Clinical and Genomic Characterization of Serratia Bloodstream Infections

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Genomics

Background:

• Serratia, once rare, is now an emerging cause of bacteremia.
• This study compares risk factors and outcomes of Serratia bacteremia to other Enterobacterales.

Purpose of the Study:

• To compare risk factors and outcomes of Serratia bacteremia versus other Enterobacterales.
• To investigate the association between Serratia and device infections.
• To analyze the genomic diversity of Serratia isolates from device infections.

Main Methods:

• Prospective enrollment of hospitalized patients from 2002-2021.
• Comparison of patient characteristics and outcomes for Serratia vs. other Enterobacterales bacteremia.
• Whole genome sequencing (WGS) of Serratia isolates to assess phylogenetic diversity.

Main Results:

• Serratia bacteremia was associated with increased risk of general device infection (aOR 2.03) and cardiac device infection (OR 3.95).
• Patients with Serratia bacteremia had a higher risk of persistent bacteremia (aOR 1.66).
• WGS revealed significant genetic diversity among Serratia isolates, with no clear association with device infections.

Conclusions:

• Serratia bacteremia increases the likelihood of device-associated infections, particularly cardiac devices, and persistent bacteremia compared to other Enterobacterales.
• The genomic diversity of Serratia suggests device infections are not driven by specific clonal strains.
• Further research is needed to understand the molecular mechanisms behind Serratia's role in device infections.