Klebsiella and Gastrointestinal Syndromes with Particular Emphasis on Klebsiella oxytoca Antibiotic-Associated Colitis

The genus Klebsiella (family Enterobacteriaceae), of which K. pneumoniae and K. oxytoca are the two most commonly isolated members, consists of gram-negative, non-motile, encapsulated rods. As opportunistic pathogens, Klebsiella spp. can cause a variety of illnesses including pneumonia, urinary tract infections, septicemia, soft tissue, intravenous, meningitis, liver abscess, and gastrointestinal disease, in the immunocompromised or those with underlying conditions. Current studies strongly suggest that klebsiellae, and in particular K. oxytoca, may also be associated with a variety of gastrointestinal syndromes that include antibiotic-associated hemorrhagic colitis.