Monotherapy with fluoroquinolone or trimethoprim-sulfamethoxazole for treatment of Stenotrophomonas maltophilia infections

Antimicrob Agents Chemother. 2014;58(1):176-82. doi: 10.1128/AAC.01324-13. Epub 2013 Oct 21.


The treatment of choice for Stenotrophomonas maltophilia is trimethoprim-sulfamethoxazole (SXT). Fluoroquinolones (FQs) have in vitro activity against S. maltophilia; however, there is limited published information on their effectiveness. The purpose of this study is to compare the effectiveness of FQs and SXT for the treatment of S. maltophilia. A retrospective review of 98 patients with S. maltophilia infections who received SXT or FQ monotherapy was conducted. Patients ≥18 years old with a positive culture for S. maltophilia and clinical signs of infection who received treatment for ≥48 h were included. Microbiological cure and clinical response were evaluated at the end of therapy (EOT). In-hospital mortality and isolation of nonsusceptible isolates were also evaluated. Thirty-five patients received SXT, and 63 patients received FQ; 48 patients received levofloxacin, and 15 patients received ciprofloxacin. The most common infection was pulmonary. The overall microbiological cure rate at EOT was 63%. Thirteen of 20 patients (65%) who received SXT and 23 of 37 patients (62%) who received FQ had microbiological cure at EOT (P = 0.832). The overall clinical success rate was 55%, 52% for those who received FQ and 61% for those who received SXT (P = 0.451). In-hospital mortality was 24%, with similar rates in the two groups (25% for FQ versus 22% for SXT; P = 0.546). Development of resistance on repeat culture was 30% for FQ and 20% for SXT (P = 0.426). Fluoroquinolone and SXT monotherapies may be equally effective for the treatment of S. maltophilia infections. Resistance was documented in subsequent isolates of S. maltophilia in both groups.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Fluoroquinolones / therapeutic use*
  • Gram-Negative Bacterial Infections / drug therapy*
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Stenotrophomonas maltophilia / drug effects*
  • Trimethoprim, Sulfamethoxazole Drug Combination / therapeutic use*


  • Fluoroquinolones
  • Trimethoprim, Sulfamethoxazole Drug Combination