Klebsiella species are rod shaped-bacteria that are found in the environment and also in the human intestinal tract.
K. pneumoniae is the most common species isolated from hospital patients. Most patients are colonised in a variety of sites without serious infection but rarely K. pneumoniae can cause severe pneumonia in susceptible individuals.
Photo: Janice Carr / CDC
A second species K. oxytoca is an occasional cause of wound, bloodstream and urinary tract infections. Klebsiella species often cause outbreaks in hospital units (liver, oncology etc.).