adhesin

Virulence factors of Group-A Streptococcus

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Streptococcus are gram positive, catalase negative cocci. Are spherical or ovoid, 0.5-1µ in diameter, arranged in chains, non-motile and non-sporing. They may become gram negative in ageing culture when the bacteria die. Some of the strains possess capsules made up of hyaluronic acid while some of the strains possess capsules composed of polysaccharide. Human beings … Read more

Fimbriae

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These are thin short filamentous appendages which measure about 1-1.5 micron in length and less than 4 to 8 nm in width. They extrude from the cytoplasmic membrane and are also called pili. They are found in certain gram-negative bacilli, including saprophytic, intestinal commensals, and pathogenic species in the family These are different kind from … Read more