Is a second urine specimen necessary for the diagnosis of asymptomatic bacteriuria?

By use of pulse-field gel electrophoresis, we evaluated the molecular identity of 32 Escherichia coli isolates obtained in 2 consecutive urine cultures from 16 patients as part of a large study of asymptomatic bacteriuria in diabetic women and found different E. coli isolates in 7 of 16 patients, meaning that nearly half (44%) of the patients who had been previously classified as having asymptomatic bacteriuria were reinfected with a different strain.