Klebsiella pneumoniae Overview

Klebsiella pneumoniae Overview

Rising resistance to last-resort drugs is cause for concern

Background

Klebsiella pneumoniae is a member of the Enterobacteriaceae family, which along with E. coli accounts for the vast majority of hospital and community-acquired urinary tract infections (UTIs). It is also a frequent cause of nosocomial (health care–associated) bloodstream infections and community-acquired pneumonia among alcoholics.

The observed rise of carbapenem-resistant K. pneumoniae (CRKP) is disconcerting for several reasons. First, K. pneumoniae carbapenemase (KPC) infection is associated with a fatal outcome in 47%–57% of cases. Second, treatment is limited to either collistin (an old antibiotic rarely used because of its kidney toxicity) or tigecycline (which fails to clear bloodstream infections) – a limitation that highlights the urgent need to develop drugs active against Gram-negative bacteria. Third, the ability of carbapenemase-encoding genes to spread through plasmid transfer enables the spread of resistance to related species like E. coli, a transfer that may occur even in the same patient. Finally, the presence of KPC is difficult to detect in routine laboratory testing. The epidemiology of carbapenem-resistant bacteria may therefore follow the endemic spread of MRSA beyond hospitals and into the community.