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

Abstract

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 in strain were uncommon, one change in 11.6 patient years, and thus are not a characteristic feature of the course of asymptomatic bacteriuria.