Diphtheria Toxic

Diphtheroids are bacteria of the genus Corynebacterium, family Actinobacteria. Diphtheria bacilli are named after the toxins contained in their bodies: hence the name of the bacterium: Corynebactin - anti-diphtheria toxin. Corynebacteria are normal inhabitants of the skin of the nose and pharynx in mammals, closely related to humans, as the main carrier of diphtheria. In humans, corynobacteria are located on the skin and mucous membranes where it is safe, for example, in the respiratory tract. The diphtheria bacillus is a larger bacilli than most bacteria and can reach 1-4 mm in length and 0.2-0.5 mm in diameter. It stains gram-positive (except for certain atypical species of Corynobacteria). There is no dispute. Without staining, the diphtherin test appears negative or difficult. Contagiousness is high; quickly collapses when heated. Chemoorganotrophs, grow slowly on ordinary media, with the exception of blood, on special media - within several hours, sometimes days. Bacteria can be sterilized by heating at a temperature of 80-112 ° C for 90 minutes; acid-resistant for freeze drying. The microorganism reproduces from aerobic respiration; use nutrients by fermenting sugars, but do not always require CO2 and bile. Sterol rods do not react with the chromium mixture, which gives a characteristic reaction. Mineralization occurs due to the fermentation of carbohydrates without CO2, which can be accelerated by the addition of organic acids; The growth of bacteria is also necessary for the growth of microorganisms - an environment of 37-38 degrees C. Typical cell walls, vitamin synthesis is carried out only by non-cellular pathways. Usually diplococci. Gram positive. Obligate aerobes. These are typical stationary sticks. Catalase negative. There is no mobility due to the rigid capsule polymer coating; the capsule protects Corynebacterium from the action of a number of antibiotics (streptomycin).

For the time being, most diphtheria bacilli were excellent cultural objects. Since the cell wall maturity test was positive (which would require the administration of streptomycin), they were considered to be alive. Other characteristics included the absence of Bacillus Caesarea pigmentation or gram-negative hemolysis. The determination of total sugar is not observed, since it contains a lipid substance. Bacteria are quickly identified by CuSO4 reduction; the color changes to blue and becomes stable. The pH of the environment indicates their viability: pH=2.4 has a small