Zoo on our skin

After washing your hands thoroughly with soap and water, you proceed to dinner.

Take clean hands bread or, say, a hamburger… or maybe you eat porridge with your hands, because it tastes better… and why not eat porridge with clean hands, from which you two minutes earlier washed away all the germs to such and such a microbial grandmother?

All of them?

Ask any person who is far from medicine – does washing your hands with soap get rid of germs? – and you will hear an affirmative answer. How could it be otherwise? Soap and water are the main enemies of microbes!

Well, actually, water is more of a friend to microorganisms than an enemy. This is dryness most of them do not like, in a dry environment, microorganisms die quite quickly if they do not form cysts or spores.

It is considered that in everyday life there is nothing dirtier than money. And not only figuratively, but also literally. Banknotes with coins are constantly changing hands and each hand leaves a part of its microbes on them. Can you imagine what kind of “zoo” is on a regular ruble coin, which, according to statistics, changes its owners faster than other banknotes? Collect all the zoos in the world in one pile, and you will not get even a tenth of the species diversity that can live on a ruble coin. On a single page.

In fact, the great and incredible contamination of banknotes by microorganisms is a myth, only a myth and nothing but a myth. Money isn’t as dirty as rumor has it. In a dry environment, microorganisms do not live long. And this is for the best, otherwise we would not be able to distinguish banknotes by denomination – they would be covered with solid layers of microbial cultures. Have you seen mold growing on products or, say, on walls? That’s about it. This, of course, does not mean that the seller of pies or doughnuts can take “bare” hands of goods and money. Just do not consider money the Main Source of Universal Infection. There are worse sources, I mean, much dirtier.

In fact, the first place in this Chapter should have been another myth – the myth that the usual washing of hands with soap completely eliminates them from germs. But while we were getting close to it, we managed to debunk the myth of “very dirty” money. In Microbiology, myths get in the way.

Does regular hand washing with soap completely rid them of germs?

If so, why do surgeons bother so much with washing their hands before surgery? If you think that they just wash their hands with soap for a long time and carefully, as shown in the TV series, then you are mistaken. It’s not that simple.

Surgical treatment of hands before putting on sterile gloves includes regular washing of hands with soap and their washing (their treatment) using a special antimicrobial agent.

“Normal” surgical hand washing is actually not quite normal. Hands are completely covered with liquid detergent and thoroughly washed under warm water for at least a minute. In addition, special sticks or brushes clean the skin under the nails.

What happens as a result of such thorough washing? Absolute sterility?

If so. Surgical hand washing removes “inanimate” dirt-a mixture of dust and other things with sebum (fat secretions secreted by the sebaceous glands located in the skin) and some of the microorganisms.

Only some part, please note!

Other microbes are disposed of using various disinfectants (mainly alcohol-based). The product is applied five times (Yes – as many as five times) to the skin and carefully rubbed into it. After the fifth time, the hands can be considered sterile. You can wear sterile gloves and go to rescue another patient without the risk of bringing an infection into the surgical wound.

Conditionally sterile?

Yes-conditionally. Even with this treatment, some small part of the microbes living on the skin can survive. Did you think that sterile gloves only serve to protect the skin of the surgeon’s hands from the patient’s blood and other biological fluids? No, they also protect the patient from micro-organisms, remaining after treatment in the hands of the surgeon.

But on sterile gloves until the opening of their individual packaging, there is not a single microbe, even the most stable. That’s why they are called sterile. Sterilization is the complete destruction of microorganisms on any object or material. This can be achieved by various methods. The most common, and also available in everyday life, is the method of thermal sterilization. At home, we use boiling water or an iron for sterilization, and in medical institutions we use steam. When treated with steam that has a temperature of 132 °C under a pressure of two and a half times higher than normal atmospheric pressure, all microorganisms, including the most persistent, die in three and a half minutes. Twenty-minute treatment with this steam kills prions (remember what it is, we talked about them).

Of course, you can’t sterilize your hands like that. That’s why even after surgical washing and treatment, they are considered conditionally sterile.

What conclusion can be drawn from all this?

Option one – do not bother to wash your hands at all, because this is a useless procedure.

Option two-hands should be washed thoroughly, and in some cases (if there is a probability of heavy contamination by microbes or after contact with infectious patients), after washing, treat with a disinfectant.

Do I need to explain why the first option is incorrect? Probably don’t need. It is clear to reasonable people without explanations that they need to wash their hands, and unreasonable people, including those who like to “train” their immune system, will still prefer to do without this procedure. Let’s go straight to the correct second option and expose another myth.

Let’s imagine this situation.

While visiting the toilet of the Delhi bus station Kashmiri gate (the city of Delhi and this bus station are selected at random, nothing personal), you assessed the situation as fraught with abundant contamination of your hands with microbes. Therefore, instead of the usual “public” soap from the dispenser over the sink, you carefully washed your hands with your own antibacterial soap brand “Smerm” (short for “death to microbes”).

Question – did you do the right thing? Maybe it would be better to wipe your hands with a damp cloth soaked in some kind of disinfectant?

In fact, you could wash your hands with ordinary soap. But only your own, so as not to touch the dispenser once again in a place fraught with abundant contamination.

The antibacterial effect of an antibacterial soap or an antibacterial napkin is a myth, a belief in which can turn into an infectious disease.

Remember how surgeons treat their hands before surgery. Five times RUB the disinfectant into the skin, RUB it thoroughly and thoroughly.

And what happens when you wash your hands with soap, even if it contains some antibacterial additives? You apply it on your hands, not rubbing it into the skin, but only foaming it, and immediately wash it off with water. Does the disinfectant have time to take effect in such a short period of time? And what will be its concentration at any dosage of soap and dilution of soap with water? Please note that surgeons do not wash off the disinfectant during preoperative hand treatment – RUB one portion of the product into the skin and apply the next one on top. And so five times!

A napkin is slightly better than soap, because the product that it is soaked in, you will not immediately wash off your hands. But how much of that stuff is in the napkin? Just a little. If you want to squeeze a napkin, you can’t squeeze more than a couple of drops out of it. Again, immediately after opening the package, the liquid that is impregnated with the napkin begins to evaporate and decompose. Well, if you use three consecutive antibacterial wet wipes from the newly opened pack, then you can assume that you have processed your hands.

“What should I do? you ask. – Never go to the toilets at bus stations?»

No, go as far as you need, just keep a bottle of liquid disinfectant, which is called “antiseptic [33] for hands” in pharmacies. Such substances are of two types – alcohol-based and water-based. Alcohol-based antiseptics are more effective in comparison with water-based antiseptics, since the disinfectant action of reagents is added to the disinfectant action of alcohol. In addition, alcohol-based antiseptics act faster and have a prolonged effect, that is, their effect persists for several hours after use. But water-based antiseptics do not cause irritation and dryness of the skin, and can also be used by children (keep in mind that ethyl alcohol is very easily and quickly absorbed into the blood through the skin, so that contacts of alcohol-containing liquids with the skin of the child should be avoided).

Treatment of hands with a disinfectant should be carried out twice, and the product should be applied to the skin generously, “from the heart”, because saving a few drops of antiseptic can result in large expenses for medicines. Once may not be enough, but more than twice you do not need, you are not going to operate, but just want to get rid of the “gifts” received in the toilet of the bus station.

By the way-about toilets. People are afraid of the abundance of microorganisms on toilet seats and door handles, but in these ” hot ” places there are not so many different microscopic animals. The washbasin tap is the most microbe-infested area. Not only does everyone touch it with dirty hands, it is also constantly wet, and in a humid environment, as has been said many times, microbes live for a long time.

We have debunked the myths, now it’s time to get acquainted with our skin microflora.

According to various data, on the surface of our skin lives from twenty million to a billion different microorganisms.

Why is there such a huge difference? And can we even believe data that has such a huge spread?

The fact is that it is impossible to conduct a “piece-by-piece” inventory of microbes. All methods of counting them are more or less conditional. The calculation is made on a small area of skin, and then the data obtained are multiplied by the area of skin areas with identical microbial contamination. Areas of skin with identical contamination, please note, not the entire surface of the skin. The number of microbes on different parts of the skin can vary by orders of magnitude. Where it is wet and warm, that is, in the armpits, between the toes and in the folds of the skin, more microorganisms live. However, not all hiding places microbes like. There are very few of them behind the ears, because it is dry there. Figuratively speaking, the uneven population of the skin by microbes can be compared with the uneven population of people on our planet. The palms are Shanghai, and the area behind the ears is Antarctica.

Those who wash more often will have much fewer skin microbes than those who wash less often. Depends on the population, that is, the contamination of the skin and on the physiology of a particular person, on how much he sweats, and on the antiseptic properties of his sebum and his sweat (Yes, sweat also has such properties).

Again, methods for counting microorganisms are constantly being reviewed and improved. So the only correct answer to the question: “How many microorganisms live on our skin” is: “a Lot.” A lot of them live, and the specific number is constantly changing. On the skin live both our permanent companions-resident microorganisms, and “guests” coming from the environment. “Guests” these scientifically called transient microorganisms and for microbiological slang – “transients”.

The main residents, that is, the most common representatives of our skin microflora, are Staphylococcus epidermidis or epidermal Staphylococcus, Staphylococcus saprophyticus and fungi of the genus Candida.

Residents protect us from transit workers passively and actively. By occupying all our “skin” ecological niches, residents make it impossible for outsiders to settle in them, this is a passive way of protection. In some cases, residents actively rebuff those who risk asking them to “stay” – they produce substances that kill uninvited guests. In General, everything is the same as in the colon. The only difference is that on the skin of uninvited guests are not digestive enzymes, and sebum, produced by our numerous sebaceous glands, and sweat, which is produced by sweat glands. Fat not only lubricates the skin, but also kills many microorganisms due to the content of acids in it. Sweat has an identical effect. Acidic environment is unfavorable for most microorganisms. Residents who live permanently on our skin have adapted to it and even learned to produce acids (for example, lactic acid) to scare off uninvited guests. But transient microorganisms do not have time to get used to the acidic environment, they are not allowed to do this.

Who is not among our skin residents! There are staphylococci, streptococci, and other cocci, and bacilli, and fungi, and protozoa, and viruses… A whole zoo! But if we are to be honest, without pathos and exaggeration, the number of species of permanent inhabitants of our skin is relatively small – not even up to two hundred.

Many of the inhabitants of our skin “zoo” behave like real predators in the zoos. While they sit in their cells, that is, in niches, they do not pose any danger to us, but if they accidentally break free – they can cause inflammation if they get into a wound. The main” predator ” is considered to be the epidermal Staphylococcus, which sleeps and sees how to infect something.

The fact that infection of wounds is necessarily caused by “extraneous” microbes (dirt got into the wound, etc.) is another myth. In this case, you can safely do on your own, with your resident microorganisms. So keep in mind the following – you need to treat any wound with a disinfectant, even if it was received in the purest home conditions with the help of a knife that you took out of the dishwasher just before cutting the salad. Keyword: “any”. Example in the subject-shaving is usually done in fairly clean conditions. A person rinses the area of skin to be shaved with water, applies soap foam, shaves with a clean (well, relatively clean) razor, then immediately washes off the soap and the remnants of hair with water… But if you do not disinfect the cut received during shaving, then there is a great risk that the wound will become inflamed.

Sometimes some of the transits still manage to settle on our skin, recapture an ecological niche for themselves and reproduce in it for a while. Such transits are called temporary residents. In fact, it is in reproduction that the main difference between residents and transit workers lies. Residents lead a sedentary lifestyle, create families, have offspring, and transit travelers pass by, unless they stop for the night… Well, somehow, the truth about families was a joke, microorganisms do not have families, only colonies.

With temporary residents, the neighbors, with the support of our body, “sort out” quite quickly, without giving them a chance to move from temporary residents to permanent ones. And this is great, because temporary residents are usually able to cause us a lot of problems. Roughly speaking, they are looking for opportunities to gain a foothold in a new place better, to reproduce as actively as possible, to push their neighbors as much as possible. It’s Good that we can help our permanent residents fight the temporary ones. How? Yes, the usual washing, because during this process, strangers who do not have time to “put roots” in the skin, are completely removed. Only permanent residents can survive water, soap, and a washcloth.

In short, clean skin is healthy skin, and clean hands are a healthy body. Note that approximately eighty percent of infectious diseases are transmitted by contact, and the first most common contact is hand-to-hand contact (what you are thinking about now is second).

Here’s a quick question for you. What time of year do we have more microbes living on the skin of our forearms-in summer, when we mostly wear short-sleeved clothing, or in winter, when the sleeves are long?

At first glance, it may seem that in the summer more microbes live on the forearms, because they are open and clothing does not prevent the skin from “collecting” microbes from the external environment. But in fact, the number of microbes on the skin of the forearms increases with the transition from short sleeves to long ones. The environment becomes wetter and warmer, which favors the reproduction of microorganisms.

Finally, that is, at the end of the Chapter devoted to the inhabitants of our skin, let’s debunk another myth – the myth that with the help of “useful” microorganisms (most often bacteria), it is possible to treat skin diseases, such as eczema – a recurrent [34] inflammatory skin disease characterized by rashes and itching of varying degrees of severity, or psoriasis similar to it in symptoms.

The logic is simple – “useful” microorganisms must suppress their ” bad ” counterparts or secrete certain healing substances. There are probiotics on sale that are recommended by “leading scientists with a world name” (quotes are not random) for the treatment of skin diseases. And on online forums, you can find a lot of reviews on the topic, “how well and quickly bacteria helped me get rid of psoriasis (or eczema, or something else).”

An interesting thing is that there are a lot of messages on the forums, but there are no data from clinical trials. There are only articles in the media that “bacteria will defeat eczema and other skin diseases”. And there are also separate reports in scientific journals about individual experiments on the use of certain microorganisms in the treatment of skin diseases. Scientists have just started research on this topic, and it is still unclear whether this will be of any real use. However, the sense is already there-manufacturers of ointments with “healing” bacteria get a profit from this business and, apparently, a good one, otherwise they would have switched to something else long ago.

One piece of General advice. If you hear or read about something miraculous that cures most of the known diseases or those that are considered incurable, then be on your guard – you are being misled. If this is the most “miraculous” and also “alive”, that is, it is some kind of biological drug, then you need to be doubly alert. Somehow, and in no other way.

The health of your wallet is in your hands!

Take care of yourself and your money, which is never superfluous or unnecessary.

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