How best to disinfect a plastic beverage cap that fell on the floor?

[CharonY]

28 minutes ago, mistermack said:

The thing with ecoli is that it can survive and multiply in the gut, which is how one bacterium can be dangerous. I can't remember where I read that, but it did include the info that people with lower levels of acid in the stomach are especially vulnerable. And that includes people who take acid suppressors, including Omeprazole, which I take, one a day. That's what made it stick in my memory.

All of the ones mentioned are able are food-borne diseases, i.e. they are able to survive and multiply after ingestion (which is why I listed them, though intestinal infection with C. botulinum is perhaps less common). But as I mentioned, a single EHEC is very unlikely to establish infection (for a variety of reasons, some related to the pathobiology and expression of the mentioned Shiga toxin, which is partially regulated via quorum sensing and requires some cell density in order to establish successful infections and to compete with the existing microbiota, which includes other E. coli), though 10-100 is pretty much at the lower end of observed dosages for bacteria. 

[mistermack]

One single bacterium can become 16 after four replications. And a possible 128 after 7.  So what stops the process, in the case of a single bacterium, in a person with low acid levels in their stomach? 

[CharonY]

33 minutes ago, mistermack said:

One single bacterium can become 16 after four replications. And a possible 128 after 7.  So what stops the process, in the case of a single bacterium, in a person with low acid levels in their stomach? 

As with all bacterial infections, it needs to overcome defenses, find a niche to colonize and compete with existing bacteria. Every part in our body that can be colonized, already is. A lone bacterium arriving in the gut even after passing the stomach will face billions and of others already occupying the niche and denying them nutrients. Pathogens have nifty tools to carve a niche, by e.g. using toxins and/or effector proteins that mess with the host and remodeling the environment for them. Even so, a single cell has little chance to be successful in acquiring enough  resources to compete. Therefore, often pathogens use quorum sensing to regulate pathogenicity factors. If they are alone, they try to stick around but cause no disease. But once there are enough coming in, they communicate with each other and start producing toxins and other factors,  which make the host sick.

BTW, my wife, who is more on the clinical side mentioned that infectious dose I mentioned was likely an underestimate based on an error in one early paper on EHEC. About 500-700 cells are more likely, which is still considered very low for a food-borne pathogen. In folks with stomach acid issues they might be lower, but just physically a single cell (except of in vitro, perhaps) is unheard of.

[mistermack]

I think you and your wife are confusing "infectious dose" with what I am talking about, which is the possibility of an infection from one bacterium. It's a totally different question. The term "infectious dose" used as standard in the business refers to the ID50, which is the dose that will infect 50 percent of an average population. 

Of course 500-700 cells is more likely, in that case. But that says nothing about the potential for one bacterium, in the right circumstances, being able to replicate and cause an infection. I know that I read or heard that one strain of ecoli can, under the right circumstances, cause a harmful infection from a single bacterium. I didn't dream it, it was from an informed source, but of course I didn't note it at the time as I didn't anticipate ever discussing it. 

This link is interesting. The first post is from someone who works in the field : Quote : " That said, I spend all day every day studying bacterial pathogens, " and : In this case, it depends on the particular species of bacteria you're talking about. Some species can cause an infection from just a couple of bacteria; others can need hundreds (or more!) in order to reliably infect a host."        

It's not a paper, it's a discussion, but it's the sort of thing that I'm talking about. The source that I remember made it clear that this strain of ecoli is highly unusual in being able to cause infection from such a small initial dose. 

https://www.reddit.com/r/askscience/comments/1go68r/can_i_get_sick_from_a_single_bacteria_cell_or/     

 

[StringJunky]

24 minutes ago, mistermack said:

I think you and your wife are confusing "infectious dose" with what I am talking about, which is the possibility of an infection from one bacterium. It's a totally different question. The term "infectious dose" used as standard in the business refers to the ID50, which is the dose that will infect 50 percent of an average population. 

Of course 500-700 cells is more likely, in that case. But that says nothing about the potential for one bacterium, in the right circumstances, being able to replicate and cause an infection. I know that I read or heard that one strain of ecoli can, under the right circumstances, cause a harmful infection from a single bacterium. I didn't dream it, it was from an informed source, but of course I didn't note it at the time as I didn't anticipate ever discussing it. 

This link is interesting. The first post is from someone who works in the field : Quote : " That said, I spend all day every day studying bacterial pathogens, " and : In this case, it depends on the particular species of bacteria you're talking about. Some species can cause an infection from just a couple of bacteria; others can need hundreds (or more!) in order to reliably infect a host."        

It's not a paper, it's a discussion, but it's the sort of thing that I'm talking about. The source that I remember made it clear that this strain of ecoli is highly unusual in being able to cause infection from such a small initial dose. 

https://www.reddit.com/r/askscience/comments/1go68r/can_i_get_sick_from_a_single_bacteria_cell_or/     

 

It's Lethal Dose 50 - The amount it takes to kill half a population.

[mistermack]

11 minutes ago, StringJunky said:

It's Lethal Dose 50 - The amount it takes to kill half a population.

No, you're wrong. Both terms are used, but the common one is ID50. 

This is wiki article is interesting, it sheds more light on the subject, and really does illustrate how few ecoli are needed to cause infection :

 

However, experience shows that it may be easier for the mind to compare the doses causing the effect in 50% or 1% of consumers. Here are some values of D1 (dose causing the effect considered in 1% of consumers exposed to the hazard):

• Escherichia coli (EHEC), haemolytic-uremic syndrome in children under 6 years: 8.4 bacterial cells;
• Escherichia coli (EHEC), haemolytic-uraemic syndrome in children aged 6 to 14 years: 41.9 bacterial cells;           

You can see from that article that it only takes 8.4 cells to infect 1% of children under 6, contrary to what Charon has been posting. To be honest, I think that proves my point. I'm not talking about 1%, I'm talking about the chance of one bacterium causing an infection, in favourable circumstances. 

https://en.wikipedia.org/wiki/Minimal_infective_dose#:~:text=However%2C experience shows,41.9 bacterial cells%3B  

 

[StringJunky]

24 minutes ago, mistermack said:

No, you're wrong. Both terms are used, but the common one is ID50. 

This is wiki article is interesting, it sheds more light on the subject, and really does illustrate how few ecoli are needed to cause infection :

 

However, experience shows that it may be easier for the mind to compare the doses causing the effect in 50% or 1% of consumers. Here are some values of D1 (dose causing the effect considered in 1% of consumers exposed to the hazard):

• Escherichia coli (EHEC), haemolytic-uremic syndrome in children under 6 years: 8.4 bacterial cells;
• Escherichia coli (EHEC), haemolytic-uraemic syndrome in children aged 6 to 14 years: 41.9 bacterial cells;           

You can see from that article that it only takes 8.4 cells to infect 1% of children under 6, contrary to what Charon has been posting. To be honest, I think that proves my point. I'm not talking about 1%, I'm talking about the chance of one bacterium causing an infection, in favourable circumstances. 

https://en.wikipedia.org/wiki/Minimal_infective_dose#:~:text=However%2C experience shows,41.9 bacterial cells%3B  

 

Yes, ok. That's a bit confusing to the casual eye that may mistake LD50 for ID50, or vice versa.

[mistermack]

7 minutes ago, StringJunky said:

Yes, ok. That's a bit confusing to the casual eye that may mistake LD50 for ID50, or vice versa.

Yes, I only noticed that after I posted. Capital i is confusing, i should have used the lower case. ☺️

[StringJunky]

3 hours ago, mistermack said:

Yes, I only noticed that after I posted. Capital i is confusing, i should have used the lower case. ☺️

That may be what the pros do as well. It was general comment, not targeted at you specifically.

Edited January 15, 2022 by StringJunky

[CharonY]

7 hours ago, mistermack said:

I think you and your wife are confusing "infectious dose" with what I am talking about, which is the possibility of an infection from one bacterium. It's a totally different question. The term "infectious dose" used as standard in the business refers to the ID50, which is the dose that will infect 50 percent of an average population. 

No, I was referring to the minimal infective dose and I was also referring to adult dosages as unless I missed something we were not talking about children. But more importantly, for children the numbers are even less certain than for adults. A challenge is that to establish these values, the most accurate way is to feed people defined doses. But generally you cannot do it with children and also you don't do it in cases where serious illness is likely (as is with EHEC). There, we use a few ways to provide estimates, but obviously a large error bar is attached to those. While I have seen a study which estimated something between 10-100 cells, if you look a t more estimates, the values are pushed up closer to 500 for EHEC. For Shigella dysenteriae there is actually a paper with volunteers (very small cohort) where a dose of 10 cells caused symptoms but that is probably close to the lower limit. 

 

6 hours ago, mistermack said:

his is wiki article is interesting, it sheds more light on the subject, and really does illustrate how few ecoli are needed to cause infection :

 

However, experience shows that it may be easier for the mind to compare the doses causing the effect in 50% or 1% of consumers. Here are some values of D1 (dose causing the effect considered in 1% of consumers exposed to the hazard):

• Escherichia coli (EHEC), haemolytic-uremic syndrome in children under 6 years: 8.4 bacterial cells;
• Escherichia coli (EHEC), haemolytic-uraemic syndrome in children aged 6 to 14 years: 41.9 bacterial cells;   

While the numbers might be reasonable and make sense given the reported dosages for adults (and obviously children are more susceptible), I note that they are still higher than one bacterium (and therefore significantly higher in adults)  and perhaps more problematic, it is unclear where the values come from as no studies are cited. But given the issues I mentioned above, it is unlikely that one can establish ID1 or ID50 doses with EHEC in humans. There is one estimate that places the minimal infective dose in the area of S. dysenteriae (and considering the actions of the Shig toxin might not be entirely unreasonable).

But to provide an example how these estimates are done. One of the lowest values I am aware of were reported by Tilden et al. (Am J Pub Health, 1996 86:1142-1145). Here they investigated bacterial titer in salami from which folks got sick and based on self-reporting of patients of how many slices of salami they consumed and the bacterial load they found in samples they estimated numbers between 2-45 cells causing the disease. As you can imagine, each step is rather prone to errors. Moreover the data is based on four patients, of which 3 were under the age of five. Another issue is that traditionally, bacterial titer is estimated from colony forming units, isolated from food. Newer analyses which focuses more on microscopic analyses indicate that these may often result in lower actual bacterial presence (depending on from which matrix you isolate and how you cultivate the colonies).

I will say that due to lack of data the original estimate I provided (10-100) as lower bound might not be entirely unreasonable, but there is good reason to believe that it is at least somewhat higher. There is no data to support single-cell infections, however (which would be almost impossible to assess in either case).

 

[mistermack]

To be honest, I have more confidence in the people behind the links I provided, than your bluster. I was originally not sure if I remembered the original source correctly, but I'm now quite sure that I did. The 8.4 cells on average, needed to infect 1% of the young children, makes it clear that I recalled it correctly. I said that a single bacterium can lead to an infection, and it's perfectly clear from those links that it can. Obviously, not in 50% of the population, or 1%,  but in some cases. 

[CharonY]

39 minutes ago, mistermack said:

To be honest, I have more confidence in the people behind the links I provided, than your bluster. I was originally not sure if I remembered the original source correctly, but I'm now quite sure that I did. The 8.4 cells on average, needed to infect 1% of the young children, makes it clear that I recalled it correctly. I said that a single bacterium can lead to an infection, and it's perfectly clear from those links that it can. Obviously, not in 50% of the population, or 1%,  but in some cases. 

You mean the unreferenced wikipedia link vs the references I have given above? I mean, you do you, but it is funny that the link you provided actually does not support your claim (and it is actually in the range of the references given so no big discrepancy there, really).

I will concede that the comment regarding underestimation based on CFUs is a bit technical and is more of an ongoing discussion in the community whereas safety regulations still rely on this method (the alternative techniques we have been using is based on flow cytometry, which is becoming more prevalent in food and water testing).

So the estimate of 10-100 cells given above (but not 1) is a fair estimate, if you choose to ignore the above caveat regarding the limits of plate counting.

And I do apologize to OP for taking it so far off-topic. 

[Doogles31731]

The LD50 was an old yardstick used by Therapeutic Goods Agencies as a broad guidelines to the safety of medications. At one stage, it was compulsory in Australia for Drug Companies to present an LD50 with any new pharmaceuiticals. It represented the dose rate that would kill 50% of a batch of mice or rats. It has been discontinued for animal welfare reasons. It had nothing to do with bacterial counts.

As far as the dropping of a beverage cap on a floor is concerned, if it occurs in an average household, just pick it up, wipe any dirt off with your finger, a tissue or handkerchief and shove it back on the bottle. Average household floors possibly have more soil or bitumen or cement dust contamination than benches, but the chances of the floor alone containing pathogenic organisms in sufficient quantity to cause any probems are remote. Soil bacteria are mostly saprophytes.

If you were compelled to disinfect it, you could place it in a cup or glass of bleach solution at the recommended strength for a few minutes. If you did not wish to have any of the residual bleach contact your mouth, you would have to use sterilized forceps to hold the cap for a rinse under cold, but previously-boiled water. And no matter where you put it after that, it will contact other micro-organisms. So any such procedure would be a waste of time.

The floors in hospital-type buildings are a different matter, and there is an article on the importance of considering floor disinfection in  this article -- https://infectioncontrol.tips/2021/06/09/floor-hygiene-and-the-under-studied-risk-of-pathogen-dissemination/ . This article also discusses the unlikelihood of picking up pathogenic micro-organisms from floors.

[mistermack]

4 hours ago, Doogles31731 said:

The LD50 was an old yardstick used by Therapeutic Goods Agencies as a broad guidelines to the safety of medications. At one stage, it was compulsory in Australia for Drug Companies to present an LD50 with any new pharmaceuiticals. It represented the dose rate that would kill 50% of a batch of mice or rats. It has been discontinued for animal welfare reasons. It had nothing to do with bacterial counts.

No, that's the iD50. The infectious dose, which is obviously nothing to do with medications. It's the dose that will infect 50% on average. 

Charon claims that he was talking about the "minimal infectious dose", but he contradicted himself. It's obvious from the figures that the minimal dose would apply to young children, not adults, but he immediately claimed to be talking about adults, not children. 

He is also claiming that the "minimal infectious dose" was 500 to 700 cells, before backtracking in the face of evidence that 8.4 cells infects 1% of children. 

My point is that if the iD1 is 8.4 cells, then it's obvious that the minimal infectious dose will have to be considerably less than that, taking it down around the single bacterium level. 

[CharonY]

You seem to interpret rather than read and forget what actually has been said. You said EHEC required a single cell, I said lit says 10-100. No one was talking about children at this point. 

I said the real value is likely higher as plate counting often underestimates cell counts (which applies mostly to dried or processed food). Then you came with an unreferenced wiki (which actually states to having quality issues) indicating id1 of around 8 for children. This introduced children for the first time.

While it is unclear how they calculated this, as for EHEC you cannot make actually dose response curves and especially not in children, it does not provide evidence of single cell infection beside your gut feeling. I think I should stop taking it off-topic further, especially in the face of strong resilience to information.

For those interested, one of my references above actually estimated the minimal infective dose in children as low as 2. But I also mentioned why the methodology (self-reporting) is problematic.

[J.C.MacSwell]

Pick it up within 5 seconds and quickly put it back on the bottle:

https://kidshealth.org/en/kids/5-seconds.html#:~:text=What's the 5-Second Rule,in 5 seconds or less.

[TheVat]

I've been missing the soothing cheerful hum of germophobic hand-wringing that once came from this thread.   

Stunted immune systems are proliferating wildly as people refuse to eat floor food and the like.

The best course is to take the bottle cap, swirl it around in the cat's litter box, then rinse off in the toilet bowl, then put back on the bottle.  

You're welcome.

[J.C.MacSwell]

3 hours ago, TheVat said:

I've been missing the soothing cheerful hum of germophobic hand-wringing that once came from this thread.   

Stunted immune systems are proliferating wildly as people refuse to eat floor food and the like.

The best course is to take the bottle cap, swirl it around in the cat's litter box, then rinse off in the toilet bowl, then put back on the bottle.  

You're welcome.

...don't wash, don't rinse, but repeat...

[ScienceNostalgia101]

Not sure if this is worth a separate thread or not, but since it involves vinegar and household food / beverage items I figure this is closely-enough related.

 

I recently threw away a big bag of potatoes (it was originally a big bag of mixed vegetables when I first got it months ago, but I finished everything but the potatoes first) because they were starting to look discoloured. As a precaution, I poured some vinegar onto the section of the fridge the bag had been touching, but then immediately wiped off the vinegar with some tissues. Is a few seconds' worth of soaking in vinegar adequate to disinfect it or would it need to be soaking for longer and/or soaking in something else?

[mistermack]

I would say that a wipe over with a slightly soapy cloth would be more than enough for your fridge. Vinegar or cleaning products might give a taste to other items in the fridge. 

I make sourdough bread, and keep a culture of yeast and bacteria alive in the sourdough starter. At room temperature, it needs refreshing twice a day. In the fridge, once a week is more than enough. So a crude estimate is that the fridge slows down moulds and bacterial action by a factor of 14 but it's probably more. 

Anyway, you breathe in mould and bacteria spores with every breath, and they flood in when you open the fridge door. So even if you sterilised the fridge interior, you would still get germs in it. So just a wipe clean with a damp rag is as good as anything.

[StringJunky]

18 hours ago, ScienceNostalgia101 said:

Not sure if this is worth a separate thread or not, but since it involves vinegar and household food / beverage items I figure this is closely-enough related.

 

I recently threw away a big bag of potatoes (it was originally a big bag of mixed vegetables when I first got it months ago, but I finished everything but the potatoes first) because they were starting to look discoloured. As a precaution, I poured some vinegar onto the section of the fridge the bag had been touching, but then immediately wiped off the vinegar with some tissues. Is a few seconds' worth of soaking in vinegar adequate to disinfect it or would it need to be soaking for longer and/or soaking in something else?

Haven't you got a working immune system?

[zapatos]

Not to mention that keeping potatoes in the fridge is frowned upon as it makes the potatoes taste sweet and leads to increases in acrylamide, a cancer causing chemical, when cooked.

[ScienceNostalgia101]

I... was not aware of that. At all. I thought all it'd do was increase the veggies' shelf life. Next time I'll only buy enough to use within however long they last in the cupboard. (Although looking up acrylamide on Google, I'm some glad I boiled my potatoes instead of frying or roasting them.)

 

As for my immune system... I'm not immunocompromised or anything on that level, but I don't fully trust it, what with it having attacked my own insulin-producing cells as a type 1 diabetic. Isn't it early in childhood that the immune system figures out what's harmful and what isn't? How much further benefit is there in adulthood to deliberately eating food that was put on the same glass surface a bag of discoloured potatoes was previously on? Or is a few seconds' worth of immersion in vinegar going to make the point moot now anyway?

 

I don't intend to walk on eggshells or anything like that, I just prefer to take precautions where it's not too much trouble.

[zapatos]

21 minutes ago, ScienceNostalgia101 said:

I... was not aware of that. At all. I thought all it'd do was increase the veggies' shelf life. Next time I'll only buy enough to use within however long they last in the cupboard. (Although looking up acrylamide on Google, I'm some glad I boiled my potatoes instead of frying or roasting them.)

 

I learned about that when I put potatoes in the fridge and made potato salad that tasted AWFUL it was so sweet! 😄

[CharonY]

1 hour ago, ScienceNostalgia101 said:

Isn't it early in childhood that the immune system figures out what's harmful and what isn't?

No, your adaptive immune response changes throughout your whole live. It is kind of the point of it, too.