Topic Completed: 1 September 2011

Minor changes: 7 August 2020

Copyright: 2003-2021,, Inc.

PubMed search: Pseudomonas aeruginosa [title] pulmonary infection

Elliot Weisenberg, M.D.
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Cite this page: Weisenberg E. Pseudomonas. website. Accessed October 16th, 2021.
Clinical features
  • Aerobic, mobile, flagellated Gram negative bacillus that survives in water, soil and vegetation
  • Worldwide distribution (eMedicine)
  • Resistant to many disinfectants, common in hospital environment, common cause of hospital acquired infections
  • Commonly colonizes humans, but rarely causes disease in healthy subjects
  • Affects primarily infants, cystic fibrosis, immunocompromise, critically ill, neutropenia and burns / on ventilators
  • Immunocompromised usually have paucicellular pattern, rapidly progressive course with bronchopneumonia and bacteremia
  • Immunocompetent have a cellular pneumonia, more protracted course
  • Perivascular bacterial infiltration is somewhat specific for pseudomonas

  • Rare: 0.3% of neonatal ICU admissions
  • Usually low birth weight (1.2% of low birth weight admissions)
  • Mortality 32% - 87% with death within 1 - 2 days
  • Diagnosis made by culture
Case reports
  • 49 year old woman with fatal pneumonia likely associated with contaminated hot tub (Infection 2011;39:265)
Gross images

Contributed by Yale Rosen, M.D.
Pseudomonas pneumonia Pseudomonas pneumonia

Pseudomonas pneumonia

Microscopic (histologic) description
  • Necrotizing pneumonia with 2 patterns: paucicellular coagulative confluent bronchopneumonia with perivascular bacillary infiltration (bacteremic) or cellular pneumonia without evidence of perivascular organisms (nonbactermic)
  • Nonbacteremic: often occurs in debilitated patients with chronic lung or heart disease through aspiration
Additional references
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