Pseudomonas aeruginosa Bloodstream Infections Show High Genetic Diversity and Antimicrobial Resistance

Strategic Insights -

Researchers from Bellvitge University Hospital have analyzed Pseudomonas aeruginosa strains causing bloodstream infections in neutropenic cancer patients across five Spanish hospitals between 2006 and 2018. The study aimed to characterize PA strains and assess the association between microbiological features and clinical outcomes. The research found high genetic diversity among PA strains, with ST175 being the most prevalent clone. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains accounted for 10.3% and 18.1% of cases, respectively. The highest resistance rates were observed for ciprofloxacin and imipenem, driven primarily by chromosomal mutations. The presence of ExoU was associated with serotype O11 and ST253, but not significantly with mortality. Polymicrobial infection and septic shock significantly impacted early 7-day mortality, underscoring the need for early diagnosis and optimized treatment strategies.

Key Takeaways:

  • Pseudomonas aeruginosa bloodstream infections in neutropenic cancer patients showed high genetic diversity, with ST175 being the dominant clone (28.7%).
  • Multidrug-resistant (MDR) non-XDR and XDR strains accounted for 10.3% and 18.1% of cases, respectively.
  • The highest resistance rates were observed for ciprofloxacin (42.6%) and imipenem (36.2%), driven primarily by chromosomal mutations.
  • The presence of ExoU was associated with serotype O11 and ST253, but not significantly with mortality.
  • Polymicrobial infection and septic shock significantly impacted early 7-day mortality.
  • The study highlights the need for early diagnosis and optimized treatment strategies for Pseudomonas aeruginosa bloodstream infections.
  • Irene Cadenas-Jimenez and colleagues investigated the molecular epidemiology and antimicrobial resistance profiles of Pseudomonas aeruginosa causing bloodstream infections in neutropenic cancer patients.

Statistics:

  • 94 BSI episodes were analyzed in neutropenic cancer patients across five Spanish hospitals (2006-2018).
  • 24.4% of strains carried the virulence gene ExoU.
  • 7-day and 30-day mortality rates were 21.3% and 31.9%, respectively.
  • Multidrug-resistant (MDR) and extensively drug-resistant (XDR) PA strains accounted for 10.3% and 18.1% of cases, respectively.
  • Resistance rates for ciprofloxacin (42.6%) and imipenem (36.2%) were the highest among the antimicrobials tested.

Sources:

  • Molecular epidemiology and antimicrobial resistance profiles of Pseudomonas aeruginosa causing bloodstream infections in neutropenic cancer patients. Frontiers in Microbiology, 2025,16. (Frontiers in Microbiology - http://www.frontiersin.org/microbiology)
  • NewsRx. Bellvitge University Hospital Researchers Advance Knowledge in Pseudomonas aeruginosa (Molecular epidemiology and antimicrobial resistance profiles of Pseudomonas aeruginosa causing bloodstream infections in neutropenic cancer patients). Cancer Weekly. October 14, 2025; p 442.