True statement regarding Pneumococcus is ?

Ans. is 'a' i.e., Virulence is due to polysaccharide capsule Virulence factors . The most impoant virulence factor of pneumococci is capsular polysaccharide. . The antibody to capsular polysaccharide affords protection against infection. Type-3 pneumococcus is most virulent due to abundance of its capsular material. . Non capsulated strains are avirulent except for strains that cause conjuctivitis. . Other virulence factors of pneumococci - Pneumolysin - IgA, protease - Autolysin - Cell wall constituents (teichoic acid, C substance and peptidoglycan). Following virulance factors have been added in 18th/e of Harrison . Pneumococcal iron acquisition A ( Pia A) and Pneumococcal iron uptake A ( Piu A) . Pneumococcal surface protein A (PspA) and Pneumoccocal surface protein C( choline binding protein A) . Pneumococcal surface antigen A ( Psa A) . Choline binding protein G . Hyaluronate lyase, enolase, histidine triad ( Ph + A,B,C,D,E) . Pseudophosphorylcholine, neuraminidase, penicillin binding protein . Pili Antibiotic susceptibility of pneumococci $ - lactam antibiotics are the antibiotics of choice for pneumococcal infection; parentral penicillin for serious infections and amoxycillin for milder ones, provided the infecting strain is penicillin sensitive. During last two decades, an increasing number of isolates have shown some degree of resistance to penicillin. Many penicillin resistant strains are also resistant to other antibiotics like erythromycin and tetracyclin. Penicillin resistance is due to alteration in penicillin binding protein.