A nonmotile,gram - positive bacterium(Streptococcus pneumoniae)that is the most common cause of bacterial pneumonia,associated with meningitis and other infectious diseases.

• 肺炎球菌一种非游走的革兰氏阴性细菌（肺菌链球菌），是细菌性肺炎最常见的致病原因，并与脑膜炎和其它传染性疾病有关