Which of the following characteristics is true for Strep pneumoniae?

Streptococcus pneumoniae is known for being encapsulated, which is a crucial feature that allows it to evade the host's immune system. The capsule is composed of polysaccharides and serves as a protective layer that inhibits phagocytosis by immune cells. This characteristic significantly enhances the bacterium's virulence, making it more capable of causing infections such as pneumonia, meningitis, and otitis media.

The capsule allows Streptococcus pneumoniae to remain viable within the host by preventing recognition and elimination by the immune system. This feature is essential for its pathogenicity, as it can lead to severe disease, particularly in vulnerable populations such as young children and the elderly. Understanding the encapsulated nature of this bacterium is critical when studying its pathogenesis and the development of vaccines targeting its polysaccharide capsule.