Mycobacterium

Mycobacterium - gram, motionless, aerobic, do not form spores microorganisms. On the ends of sticks are usually visible inclusions in the form of beads and beads. Often form chains of bacteria, sometimes branchy. A characteristic property of mycobacteria is acid-, alcohol - and deleteproject (see Acid bacteria), associated with the accumulation in the cell wax-like substances and the specific structure of the cell membrane. Mycobacteria are cultivated on enriched dense nutrient media with the addition of eggs, milk, potatoes and synthetic liquid media with the addition of albumin. For mycobacteria are pathogens of tuberculosis, leprosy.

Mycobacterium - organisms belonging to the genus Mycobacterium, SEM. Mycobacteriaceae, order Actinomycetales. Widely distributed in nature as saprophytes (live in water, soil, food products, in the discharge or on the skin of animals, human and other) and parasites of various animals and humans. Bacilli, usually have a rod-shaped form; under certain conditions of cultivation and in the body of the owner form filamentous forms and true branching (hence the generic name "Mycobacterium", GRK. mykes - fungus). Mycobacterium conidia do not form; M - aerobes, gram-positive. Most pathogenic species M. refers to the acid-fast bacteria (see). M. grow slowly, at a special nutrient medium, temperature 37-38-42 degrees.
In Berga (D. Bergey, 1957), pathogenic representatives of mycobacteria include seven species: M. tuberculosis hominis, M. tub. bovis, M. tub. avium, M. microti, M. para tuberculosis, M. leprae hominis, M. lep. murium. Recently in pathogenic group M included 8-th - M. ulcerans. Mycobacterium this species grow when temperature is not above 33°allocated from ulcerative lesions of the lower limbs of the person, in the experiment causes skin lesions in mice and rats. Special potentially pathogenic group consists M, isolated from skin lesions man, cattle, from cold-blooded animals - fish, snakes, and others, from the soil. The main representatives of the group - M. fortuitum, M. marinum, and M. thamnopheos, M. platypoecilus the rise in temperature of 10-20 - 25oC; for pigs, rabbits, mice are not pathogenic.
True saprophytes morphologically and tinctorial similar pathogenic mycobacteria, but they are more polymorphic, relatively acid, weak alkali - and spirostachys. Quickly grow into the common and special media at temperature of 10-20 degrees. The main representatives of saprophytes: M phlei (wand Timofeeva grass) - grows with temperature 28-52 degrees and in the form of a plaque or grayish yellow, forming during aging folds; M. smegmatis - polymorphic, relatively short sticks, grow 2-4 days for all environments when temperature 28-45 degrees and in the form of a juicy, oily cream plaque, sometimes dry. Both species are not pathogenic for experimental animals.
Special heterogeneous group consists of so-called atypical or abnormal, unclassified mycobacteria. Nature and their importance in human pathology is not determined for sure. Allocated relatively rare material from people with tuberculosis or clinically similar diseases (a"mycobacteriosis" the lungs, pleura, lymph nodes, joints and other). Temporarily differentiation is "anonymous" M into 4 groups: 1) photochromogenic M (Kansas type); their culture, usually amelanotic when grown in the dark, even with a short exposure to light acquire lemon-yellow color; 2) skotoprogonnaya mycobacteria culture orange when growth in the dark; 3) photogrammetrie, amelanotic Mycobacterium - grey, pale yellow, do not produce the pigment in the light; 4) fast growing at room temperature. In dense media atypical Meters form a smooth, melcockletocny, often oily coating, liquid environments grow on the bottom in the form of flakes, and on the surface of the environment - in the form of a thin, oily film. Cell atypical mycobacteria polymorphic grow at different nutrient substrates at temperature 20-37-38°, "harnesses" do not form. Most strains of not pathogenic and not virulence for Guinea pigs and rabbits, some, especially photochromogenic, in large doses virulent for white mice when administered intravenously (0.5 to 1 mg) and Golden hamsters intraperitoneal (1-10 mg). Acid-resistant; painted by Zn Nelsen red. Have a pronounced catalase activity, mostly initially resistant to such anti-TB drugs (see), as tubazide, paraaminosalicylic sodium. Tuberculin reaction in humans and experimental animals, patients ' mycobacteriosis", impermanent.
M. tuberculosis - see Tuberculosis.