The common pathogen of pneumonia is Klebsiella pneumoniae. Long-term bed-ridden patients are often accompanied by a history of chronic diseases such as diabetes, tumors, strokes, etc., and their poor resistance makes it easy for the bacteria to invade the body. Gram-negative bacilli contain a large amount of endotoxin, which is more likely to invade the body with its strong virulence. Therefore, the causative organisms of pneumonia are mainly gram-negative bacilli, and the most common causative organism is Klebsiella pneumoniae. In addition, other gram-negative bacilli, such as Escherichia coli, Pseudomonas aeruginosa, Haemophilus influenzae, as well as bacillus pertussis, dysentery bacilli, etc., can cause pneumonia.