Klebsiella pneumoniae (K. pneumoniae) is a gram-negative bacteria that can cause community-acquired and hospital-acquired infections (pneumonia, bloodstream infections, wound or surgical site infections, and meningitis).

Klebsiella bacteria have developed antimicrobial resistance, most recently to the class of antibiotics known as carbapenems. The percentage of K. pneumoniae resistant to carbapenems continued to slowly increase from 8% in 2014 to 10% in 2020.

K. pneumoniae is normally found in the human intestines (where they do not cause disease). In healthcare settings, Klebsiella bacteria can be spread through person-to-person contact (from patient to patient via the contaminated hands of healthcare personnel, or other persons) or, by contamination of the environment. The bacteria are not spread through the air.

Patients in healthcare settings also may be exposed to Klebsiella when they are on ventilators (breathing machines) or have intravenous (vein) catheters or wounds (caused by injury or surgery).