Antibiotic Resistance Patterns Among Uropathogens in Female Outpatients Affected by Uncomplicated Cystitis: Focus on Fosfomycin Trometamol

Int J Antimicrob Agents. 2023 Nov;62(5):106974. doi: 10.1016/j.ijantimicag.2023.106974. Epub 2023 Sep 20.

Abstract

Objectives: To report the resistance rate against fosfomycin trometamol among outpatient women with symptoms related to urinary tract infections over a 6-year period in a multicentre, cross-sectional study.

Methods: Urinary samples were collected from three high-volume laboratories from January 2015 to December 2020. The pattern of resistance to fosfomycin was analysed by using the Vitek II automated system.

Results: A total of 7289 urinary samples were collected and 8321 strains were analysed during the study period. The most commonly isolated uropathogen was Escherichia coli (n = 6583, 79.1%). The mean resistance rate against fosfomycin was 9.7% (range 7.1-11.3). No statistically significant difference was found between the three laboratories (P = 0.53). There was no significant increase in resistance rate during the study period. The mean resistance rate against fosfomycin was higher among extended-spectrum β-lactamase (ESBL)-producing bacteria when compared with non-ESBL-producing strains (10.8% vs. 7.9%; P < 0.001).

Conclusion: Uropathogens isolated from women affected by cystitis remained highly susceptible to fosfomycin. These findings confirm recommendations in international guidelines that advocate fosfomycin trometamol for empirical treatment of uncomplicated cystitis in women.

Keywords: Antibiotic stewardship; Antibiotics; Fosfomycin; Resistance; Urinary tract infections.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Cross-Sectional Studies
  • Cystitis* / drug therapy
  • Drug Resistance, Microbial
  • Escherichia coli
  • Female
  • Fosfomycin* / pharmacology
  • Fosfomycin* / therapeutic use
  • Humans
  • Microbial Sensitivity Tests
  • Outpatients
  • Tromethamine
  • Urinary Tract Infections* / drug therapy
  • Urinary Tract Infections* / microbiology

Substances

  • Fosfomycin
  • Anti-Bacterial Agents
  • Tromethamine