Endospore Forming Gram Positive Rods and Cocci

Endospore forming, gram-positive rods and cocci consist mainly of rod-shaped bacteria of the genera Bacillus and Clostridium. Another cocci bacteria included in this group are of the genus Sporosarcina. These bacteria have no clinical significance and are saprophytic soil bacteria. Saphrophytes are organisms that feed on dead organic matter.

These bacteria can be strict aerobes, facultative anaerobes, obligate anaerobes or microaerophiles. Microaerophiles are bacteria that grow best in an environment that has a small amount of free oxygen.

The formation of endospores by bacteria is important in medicine and the food industry because these endospores are resistant to heat and many chemicals.

There are three genera in this section. These are:

• Bacillus: Bacillus consists of the following bacterium:

• Bacillus anthracis. Bacillus anthracis causes anthrax, a severe blood infection that infects cattle, sheep and horses and can be transmitted to humans. B. anthracis is a non-motile facultative anaerobe and produces exotoxin. Anthrax can result in central nervous system distress, respiratory failure, anoxia and death.

• Bacillus cereus. Bacillus cereus produces enterotoxin (a toxin that affects the intestine) and causes gastroenteritis (food poisoning).

• Bacillus thuringiensis. Bacillus thuringiensis produces a toxin that attacks the digestive system of insects, causing the insects to stop feeding by causing paralysis of the insects guts.

• Sporosarcina. Sporosarcina are bacteria that inhabit the soil and receive nutrients by feeding on dead organic matter.

• Clostridium. Clostridium are rod-shaped bacteria that exist in water, soil, and in the intestinal tract of animals and humans. These bacteria do not require oxygen. They release toxins that cause disease. Here are the common types of Clostridium:

• Clostridium tetani. Clostridium tetani, also known as C. tetani, causes tetanus, commonly referred to as lockjaw.

• Clostridium difficile. Clostridium difficile, also known as C. difficile, causes gastroenteritis.

• Clostridium perfringes. Clostridium perfringes, also known as C. perfringes, causes myonecrosis—better known as gas gangrene—which produces hydrogen gas in deep tissue wounds, resulting in cell death.

• Clostridium botulinum. Clostridium botulinum, also known as C. botu-linum is a cause of food poisoning usually as a result of improperly canned food. It produces an exotoxin that causes flaccid paralysis (weakness of muscle tone) due to the suppression of acetylcholine, which is a neurotransmitter. The result is vomiting, difficulty speaking, and difficulty swallowing, which can lead to respiratory paralysis and death. Physicians use Clostridium botulinum as a neural block that inhibits muscle contraction. Clostridium botilinum is also used cosmet-ically to relax muscles that cause facial wrinkles (Botox injections). The C. botulinum toxin blocks the exocytosis of synaptic vesicle of the neu-romuscular junction, where motor neurons meet muscle.

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