Pneumonia exposure to cigarettes or air pollution, malnutrition, and poverty. The use of acid-suppressing medications — such as proton-pump inhibitors or H2 blockers — is associated with an increased risk of pneumonia. Approximately 10% of people who require mechanical ventilation develop ventilator associated pneumonia, and people with gastric feeding tube have an increased risk of developing of aspiration pneumonia. For people with specific variants of FER gene, the risk of death is reduced in sepsis caused by pneumonia. However, for those with TLR6 variants, the risk of getting Legionnaires' disease is increased. Bacteria are the most-common cause of community-acquired pneumonia (CAP),
Legionella cherrii were cultured around 36 °C in an environment containing 2.5% carbon dioxide. The genus "Legionella" is named after the 1976 pneumonia ("Legionella pneumophila") outbreak at the American Legion convention at the Bellevue-Stratford Hotel in Philadelphia. The genus was previously unknown, but it was established three years later. The specific term "cherrii" is derived from the scientist William B. Cherry due to his contributions on the studies of Legionellae. "L. cherrii" is rod-shaped and considered an oxidase-negative bacterium since it lacks cytochrome c oxidase and does not use oxygen in its electron transport chain. "L. cherrii" also has the ability to