Fastidious, lancet-shaped gram positive diplococci.
Possess a capsule of polysaccharide that permits typing
with specific antisera.
Found as a normal flora in the upper respiratory tract.
Fig. 3.3 Streptococcus pneumoniae
Antigenic structure: . Capsular polysaccharide: Pathogenicity determinant with anti-phagocytic property. There are more than 80 serotypes of the bacteria based on capsular typing.