Influence of antibiotic therapy on clinical outcomes of patients with Stenotrophomonas maltophilia blood stream infection in the intensive care unit

Abstract Background: The aim of this study was to assess the relationship between appropriate antibiotic therapy and the outcome in intensive care unit (ICU) patients with bloodstream infection (BSI) due to Stenotrophomonas maltophilia. Methods: ICU patients with monomicrobial BSI due to S. maltophilia admitted during the period from January 2004 to December 2019 were included. The included patients were divided into two groups—those with- and without appropriate antibiotic therapy after BSI—for comparison. The primary outcome was the relationship between appropriate antibiotic therapy and 14-day mortality. The secondary outcome was the influence of different antibiotic therapies: levofloxacin- and trimethoprim–sulfamethoxazole-containing regimens, on 14-day mortality. Results: A total of 214 ICU patients were included. One hundred thirty-three patients receiving appropriate antibiotic therapy after BSI had a lower 14-day mortality than those (n = 81) who did not receive an appropriate antimicrobial therapy (10.5% vs. 46.9%, p < 0.001). After a propensity score matching, 61 well-balanced matched pairs showed similar results of regarding the association of appropriate antibiotic therapy with a lower 14-day mortality (11.5% vs. 39.3%, p< 0.001). Furthermore, proportional hazards regression for propensity score-matched cohort consistently revealed that APACHE score (hazard ratio (HR) 1.118, 95% confidence interval (CI) 1.056–1.184, p < 0.001) and appropriate antibiotic therapy (HR 0.222, 95% CI 0.095–0.518, p = 0.001) were independent factors associated with 14-day mortality. Among ICU patients receiving appropriate antibiotic therapy, those receiving a levofloxacin-containing regimen exhibited a trend toward lower 14-day mortality after BSI onset than those receiving a trimethoprim–sulfamethoxazole regimen (HR 0.233, 95% CI 0.050–1.084, p = 0.063) Conclusion: Appropriate antibiotic therapy was associated with decreased 14-day mortality in ICU patients with S. maltophilia BSI. No significant efficacy differences were noted between levofloxacin- and trimethoprim–sulfamethoxazole-containing regimens in treating S. maltophilia BSI.