True statement regarding Pneumococcus is

The virulence of Streptococcus pneumoniae depends on the capsular polysaccharide. The capsular polysaccharide because of its acidic and hydrophilic propeies, protects the cocci from phagocytosis. Capsulated streptococcus pneumoniae are not phagocytosed efficiently in fluid media or exudates, however, they are susceptible to surface phagocytosis, being engulfed against a firm surface, such as a fibrin clot or epithelium . The enhanced virulence of type 3 Streptococcus pneumoniae is due to the abundance of its capsular material. Non-capsulated strains are avirulent. Antibody to capsular polysaccharide affords protection against infection. Penicillin-resistant strains and strains resistant to erythromycin and tetracycline are found. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 226