• See Also
  1. Enterobacteriaceae
  2. Gram Negative Bacteria
  3. Gram Negative Pneumonia
  • Definitions
  1. Klebsiella
    1. Klebsiella is a genus in the Enterobacteriaceae family
    2. Klebsiella species are facultatively anaerobic, nonmotile Gram-negative rods
    3. This page described Klebsiella Pneumoniae specifically, which is the primary pathogen in the Klebsiella genus
  • Pathophysiology
  1. Klebsiella Pneumoniae are facultatively anaerobic, gas forming, Gram-negative rod in Enterobacteriaceae family
  2. Grouped with EKP Gram Negative Bacteria (Escherichia coli, Klebsiella Pneumoniae, Proteus Mirabilis)
  3. Normally colonizes the oropharynx and Gastrointestinal Tract in healthy persons
  4. First described by Carl Friedlander in 1882, who isolated the bacterium from a deceased Pneumonia patient
  5. Klebsiella Pneumoniae Identifying charactistics
    1. Encapsulated (O Antigen positive)
    2. Non-Motile (H Antigen negative)
    3. Oxidase negative
    4. Generates acid from various Carbohydrates (Glucose, Mannitol, rhamnose, arabinose and amygdalin)
  6. Virulence factors
    1. Polysaccharide capsule
      1. Cloaks surface Opsonins (immune targets), thereby avoid Phagocytosis by Macrophages
    2. Lipopolysaccharide (LPS)
      1. Triggers a severe inflammatory response
    3. Fimbriae
      1. Allows organism to adhere to host surfaces
    4. Siderophores
      1. Harvests iron from host
  7. High rate of Antibiotic Resistance
    1. Carbapenem-Resistant Enterobacteriaceae (CRKP)
    2. ESBL-Producing Enterobacteriaceae
  • Associated Conditions
  1. Urinary Tract Infections
    1. Common cause of Urinary Catheter associated Urinary Tract Infection (CAUTI, esp. hospitalized patients)
  2. Klebsiella Pneumonia
    1. See Gram Negative Pneumonia
    2. Increased risk in Diabetes Mellitus and Alcohol Use Disorder
    3. Klebsiella Pneumonia is associated with Bloody Sputum in half of cases
    4. Sputum appears similar to red currant jelly (due to O Antigen)
    5. Severe Pneumonia with cavitary lesions
    6. Associated with high mortality rate
  3. Nosocomial Infections (3-8% of cases)
    1. Klebsiella Pneumoniae is among the most common causes of nosocomial Sepsis
  • Resources
  1. Klebsiella Pneumoniae (Stat Pearls)
    1. https://www.ncbi.nlm.nih.gov/books/NBK519004/
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 75