Clinical characteristics and outcomes of community and hospital-acquired Acinetobacter baumannii bacteremia

J Microbiol Immunol Infect. 2019 Oct;52(5):796-806. doi: 10.1016/j.jmii.2019.03.004. Epub 2019 Apr 12.

Abstract

Purpose: We aimed to characterize clinical manifestations of the patients with bacteremia due to community-acquired Acinetobacter baumannii and evaluate the outcomes of these patients.

Methods: We conducted a retrospective study to include adult patients with A. baumannii bacteremia and then classified them into two groups: community-acquired A. baumannii bacteremia and hospital-acquired A. baumannii bacteremia. Characteristics and outcomes between 2 groups were compared. The Galleria mellonella infection survival model was used to determine the virulence of A. baumannii in these 2 groups.

Results: There were 63 patients with A. baumannii bacteremia: 21 patients with community-acquired (CA) bacteremia and 42 patients with hospital-acquired (HA) bacteremia. Three patients with CA bacteremia were excluded due to healthcare-associated risks of infection. The remaining 18 patients with CA bacteremia had carbapenem-susceptible A. baumannii (CA-CSAB). Among the 42 patients with HA bacteremia, 11 patients had carbapenem-susceptible A. baumannii (HA-CSAB) and 31 patients had carbapenem-resistant A. baumannii (HA-CRAB). The 30-day mortality rates of those with CA-CSAB did not differ from those with HA-CSAB bacteremia but were significantly lower than those with HA-CRAB (p = 0.003). The factors influencing 30-day mortality were infection with CRAB (p = 0.004), appropriate empirical antimicrobial therapy (p = 0.002), and higher Acute Physiology and Chronic Health Evaluation II score (p < 0.001). The G. mellonella assay showed no differences in survival rates among CA-CSAB, HA-CSAB, and HA-CRAB.

Conclusions: Patients with bacteremia due to CA-CSAB and HA-CSAB had similar outcomes. Similar virulences of CA-CSAB and HA-CSAB were confirmed with the G. mellonella infection model.

Keywords: Acinetobacter baumannii; Community-acquired; Galleria mellonella; Outcomes.

MeSH terms

  • Acinetobacter Infections / drug therapy*
  • Acinetobacter Infections / microbiology
  • Acinetobacter Infections / physiopathology*
  • Acinetobacter baumannii / drug effects*
  • Adult
  • Aged
  • Animals
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / drug therapy
  • Bacteremia / physiopathology
  • Carbapenems / therapeutic use
  • Community-Acquired Infections / drug therapy*
  • Community-Acquired Infections / microbiology
  • Community-Acquired Infections / physiopathology*
  • Disease Models, Animal
  • Female
  • Hospitals
  • Humans
  • Kaplan-Meier Estimate
  • Larva / microbiology
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Mortality
  • Retrospective Studies
  • Risk Factors
  • Virulence

Substances

  • Anti-Bacterial Agents
  • Carbapenems