Community-Acquired Pneumonia Due to Multidrug- and Non-Multidrug-Resistant Pseudomonas aeruginosa

Chest. 2016 Aug;150(2):415-25. doi: 10.1016/j.chest.2016.03.042. Epub 2016 Apr 7.


Background: Pseudomonas aeruginosa is not a frequent pathogen in community-acquired pneumonia (CAP). However, in patients with severe CAP, P aeruginosa can be the etiology in 1.8% to 8.3% of patients, with a case-fatality rate of 50% to 100%. We describe the prevalence, clinical characteristics, outcomes, and risk factors associated with CAP resulting from multidrug-resistant (MDR) and non-MDR P aeruginosa.

Methods: Prospective observational study of 2,023 consecutive adult patients with CAP with definitive etiology.

Results: P aeruginosa was found in 77 (4%) of the 2,023 cases with microbial etiology. In 22 (32%) of the 68 cases of P aeruginosa with antibiogram data, the isolates were MDR. Inappropriate therapy was present in 49 (64%) cases of P aeruginosa CAP, including 17/22 (77%) cases of MDR P aeruginosa CAP. Male sex, chronic respiratory disease, C-reactive protein <12.35 mg/dL, and pneumonia severity index risk class IV to V were independently associated with P aeruginosa CAP. Prior antibiotic treatment was more frequent in MDR P aeruginosa CAP compared with non-MDR P aeruginosa (58% vs 29%, P = .029), and was the only risk factor associated with CAP resulting from MDR P aeruginosa. In the multivariate analysis, age ≥65 years, CAP resulting from P aeruginosa, chronic liver disease, neurologic disease, nursing home, criteria of ARDS, acute renal failure, ICU admission, and inappropriate empiric treatment were the factors associated with 30-day mortality.

Conclusions: P aeruginosa is an individual risk factor associated with mortality in CAP. The risk factors described can help clinicians to suspect P aeruginosa and MDR P aeruginosa.

Keywords: Pseudomonas aeruginosa; community-acquired pneumonia; multidrug-resistant; pneumonia.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use
  • C-Reactive Protein / metabolism
  • Chronic Disease
  • Cohort Studies
  • Community-Acquired Infections / drug therapy
  • Community-Acquired Infections / epidemiology*
  • Community-Acquired Infections / microbiology
  • Community-Acquired Infections / mortality
  • Drug Resistance, Multiple, Bacterial / physiology
  • Female
  • Humans
  • Liver Diseases / epidemiology
  • Logistic Models
  • Male
  • Middle Aged
  • Mortality
  • Multivariate Analysis
  • Nervous System Diseases / epidemiology
  • Nursing Homes
  • Pneumonia, Bacterial / drug therapy
  • Pneumonia, Bacterial / epidemiology*
  • Pneumonia, Bacterial / microbiology
  • Pneumonia, Bacterial / mortality
  • Prevalence
  • Prospective Studies
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / epidemiology*
  • Pseudomonas Infections / microbiology
  • Pseudomonas Infections / mortality
  • Pseudomonas aeruginosa / physiology
  • Respiratory Distress Syndrome / epidemiology
  • Respiratory Tract Diseases / epidemiology
  • Risk Factors
  • Severity of Illness Index
  • Sex Factors


  • Anti-Bacterial Agents
  • C-Reactive Protein