About Streptococcus Pneumoniae

Streptococcus Pneumoniae is a gram-positive, alpha-hemolytic diplococcus aerotolerant anaerobe and a member of the genus Streptococcus. Pneumoniae was recognized as a major cause of pneumonia in the late 19th centurey and is the subject of many humoral immunity studies. It causes many types of infection other than pneumonia like: acute sinusitis, otis media, meningitis bactereemia, osteomyelitis, septic arthritis, endocarditis peritonitis, pericarditls, cellultis, and brain abscess. It is the most common cause of bacterial meningitis in adults and chilren. The cell wall of S. pneumoniae is roughly six layers thick and is composed of peptidoglycan with teichoic acid attached to approximately every third N-acetylmuramic acid. Lipoteichoic acid is chemically identical to the teichoic acid but is attached to the cell membrane by a lipid moiety. Both the teichoic acid and the lipoteichoic acid contain phosphorylcholine; two choline residues may be covalently added to each carbohydrate repeat. This is an essential element in the biology of S. pneumoniae since the choline specifically adheres to choline-binding receptors that are located on virtually all human cells.