Background: Escherichia coli is the leading cause of urinary tract infections (UTI). Current Infectious Diseases Society of America (IDSA) guidelines recommend the use of fluoroquinolones when resistance to trimethoprim-sulfamethoxazole is greater than 10% to 20%. Identification of risk factors for fluoroquinolone-resistant E. coli may provide information to help in choosing the optimal empiric treatment of patients with UTI.
Objective: To identify risk factors for fluoroquinolone-resistant E. coli in patients with UTI.
Methods: Retrospective case control study of UTI caused by quinolone-resistant E. coli.
Results: Risk factors for fluoroquinolone-resistant E. coli UTI included recurrent UTI (odds ratio [OR], 2.28; P = 0.017), underlying medical disease (OR, 5.28; P < 0.001), urinary tract abnormalities (OR, 2.99; P = 0.002), prior hospitalization within the last 6 months (OR, 5.58; P = 0.032) and prior treatment with antibiotics within the last 6 months (OR, 13.72; P < 0.001). Isolates were susceptible to nitrofurantoin (94.9%), cepholosporins (79.7%), aminoglycosides (amikacin 97.5%, gentamicin 75.9%), and imipenem (98.7%).
Conclusions: Fluoroquinolones should be used with caution in patients with UTI and risk factors for fluoroquinolone-resistant E. coli.
From the *Henry Ford Health System, Detroit, MI; †British American Hospital, Lima, Peru and ‡Wayne State University School of Medicine, Detroit, MI.
Reprints: Marcus J. Zervos, MD, Infectious Diseases, Henry Ford Health System, Wayne State University School of Medicine, 2799 W. Grand Blvd., Detroit, MI 48202. E-mail: firstname.lastname@example.org.