Causes & Types of Pneumonia
Article Series on Bacterial, Viral and Fungal Pulmonary Infection
Pneumonia is an inflammation of the lungs caused by bacteria, virus, fungus or the inhalation of foreign substances. Here are some quick links to articles on pneumonia.
What Is Pneumonia?
Pneumonia occurs when the air sacs and small airways in the lungs fill with liquid and cannot function properly. When gas exchange is impeded, the body cannot take in oxygen as it normally would. Oxygen is vital to the body’s cells, where it is needed for aerobic respiration; the breakdown of glucose to obtain energy for cellular work.
The following are quick links to articles on the different causative agents of pneumonia.
Quick Links to Pneumonia Articles
Gram Negative Bacterial Pneumonia
Gram-negative bacteria can cause serious pneumonia most often occurring in people who are hospitalized, infants, the elderly, alcoholics, and those with chronic diseases, particularly immune system disorders. These bacteria rarely infect the lungs of healthy adults.
Gram Positive Bacterial Pneumonia
Of the different types of pneumonias, bacterial tend to be the most serious and, in adults, the most common. Bacterial pneumonia may follow influenza or even a common cold, particularly the elderly or immune compromised. Gram-positive bacteria have cells walls that are particularly vulnerable to certain antibiotics.
Respiratory infection from bacteria-like Mycoplasmas causes atypically mild symptoms. Mycoplasmas can colonize the mucous membranes of the respiratory and urinary tracts, and therefore are commonly associated with pneumonia and urinary tract infections (UTIs). At least forty-six species of Mycoplasmas have been identified, but of these, only a few are human pathogens.
Pneumonia that is caused by a viral infection causes irritation, swelling, and congestion in the lungs. Also called pneumonitis (nu-mo-NI-tis), this infectious disease occurs most often in the winter, afflicting 1 in 100 people. Viruses are the most common cause of pneumonia in children.
Fungal pneumonia is an infection in the lungs caused by any one or a combination of endemic and opportunistic fungi. Unlike opportunistic fungi, endemic fungal pathogens are able to cause infection in both healthy and immunocompromised individuals. The most frequently encountered endemic fungi are Cryptococcus, Histoplasma, Blastomyces.
Opportunistic Fungal Pneumonia
Fungal pneumonia is an infection of the lungs caused by any one or a combination of endemic or opportunistic fungi. Opportunistic fungal organisms cause pneumonia in immune-compromised patients.
Pneumonia Resources
For more information on pneumonia, see the Mayo Clinic: Infectious Diseases or Science Prof Online.
This article is a summary of different types of pneumonia. It is not meant to be used for self-diagnosis or as a substitute for professional medical care.
Sources
Bauman, R. (2005) Microbiology.
Park Talaro, K. (2008) Foundations in Microbiology.
