Research Article

Untreated asymptomatic bacteriuria in girls: I--Stability of urinary isolates.

BMJ 1989; 298 doi: (Published 01 April 1989) Cite this as: BMJ 1989;298:853
  1. S. Hansson,
  2. D. Caugant,
  3. U. Jodal,
  4. C. Svanborg-Edén
  1. Department of Paediatrics, Gothenburg University, East Hospital, Sweden.


    OBJECTIVE--To assess the frequency of spontaneous changes of bacterial strains in patients with untreated asymptomatic bacteriuria. DESIGN--Retrospective analysis of samples from all patients with renal scarring and random sample of patients with normal kidneys. SETTING--Outpatient clinic for children with urinary tract infections. PATIENTS--54 Girls aged 3.3-15.5 years with untreated asymptomatic bacteriuria caused by Escherichia coli. INTERVENTION--None. END POINT--Change in bacterial strain. MEASUREMENTS AND RESULTS--Serotyping and electrophoretic analysis of sequential bacterial isolates, representing 151 patient years of untreated asymptomatic bacteriuria. A total of 24 changes of strain were identified. Eleven were related to medical interference such as treatment of other infections with antibiotics. CONCLUSIONS--Spontaneous changes of strain were uncommon, one change in 11.6 patient years, and thus are not a characteristic feature of the course of asymptomatic bacteriuria.