Acute Morphology of Streptococcus pyogenes Essay -- Medical Disease Ba

Acute Morphology of Streptococcus pyogenes Abstract: Streptococcus pyogenes is a gram positive coccus bacterium that is extremely common bacteria. This bacterium is part of group A streptococci, which meant that it has a certain type of polysaccharide antigen on its cell surface. It is commonly known as pharyngitis, or strep throat and produces over twenty exotoxins. Even though this bacterium has been around for thousands of years it still has a susceptibility to penicillin and there have only been a few cases of resistance. Streptococcus pyogenes is a gram positive bacteria that is associated with multiple types of diseases. Streptos means a chain of links and coccus means a round object. Together this describes the shape of Streptococcus pyogenes, a round chain of ten or more cocci, each measuring 0.5 to 0.75 ÃŽ ¼m in diameter. This bacterium can cause scarlet fever, streptococcal pharyngitis and erysipelas in humans. It is identified mainly by its ability to create ÃŽ ²-haemolysis in blood agar plates. Streptococci can be separated into groups by a polysaccharide antigen that is deep inside the cell wall. The groups are labeled by the letters ranging from A to R, each group represents a different type of organism that it mostly infects. Group A is mainly pathogenic to humans, while group B is found in cattle. Groups C to R infect animals of lesser complexity. Streptococcus pyogenes is part of group A, which means that the polysaccharide antigen is composed of rhamnose and N-acetylglucosamine and its main host is in humans. The morphology of S. pyogenes is a chain of cocci that are normally in groups of ten and each cocci range in diameter from 0.5 to 0.75 ÃŽ ¼m. They are nonmotile, which means that they 2 have no form of moveme... ...agar plates. S. pyogenes produces many extracellular products, they are called streptococcal pyrogenic exotoxins and are classified into three serotypes, A-C. SPE B is the most unique of the three and is responsible for multiple diseases, including toxic shock syndrome. This bacteria does have a weak point, almost all streptococci are susceptible to penicillin. 7 Works Cited Christie, A. B. (1987). Infectious Diseases (Vol. 2, 4th ed.). New York: Churchill Livingstone. Evans, A. S. (1991). Bacterial Infections of Humans (Vol. 1, 2nd ed.). New York: Plenum Medical Book Company. Kaplan, E. L. (2000). Streptococcal Infections (Vol. 1). New York: Oxford University Press. Todar, K. (2002). Streptococcus pyogenes (Vol. 1). Madison: University of Wisconsin-Madison Department of Bact. Retrieved July 30, 2008, from http://www.textbookofbacteriology.net/streptococcus.html