[A study on bacteria within stones in urolithiasis].

The bacteria in 37 stones obtained from 37 patients with urinary stone diseases, that is, 11 renal stones (containing 2 staghorn calculi), 21 ureteral stones, 4 bladder stones and 1 urethral stone, were studied, according to the Nemoy & Stamey's method. The stones were collected by partial nephrectomy (1 case), nephrolithotomy (1 case), pyelolithotomy (1 case), percutaneous nephrolithotripsy (PNL) (6 cases), 12 ureterolithotomies, transurethral ureterolithotripsy (2 cases), cystolithotripsies (4 cases) and spontaneous deliveries (10 cases). According to a stone analysis by infrared spectrophotometer revealed 30 were noninfection stones (81.1%) and 7 infection stones (18.9%). Of these 37 stones, 5 stones (13.5% of 11 stones) had bacteria within them. These stones consisted of 4 infection stones (57.1% of all infection stones) and 1 noninfection stone (3.3% of all noninfection stones). Out of 4 patients having bacteria within their stones, urine culture of whom were carried out before stones were collected, only one patient (25%) had the same species of bacterium (E. coli) both within the stone and in urine. The E. coli within the stone and that in urine, however, showed quite different reactions to some antibiotics. The fact that all organisms within stones cannot be detected by urine culture before collecting stones of the patients in our present study, suggests that patients undergoing endourological surgery, such as extracorporeal shock wave lithotripsy and PNL, may have a risk of complications, such as severe urinary tract infection and urosepsis, if the possibility of the presence of organisms within stones is not taken into consideration.