What about sticks? This is not a book about Chinese cuisine, in which the sticks are not only sticks, but also forks, and spoons, and sometimes ladles…
No, it’s a book about Microbiology and only about it. The fact that the word “bacteria” is formed from the Greek word “bacteria”, meaning “stick”. Antony van Leeuwenhoek, who revealed to the scientific world the existence of bacteria that he saw in a microscope of his own design, did not bother to come up with a special name for them. The term “bacteria” appeared only in the early NINETEENTH century. The German naturalist Christian Gottfried Ehrenberg has combined all the known rod-shaped bacteria that do not form spores in the genus Bacterium, and spore-forming bacteria in the genus Bacillus. Is the word “Bacillus” familiar? Say thank you to Herr Ehrenberg.
Ehrenberg did not get a scientific classification, but a “combined hodgepodge”, because on the basis of only the rod-shaped form and the ability to form spores, it was impossible to combine microorganisms into genera. But he is forgivable, because the primitive microscope did not give the opportunity to look at the differences between bacteria. Small gray lines (such saw “sticks” Ehrenberg) were all on one face…
But it also happens that a scientist will make a mistake, and a trace in science will still leave behind. The terms “bacterium” and “Bacillus” have taken root and survived to this day.
Bacteria (Bacteria) is the domain or overgrowth of prokaryotic microorganisms. Domain, if anyone does not know, it is the highest level of grouping of organisms in biological taxonomy, including one or more kingdoms. Cellular organisms are divided into three domains: Archaea, Bacteria and Eukaryota. We are eukaryotes because our cells have an interior core. But recently, everything alive was shared just for prokaryotes and eukaryotes, and the bacteria with the archaea were considered “cousins” and family – archaea called archebacteria. But then scientists decided that the archaea deserve a separate domain. Well – they know better. We, as microbiologists, the first and second dans that the bacterium is that the Archaean – all is one.
If you have a question: “Where are the viruses?”then please remember that the world scientific community has not yet decided whether to consider them living beings or not. Allocated viruses conventionally, a separate domain, in order to classify them, without “accounting” in science can not do, but only just. And note that it was said above, “cell organisms are divided into three domains,” not “all living things are divided into three domains.”
Bacilli and now called all rod-shaped spore-forming bacteria. Stickiness this conditional. Among the bacilli there are coccobacilli, having an intermediate, hemispherical form.
Now try not to get confused.
Bacillus – a genus of microorganisms in the class of Bacillus. Class is one of the main levels (ranks) of hierarchical classification in biological systematics. In order to understand it, consider the picture.
In Latin, the class of Bacillus with the genus Bacillus is not confused – different endings. And the term “Bacillus” is used in Microbiology in relation to any bacterium rod-shaped.
Are you dizzy? Yes, it’s not easy. Remember that every time you hear the word “Bacillus” (or see it in the text), you need to delve into the essence, try to understand what it is – about the class, about the genus or just about the “stick”.
It is time for us to expose another myth microbiological. In everyday life it is considered that “bacteria” are called “good”, that is useful or at least harmless microbes, and “bacilli” – “bad”, causing diseases in humans and animals. It is not necessary to go far for an example, it is enough to remember the harmful plague Bacillus and the most useful lactic acid bacteria. In fact, not so clear, i.e. it’s not “harm”, but only in the ability to spore formation. Yes, some of the bacilli are the causative agents of such dangerous diseases as plague or anthrax, as well as the causative agents of food poisoning. But there are among the bacilli and harmless, non-pathogenic. A useful lactic acid bacteria, so you know, belong to the class of Bacilli.
And there is also the Vibrio! Everyone is familiar with cholera Vibrio (the author hopes that all readers have this acquaintance “correspondence”)? Far from biology, people “consonant” believe vibrions viruses, but it is also from the field of mythology. Vibrions are curved rod-shaped bacteria that do not form a dispute and have mobility, due to the presence of flagella.
By the way, cholera Vibrio is not the most dangerous of this kind of bacteria. The most dangerous is considered to be among the vibrios Vibrio vulnificus (Vibrio vulnificus) that live in water (mostly in the subtropical regions of the Northern hemisphere) and is known under the name of “bacteria eating flesh.”
The shape of the bacteria are divided into rod-shaped, spherical (cocci) and twisted (eg, spirochetes). This is the main, and then start the nuances.
If globular bacteria are grouped into two, they are called diplococci.
If globular bacteria are grouped into four, they are called tetracocci.
If globular bacteria are grouped in packages, they are called sardines (Yes, imagine – it is sardines!).
If globular bacteria are pulled into chains, they are called streptococci.
If globular bacteria are collected in the form of clusters, albeit asymmetrical, they are called staphylococci.
Rod-shaped bacteria, resembling a spindle, called clostridia.
Rod-shaped bacteria, curved like a comma is called a Vibrio.
Rod-shaped bacteria, having several curls, called spirillami.
Rod-shaped bacteria, having the form of a thin twisting sticks, called spirochetes. A type of spirochete, or rather representative of a type, class, and order (here’s how – just three!) the pallidum is the causative agent of syphilis Treponema pallidum, better known as Treponema pallidum.
Most bacteria have two membranes – a thin inner cell or cytoplasmic membrane and a thicker outer cell wall. Archaea, fungi and plants also have a cell wall. Many protozoa, as well as cells of multicellular animal organisms, cell walls do not have.
Bacteria that do not have a cell wall are called mycoplasmas.
Spore-forming bacilli are the most resistant of bacteria, and deprived of the cell wall of Mycoplasma – the least resistant. “Resistance” refers to resistance to environmental factors. It is clear that the bacteria, “Packed” in the dispute, much uneasy, but the delicate, thin cell membrane of Mycoplasma is very easily damaged.
Since we are talking about resistance and Treponema, let’s debunk another myth – the myth of the transmission of diseases such as gonorrhea and syphilis in everyday life.
Pale Treponema, despite the presence of her cell wall, quite a pampered creature. In the external environment, that is, outside the human body, it quickly dies. Ordinary soap foam, not to mention seventy percent alcohol solution, is harmful to Treponema, as well as relatively high temperatures.
The causative agent of gonorrhea gonococcus is as unstable as pale Treponema – dryness, heat, soap foam, any disinfectant solutions are harmful to it.
With resistance, that is, with the instability of our “defendants”, we figured out. Now let’s look at how the pollution of objects that can become “accomplices” household infection with syphilis or gonorrhea? Given the fact that Treponema pallidum, unlike gonococcus, penetrates into the blood, syphilis, it would seem, more opportunities to be transmitted by domestic means. “It would seem”, because in saliva, sweat and urine Treponema from the blood does not penetrate. In saliva, they can only be in the presence of syphilitic rashes in the oral cavity. But we must take into account that saliva containing bactericidal substance lysozyme, as well as splitting carbohydrates enzymes amylase and maltase, kills pale treponem. In the saliva of a patient with syphilis, even in the presence of rashes in the oral cavity, it is unlikely that Treponema will be contained, and if they are, then in a single amount, insufficient to cause the disease, and in addition also in an oppressed state due to the action of lysozyme and saliva enzymes on them. So Smoking one cigarette for two with a syphilis patient [6] or drinking from one bottle with him is almost safe in the sense of infection. Again, it is necessary to take into account that you obtained an isolated and oppressed Treponema pallidum (if you get them at all) will work with your saliva, finally they are finishing off. And if some Treponema and gets saliva into the stomach alive, here it will deal with the enzyme gastric juice pepsin and hydrochloric acid produced by the cells of the gastric mucosa. The chances of treponem in this situation there is absolutely no. This is not “favourable” (from the point of view of treponemes, of course) infiltration the body through the genitals – found a hairline fracture in the mucosa, penetrate into blood and live multiply.
In the presence of an inflammatory focus in the oral cavity, resulting from oral sex, in saliva may be gonococci. The same can be said about them as about treponemas – “a rare bird will fly to the middle of the Dnieper”. That is, what is the gonococcus rarely gets to the stomach. And if he does, then he’ll get the drop! Complete and final.
Let’s consider another option of “household infection” (quotes are not accidental) with syphilis or gonorrhea – a bench in the bath. Yes, it is in the bath. Where else would a naked booty sit on a bench? The temperature in the Russian bath is kept within 65-70 °C, and in the sauna can exceed 100 °C, well, below 90 °C never falls. At such temperatures, pale Treponema and gonococci die immediately, instantly. If a sick person soiled the bench with their secretions containing bacteria, then after a second or two of these bacteria will not. What kind of infection can we talk about?
In case of accidental contact of naked bodies, for example, if you touch someone’s shoulder in the shower, it is impossible to get infected with syphilis, because sweat does not contain pale Treponema. Similarly, it is impossible to get infected in the toilet, even if you immediately after the patient with syphilis touched the door handle or, say, the tap.
What if there were gonococci on the doorknob? Can a person with purulent discharge from the genitals when visiting the toilet stain these secretions door handle? Easily can, if he does not comply with the rules of personal hygiene… And soon, almost immediately after him, for this pen you took, not noticing that it is something dirty. Or, say, there was so little infectious biological material on the handle that you just couldn’t see the dirt. You took the contaminated handle, and part of the gonococci, not yet had time to die, was on your hand…
“Calmness, only calmness!”as Carlson said. You’re not infected yet. Gonorrhea is not scabies and getting gonococcus on the skin does not mean infection with gonorrhea. To get sick, you have to move gonococci in a place favorable for their habitat and reproduction – in the vagina, in the urethra, in the rectum, in the eyes or in the oral cavity. And it must be done quite quickly, almost immediately, until these gentle gonokokki not killed. In other words, for infection with gonorrhea, you need almost immediately after touching the door handle to enter the finger with gonococci in the vagina or rectum, or put it in your mouth and hold there for a while, or for some time rubbing your finger eyes or the opening of the urethra on the head of the penis.
Immediately! Hard! With an unwashed finger!
Will you do that?
Scarcely.
And if during the departure of natural needs you just touch the “infected” hand of the genitals, the infection will not occur. It is necessary to try hard to introduce bacteria in a favorable environment for them. For example, to commit sexual intercourse.
If you give first aid to a person with syphilis bleeding and you have blood on your hands or face (in General – on the skin) containing pale Treponema, then you will not get infected in this case. In the light, in the air Treponema will not be able to cause infection. In addition, the drops of blood on you will dry up faster than the Treponema will have time to penetrate through the skin into your body. Unless you have some wounds on your hands… That’s through the damaged skin Treponema penetrate quickly. But again, getting one drop of infected blood on your sore will not cause the disease. Another thing, if you for some time will massage the wounded finger vagina or rectum of a sick person. Appreciated the difference? If so, let’s move on.
Infection through the polluted seat of a public toilet – this is the most terrible and most common (and at the same time the most mythical) hygienic horror story. Yes, infection in this way is possible theoretically, but practically its probability is close to zero. In order to cause the disease, pale Treponema and gonococcus need to get inside the body – in the urethra, in the vagina, in the rectum… do Not jump the bacteria there from the seat really… How do bacteria get, for example, in the urethra to men? They get there immediately after ejaculation, when a small part of the sperm remains in the urethra. On this here is the “great waterway” bacteria and “introduced” into the body. With a seat in the toilet, you see, a slightly different situation.
To sort out one by one all possible cases is not necessary, because you have already become clear that domestic infection with syphilis or gonococcus is more of a paradox than a reality.
Yes, in serious literature described cases of domestic infection with syphilis and gonorrhea. But what? For example, the infection of children, breastfeeding, if the mothers of syphilitic lesions of suppurative nature in the area of the nipples. During feeding, the child systematically receives a portion of treponem in the discharge from the rash, and thus becomes infected with syphilis. And gonorrhea in the home from sick parents, too, are infected with small children who sleep together with parents. Or infection occurs when sick parents change clothes (wash away, bathe, etc.). p.) their children dirty hands, soiled secretions from the genitals. By the way, some people (mostly women) gonorrhea may be asymptomatic. In this case, the probability of household infection of children from sick parents increases.
If you have a friend or, say, a neighbor who “managed” to get infected with syphilis in the bath, then do not rush now to give it as a refuting example. Keep in mind that the household path of infection with syphilis and gonorrhea doctors set based on humanistic considerations. It happens so – sin, without expecting it, a decent person on the side and get sick with something bad. And a man has a family. He’s remorseful, poor, worried. Is it good because of one mistake to break a person’s life? Not good! It is easier to explain the fact of the disease in some other way, sinless everyday way.
Do you know the name “Rickettsia”? Rickettsia called small bacteria (up to 2 microns) – intracellular parasites that can multiply only within the host cell. One of rickettsiae – Rickettsia of Prowazeki, is the causative agent of typhus.
It’s a myth that typhus is the same. Typhoid fever and typhoid fever are two different diseases with different clinics and different pathogens. Typhoid fever causes typhoid Salmonella. And then there is relapsing fever caused by spirochetes of the genus Borellia. Typhus is a common, collective name for a number of infectious diseases, accompanied by mental disorders against the background of severe fever and intoxication (poisoning of the body by the products of the pathogen or products formed during its death).
The name “Rickettsia” has a sad origin. The bacteria received it in honor of the biologist Howard Taylor Ricketts, who died in 1910 in Mexico from typhus, the study of which he was engaged there.
Unlike Rickettsia, other intracellular parasites – chlamydia-are widely known because they cause chlamydia, one of the most common sexually transmitted diseases. Such a well-known (in our time, fortunately – mainly from the literature) eye disease, as trachoma, is also caused by chlamydia.
Microbiologists jokingly call chlamydia and Rickettsia “the transition stage from bacteria to viruses” or “the transition stage from viruses to bacteria”, because they are more complex than viruses, but easier than bacteria.
According to the method of respiration, bacteria (like other microorganisms) are divided into aerobic, requiring the presence of free oxygen in the environment, that is, in the air, and anaerobic, using bound oxygen of various chemical compounds. Anaerobic microorganisms oxygen of the air “to the bulb”, they do not need it and do not know how to use it.
Bacteria multiply by simply dividing one parent cell into two daughter cells. Male and female organisms in bacteria does not happen, they are asexual. The division is fast, in favorable conditions, some bacteria are able to divide every twenty minutes. Theoretically, one bacterium the size of seven days of continuous reproduction can produce a bacterial mass equal in volume to our planet. On the condition that all her offspring remain and continue to reproduce.
The picture of “apocalyptic” reproduction of bacteria is brightly described by Alexander Belyaev in the fantastic story “Eternal bread”. A Professor, wanting to rid the world of hunger, brought the kind of edible, nutritious and fast-growing bacteria. Residents of the fishing village violated the instructions of the Professor, and nutritious “dough” broke free. At first, people tried to eat the “dough”, but soon it became clear that this way to destroy the “dough” will not succeed. “Dough” filled the houses, crept out into the streets and spread over them, threatening to flood the entire village. Desperate fishermen tried to drown the “dough” in the sea, but it did not help. In the water, the “dough” grew much faster than on the ground. It sucked the entire coastal strip and crawled onto land…
About how bacterial “dough” was destroyed, you will learn from the fifth Chapter. Well, if you are impatient, you can put this book aside for a while and read “Eternal bread”, this is a small story.
In order to multiply intensively, you need to eat well.
How and what do bacteria eat?
Nutrition in bacteria occurs through the absorption of nutrients from solutions or from the air through the cell wall. There are bacteria-“foodies” who want to eat strictly certain set of substances that are not picky, and there are those, who, with the help of emitted substances transform is not suitable for the supply of the surrounding substances in the fit. Thanks to this feature, bacteria can live everywhere. Those bacteria that feed on ready-made organic substances are heterotrophic organisms (heterotrophs). By the way, we are heterotrophs too. And those bacteria (and living organisms in General), which can synthesize organic substances from carbon dioxide, water and other inorganic substances due to the chemical energy of oxidation or using the energy of solar radiation, called autotrophic or autotrophs.
In the “Eternal bread” Belyaev is talking about bacteria-autotrophs, receiving all the necessary substances for their life from the air or sea water.
“Trofos” in Greek means “food”. “Auto” or “auto” – “himself” or “its.” “Hetero” – “other”, “alien”. Autotrophs feed themselves, that is, synthesize the necessary organic substances – proteins, fats and carbohydrates, independently. And heterotrophs feed on other people’s organic substances, split them into component parts, from which they synthesize organic substances for themselves.
Yes – not only plants, but also some bacteria, as well as some archaea and some simple eukaryotes can be autotrophs. But at the household level, it is widely believed that only plants can create a biological mass, that is, organic substances “from nothing” (quotes are not accidental, because nothing can be created from nothing but nothing and nothing more).
The secrets of the microscopic Universe are waiting for their researchers – most of the existing bacteria to date has not been described! Don’t look for typos where they don’t exist. And of the bacteria known to science, only half can be grown in the laboratory. So the work of bacteriologists (so-called microbiologists specializing in the study of bacteria) no end.
Food for the sake of bacteria is not yet grown, there is no special need, but in the food and pharmaceutical industry, these microscopic assistants are widely used. Without the participation of bacteria you will not get any cheese or kefir, or sauerkraut, or a number of drugs. (Well-known penicillin, like many other antibiotics, do not produce bacteria, and fungi). And bacteria are involved in the processing of waste and are used instead of poisonous pesticides for biological plant protection.
And finally, that is, in conclusion of the conversation about bacteria, let’s debunk another myth, very, very dangerous.
It is considered that the food suitable for the use smells good, but not suitable – badly.
This statement is not always true. If there is an oxidation of fats or decomposition of proteins, the food gets an unpleasant smell and taste. But the bacteria that cause food poisoning in us may not change the color, smell, or taste of the food at all.
Once again – the bacteria that cause us food poisoning, can not change the color, smell and taste of food.
What conclusions can be drawn from this?
The first conclusion – should be guided by the shelf life of the product and the integrity of its packaging, and not its appearance, smell and taste.
The second conclusion – avoid catering establishments that are questionable from a sanitary and hygienic point of view, as it is attractive (and sometimes – just stunning!) may look like they served food.
Dangerous food can look perfectly safe.
When evaluating food, use not only vision, sense of smell and taste, but also the mind.
And you will be happy! I mean – you will avoid an emergency meeting with infectious disease doctors, and even with resuscitators.