Clinical relevance of laboratory-reported antibiotic resistance in acute uncomplicated urinary tract infection in primary care

C. A. M. Mcnulty, J. Richards, D. M. Livermore, P. Little, A. Charlett, E. Freeman, I. Harvey, Michael David Thomas

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97 Citations (Scopus)


Objectives: To determine whether patients with an uncomplicated community-acquired urinary tract infection (UTI) and an isolate resistant to trimethoprim had worse clinical outcomes following empirical treatment with trimethoprim 200 mg twice daily for 3 days than did those with a susceptible isolate.

Patients and methods: This was a prospective cohort study of clinical outcome. We enrolled 497 women (>= 18-70 years) presenting to general practitioner surgeries in Norwich and Gloucester with at least two symptoms of acute (< 7 days) uncomplicated UTI. Significant bacteriuria was defined as >= 10(4) cfu/mL from a mid-stream urine (MSU).

Results: Of enrolled patients 75% (334/448) had significant bacteriuria, and trimethoprim resistance was present in 13.9% (44/317) of isolates. Patients with resistant isolates had a longer median time to symptom resolution (7 versus 4 days, P=0.0002), greater reconsultation to the practice (39% versus 6% in first week, P < 0.0001), more subsequent antibiotics (36% versus 4% in first week, P < 0.0001) and higher rates of significant bacteriuria at 1 month (42% versus 20% with susceptible isolate, P=0.04). Half of patients reconsulting in the first week had a resistant organism.

Conclusions: Patients with uncomplicated UTI caused by trimethoprim-resistant organisms had significantly worse clinical outcomes than those with trimethoprim-susceptible organisms. Nevertheless, trimethoprim resistance was rarer than predicted from routine laboratory submissions and we calculate that 23 women require microbiological investigation to prevent one reconsultation arising from resistance-based treatment failure. We therefore suggest empirical antibiotic treatment in acute, uncomplicated UT's. If patients reconsult in the first week, we suggest a change of antibiotic treatment with urine culture and susceptibility testing then done. More generally, laboratory resources should concentrate on resistance surveillance to inform empirical antibiotic choice.

Original languageEnglish
Pages (from-to)1000-1008
Number of pages9
JournalJournal of Antimicrobial Chemotherapy
Publication statusPublished - 1 Nov 2006


  • UTI
  • clinical outcome
  • trimethoprim
  • community/primary care
  • cohort
  • randomized controlled-trial
  • spectrum beta-lactamases
  • individual patient data
  • general-practice
  • double-blind
  • adult women
  • community
  • nitrofurantoin
  • cotrimoxazole


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