Streptococcus pyogenes: Difference between revisions
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Streptococcus pyogenes is a spherical Gram-positive bacterium around 0.6-1.0 µm in diameter, which is enclosed in a capsule and exists in pairs or in chains. It is a non-motile, facultative organism where its metabolism allows it to grow in the presence and absence of | ''Streptococcus pyogenes'' is a spherical [[Gram-positive|Gram-positive]] bacterium around 0.6-1.0 µm in diameter, which is enclosed in a capsule and exists in pairs or in chains. It is a non-motile, [[facultative organism|facultative organism]] where its metabolism allows it to grow in the presence and absence of [[Oxygen|oxygen]]. ''Pyogenic streptococci'' are beta-haemolytic and so subsequently cause complete lysis of [[Red blood cells|red blood cells]] in [[Blood agar|blood agar]], making them clear and colourless. They produce a large number of enzymes and toxins which contribute to the invasion and pathogenesis of infections that ''Streptococcus pyogenes'' causes <ref>Folds, J. D. and Normansell, D. E. (1999) Pocket Guide to Clinic Immunology. Washington, D.C.: American Society for Microbiology</ref> <ref>Sleigh, J. D. and Timbury, M. C. (1998) Notes on Medical Bacteriology. 5th ed. New York: Churchill Livingstone.</ref>.<br> | ||
They are most commonly found in the oral cavity and from the throat they are able to spread infection elsewhere. | |||
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Latest revision as of 11:22, 27 October 2012
Streptococcus pyogenes is a spherical Gram-positive bacterium around 0.6-1.0 µm in diameter, which is enclosed in a capsule and exists in pairs or in chains. It is a non-motile, facultative organism where its metabolism allows it to grow in the presence and absence of oxygen. Pyogenic streptococci are beta-haemolytic and so subsequently cause complete lysis of red blood cells in blood agar, making them clear and colourless. They produce a large number of enzymes and toxins which contribute to the invasion and pathogenesis of infections that Streptococcus pyogenes causes [1] [2].
They are most commonly found in the oral cavity and from the throat they are able to spread infection elsewhere.