Streptococcus pneumoniae, commonly known as pneumococcus, is a bacterium that typically appears in pairs and has a shape reminiscent of a surgical knife with a short, wide, double-edged blade. This bacterium is responsible for causing bacterial infections including those of the middle ear, as well as other conditions such as bacterial pneumonia. Vaccines are available to protect against pneumococcal infections. The bacterium's official name is still Streptococcus pneumoniae. The prefix "strepto-" signifies twisted, while "kokkos," derived from Greek, means berry. Due to its tendency to pair up, it has also been referred to as Diplococcus pneumoniae. The term "pneumoniae" highlights its tendency to target the lungs, leading to pneumonia.
