Wednesday, August 28, 2019
Clostridium tetani Essay Example | Topics and Well Written Essays - 1250 words
Clostridium tetani - Essay Example The author has rightly presented that Clostridium tetani is obligate anaerobe and doesnââ¬â¢t grow in the presence of oxygen. Optimal conditions for growing this bacterium are temperature of 37 degrees Celsius, with PH of 7.4. It grows on different nutrient media including agar enriched with blood. When cultivated on agar enriched with blood it manifests alpha hemolisis, but with prolonged cultivation it produces beta hemolisis. Because Clostridium tetani is mobile bacteria and has flagella when cultivated produces the effect of swarming and tends to spread over the complete area of the culture. When cultivated produces very thin and see-through layer of bacteria that is very hard to notice with a naked eye, except on the edges of the colonies. It is difficult to obtain a pure culture of Clostridium tetani, this is why method called Fildes technique is often used, when the bacteria is inoculated on a small area on an agar plate and after incubation of 10 hours another subcultures are made from the edge of the swarming area that is constituted mostly of Clostridium Tetani. In suboptimal conditions, Clostridium tetani forms spores that are relatively resistant. Spores are killed in boiling water for 10-15 minutes, and in the moist heat of 121 degrees Celsius after 20 minutes. Based on the agglutination process Clostridium Tetani is classified in 10 serological types (only type IV doesnââ¬â¢t have flagella and is not mobile).... It is protein based molecule with molecular weight of 150 kDa (Kilo Daltons) and is constitutes of two parts, heavier or B chain with weight of approximately 100 kDa and lighter A chain with molecular weight of 50 kDa. Heavier B chain of this toxin bonds to the cell membrane and helps chain A to enter the cytosol of the cell (Farrar et al. 2000). The A chain than migrates through the axons to the central nervous system. Lighter A chain of the tetanospazmin toxin in the CNS impairs the release of inhibitory neurotransmitters in the brain (GABA-gamma aminobuteric acid and glycine) by degrading protein called synaptobrevin (small membrane based protein). Consequence of this effect is hyperactivity of the skeletal muscles in the body and development of muscle contractions and muscle spasm (Schiavo et al. 1992). Infection with C Tetani may cause development of condition called tetanus. It is disease that is characterized by presence of generalized spasms of the skeletal muscles in the bod y that is produced by the tetanospasmin toxin. It is caused when a wound is contaminated with spores of Clostridium Tetani. C Tetani are widespread bacteria that are present in the soil, dust, manure of domestic animals, our clothing and in about 20 percents of human gastrointestinal tract (Bleck 1995). If the wound is deep enough spores of C. tetani in anaerobic conditions can develop in viable bacteria that start to release toxins. Toxins are released when the bacteria are destroyed and bacterial cytosol along with toxins is released into the human tissues. Incubation period between the infection and occurrence of first symptoms ranges between 3 and 21 days, but that depends mostly on the site of primary infection. As early sign patients may report dysphagia and sore throat and some
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