Bacillus. Bacillus is a rod-shaped bacterium What diseases are caused by bacilli
Loans. in the second half of the 19th century. from it. lang., where Bazillen from lat. bacilla, forms pl. numbers from bacillum "stick", reduce - caress. formations from baculum "stick". The bacterium was named by the German scientist W. Kohn for its rod-shaped form. Etymological Dictionary of Shansky
Bacilli belong to the department Frmicutes, the Group of rods and cocci that form endospores, the genus Bacillus.
Bacilli are straight rods, often large, 2-10 microns, with rounded or chopped ends, often arranged in chains in a smear. A distinctive feature of bacteria of the genus Bacillus is the ability to form endospores, which are characterized by high thermal stability, impermeability to many dyes and disinfectants, resistance to UV rays, ionizing radiation. Spores are oval or cylindrical, not thicker than a vegetative cell. Located centrally, subterminally or terminally. Inside each vegetative cell, one endospore is formed, which, after maturation, is released during cell lysis. Free endospores are metabolically inactive. For decades, they can be in a state of cryptobiosis (complete rest). The formation of endospores is often accompanied by a lack of nutrients in the environment, the accumulation of metabolic products, etc. This is one of the forms of existence of these types of microorganisms. The most intensive sporulation is carried out by biologically high-grade mature cells grown in favorable conditions.
Bacteria of the genus Bacillus are of great practical importance. Some soil bacilli are capable of non-symbiotic fixation of atmospheric nitrogen. Among the bacilli there are species that have found wide application in the textile industry, in the production of silk, paper, coffee, and in leather dressing. Producers of antibiotic substances are used in the food industry and in agriculture. A number of bacilli cause food spoilage, including canned food (bacteria of the hay and potato sticks), dairy and culinary products (B. cereus). Sporiferous bacteria, especially their thermophilic forms, play a significant role in the processes of grain self-heating. Many species have phytopathogenic properties (mainly bacteria of the potato stick group). There are pathogenic species, including the causative agent of anthrax - Bacillus anthracis.
Bacillus subtilis - hay stick- a typical representative of the genus Bacillus - found everywhere in the settled dust, in the soil, on plants. Forms long chains on nutrient media. On liquid media, it grows as a wrinkled white or gray film on the surface. On dense media forms flat, dry, matte gray colonies with uneven wavy edges. Actively breaks down organic nitrogenous compounds (the culture smells like ammonia). Spores withstand boiling for up to 30 minutes, which is used in the isolation of the culture. Bacteria of the subgroup B. subtilis are of great importance as producers of the antibiotics subtilin and bacitracin. These bacilli are contained in the plant protection preparation phytosporin.
Bacillus mesentericus - potato stick. It has the appearance of a thin stick 0.5-0.6 / 3-10 microns in size, often forming long threads. Vegetative cells are mobile, gram-positive, form oval spores, while the cells do not swell, but retain their cylindrical shape. Colonies yellow-brown, dry, wrinkled. On the surface of liquid media, a potato stick forms a powerful folded film, on potato slices - a folded coating (hence the name). It liquefies gelatin, alkalizes and peptonizes milk, forms acid from glucose, sucrose and maltose, does not decompose starch. Potato stick is widely distributed in nature (in soil, food, etc.). Its spores, getting into the dough together with flour or yeast, do not die when baking bread and, germinating, can cause a "stringy" or "potato" disease of bread (the crumb of bread becomes slimy and viscous, and the bread acquires an unpleasant smell).
Bacillus thuringiensis. By morphological and cultural-biochemical properties it is close to Bacillus mesentericus. They are large (5 x 1 µm) bacilli. Motile, form a heat-resistant spore located subterminally. In the center of the cell there is a toxin crystal stained with aniline black dye (systematic feature). B. thuringiensis is characterized by the formation of products that exhibit selective insecticidal activity. The toxic properties of the resulting toxins affect only if they enter the insect's digestive tract (harmless to humans and mammals). A toxin crystal is an aggregate consisting of a high molecular weight organic compound. It is a protoxin (preliminary activation is required), practically insoluble in water and safe for all vertebrates (including humans) and most insects (including bees and bumblebees), showing high specificity with respect to the insect host. After dissolution in the intestine, it undergoes cleavage by proteases with the formation of active δ-toxin. The active toxin attaches to the membranes of the midgut epithelium of insects, causing an equalization of ion concentrations outside and inside the cells, which leads to disruption of the digestive system of the larva, gradually causing starvation. Strains of B. thuringiensis cause the death of insect pests of the forest (in particular, the Siberian silkworm), many pests of the garden and crops (cabbage whites, cotton bollworms, etc.), as well as some species of flies. At present, various variants of the B. thuringiensis culture are widely used for the manufacture of insecticide preparations (entobacterin, insectin, lepidocide, bitoxibacillin, etc.). Their use allows you to quickly destroy pests in large areas without harming the environment.
In cereus- waxy wand. A typical soil microorganism. The causative agent of decay processes. Sometimes causes plant diseases. May cause microbial spoilage of food. When accumulated in food products, it can cause food poisoning in people - toxicoinfection. B.cereus - large gram-positive, mobile, spore-forming rods. The capsule does not form. In smears, they are arranged in the form of long chains and threads. They grow well on simple nutrient media. On the MPB, they form haze, a film on the surface and a precipitate. On MPA - medium and large, gray, flat colonies, similar to frozen drops of wax. On blood agar, a zone of hemolysis forms around the colonies. They show strong proteolytic activity (peptonize milk, liquefy gelatin, ferment urea). B. cereus exhibits strong antagonistic activity against enterobacteria (causative agents of acute intestinal infections). Therefore, special strains of this microorganism are used as part of medicinal probiotic preparations, such as "bactisubtil". B. cereus are similar in properties to the anthrax pathogen B. anthracis, therefore they are called anthracoids and are differentiated in the bacteriological diagnosis of anthrax.
Bacillus anthracis is a Gram-positive, large, non-motile, spore-forming, capsule-forming bacillus. The causative agent of anthrax. The first proven causative agent of human diseases, isolated in pure culture by R. Koch in 1877.
anthrax
Anthrax (anthrax) is known since antiquity, a particularly dangerous infectious disease of agricultural and wild animals of all kinds, as well as humans. The common name for anthrax today is anthrax, which in Greek means "coal": this name was given by the characteristic coal-black color of the anthrax scab (the center of the abscess) in the skin form of the disease. The name "anthrax" was given by the Russian researcher Andrievsky in the 18th century, since epidemics and epizootics of this disease raged most often in Western Siberia.
Epizootics and epidemics of anthrax are territorially tied to soil foci - storages of pathogens. Primary soil foci are formed as a result of direct infection of the soil with the secretions of sick animals in pastures, in places of stall keeping of animals, in places of burial of corpses (cattle burial grounds), etc. waters.
The anthrax bacterium outside the body forms spores with the access of air oxygen, as a result of which it is highly resistant to high temperature, drying and disinfectants. Spores can persist for years; An area contaminated with the blood, feces, and urine of sick animals can retain anthrax spores for many years.
Infection can occur with the participation of a large number of transmission factors. These include secretions and skins of sick animals, their internal organs, meat and other food products, soil, water, air, environmental objects contaminated with anthrax spores. Infection with anthrax occurs through contact, wounds, insect bites, alimentary (with food), aerogenic (by inhalation of dust containing pathogen blinders).
Conventionally, 3 forms of anthrax are distinguished: skin - the formation of edema and carbuncles (abscesses with a black center) at the sites of penetration of the pathogen, intestinal and pulmonary (in these cases, foci of inflammation are formed in the intestines or lungs, septicemia quickly occurs, which leads to death). The most susceptible to anthrax are sheep, goats, and cattle. Camels, wild herbivores, horses can get sick. Anthrax in animals is characterized by the following features:
1) a short incubation period, usually not exceeding 3-4 days;
2) the development of a severe febrile state, edema and carbuncles of the head, neck, dewlap;
3) a decline in cardiovascular activity, bloody diarrhea and vomiting ending in the death of animals during, as a rule, the first 2-3 days.
In pigs, an atypical form in the form of a sore throat is more common, carnivores are insensitive. A person often develops carbunculous, cutaneous form of anthrax.
Diagnosis of anthrax.
Material for research: In veterinary medicine, it is prohibited by law to open corpses if anthrax is suspected in order to reduce the risk of spreading the spore-forming pathogen in the external environment!! Therefore, from the corpse of a fallen animal, an ear is taken for examination, cut off from the side on which the corpse lies. If anthrax is suspected during the autopsy, the autopsy is stopped, pieces of the spleen, liver, altered lymph nodes, and blood are taken for examination.
Microscopy: Gram stain, per capsule and spore. The morphology of Bacillus anthracis depends on the material from which the smears are made.
In smears from blood and fresh pathological material - large Gr+ rods in the form of short chains, 2-3 each. The ends of the cells facing each other in a chain are, as it were, “chopped off”, and outside they are rounded. There is a capsule common to the entire chain. Motionless.
In a young to-re with MPA or MPB, long, intertwining chains of large Gr + rods, sometimes thickened, at the ends and reminiscent. "bamboo cane"
In old cultures, with the access of O 2, rounded endospores are formed, then the vegetative parts of microbial cells die, leaving spores.
Cultural properties: B.anthracis - chemoorganoheterotroph, facultative anaerobe. At the MPB - Wednesday transparent, at the bottom of the sediment in the form of a "lump of cotton wool". On MPA - large, matte gray-white colonies in the R-shape with a curl-like, fringed edge; under low magnification. microscopes are characterized as "head of Medusa", "lion's mane". There is no hemolysis on blood agar.
Various tests are used to differentiate Bacillus anthracis from other soil bacilli, including the pearl necklace test. To do this, the test culture is sown on "penicillin agar", that is, MPA containing the antibiotic penicillin. Grow colonies, then view the preparation under a microscope. Under the action of penicillin, the cell wall of anthrax is destroyed. They bulge into balls. Therefore, when microscopy of such a preparation, chains are observed not from sticks, but from balls similar to “pearls”. To establish the virulence of the culture, a bioassay is carried out, i.e. infect white mice (mice die). To make a diagnosis of anthrax, phage diagnostics, serological, allergic and molecular genetic methods are also used.
BACILLA
rod-shaped bacteria. They live in water, soil, the digestive tract of animals and humans. Many (E. coli, etc.) are involved in digestion, some (pathogenic) are pathogens of infectious diseases. With a sufficiently high immunity, the latter do not cause signs of illness in a person, but he releases bacilli into the external environment (bacillus carrier). Under unfavorable conditions, bacilli form spores that retain pathogenic properties for decades. Non-spore-forming gram-positive rods (lactobacilli) that cause lactic acid fermentation are used for the production of fermented milk products.
Encyclopedia Biology. 2012
See also interpretations, synonyms, meanings of the word and what is BACILLA in Russian in dictionaries, encyclopedias and reference books:
- BACILLA in the Big Encyclopedic Dictionary:
(from lat. bacillum - stick) rod-shaped bacteria. In a narrow sense, bacilli are a genus of Gram-positive, rod-shaped bacteria that form intracellular spores. Majority … - BACILLA in the Great Soviet Encyclopedia, TSB:
(from Latin bacillum - stick), rod-shaped bacteria, the development cycle of which includes sporulation. B. belong mainly to the family Bacillaceae; … - BACILLA
cm. … - BACILLA in the Modern Encyclopedic Dictionary:
- BACILLA in the Encyclopedic Dictionary:
(from the Latin bacillum - stick), rod-shaped bacteria. In a narrow sense, bacilli are rod-shaped bacteria that form intracellular spores (resting forms, resistant ... - BACILLA in the Big Russian Encyclopedic Dictionary:
BACILLA (from Latin bacillum - stick), rod-shaped bacteria. In the narrow sense, B. is a gram-positive genus. rod-shaped bacteria that form intracellular spores. Majority … - BACILLA
? cm. … - BACILLA in the Dictionary for solving and compiling scanwords:
Rod-shaped … - BACILLA in the New Dictionary of Foreign Words:
(lat, bacillum bacillus) bacteria that have the shape of a stick and form spores; most bacilli are pathogens of infectious diseases; more broadly … - BACILLA in the Dictionary of Foreign Expressions:
[bacteria that are rod-shaped and form spores; most bacilli are pathogens of infectious diseases; in a broader sense - all sorts of ... - BACILLA in the Dictionary of the Russian Language Lopatin:
- BACILLA in the Complete Spelling Dictionary of the Russian Language:
bacilli, -ill, s. -illa, ... - BACILLA in the Spelling Dictionary:
bacillus, -`ill, sing. -`illa, ... - BACILLA in the Modern Explanatory Dictionary, TSB:
(from lat. bacillum - stick), rod-shaped bacteria. In a narrow sense, bacilli are a genus of Gram-positive, rod-shaped bacteria that form intracellular spores. Majority … - BACTERIA in the Encyclopedia of Biology:
, microscopic, usually unicellular organisms, which are characterized by the absence of a formed nucleus (see prokaryotes). Distributed everywhere: in soil, water, air, ... - PLAGUE in the Encyclopedic Dictionary of Brockhaus and Euphron:
Story. In former times, Ch. called many epidemic diseases that struck contemporaries with colossal mortality. Therefore, it is very difficult according to the descriptions of the ancients ... - PURE CULTURES in the Encyclopedic Dictionary of Brockhaus and Euphron:
under this name in bacteriology cultures of microorganisms are known that contain one specific species, so "Ch. culture of the plague bacillus" means that ... - ANIMAL TUBERCULOSIS in the Encyclopedic Dictionary of Brockhaus and Euphron:
a contagious disease, equally characteristic of all types of domestic animals and humans, is caused by a special bacillus, known as the Koch bacillus. T. the most ... - TYPHUS MOUSE in the Encyclopedic Dictionary of Brockhaus and Euphron:
Prof. Leffler (Loeffler) described in 1892 the epizootic observed by him in Greifswald among white mice intended for various experiments. The causative agent ... - SOIL SANIT. in the Encyclopedic Dictionary of Brockhaus and Euphron:
topographic conditions and the geological character of P., revealing a significant influence on the climate and on the social and economic conditions of the population, to a large extent ... - ZHDANOVSKAYA LIQUID in the Encyclopedic Dictionary of Brockhaus and Euphron:
proposed in the forties of this century as a remedy for the destruction of stench; got its name from the name of its inventor, process engineer N. ... - BACTERIA in the Encyclopedic Dictionary of Brockhaus and Euphron.
- PLAGUE in the Encyclopedia of Brockhaus and Efron:
? Story. In former times, Ch. called many epidemic diseases that struck contemporaries with colossal mortality. Therefore, it is very difficult to describe ...
BACILLA BACILLA
(from Latin bacillum - stick), any rod-shaped bacteria. In the narrow sense B. - aerobic and facultative anaerobic gram-positive. rod-shaped bacteria of the genus (Bacillus), forming heat-resistant endospores.
.(Source: "Biological Encyclopedic Dictionary." Chief editor M. S. Gilyarov; Editorial board: A. A. Babaev, G. G. Vinberg, G. A. Zavarzin and others - 2nd ed., corrected . - M .: Sov. Encyclopedia, 1986.)
bacillirod-shaped bacteria. They live in water, soil, the digestive tract of animals and humans. Many ( coli etc.) are involved in digestion, some (pathogenic) are the causative agents of infectious diseases. With a sufficiently high immunity, the latter do not cause signs of illness in a person, but he releases bacilli into the external environment (bacillus carrier). Under unfavorable conditions, bacilli form spores that retain pathogenic properties for decades. Non-spore-forming gram-positive rods (lactobacilli) that cause lactic acid fermentation used for the production of fermented milk products.
.(Source: "Biology. Modern Illustrated Encyclopedia." Editor-in-Chief A.P. Gorkin; M.: Rosmen, 2006.)
Synonyms:
See what "BACILLA" is in other dictionaries:
Bacillus Hay stick, Gram stain Scientific classification ... Wikipedia
Modern Encyclopedia
- (from lat. bacillum bacillus) rod-shaped bacteria. In the narrow sense, bacilli is a genus of Gram-positive, rod-shaped bacteria that form intracellular spores. Most bacilli are saprophytes. Some bacilli cause diseases in animals and humans, for example ... ... Big Encyclopedic Dictionary
1) the trivial name of any rod-shaped bacteria; 2) representatives of the genus Bacillus, including aerobic and facultative anaerobic gram-positive rod-shaped spore-forming bacteria; 3) in non-scientific word usage, various ... ... Dictionary of microbiology
bacilli- (from the Latin bacillum bacillus), rod-shaped bacteria. In the narrow sense, bacilli are rod-shaped bacteria that form intracellular spores (resting forms that are resistant to high temperatures, radiation and other adverse effects). ... ... Illustrated Encyclopedic Dictionary
Microscopic organisms in the form of long sticks. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. BACILLES, see BACTERIA. Dictionary of foreign words included in the Russian language. Pavlenkov F., 1907 ... Dictionary of foreign words of the Russian language
Exist., number of synonyms: 1 shoes (119) ASIS synonym dictionary. V.N. Trishin. 2013 ... Synonym dictionary
BACILLA- BACILLES, see Bacteria... Big Medical Encyclopedia
bacilli- Rod-shaped bacteria whose development cycle includes sporulation Topics in biotechnology EN bacillus … Technical Translator's Handbook
bacilli- * bacillus * bacillus (lat. bacillus) rod-shaped bacterium (see) ... Genetics. encyclopedic Dictionary
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Bacteria are the smallest, microscopic organisms that are not visible to the naked eye. They do not have a shell-bound core. More than 3,000 species of such microorganisms are known to modern science, among which a wide segment is occupied by bacilli. Bacillus is a rod-shaped bacterium. And its name directly indicates the appearance (Latin: bacillum - stick). These bacteria were named by the German scientist W. Kohn in their form, resembling a stick.
Genus of bacteria
What in bacteriology is meant by the general name "bacillus"? This is a rather extensive genus of characteristic form. And first of all, in addition to their appearance, they are united by the ability to form intracellular spores that serve to reproduce and preserve the species in adverse conditions. Not all, but some of the bacilli cause diseases and toxic infections in humans, which means they are pathogenic (we will talk about them in more detail below). And many of these bacteria are saprophytes, mostly living in the soil.
Conditionality of classification
It should be noted that "bacillus bacteria" is a rather conditional classification. Today it is rarely used in microbiology. This convention is due to the fact that the shape of bacilli is characteristic of many bacteria (except cocci, which have a rounded shape), and a great many microorganisms can be characterized in appearance as rods. But still, it is possible to determine some basic characteristics that generalize the genus.
Main characteristics
- Most bacilli are saprophytes. They convert organic matter into inorganic compounds as a result of their vital activity.
- Tolerance to oxygen. For them, it is not a poison, and many use it for breathing (aerobic).
- Bacilli carry out their vital activity due to chemical reactions.
- These bacteria are motile and carry out movement with the help of flagella.
- Virulence: Many bacilli cause disease in humans.
Associations
Many rod-shaped bacilli are grouped into several cells.
controversy
A bacillus is a bacterium capable of producing spores. This may serve as one of the most obvious signs for classification. Moreover, the shape of the bacilli varies from the position of the spores in the bacterial cell. For example, spores cluster on the ends of cells, giving them the appearance (clostridia). And in butyric bacilli - in the middle part of the cells, so they give them a spindle shape (plectridia).
Bacterial spores are recognized by scientists as the hardiest formations of all life forms on planet Earth. Characteristically, spores have no metabolism at rest. They are resistant to steam, drying, radiation, lack of oxygen, acids. At rest, spores are very long-lived. They are found in all habitats on Earth. And if favorable conditions arise, then the spores immediately quickly react to the environment and germinate, resuming active growth.
Examples of pathogenic bacilli
- Bacillus anthracis - causative agent It is assigned to the second pathogenicity group.
- Bacillus cereus is the causative agent of foodborne toxic infections in humans.
- Bordetella pertussis - found in the lungs, causes whooping cough.
- Koch bacillus is the cause of tuberculosis infection and disease.
- Tetanus bacillus is the causative agent of tetanus.
But not all bacilli are harmful. Modern science has learned to use their positive qualities. Some bacilli are used in production as producers of proteinases and amylases. And the toxins they produce are used as insecticides to protect cultivated plants.
