Klebsiella pneumoniae is a rod-shaped bacterium and the causative agent in Klebsiella pneumonia. It is found normally in the skin, mouth, and intestines of humans, and capable of both aerobic respiration and fermentation when required. More recently Klebsiella pneumoniae has been responsible for a greater number of nosocomial infections, or those infections contracted within hospitals. Hans Christian Gram, after which Gram staining was named, developed the technique in order to differentiate Klebsiella pneumoniae from other similar species of bacteria.
As stated previously, Klebsiella pneumoniae has the potential to cause Klebsiella pneumonia. Like other forms of pneumonia, this disease causes serious inflammation and fluid release in the lungs. Sufferers tend to cough up bloody sputum and show high fever. Most infections are caused by inhalation of these pathogenic microbes. Outside of hospitals, the most common sufferers of the illness are alcoholics that inhale the microbes.
Infections from Klebsiella are most commonly seen in the elderly or individuals with otherwise chronic immune system debilitating illnesses. Statistics show that individuals suffering infection typically have lowered respiratory system defenses, caused by other diseases such as diabetes, liver disease, or obstructive pulmonary disease. This explains the prevalence of Klebseilla pneumoniae infections in hospitals, where individuals are already in a weakened state. For this reason, Klebsiella pneumoniae is often called an opportunistic pathogen which people simply want to eliminate.
This bacterium can also cause less common infections, including rhinoscleroma and ozena. Rhinoscleroma is a disease of the upper respiratory tract most apparent when it affects the nose. While not fatal on its own, infection can lead to sepsis which can be fatal if not treated. Ozena, also known as atrophic rhinitis, is a similar condition affecting mucous membranes in the nose. Both conditions can cause serious swelling of the nose, however when the disease has progressed to this point, the scarring is usually irreversible.
The most medically relevant characteristic of Klebsiella pneumoniae is its ability to resist antibiotics. In recent history, many resistant strains have been documented, especially in hospitals, transported via contaminated surgical instruments. One particular strain known as CRKP has caused the medical community issues recently because it is resistant to nearly all antimicrobials. Healthcare professionals are worried they may eventually have trouble keeping up with the mutations of certain strains, leading to infections for which little treatment is available. In 2006, the complete genome of Klebsiella pneumoniae was mapped at the Genome Sequencing Center at Washington University. The genome has been found to be similar to that of E. coli.