The bacteriology of operated renal stones.

In a group of patients consecutively operated on for renal stones, more than half of the patients had urinary tract infection. In a significant number of the patients with infection stones containing magnesium ammonium phosphate, no urease-producing microorganism could be cultured. Escherichia coli was on the other hand rather frequently cultured from the stone in these patients. This suggests the possibility that E. coli might be involved in stone formation. The correlation between stone and voided urine cultures was incomplete. It is thus important to perform stone cultures. This could be done without loss of accuracy by culturing crushed stones.