Asymptomatic bacteriuria in schoolgirls. VI. The correlation between urinary and faecal Escherichia coli. Relation to the duration of the bacteriuria and the sampling technique.

The occurrence of the urinary strain in the anus, rectum and faeces was investigated in 27 girls with asymptomatic bacteriuria (ABU). In patients with bacteriuria of relatively short duration 46% of the faecal isolates were of the urinary strain as compared to only 18% in patients with bacteriuria of relatively long duration. In general the correlation between the urinary and faecal flora is striking at the time of establishment of ABU but diminishes with time. The diminished correlation may be due to two factors: firstly, the composition of the faecal flora changes with time. Secondly, the correlation may be obscured by complex changes in the properties of bacterial strains established in the urinary tract. Contamination by the infected urine did not seem to be a serious problem when the rectal mucosa was swabbed proximal to the anal canal.