Multiple choice

” Streptococcus pneumoniae (Diplococcus pneumoniae) is responsible for causing pneumonia in 70% cases.”- What is the major virulence factor of it?

  1. Pneumolysin-O

  2. Oxygen-labile haemolysin

  3. Polysaccharide capsule

  4. Alpha lysin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Polysaccharide capsule is the major virulence factor of Streptococcus pneumoniae (Diplococcus pneumoniae). Unlike other streptococci, S.pneumoniae’s cells appear in form of diploccocci. Polysaccharide capsule prevents phagocytosis. In lungs, pneumococci begin an inflammatory response. Fluid of neighboring blood capillaries start to affect air sacs causing the affected region of lung becomes tough and solid. Encapsulated pneumococci are extremely resistant to phagocytosis.

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