Streptococcus pyogenes: multipurpose monstersStreptococcus pyogenes is a type of group A streptococcus that causes many infectious diseases. This bacterium is commonly found in a variety of organisms, but is usually harmless unless the body's defenses are compromised. When harmful, group A streptococci cause infections such as impetigo, ecthyma, scarlet fever, and necrotizing fasciitis. Each of these infections has different symptoms and requires different treatment. These treatments are mainly antibiotics, because antibiotics are still the main treatment for GAS bacterial infections. One of the most interesting, rare, and fatal infections caused by Streptococcus pyogenes is necrotizing fasciitis, and while it can cause some serious symptoms, a simple dose of antibiotics can prevent or even cure this dangerous infection. Streptococci are a large and diverse group of bacteria that are gram-positive cocci (Sharma). Streptococcus Pyogenes, a group A streptococcus, is a universal organism that can cause many different diseases in humans (Sharma). Group A streptococci are commonly referred to as GAS and are commonly identified on blood agar plates as white or gray (Sharma) colonies. They commonly appear in pairs or short chains that are non-motile and do not form spores (Sharma). Furthermore, they have a fermentative metabolism and are facultative anaerobes that require blood to grow (Todar). For this reason GAS bacteria are often found in mammals. It is estimated that 15%-20% of all healthy individuals contain this pathogen in their bodies, particularly in the respiratory tract, without signs of disease (Todar). However, it is believed that bacteria can cause harm if the body's defenses are compromised or if...... middle of paper ......July 2008 .DeLeo, Frank R. and Michael Otto. Methods and protocols of bacterial pathogenesis. Microbiology Methods 431. Totowa, NJ: Humana Press, 2008. “Necrotizing fasciitis (flesh-eating bacteria).” WebMD. December 6, 2007. Healthwise Inc. July 14, 2008. Rene, Caravano. Current research on group A streptococcus. Paris, France: Excerpta Medica Foundation, 1968.Sharma, Sat, MD. “Group A Streptococcus Infections.” eMedicine. May 5, 2006. WebMed. July 24, 2008 .Todar, Kenneth. "Streptococci pyogenes". Todar's Online Textbook of Bacteriology. 2002. University of Wisconsin-Madison. July 14th 2008 .