Question

What is the role of polysaccharide coat in making streptococcus pneumonia virulent or avirulent?

Answer 1

Dear student,
The presence of polysaccharide capsule make the Streptococcus pneumonia virulent and absence of polysaccharide capsule makes the bacteria avirulent. Bacteria containing polysaccharide coat can not be engulfed by phagocytic cells of animals circulatory system. Hence they can multiply and cause pneumonia. Avirulent strain bacteria can be engulfed by phagocytic cells and get destroyed therefore they do not cause pneumonia. There is the presence of ​choline binding protein, PspA (protective antigen), LytA, B and C (autolysins) attached to the cell wall of Streptococcus pneumonia which is responsible for virulence.

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