Microbiology

Microbiology Study Guide

and jaw, paralysis of respiratory muscles, interruption in heart functioning, and even death in extreme cases. Possible treatments for tetanus include immunization of the tetanus toxoid in the DPT vaccine, penicillin, and other tetanus antitoxins. Staphylococcal Infections Staphylococcal infections are caused by the gram-positive cocci belonging to the species Staphylococcus aureus . Toxins produced by the bacterium cause scalded skin syndrome, in which the infection develops over the vesicles on the surface of the body and the skin starts to peel and appears burnt. The infection is transmitted through fomites and physical contact with infected skin. The organism causes infection in hair follicles, leading to folliculitis. In extreme cases, the skin tissues are injured, causing pus-filled lesions, furuncle, boils, and abscesses. Treatment is possible through an antibiotic drug therapy of penicillin or erythromycin. Anthrax Anthrax is caused by the gram-positive, spore forming bacterium rod Bacillus anthracis . It is transmitted from air, contaminated soil, sheep, and cattle. Symptoms include hemorrhage and inflammation of blood in organs, like the spleen and kidneys. In the lungs, anthrax is called Woolsorter's disease and is accompanied by pneumonia. Aggressive antibiotic therapy is necessary to prevent death. Leprosy Leprosy is caused by acid-fast bacillus from the species of Mycobacterium leprae . This organism destroys the peripheral nerves and impacts the nervous system of affected individuals, followed by injury to the tissues of the skin. Symptoms of the disease include deformed hands and feet and erosion in the bones, fingers, and toes. When pigments in the skin are lost, it is termed tuberculoid leprosy. When the disfiguring of the skin due to skin nodules occurs, it is known as lepromatous leprosy. The disease can be treated with a drug therapy of Dapson. Gas Gangrene Gas gangrene is caused by the anaerobic rods of the genre Clostridium belonging to the species of Clostridium perfringens, C. novyi, and C. septicum . The disease is often transmitted through wounds, wherein they germinate under the dead anaerobic portion of the wound tissues. These bacteria decompose proteins and ferment the carbohydrates in the skin, forming a gas that encourages the tissues to expand significantly. Due to the paucity of oxygen in the skin cells, they begin to die and it becomes gangrene. In extreme cases, the bacteria travel through the blood cells and infect the entire body, causing degeneration of muscle fibers in the body. The disease can be treated with the help of aggressive antibiotic therapy and surgery for removal of the dead tissues. Viral Diseases Smallpox Smallpox is caused by a DNA containing virus and has a very complex shape. The main symptom of

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