Ureaplasma urealyticum-induced urinary tract stones in rats.

This study investigated the possible role of Ureaplasma urealyticum, which is predominantly located in the urogenital tract, in the formation of infectious stones. A standardized Ureaplasma urealyticum broth culture isolated from a human urogenital specimen was inoculated into the renal medulla of five male rats (Rattus norvegicus L., Wistar C, weighing 170 +/- 10 g) and the same amount of culture media was used for five identical control rats. Five days after the inoculation, the rats were killed and fresh preparations from the bladders and the inoculated kidneys of both groups were prepared. At the same time biochemical and histopathological analysis of the contents of the bladders and the inoculated kidneys of both groups was performed. Crystal formation within the bladders of the inoculated rats was demonstrated and biochemical analysis of the crystals showed calcium, magnesium and phosphate, which indicated the existence of infection-induced crystals. These findings were absent in the control rats. The role of Ureaplasma in the production of urinary tract infectious stones was thus demonstrated in vivo.