago
  This is a real life case. This article explores surface disinfection (commonly bleach in the hospital). Although provider gowns are removed after entering contaminated rooms, disinfected surfaces commonly come into contact with provider scrubs which are not laundered in between same day patient encounters as well as other patients (such as the table of a CT or MRI). I don’t see the gymnastics you’re referring to, other studies have looked at laundering processes which is not the focus of this study. https://pubmed.ncbi.nlm.nih.gov/30322417/ https://pubmed.ncbi.nlm.nih.gov/30322417/ https://academic.oup.com/lambio/article/75/6/1449/6989408 https://academic.oup.com/lambio/article/75/6/1449/6989408
derefr 3y ago
You don't just sterilize fabric with bleach. (How would that even work? Hang the gown, spray the bleach on it, and let it drip off?) You sterilize fabrics with bleach + water + detergent + heat + agitation — with the goal not being to lyse the spores/other germs, but rather to detach all the contaminants from the fabric and suspend them in the water — which then gets flushed away. In theory, bleach could help decrease the adhesion of the spore to a surface. A possible mechanism would be if it oxidized — and so weakened/destroyed — some spiky organic hooks that the spores were using to adhere to the fabric. Of course, agents other than bleach — things not normally considered biocides, in fact — would likely be a lot more effective at removing spores during fabric washing, since the goal is detachment, not lysing the spore. The obvious things (detergents themselves, and other soaps) would work, of course, to varying degrees. But also, less-obvious things could provide benefits here. For example, if spores tended to stay adhered to fabrics because they possessed a rough proteinous exosporium that acted sort of like nano-scale velcro, then conditioners (yes, like the kind you use in hair) might get that protein coat to relax and lay flatter, in a way that disrupts the velcro-like effect. Lubricants might also work, by "filling up" the rough valleys of the spore's surface. (Of course, you'd then need an extra wash cycle to remove the lubricants.)
- exmadscientist 3y ago
  There are some really amazing detergents out there. My go-to for cleaning anything I don't have specific information about is Tergajet. It's gentle, extremely powerful, low-foaming (so machine compatible), oxidizing, bleach compatible, and contains a protein degradation enzyme potent enough to disrupt prions: https://technotes.alconox.com/detergents/tergazyme/do-enzyme-detergents-disinfect/ https://technotes.alconox.com/detergents/tergazyme/do-enzyme... The downside to this magic stuff is that it's fairly expensive ($45 for 4 pounds). So, not for wanton use. But well worth it to solve tough problems or when time is more important than money.
  - hinkley 3y ago
    oxidizing and bleach compatible is an unusual pairing is it not? There are a bunch of chemicals you can't mix with bleach because you create chemical weapon precursors if you do. Even the precursors can send you to the ER.