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[–]carmacae 77 points78 points ago

[–]ficknerich 111 points112 points ago

Basically silver denatures enzymes involved in key metabolic processes

[–]Nacho_Average_Libre 72 points73 points ago

Could you dumb that down just a little more...

[–]kennerly 173 points174 points ago

Basically silver breaks down key enzymes making them useless to the bacteria. So the bacteria die without them.

[–]Nacho_Average_Libre 127 points128 points ago

On behalf of all the dumb asses, thank you!

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[–]USRB 91 points92 points ago

There's these chemicals that do really important things, but they're really fussy about when they work. Heat them up too much, cool them down too much and they'll just stop working. What ficknerich said is that silver stops these chemicals working. These chemicals are enzymes.

Denaturing them means that you're breaking them, so they won't work again. Involved in key matabolic processes means that you need them to live. So you're breaking stuff that you need to live. This kills the bacteria.

[–]Crypticusername 2 points3 points ago

What does silver do to it?

[–]USRB 5 points6 points ago*

I believe that the silver forms chemical bonds with the enzymes. So this is like the silver is 'sticking on' to the enzymes, basically gluing them to the silver, so they can't do whatever it is that they do (apparently, the enzymes help to make energy for the cell). Kind of like the enzymes are licking the metal pole, but it's winter, so it can't pull away. Then the enzymes can't make energy for the cell anymore, so it dies.

I only skimmed a bit of the article, I think you would need to read it yourself, but I saw stuff like 'ADP and ATP', 'energy generation' and 'stable S-Ag bonds', which seems to mean that the silver just latches on to sulfur that is found in enzymes located on the outside of the cell, so they can't transport energy around. I'm just a high-school student, so this is almost, but not quite, educated guessing.

[–]badastrobiology 10 points11 points ago*

Kinda. So enzymes are like weird bundles of stuff with different areas displaying different properties, including but not limited to hydrophobicity, charge distribution/acidity, hydrogen bonding, and "rigidity". This is all due to the chemical properties of the R- groups on the NH2-CH3R-COOH amino group. These amino groups can string together and form a peptide chain(+ NH3-CH3R1-CO=NH-CH3R2-COO-), and a given amino acid can be made out of multiple peptide chains (often the same peptide chain interacting with itself).

Another thing to consider is that enzymes go through a lot of processing after and as they are transcribed, so sometimes other enzymes will cause for reactions to occur on the peptide chain that cause for certain segments of a peptide chain to bond to itself, and other times prevent or undo it (pretty sure on that).

There is this specific kind of bond, called a disulfide(R-S-S-R) bond that can form under certain conditions when two thiol (R-SH) groups are near each other in space. What the silver ion can do, is catalyze a reaction between free O2 in the bacteria's cytoplasm (inside jelly of the cell) and the hydrogen atoms of the R-S-H bond, forming water and an R1-S-S-R2, or disulfide, bond. Because enzymes are weird bundles of stuff with different areas displaying different properties, this will generally fuck up the function of the enzyme to some extent.

It also goes on to say that the silver ion is able to wedge itself between adjacent purine and pyrimidine bases in DNA, disrupting the binding between the two (what keeps DNA in its double helical shape that is recognized by many of the enzymes that interact with it).

And apparently silver is able to enter cells through proteins that either form a channel or transport other similarly-charged ions across the membrane.

Hope that explained things well!

It probably does more, but I stopped reading there.

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[–]ShakaUVM 0 points1 point ago

Why does this affect bacterial cells, but not human cells?

[–]Crypticusername 0 points1 point ago

Makes sense, thanks!

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[–]Oiman 10 points11 points ago

Think of enzymes as power tools. Every power tool can be used for a specific purpose. Likewise, every enzyme can perform a specific action (pretty much any chemical action, from breaking down toxins to repairing DNA).

Like power tools, enzymes can 'break' when used in the wrong environment. Imagine submerging your electric drill in water, or using your chainsaw on the (sun-facing) surface of Mercury. Both tools likely won't be able to perform their particular tasks anymore.

On a molecular level, enzymes are 'bent out of shape' by those environmental conditions. They just won't fit onto the chemicals they are supposed to fit on, even if the hostile environmental conditions are removed.

If the chemicals those enzymes work on are vital to the cell, the cell dies.

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[–]halogen1212[S] 9 points10 points ago

Thank you! I think this is exactly what I was looking for.

[–]khazzar12 144 points145 points ago*

Finally an AskScience question I can be genuinely helpful in!

I'm currently working on this for my final year under graduate project and I recently completed a literature review on the antimicrobial properties of silver nanoparticles (very very small amounts of silver). While their antimicrobial action isn't exactly the same as colloidal silver or solid silver I think it's still relevant so I'll just copy+paste what I wrote about it:

There is still quite a lot of debate in the scientific community on the exact mechanism by which silver nanoparticles carry out their antimicrobial action. However, the main mechanism by which silver nanoparticles exhibit their antimicrobial action appears to be through the release of silver ions.[14] There has, however, been quite a lot of contradicting literature on the subject. It has also been suggested that the silver nanoparticles causes the formation of reactive oxygen species (ROS)[15] and that silver nanoparticles directly damage the bacterial cell membrane. In fig.1 below these three mechanisms are illustrated.

If the silver nanoparticles released silver ions, the ions may interact with membrane proteins and affect their function. The silver nanoparticles may also induce the formation of ROS which could cause the degradation of the bacterial cell’s DNA. The ROS could cause oxidative damage to the bacterial cell membrane as well as membrane proteins. The silver nanoparticles could also directly affect the membrane of the bacterial cell.[16]

Edit: Was asked to provide my citations:

[14] Feng, Q.L et al., 2000. A mechanistic study of the antibacterial effects of silver ions on Escherichia coli and Staphylococcus aures. Journal of Biomedical Materials Research, 52(4), 662-668. Additional Pubmed link.

[15] Jun, S.K et al., 2007. Antimicrobial effects of silver nanoparticles. Nanomedicine: Nanotechnology, Biology and Medicine, 3(1), 95-101.

[16] Marambio-Jones, C. et al., 2010. A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment. Journal of Nanoparticle Research , 12(5), 1531-1551.

Sorry for using tinyurl links but the actual urls had internal parentheses that messed with the formatting.

[–]ColloidMan5000Colloidal Materials|Nanoparticles|Catalysis 12 points13 points ago

Interesting sounding project, but how are you differentiating between silver nanoparticles and colloidal silver? They are more or less the same thing with some subtle differences.

[–]khazzar12 5 points6 points ago

I can't say. The head researchers on this project are currently trying to acquire IP rights and patents over the process and developed materials so I'm not really allowed to talk about it. Sorry.

[–]jij 3 points4 points ago

log in as new account and make a "guess" ;)

[–]BrainSturgeonMicrofluidics|Chemical Engineering 1 point2 points ago

Is a nanoparticle suspension not also a colloid?

[–]ColloidMan5000Colloidal Materials|Nanoparticles|Catalysis 0 points1 point ago

Yes, absolutely. Unfortunately my initial post wasn't nearly as clear as it should be; I was more interested in the differences between suspended cf immobilized particles.

[–]EagleFalconnPhysical Chemistry|Glass Physics[M] 11 points12 points ago

Please provide citations, or I'm afraid I'll have to delete this as speculation.

[–]khazzar12 62 points63 points ago

Sorry, first time ever posting a proper AskScience reply, are the citations/links I've provided ok?

[–]EagleFalconnPhysical Chemistry|Glass Physics 30 points31 points ago

Perfect, many thanks.

[–]mrlemax 1 point2 points ago

So silver could be the next antibiotic/cure for lots of stuff?

[–]khazzar12 4 points5 points ago

Actually, we have been using silver in one form or another to kill bacteria for thousands of years. Ancients greeks and romans used to store their water in containers lined with silver to keep it fresh. During WW1 soldiers' burns were treated with silver foil to help stop infection.

When antibiotics became readily available in the early 1940's they were seen as a new wonder-drug that would cure anything and the use of silver was almost completely stopped. Now, with the advent of antibiotic-resistant strains of many bacteria we need to find new (or in this case old) ways of fighting bacterial infection.

Silver isn't some magic cure all though. Just as bacteria become resistant to antibiotics, they can become resistant to silver as well.

[–]CassandraVindicated 2 points3 points ago

Is there any evidence of silver resistance in bacteria?

[–]khazzar12 7 points8 points ago

Yes there have already been cases of silver resistant bacteria reported here and here.

[–]badastrobiology 2 points3 points ago

Did they look at all into what mutations (like alteration of an ion channel, overproduction of some peptide/messenger, or altered gene transcription) caused for them to become resistant?

[–]I_Like_Eggs123Bacterial Pathogenesis 1 point2 points ago

Here is a paper I found that could possibly explain the resistances to silver seen in the enterobacteria noted above.

[–]khazzar12 0 points1 point ago

Neither of those papers suggest what action may be occurring in the bacteria to inhibit the silvers antimicrobial properties but the first paper does suggest that the gene that codes for silver resistant may be present on the same region of the bacteria's plasmid DNA as the gene that promotes antibiotic resistance.

After a quick search I couldn't find any information relating to the mechanism of resistance but I didn't do a very deep/thorough search (it's 2am) so there might be some research on it.

[–]mrlemax 0 points1 point ago

Thnx, TIL!

[–]notinkansas1911 0 points1 point ago

Are you part of CEINT (center for the environmental implications of nanotechnology)?

[–]khazzar12 0 points1 point ago

I am not, but this is exactly the kind of thing I'd love to get into when I finish my degree.

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[–]retr0rocket 116 points117 points ago*

i believe the antibacterial effects of silver and silver ions come from Oligodynamic effect (http://en.wikipedia.org/wiki/Oligodynamic_effect) which is like heavy metal poisoning for microbes. this effect in silver has been pretty well documented, they use silver to line the water tanks of ships and stuff to keep the water drinkable.

http://en.wikipedia.org/wiki/Medical_uses_of_silver

also the WHO recommends silver as one of the ways to disinfect water in third world countries, http://whqlibdoc.who.int/paho/2003/a85637.pdf (pg147)

"Silver has disinfecting properties only in its colloidal state —when it is in the form of extremely small particles in suspension which, because of their size, are easily charged electrically. In this state, it is also known as silver protein, silver salts, weak silver protein and strong silver protein. The salts that are used are silver chloride and silver iodide. In its colloidal form, silver does not eliminate viruses, but is considered highly effective in destroying different types of bacteria. Silver’s disinfection mechanism acts by inactivating bacteria and mold cell enzymes that need oxygen for their metabolism; its causes their cellular disruption, although over periods that vary widely according to the water temperature. Very long periods are required at temperatures of 10 °C or less, making it difficult to determine silver’s precise germicidal power. Colloidal silver can remain in the water for a long period of time, but is not considered to have good residual power because of the slowness of its reactions in eliminating organic matter. The recommended dose for high germicidal efficacy is in the range of 25 to 75 micrograms of silver per liter (0.025 – 0.075 mg/l)."

[–]YoohooCthulhuDrug Development|Neurodegenerative Diseases 87 points88 points ago*

There's an glaring error or confusion in that WHO doc, BTW (it was obviously written by someone who knows nothing about chemistry). "Colloidal silver" almost always refers to the bogus alternative medicine preparation, which contains mostly reduced silver metal (Ag) and not the soluble bactericidal ion (Ag+) which acts via the oligodynamic effect. Synonyms for the bogus preparation are "silver protein". Generally, silver in it's active bactericidal (generally a salt) form will be referred to as its actual chemical name, e.g. silver iodide, silver nitrite or silver sulfadiazine. In general, metals in reduced (nonionic) form are less active because they're not soluble in water.

TL;DR ignore the usage of "colloidal silver" or "silver protein" and replace "silver salts"

In general, you should be careful when anyone invokes "silver" because it's a favorite of the homeopathy crowd. If you look at any of the silver salt preparations used medically, they're almost always topical; homeopaths, on the other hand, will advocate ingestion of "colloidal silver" as a treatment. For reasons mentioned above, "colloidal silver" is not an effective bactericidal.

Silver in the form of alloys for construction of medical devices and surfaces DOES appear to have some bactericidal activity even though it's in the reduced form, but a silver alloy basin is nothing like suspended particles of silver in solution ("colloidal silver").

[–]taylornator7 22 points23 points ago

Although you are completely correct with being careful around the whole "Silver Homeopathy" trend going on, Colloidal silver can also mean silver nanoparticles in solution. Within the Nanotechnology/Nanoscience communities these two terms are very interchangeable, and suspended gold nanoparticles are often referred to as colloidal gold. In my Nanoscience Minor I had to write a report on the Anti-microbial effects of Nanosilver, and a quick Science Direct Search, brings up hundreds of peer-reviewed papers on the subject.

Here is one example of a paper that has both Colloidal and Nano in the title: http://www.sciencedirect.com/science/article/pii/S0927776511005388

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[–]YoohooCthulhuDrug Development|Neurodegenerative Diseases 0 points1 point ago

"Colloid" almost always refers to a microscopic suspension of solid particles. As we know that the ionic form is the actual bactericidal form, I doubt that this is true.

[–]EnterTheMan 1 point2 points ago

because of their size, are easily charged electrically

I'm surprised to hear that the size of an atom (or size of a particle in suspension) makes a large difference in the ability to be charged or not. Is that bogus as well, or at the very least, does that statement need more clarification?

[–]taylornator7 6 points7 points ago

They are definitely talking about particle sizes, and it does need some clarification. Size certainly does make a difference, and is the whole basis behind Nanoscience. In a very, very generalized nutshell, Nanoparticles of a substance can act and react differently than the same substance in the macro-scale.

[–]YoohooCthulhuDrug Development|Neurodegenerative Diseases 6 points7 points ago

They're confusing colloidal silver and ionic silver, is all.

[–]ColloidMan5000Colloidal Materials|Nanoparticles|Catalysis 4 points5 points ago

That needs a lot more clarification. Actual colloidal silver particles generally possesses a weak surface charge. It is possible that as the size is decreased the particles become more susceptible to oxidation and the charge is neutralised. It is also possible that the surface charge (as indicated by the zeta potential) has a dependence on particle size. It's not a black-and-white issue.

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[–]ColloidMan5000Colloidal Materials|Nanoparticles|Catalysis 2 points3 points ago

How can you say such a thing, DLVO theory is beautiful :(

[–]retr0rocket 0 points1 point ago*

i believe the WHO meant that colliodial as in dispersed through water, not in any sort of homeopathy/alt medicine way, as it specifically later on states that the salts used are silver chloride, and silver iodide.

It's not so much a glaring error as in a slight misuse of the term colloidal,

[–]YoohooCthulhuDrug Development|Neurodegenerative Diseases 0 points1 point ago

Well, but then they go and use the term "silver protein" which is a homeopathic term.

[–]retr0rocket 0 points1 point ago*

i believe thats just an exhaustive list of what the salts could be branded as. I doubt this is support for homeopathic medicine, when they specifically mentioned the compounds to use by name (both of which as you said, are silver salts)

because of marketing and branding, scientific terms outside of the scientific community are rarely used in it's exact sense, and while it's a shame they need to do this I don't think this is a sign of incompetence on their part

[–]Law_Student 13 points14 points ago

Is there a convenient way to introduce silver into a solution and then remove it before drinking so it can be reused, or is the silver imbibed?

[–]umlaut 25 points26 points ago

The silver is imbibed. It has the notorious side effect of turning people blue.

[–]Cody2 14 points15 points ago

Wait. What?

Can someone confirm this?

[–]philter451 20 points21 points ago

[–]Calvert4096 8 points9 points ago*

I didn't think he was serious. A quick Google search yielded this.

Chronic ingestion of silver can similarly lead to an accumulation of silver in the eye ... some areas of the skin and other body tissues to turn gray or blue-gray.

Also:

Although its pigmentary changes are permanent, argyria has no known effect on health.

Holy shit. Imma go get me some silver nose drops.

[–]greymonk 5 points6 points ago

Also, this.

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[–]JPillz 1 point2 points ago

Silver nitrate (AgNO3) is more notorious for changing skin coloration than Ag.

[–]YoohooCthulhuDrug Development|Neurodegenerative Diseases 4 points5 points ago*

We're talking very low concentrations of silver. Silver is quite toxic to humans, too; but in low doses it's a question whether bacterial infection or mild silver toxicity is worse. Note that they say third world countries, it seems like it's a bit of an extreme measure.

[–]retr0rocket 0 points1 point ago*

really? from what I have seen silver comparatively nontoxic to humans, thats why they use it for its antibacterial properties, it takes a massive ammount of silver to get agryias, and from what I've seen the worst only symptom of that is blue skin...

actually the effects of agryia is only considered a cosmetic problem... I'm pretty sure silver is nontoxic...

[–]Mulvee77 1 point2 points ago

I presume a better use of silver in this context is as a filter. Thus, dirty water can be made suitable to drink.

[–]Calvert4096 0 points1 point ago

But would that be effective? retr0rocket mentioned it can take a long time for the silver to act, and if water with harmful microbes in it just passes through a silver-coated filter, the exposure time can't be very long.

[–]CaptainCard 3 points4 points ago*

My EWB chapter has a project to do third world filters, they're just sand, gravel and are painted with a colloidal silver mix to do just this. They're working on ways to avoid this to lower costs.

[–]doctor_badmind 0 points1 point ago

If its heated will the process be faster?

[–]retr0rocket 3 points4 points ago

there are water filters that use silver coated filters to do it for you =D

[–][deleted] 6 points7 points ago

I know that copper also has anti-microbial properties. Do you know if the mechanism is similar?

[–]BitRex 2 points3 points ago

[–]retr0rocket 2 points3 points ago*

yes its in the wiki article about the Oligodynamic effect, brass, gold, copper etc also i believe have antimicrobial effects... edit: mhmmm but the copper antimicrobial page makes no mention of it .... strange

[–]alexgbelov 7 points8 points ago

How can it be called both strong and weak silver protein?

[–]PostPostModernism 1 point2 points ago

I think (though I'm not positive) that those are just nicknames that you might encounter it under. I'm making this guess based solely on the context and wording of retrorocket's reply.

[–]retr0rocket 0 points1 point ago

yes i think that is what the WHO meant, its just the nicknames of the forms of silver salts

[–]lostminty 0 points1 point ago

I don't know for sure. But there are different types of bonding. Vanderwaals forces for instance is a weak interatomic bond where things are electrostatically attracted, it is what holds graphite sheets together in a pencil lead. Then there are ionic bonding which are VERY strong and also covalent bonding although that type of bond seems unlikely.

[–]twoplustwoequals5 5 points6 points ago

Firstly, thanks for the concise explanation. Just as a side, it is not limited to silver ions (not that you implied that) but I thought people here would find the re-introduction of copper to hospitals in a fight against MRSA interesting/relevant.

I was then wondering what are the limitations of using copper to line water tanks? I'd imagine cost?

[–]HonorAmongSteves -4 points-3 points ago*

Copper is poisonous.

Edit -To the idiots downvoting:

From the abstract:

Although normally bound to proteins, Cu may be released and become free to catalyze the formation of highly reactive hydroxyl radicals. Data obtained from in vitro and cell culture studies are largely supportive of Cu's capacity to initiate oxidative damage and interfere with important cellular events.

[–]twoplustwoequals5 3 points4 points ago*

Do you have a source? I'm doubtful as it's used to make pots and pans. Thanks for the reply anyway.

edit thanks for the reply, having a read now.

[–]retr0rocket -1 points0 points ago

in pots and pans it has to be coated, and hes right it is poisonous don't downvote him...

[–]twoplustwoequals5 0 points1 point ago

Oh don't worry I didn't downvote anyone and was just curious, turns out they coat the copper in a layer of tin as it reacts to acidic foods.

[–]Mojo17 0 points1 point ago

Wow. I thought all of the colloidal silver talk was just pseudo-science.

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[–]astrodust 15 points16 points ago

We're talking about micrograms of silver in a solution. The cost is nearly nothing.

[–]simpat1zq -4 points-3 points ago

I think it would come out to about .75 cents per liter. So about 1.5 to 2 cents a day. Not a lot, but I'm sure there are many people that still couldn't afford it.

[–]astrodust 5 points6 points ago

There are cheaper methods, absolutely. UV is probably the most cost effective.

[–]iongantas 1 point2 points ago

Or you could, you know, boil it.

[–]bannana 0 points1 point ago

Cost of fuel is too high, not even remotely doable for most people.

[–]iongantas 0 points1 point ago

Yes, it's definitely cheaper to install an electrical grid to power UV lights.

[–]astrodust 0 points1 point ago

UV still cheaper.

[–]Titanomachy 7 points8 points ago

That's incorrect. A microgram is 10-6 grams. The cost of 75 micrograms of silver is inconsequential. http://www.wolframalpha.com/input/?i=75+micrograms+*+price+of+silver

[–]Laboratory 4 points5 points ago

I think the real issue is not the cost of the silver but rather making it into a colloid and delivering it. Also, the many other real world problems one encounters in the vast third world

[–]Titanomachy 0 points1 point ago

For sure. My point was that the cost of the silver itself doesn't tell us much about the cost of the system.

[–]Laboratory 0 points1 point ago

and I agree with that completely.

[–]factoid_ 2 points3 points ago

So according to this it would be 7 cents per 100,000 liters. Seems pretty reasonable to me, though I'm sure the cost of preparing it and introducing it to the water supply would far exceed the price of the actual silver.

[–]simpat1zq 2 points3 points ago

You're right. I did a quick google search, and for some reason, the first thing said it was $15 a gram, where it's less than a dollar.

[–]tinynf89 0 points1 point ago

If I'm understanding this correctly, long periods of temperatures 10C or lower are required. I would see this as the biggest problem for many third world countries.

[–]UncertainHeisenbergMachine Learning|Electronic Engineering|Signal Processing 1 point2 points ago

If I'm understanding this correctly, long periods of temperatures 10C or lower are required.

They mean that as temperature decreases, longer periods are required to achieve similar effectiveness. But I can see how the sentences can be misinterpreted!

[–]hairyfro 1 point2 points ago

If you're going strictly by the price of silver, that would be approximately 7.5e-3 cents per liter, not .75 cents per liter.

[–]GLaDOSexe 0 points1 point ago

About $5 a year

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[–]florinandreiPhysics|Electronics 24 points25 points ago

Just keep in mind its action is mild. So drinking silver products until you turn blue will not provide any real health benefits.

[–]Hunji 11 points12 points ago

Please be cautious.

I recently finished a work project related to silver. Silver kills cultured human liver cells (at >10-5 g/ml) quite well.

[–]florinandreiPhysics|Electronics 6 points7 points ago

Out of curiosity - that sort of concentration should be far far greater than what you get when you simply stir honey into your tea with a silver spoon and then drink it, is that correct?

In other words, using silverware (made of actual silver) and wearing silver jewels shouldn't bring you anywhere near those levels. It's when you drink new age silver woo that you get all the liver-killing "benefits". Right?

I just like my silver teaspoon, that's all. :)

[–]Hunji 5 points6 points ago

Correct, silverware is safe to use. Just don't drink silver-containing solution as antibacterial drug.

[–]FrankTD 0 points1 point ago

With that in mind is it also safe to wear one of these prosthetic stump socks with silver? These may be against the skin for up too all waking hours depending on the wearer.

[–]Aeroxinth -1 points0 points ago

I agree except... there is debate over nano-particle silver.

[–]mobilehypoMedical Laboratory Science 1 point2 points ago

For ingestion?

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[–]Filmore 6 points7 points ago

"The dose makes the poison" as they say. To my understanding "correctly produced" colloidal silver will still turn you blue given a long enough timeframe... and I've never heard anyone give a statement to the effect of: "minimum effective dose of X taken for Y years has a 50% chance of causing argyria"

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[–]leonardicus 6 points7 points ago

This article of dry copper providing anti-microbial effects may also be related, and is discussed on the This Week in Microbiology podcast.

[–]pancitititoMicrobiology 2 points3 points ago

Copper is also thought to be used by the host as part of the immune response to invading bacterial pathogens (source), and some bacteria such as Mycobacterium tuberculosis have adaptations to specifically combat high copper levels (source).

[–]leonardicus 0 points1 point ago

Nice links. Thanks. :)

[–]smeezy 2 points3 points ago

Reading the responses, I find it hard to distinguish whether "solid" metal silver (as in, silver spoons, silver threads woven into "antibacterial" towels) is antibacterial, or only ionic silver, dissolved in a liquid. Can someone help me understand this better?

[–]CriticalistIntensive Care Medicine|Steroid Metabolism 3 points4 points ago

We use this property of silver in some of our burns dressings in the ICU. Acticoat and SSD (Silver Sulphadiazene Cream) are both commonly used burns dressings. You do need to be careful as they often will cause the patients white blood cell count to transiently drop, which can worry you if don't realise what is doing it.

[–]pancitititoMicrobiology 1 point2 points ago

Is copper ever used in dressings? If not, is there any particular reason? Thanks!

[–]retr0rocket 0 points1 point ago

copper toxicity i would hazard, agryia is pretty mild in comparison...

[–]FrankTD 0 points1 point ago

It is used in some prosthetic stump socks. http://amputeesupplies.com/products/xwool-prosthetic-sock.html

[–]Akeid 1 point2 points ago

Is copper anti-bacterial for the same reason?

[–]playerra 1 point2 points ago

Copper has the same anti-bacterial properties. This is the reason many door handles and railings around hospitals are coated with the element.

[–]pharmer2012Pharmacy 3 points4 points ago

While I don't doubt that this has some legitimacy, can you provide a source? I have never heard of this before.

[–]playerra 1 point2 points ago

paragraphs 12-13 from: http://www.naturalnews.com/033398_superbugs_copper.html

"Some hospitals use silver coated catheters and colloidal silver bandages, especially among burn victims, to reduce potential infections.(4)But hospitals are currently more interested in another metal to reduce infections from hospitals. That metal is copper. This copper is not in colloidal suspensions. It's hardware used for railings, door knobs, and table tops in hospitals, anywhere people touch.

Copper is meant to eliminate germs spread by physical contact, grabbing or touching, before they enter into one's body. And trials have proven that copper used where doctors, health workers, patients, and visitors commonly touch reduces bacteria up to 97%.(5)"

[–]halogen1212[S] 0 points1 point ago

Naturalnews.com doesn't seem like a reliable source I'm afraid, looking at the list of sources it refernces itself, sollodialsilvercuremrsa.com, antimicrobialcopper.com etc. etc. . The reason I asked the question is because i saw some industrial applications of silver for anti bacterial but the documented weight of research seems rather lacking.

[–]playerra 1 point2 points ago

I see. I had no documented source for my original statement. It was something one of my professors mentioned during class one day. Seemed reasonable to me, I hadn't given the idea much further thought. I apologize for the poor source :x

[–]playerra 0 points1 point ago

I see. I had no documented source for my original statement. It was something one of my professors mentioned during class one day. Seemed reasonable to me, I hadn't given the idea much further thought. I apologize for the poor source :x

[–]Trillian42 0 points1 point ago

I have a related question. Is the fact that silver is anti-bacterial the reason why earrings are generally made out of sterling silver?

[–]halogen1212[S] 6 points7 points ago

I would hazard a no. I would say it's because silver is a precious metal that is nonreactive.

[–]squidbootsPlant Pathology|Plant-Microbe Interactions|Mycology|Epidemiology 0 points1 point ago

Gold is ideal because it is completely inert, but gold is expensive. Sterling silver is a great alternative.

However, pure silver is reactive. Sterling silver, a silver alloy, is mostly silver but has a small amount of other metals mixed in which gives it some superior properties (such as resistance to tarnishing.)

Another reason why silver is so popular is that it is hypo-allergenic. Other "newer" jewelry metals like titanium and stainless steel are also hypoallergenic. But nickel, for instance, is a metal that a lot of people (including myself) are allergic to, so anything pierced with it will not heal and oftentimes will fester and form cysts. Most of those mall piercing joints use nickel jewelry to pierce ears (because it's super cheap.)

As to the original question, silver is only antibacterial when it's in its colloidal (solute) state.

[–]GreenStrong 2 points3 points ago

Actually, fine silver tarnishes only slowly, and only forms a thin yellow patina, unlike the thick tarnish that forms on sterling. It also doesn't develop an oxide skin under a jeweler's torch, it can be fused rather than soldered, and doesn't require an acid bath after hot work. It isn't used much because it is soft, both in the sense of "scratchable' and "malleable".

[–]supraman1120 1 point2 points ago

ductility???

[–]bannana 0 points1 point ago

So what of Colloidal Silver? Works or bunk?

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[–]pharmer2012Pharmacy 4 points5 points ago

Silver sulfadiazine is a sulfonamide antibiotic used for burns and is complexed with a silver ion. The antibiotic properties are from the sulfadiazine. Not the silver.

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[–]Eldritter -2 points-1 points ago

Silver nitrate (which has antibacterial properties) is dripped into the eyes of Newborn infants to prevent infections that can often get into infant eyes (from the vagina)... Silver nitrate is antibacterial because it has reactive chemical properies. Silver is not antibacterial as a metal (its also not soluble in solution). However, most of the time metals are bad for cell membrane stability so if a bacterium was on a silver ring and dried up there it would probably die.

[–]halogen1212[S] 0 points1 point ago

It's the fudgey "reactive chemical properties" that I'm interested in. What properties, why? The evidence seems thin on the ground.

[–]aazav -2 points-1 points ago

It's all about electrons. The free particles of silver are rather easily able to be charged or discharges, making them able to take an electron from something that might need it.

Copper and other metals (silver is too expensive) are often used in marine paint to prevent larval creatures from settling on the surface of ships and other submerged items.

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