Polytrauma increases susceptibility to pseudomonas pneumonia in mature mice

Isaiah R. Turnbull, Sarbani Ghosh, Anja Fuchs, Julia Hilliard, Christopher G. Davis, Grant V. Bochicchio, Robert E. Southard

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Pneumonia is the most common complication observed in patients with severe injuries. Although the average age of injured patients is 47 years, existing studies of the effect of injury on the susceptibility to infectious complications have focused on young animals, equivalent to a late adolescent human. We hypothesized that mature adult animals are more susceptible to infection after injury than younger counterparts. To test this hypothesis, we challenged 6 to 8-month-old mature mice to a polytrauma injury followed by Pseudomonas aeruginosa pneumonia and compared them to young (8-10-week-old) animals. We demonstrate that polytrauma injury increases mortality from pneumonia in mature animals (sham-pneumonia 21% vs. polytrauma-pneumonia 62%) but not younger counterparts. After polytrauma, pneumonia in mature mice is associated with higher bacterial burden in lung, increased incidence of bacteremia, and elevated levels of bacteria in the blood, demonstrating that injury decreases the ability to control the infectious challenge. We further find that polytrauma did not induce elevations in circulating cytokine levels (TNF-alpha, IL-6, KC, and IL-10) 24h after injury. However, mature mice subjected to polytrauma demonstrated an exaggerated circulating inflammatory cytokine response to subsequent Pseudomonas pneumonia. Additionally, whereas prior injury increases LPS-stimulated IL-6 production by peripheral blood leukocytes from young (8-10-week-old) mice, injury does not prime IL-6 production by cell from mature adult mice. We conclude that in mature mice polytrauma results in increased susceptibility to Pseudomonas pneumonia while priming an exaggerated but ineffective inflammatory response.

Original languageEnglish
Pages (from-to)555-563
Number of pages9
Issue number5
StatePublished - May 1 2016


  • Aging
  • immunosuppression
  • infection
  • inflammation
  • injury
  • sepsis
  • trauma


Dive into the research topics of 'Polytrauma increases susceptibility to pseudomonas pneumonia in mature mice'. Together they form a unique fingerprint.

Cite this