Resistant urinary infections resulting from changes in resistance pattern of faecal flora induced by sulphonamide and hospital environment.

The faecal flora was studied in eight children admitted to hospital for treatment of a first urinary infection with sulphonamides. The original, sulphonamide-sensitive Escherichia coli organisms were found to disappear, to be replaced by other E. coli serotypes that were almost invariably resistant to sulphonamides. Some of these serotypes carried R-factors for multiple antibiotic resistance.Possibly some urinary infections with antibiotic-resistant organisms may be due to faecal organisms whose resistance has been changed by previous antibiotic treatment. Hence it is important to study the effects of individual antibiotics on the faecal flora.