Sex, drugs, bugs, and age: Rational selection of empirical therapy for outpatient urinary tract infection in an era of extensive antimicrobial resistance

Jaime L. Rocha, Felipe Francisco Tuon, James R. Johnson

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Background: Optimal empirical therapy of urinary tract infection requires accurate knowledge of local susceptibility patterns, which may vary with organism and patient characteristics. Methods: Among 9,798 consecutive, non-duplicate, community-source urine isolates from ambulatory patients ≥ 13 years old, from clinical laboratory and an academic medical center in Curitiba, Brazil (May 1st to December 1st, 2009), susceptibility data for ampicillin, nitrofurantoin, trimethoprim-sulfamethoxazole, gentamicin, fluoroquinolones, and ceftriaxone/cefotaxime were compared with organism and patient gender and age. Results: The female-to-male ratio decreased with age, from 28.1 (among 20-29 year-olds) to 3.3 (among > 80 year-olds). Overall, susceptibility prevalence varied widely by drug class, from unacceptably low levels (53.5% and 61.1%: ampicillin and trimethoprimsulfamethoxazole) to acceptable but suboptimal levels (81.2% to 91.7%: fluoroquinolones, ceftriaxone, nitrofurantoin, and gentamicin). E. coli isolates exhibited higher susceptibility rates than other isolates, from 3-4% higher (fluoroquinolones, gentamicin) to ≥ 30% (nitrofurantoin, ceftriaxone). Males exhibited lower susceptibility rates than females. Within each gender, susceptibility declined with increasing age. For females, only nitrofurantoin and gentamicin were suitable for empirical therapy (≥ 80% susceptibility) across all age cohorts; fluoroquinolones were suitable only through age 60, and ceftriaxone only through age 80. For males, only gentamicin yielded ≥ 80% susceptibility in any age cohort. Conclusion: Few suitable empirical treatment options for community-source urinary tract infection were identified for women aged over 60 years or males of any age. Empirical therapy recommendations must consider the patient's demographic characteristics. Site-specific, age and gender-stratified susceptibility surveillance involving all uropathogens is needed.

Original languageEnglish (US)
Pages (from-to)115-121
Number of pages7
JournalBrazilian Journal of Infectious Diseases
Issue number2
StatePublished - Mar 2012

Bibliographical note

Funding Information:
Jaime L. rocha received grants from sanofi Pasteur and Pfizer. felipe francisco tuon received grants from Pfizer and Merck. James r. Johnson received research grants or contracts from Merck and rochester Medical. this material is based in part upon work supported by office of research and Development, Medical research service, Department of Veterans Affairs (J.r.J.).


  • Anti-bacterial agents
  • Drug resistance, bacterial
  • Escherichia coli
  • Fluoroquinolones
  • Urinary tract infections


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