Pneumonia is an inflammation of the lung caused by bacterial, viral, amoebic, and fungal infection. The symptoms are difficulty in breathing, chest pain, cough, high fever, and fatigue. Pneumonia is characterized by pyogenic edema (accumulation of liquid and pus) and excessive mucus which occludes (clogs up) the alveoli and bronchi. The infection in the lungs is usually caused by a bacterium called pneumococcus; before the discovery of antibiotics, bacterial pneumonia was fatal in 75% of the cases. Other dangerous form of pneumonia is caused by a type of amoeba: the entamoeba histolytica; when this is the case, the disease is called pulmonary amebiasis.TreatmentPenicillins, erythromycin and tetracycline for bacterial pneumonia. Emetine chlorhydrate for amoebic pneumonia. And amantadine and acyclovir to treat viral pneumonias.