Which bacteria is responsible for pneumococcal disease?

Streptococcus pneumoniae is the bacteria responsible for pneumococcal disease. This organism is a gram-positive bacterium that commonly resides in the upper respiratory tract of humans. It can lead to various severe infections, including pneumonia, meningitis, and sepsis, particularly in vulnerable populations such as young children, the elderly, and those with weakened immune systems.

Understanding the nature of Streptococcus pneumoniae is crucial for recognizing its significance in public health and the importance of vaccination against pneumococcal disease, as vaccines are available to help prevent infections caused by this bacterium. In contrast, the other bacteria listed do not cause pneumococcal disease; they are associated with different infections and conditions.