Gently spread the inoculum in the drop of deionized water. Remove the cap from the Bacillus, insert the sterilized inoculating loop and obtain a pinpoint of Bacillus. Sterilize an inoculating loop and allow it to cool. Add a small drop of deionized water to the center of the “E” slide.ģ. Using a permanent marker, label the top right corner of one slide with “E” for endospore.Ģ. Dispose of the cotton swab in the regular trash. Clean a glass slide with lens cleaner and a cotton swab. This infection is a common cause of healthcare associated infection (HAI) which is difficult to eradicate from the healthcare environment due to the ability to produce resistant endospores. These antibiotics kill the normal microbiome in the intestinal tract and allow C. This is usually observed in people who have been on broad-spectrum antibiotics for a long period of time. Clostridium difficile causes toxic enterocolitis and pseudomembranous colitis. Clostridium tetani causes tetanus or “lockjaw”. A small coke bottle of botulism toxin is potent enough to eliminate the entire human race!Ĭlostridium perfringens causes gas gangrene and food poisoning. Clostridium botulinum is the causative agent of botulism, a particularly lethal type of food poisoning. If the food is not properly processed, the endospores may germinate, produce toxins and cause food poisoning.Īll the medically important Clostridium produce toxins. Endospores may survive boiling for hours. Most vegetative cells are killed by temperatures greater than 70 oC. There is concern that anthrax endospores might be used in biological warfare as they are easily spread through the air.Įndospores are a unique problem for the food industry since they are resistant to the heating processes that readily kill vegetative cells. Persons who handle animals, hides, wool and other animal products are at special risk. Bacillus anthracis is the pathogen responsible for anthrax, a disease found in goats, cattle, and sheep which can be transmitted to humans. Some species of Bacillusand Clostridium are pathogenic for humans, livestock and wildlife. The presence of Bacillus in dust accounts for the fact that organisms in the genus Bacillus are common laboratory contaminants. These bacteria are commonly found in the soil and in the lower intestinal tract of humans and animals. Two medically important bacteria that produce endospores are Bacillus and Clostridium. A single endospore reverts to one vegetative cell during germination. Unlike the reproductive spores of fungi and plants, sporogenesis in bacteria is NOT a means of reproduction. Germination is normally induced by physical or chemical damage to the coat of the endospore. When an endospore reverts to a vegetative cell (metabolically active, replicating cell), the process is termed germination. The process of sporogenesis (the formation of endospores within a vegetative cell) is reversible. DNA repair enzymes contained within the endospore can repair damaged DNA during germination.Water is removed from the interior of the endospore and the resulting dehydration is thought to be important in the endospore’s resistance to heat and radiation.Specialized DNA-binding proteins saturate the endospore’s DNA and protect it from heat, drying, chemicals, and radiation.Calcium-dipicolinate within the endospore may stabilize and protect the endospore’s DNA.The heat resistance of endospores is due to a variety of factors: The impermeability of the endospore coat is thought to be responsible for its resistance to chemicals. Bacterial endospores are resistant to antibiotics, most disinfectants, and physical agents such as radiation, boiling, and drying. Endospores are the most resistant form of life known and can remain dormant for 150,000 years or more. These endospores are surrounded by an impervious layer called an endospore coat. They are formed inside the cell membrane of bacteria. Some Gram-positive bacteria, such as Bacillus and Clostridium, can produce resting cells called endospores.
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