How does Streptococcus pneumoniae avoid destruction by phagocytes?

• A. It forms endospores to resist immune attack.
• B. It produces a polysaccharide capsule that inhibits phagocytosis.
• C. It secretes exotoxins that directly kill phagocytes.
• D. It alters its cell wall to mimic host cells.

Answer: (B)

Verified step by step guidance

1. Understand the role of phagocytes in the immune system: Phagocytes are cells that engulf and destroy pathogens through a process called phagocytosis.
2. Recognize that some bacteria have evolved mechanisms to avoid being engulfed or destroyed by phagocytes, enhancing their ability to cause infection.
3. Identify that Streptococcus pneumoniae produces a polysaccharide capsule, which is a thick, slippery outer layer surrounding the bacterial cell.
4. Learn that this capsule acts as a physical barrier that prevents phagocytes from recognizing and attaching to the bacteria, thereby inhibiting phagocytosis.
5. Note that unlike some bacteria, Streptococcus pneumoniae does not form endospores, secrete exotoxins to kill phagocytes, or mimic host cell walls as its primary defense against phagocytosis.