Streptococcus pneumoniae

Definition

Streptococcus pneumoniae is a Gram-positive bacterium often found in the human respiratory tract, capable of causing diseases such as pneumonia, meningitis, and sinusitis. It exhibits virulence factors like a polysaccharide capsule that help it evade the immune system.

5 Must Know Facts For Your Next Test

1. Streptococcus pneumoniae has over 90 different serotypes based on its polysaccharide capsule.
2. The bacteria can cause invasive diseases like meningitis and non-invasive diseases like otitis media.
3. It is a common cause of community-acquired pneumonia and can be particularly severe in young children and elderly adults.
4. Streptococcus pneumoniae can acquire antibiotic resistance through horizontal gene transfer mechanisms such as transformation.
5. Vaccines like the pneumococcal conjugate vaccine (PCV) are available to protect against several serotypes of Streptococcus pneumoniae.

Review Questions

• What are some common diseases caused by Streptococcus pneumoniae?
• How does the polysaccharide capsule of Streptococcus pneumoniae contribute to its pathogenicity?
• What mechanisms allow Streptococcus pneumoniae to develop antibiotic resistance?

Related terms

Polysaccharide Capsule:

A protective layer around some bacteria that helps them evade the host immune system.

Horizontal Gene Transfer:

The movement of genetic material between bacteria through methods such as transformation, transduction, or conjugation.

Pneumococcal Conjugate Vaccine (PCV): A vaccine designed to protect against multiple serotypes of Streptococcus pneumoniae.