Streptococcus Pneumoniae (SP)

Streptococcus pneumoniae is a Gram-positive, alpha-hemolytic or beta-hemolytic, facultative anaerobic member of the genus Streptococcus. They are usually found in pairs (diplococci) and do not form spores and are non-motile. As a significant human pathogenic bacterium S. pneumoniae was recognized as a major cause of pneumonia in the late 19th century, and is the subject of many humoral immunity studies. S. pneumoniae resides asymptomatically in healthy carriers typically colonizing the respiratory tract, sinuses, and nasal cavity. However, in susceptible individuals with weaker immune systems, such as the elderly and young children, the bacterium may become pathogenic and spread to other locations to cause disease.It spreads by direct person-to-person contact via respiratory droplets and by autoinoculation in persons carrying the bacteria in their upper respiratory tract. It can be a cause of neonatal infections.