Klebsiella pneumoniae

Klebsiella pneumoniae is a bacterium in the genus Klebsiella. It is a major cause of pneumonia, found in the normal flora of the mouth, skin, and intestines. Like other Proteobacteria, it is gram negative.

Klebsiella pneumoniae
K. pneumoniae on a MacConkey agar plate.
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gamma Proteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Klebsiella
Species:	K. pneumoniae
Binomial name
Klebsiella pneumoniae (Schroeter 1886) Trevisan 1887

Carl Friedländer originally identified Klebsiella pneumoniae in 1882 as a bacteria found in the lungs of pneumonia sufferers (Friedlaender, 1882).

It is common in nature and may be found in both soil and water. It lives in dead or decaying matter. There are many different variants within the whole species (strains) and the 20% of those can capture nitrogen from the atmosphere and fix nitrogen when growing in the absence of oxygen. K. pneumoniae also happen in places that aren't feces-contaminated, including industrial wastes that are rich in nutrients (Bagley and Seidler, 1977).

Klebsiella bacteria can transmit between people in hospital environments (for instance, from patient to patient via contaminated hands of healthcare workers or other people) or, less frequently, by environmental pollution. There is no transmission of the bacterium through the air.

The bacteria Klebsiella pneumoniae typically lives in the intestines of humans (30-40% of the intestinal tract), where it is not harmful. K. pneumoniae, however, has the potential to spread to other parts of the body and cause a number of diseases, including bloodstream infections, urinary tract infections (UTI), pneumonia and meningitis. This is called systemic infection.

If inhaled, it can harm both human and animal lungs, resulting in thick mucous (sputum) being produced in lung, especially in the upper lobes. The mucus is deep red, brownish, or yellow in colour.