Many heard about the existence of streptococcal infection and even encountered it. But few seriously thought what constitutes streptococcus, what is it? But knowing the characteristics of the life and activity of the enemy is already half the victory. Streptococcus is engaged in the science of microbiology. In it, as in any other field of knowledge, there are many complex and incomprehensible terms. In this article, we will try to explain in an accessible language about the danger of streptococcus, what it is, whether it is possible and whether it is necessary to fight it, and by what methods the therapy is carried out.
"Portrait" of the parasite
A person daily and every second encounters thousands of microorganisms, which can only be examined under a microscope. A striking representative of this huge army of parasites is streptococcus. What is it, maybe someone? What type of living thing does it belong to? Let's start in order.
Streptococci are bacteria that look like microscopic balls with a radius of up to 0.5 microns. A ball is a single bacterial cell and an entire organism. Streptococci are kept in pairs of two, or in groups, connecting in a chain. They are absolutely motionless, because it has neither cilia, nor tails, nor flagella. They move only with the help of outside interference, for example, when coughing with a stream of air. Once in a new environment, the streptococcus bacteria begins to multiply almost immediately. She does this by simple cell division. The structure of its cell is such that it is able to form the so-called L-form (i.e., almost without a cell wall). This tricky property determines the easy passage of the pathogen through bacterial filters and its very low sensitivity to drugs. In order to better “get to know” such a representative of the world of microorganisms as streptococcus (we have already discussed what it is), we list its physical characteristics. So these parasites:
- anaerobic (i.e., do well without oxygen);
- gram-positive (the term does not refer to weight, but to staining the bacteria according to the method of the scientist Gram) - this property is used to diagnose diseases;
- chemoorganotrophic (feed on organics);
- Asporogenous (do not form a spore);
- parasitic.
Features of life
In humans and animals, streptococci live in large numbers and parasitize in the oral cavity, nasopharynx, gastrointestinal tract, colon, but can enter any organ with blood or other means and begin their pathogenic activity there. In addition, streptococci are located in the environments surrounding us, such as dust, any surfaces, sputum, dried pus. Despite the fact that the parasites form an L-shape and seem to be unprotected, getting rid of them is quite difficult. These bacteria are able to survive in the cold, "hold" 30 minutes at temperatures up to +55 degrees, and solutions of mercuric chloride and carbolic acid kill them in only 15 minutes. But there are species of streptococci with even wider limits of resilience. In the dried fragments of pus, sputum (dried and fresh), all types of microorganism remain viable indefinitely. But these pathogens are most active at an ambient temperature of +37 ° C and a pH close to neutral or slightly alkaline (values from 6.9 to 7.6). For information, room temperature water has a pH of 7, and in most people saliva has a pH of 7-7.4, that is, they are ideal for the development of streptococci in them. Bacteria are especially fertile if they enter an environment containing blood, blood serum, glucose, because this is their favorite food. Here they grow very quickly to huge colonies. If you place different types of streptococci in blood agar (a specially prepared solution containing the blood of some animals), some of them will not change the color of the agar, others form zones of complete erythrocyte decay (hemolysis) around their colonies, and the third will “decorate” the captured area with green. Under less favorable conditions (for example, in dust), streptococcus colonies are much smaller (up to 2.5 mm), often smooth to the touch, sometimes rough, outwardly translucent and shiny. In liquids, microorganisms try to settle down near the walls of blood vessels or at the bottom, leaving the medium itself transparent.
The biggest harm from streptococci is that they secrete very dangerous toxins that cause poisoning of the victim’s body and even can lead to death.
What are streptococci
There are several recognized classifications. According to Brown and Schottmüller, the entire army of streptococci is divided into 3 main groups:
1. Hemolytic.
2. Greening.
3. Non-hemolytic.
The most dangerous are hemolytic streptococci, but not all of them are pathogenic. At the same time, among the harmless non-hemolytic there are quite “serious” parasites.
Due to difficulties in determining the harmfulness of streptococcus, another classification was proposed. It was developed independently by Rebecca Lensfield and Frederick Griffith. They took the antigenic structure of pathogens as a basis, due to which they were divided into 17 species or groups designated by Latin letters. The first is streptococcus A, the second B, the third C, the fourth D and so on, to the S-streptococcus group. For people, the first four are the most unpleasant. We will analyze them in more detail and begin by answering the question: “Streptococcus group A - what is it?” Why precisely from it? Firstly, because it is the first on the list, and secondly, because it is the most dangerous parasite that causes a whole bunch of diseases in a person. So…
Streptococcus group A
Bacteria of this group are not only the most dangerous, but also the most numerous. In total, 53 species of these microorganisms were found in humans, and 49 of them belong precisely to group A. They are found in the respiratory organs, in the mouth, intestines, genitals, and with the help of blood, where the parasites penetrate very easily, are transferred to any part body and in any organ. Another name for these bacteria is Streptococcus pyogenes, that is, pyogenic streptococcus. What it is? From Greek pyon is translated as "pus". From the name it is clear that pyogenic streptococci cause diseases accompanied by purulent discharge (purulent infections). This is not their only dangerous property. Such microorganisms provoke complications after transferring the underlying disease - rheumatism and acute glomerulonephritis (kidney damage). The main characteristic feature of all A-group streptococci is the presence of an M-protein in the walls of their cells, and it occurs in 80 variations. This substance protects streptococci from phagocytes that exist in the blood of a person in order to eat foreign bodies. In addition, each representative of group A pathogens has a capsule that also protects them from phagocytes. Such morphological features of streptococci are “guilty” of the fact that a person who has been ill with something develops immunity only to the type of parasite that caused this disease. That is, if a-streptococcus with M1 protein caused your sore throat, then there will be immunity only to this bacterium, and there will be no immunity to the pathogen with M2 protein, which means that you can get a sore throat again. The numbers in this case determine the type of bonds in the protein.
Hemolytic streptococcus: what is it
The term "hemolytic" means destroying blood cells. If the parasite causes complete hemolysis (complete destruction of all blood cells around it), it is called beta-hemolytic. Almost all representatives of the first four groups (A, B, C, D) are just such. They cause the following diseases:
- tonsillitis;
- scarlet fever;
- face;
- impetigo (skin disease);
- infective endocarditis;
- abscesses (abdominal cavity, brain);
- meningitis, sepsis of newborns;
- postpartum sepsis;
- various infections of the genitourinary system.
There is also an alpha hemolytic streptococcus. What it is? This is the same hemolytic streptococcus (green), only it destroys red blood cells in part. This species may seem less dangerous. In fact, it causes such dangerous diseases as:
- abscesses of the peritoneum and brain;
- periodontitis;
- infective endocarditis;
- pneumonia;
- meningitis.
These streptococci, as mentioned above, are able to change the color of the medium from red to green.
There is also gamma hemolytic streptococcus. What it is? So called bacteria that do not destroy red blood cells and do not change the environment of agar (the so-called non-hemolytic). But they can cause a number of diseases:
- infective endocarditis;
- sinusitis;
- infection in the wounds.
Streptococcal tonsillitis
In general, angina is a broad concept, meaning any sore throat. It can be caused not only by streptococci, but also by other viral and bacterial pathogens. Let's discuss what to do if streptococcus is found in the throat, what it is and how not to make a mistake with the diagnosis, because the treatment method depends on it. An exact verdict can only be made by a doctor according to the results of a microbiological analysis (smear). It is taken with a sterile swab from the throat. In addition, there are two rapid tests, but the smear is the most accurate. You can get streptococcal tonsillitis only by contact with the patient, if precautionary measures are not followed. The main symptoms are:
- sore throat, especially during swallowing;
- temperature;
- general weakness, chills;
- sore neck nodes;
- swelling of the mucous membranes;
- white or purulent plaque on tonsils and throat;
- in rare cases, abdominal pain.
The disease with proper treatment lasts up to 5 days. Medicines must be selected so that the kidneys and joints do not suffer.
Most often, patients are prescribed antibiotics orally, and in special cases subcutaneously. To reduce sore throat, use sprays or rinses with antiseptics, decoctions of chamomile, and a solution of baking soda.
Scarlet fever is characterized by approximately the same symptoms as angina, only with this disease a small-pointed red rash is added throughout the body caused by streptococcal toxins. With scarlet fever, there is also a symptom of "strawberry tongue" (with a white coating and red papillae). The treatment is similar to the above.
Streptococcal skin diseases
Some patients are referred by doctors to be tested for streptococcus SPP. What it is? Yes, all the same cocci bacteria. It is more correct to call this group Streptococcus SPP. It includes the already familiar pyogenic streptococci that cause many diseases, as well as Streptococcus pneumoniae, which causes pneumonia, meningitis, bronchitis, blood poisoning, and Streptococcus mutans, which is responsible for caries and endocarditis.
Streptococcal skin diseases include impetigo and erysipelas.
The first disease is caused by pyogenic streptococci A-groups. As a rule, it is more often observed in children if sanitary standards are not followed. Streptococci in everyday life constantly fall on the skin of people. Where "friends with cleanliness" (wash their hands, do regular wet cleaning), they are removed from the skin. And where everything is not in order with hygiene, streptococci inhabit the skin constantly and with the slightest injuries, including light scratches and insect bites, penetrate the subcutaneous layer. Symptoms of impetigo are painless rashes near the nose, lips and very rarely in other parts of the body. At the first stage, these rashes look like red nodules (papules), which subsequently turn into purulent vesicles (pustules), burst and dry up with the formation of yellowish crusts. They treat impetigo with antibiotics.
Births are also caused by pyogenic streptococci. The disease occurs due to the penetration of bacteria into the subcutaneous tissue. The reasons are various violations of the integrity of the skin, from cuts to insect bites. Symptoms
- redness, soreness, swelling of the affected area of the skin;
- chills;
- fever.
One of the most unpleasant properties of pathology is the possibility of relapse many years after an apparent cure.
Pneumonia
This disease has several varieties, depending on the pathogen. Streptococcal pneumonia is one of the most dangerous. It is caused by penetration into the lungs of streptococcus Pneumoniae. You can catch the infection by inhaling the air, which contains pathogenic bacteria. Pneumonia begins suddenly, but there are cases of its gradual development. Symptoms
- heat;
- cough;
- chest pain
- dyspnea;
- fever;
- purulent effusion (accumulation of pus in the lungs) - this process has a persistent tendency to increase, and if urgent measures are not taken, commissures form in the lungs.
Diagnose pneumonia by radiography, as well as by testing sputum excreted. Treated with antibiotics and corticosteroids, as a rule, an integrated approach is required. The treatment regimen is developed only by a qualified specialist! Without proper treatment, pneumonia often leads to death.
Streptococcus agalactia: what is it
With group A streptococci, we more or less understood. Now let's talk about the parasites of group B. They were first identified by studying mastitis in cows. It was later discovered that these bacteria cause meningitis and sepsis only in the baby crumbs, and postpartum sepsis in their mothers. They called parasites Streptococcus agalactiae (in Russian - "streptococcus agalactia"). What it is? We answer: these are very dangerous bacteria, leading either to death or to serious complications. Their body (cell walls) contains capsular polysaccharides, and the latter - 9 variations. Accordingly, there are 9 serotypes of streptococcus agalactia. To determine exactly which of them caused the disease, a CAMP test is performed. The abbreviation is just the capital letters of the names of scientists involved in this problem.
Due to some confusion in the classifications, certain difficulties arise. So, take, for example, streptococcus group B. What is it? Yes, the same as streptococcus agalactia. These are two names for the same bacteria. Group B streptococci are either oval or round in shape. Their main “place of residence” is the human urogenital system. Bacteria are transmitted to newborns during birth. At the same time, sepsis develops in only 2% of children, but 50% of them die, and survivors often suffer from brain disorders. Sepsis can occur immediately (during the first day) or over time (from a week to 3 months). Symptoms
- drowsiness;
- sluggish sucking;
- respiratory failure;
- arterial hypotension;
- bacteremia (the presence of bacteria in the blood);
- pneumonia or meningitis.
In women in labor, streptococcal sepsis is manifested in soreness and bloating, bacteremia. Sometimes infectious meningitis and / or endocarditis begin.
In all categories of citizens, group B streptococci cause the following diseases:
- meningitis;
- bronchopneumonia;
- purulent arthritis;
- inflammation of the genitourinary system;
- osteomyelitis;
- abscesses of the pelvis, peritoneum, and others.
Streptococcus groups C and D
In small quantities, streptococci of other groups are found in people. The bacteria belonging to group C are beta-hemolytic and cause the same diseases as the pathogens of the A group. Group D includes both streptococci and enterococci. They cause diseases mainly in the elderly, weakened by diseases of people and in those who, due to the uncontrolled intake of antibiotics, upset the microflora balance in the body.
People often ask what the norm of streptococci is, because they do not always cause illness. As such, there is no norm. These bacteria remain harmless as long as the immune system is able to "keep them in check." Therefore, the main task of all of us is to increase and strengthen our immunity in all ways that are available. If he suddenly weakens, streptococci get out of control and attack. Destroying bacteria is unthinkable, since the place of those who left in a matter of hours will be occupied by new ones, because they are full in our environment. Streptococci account for up to 60% of all microorganisms in the oral cavity. As for streptococci of the B-group, found on the mucous membranes of the genital organs, normally they should not be.