Bacterial infections in adults with pneumonia are most commonly caused by Streptococcus pneumoniae. Other pathogens include anaerobic bacteria, Staphylococcus aureus, Haemophilus influenzae, Chlamydia pneumoniae, Chlamydia psittaci, Chlamydia trachomatis and other gram-negative bacilli, and many others. These pathogens may be transmitted through contact between people, or through contact between people and objects, but even if you are infected with these pathogens, you will not get pneumonia if your immunity is sound. It is often when the body’s resistance decreases that pathogens take advantage of the situation and make people sick. Pneumonia is transmitted by: 1. Air inhalation: A very transmissible route for people with pneumonia is air inhalation transmission, which is one of the reasons why pneumonia is a common infectious disease. 2. Transfer from other sites: For patients with other systemic diseases, such as those with intestinal tuberculosis, it is important to pay attention to the transfer of Mycobacterium tuberculosis because it can easily breed in any part of the body, which means that tuberculosis can occur in any part of the body. 3. Blood-borne spread from other parts of the body: In infectious pneumonia, bacteria and other pathogens are at risk of spreading throughout the body with the blood, including the lungs, of course, so the inflammation should be controlled promptly after it is detected. Usually pay attention to the hygiene of the local wound. 4, the upper respiratory tract colonized bacteria misinhalation: for patients with upper respiratory tract infection, especially chronic patients, its likely to have the presence of colonized bacteria, so with the extension of time, it is likely to inhale into the lungs, causing pneumonia.