Ureaplasma-urealyticum-induced bladder stones in rats and their prevention by flurofamide and doxycycline.

Struvite calculi can be produced in the bladder of Sprague-Dawley male rats after injection of ureaplasmas into the renal medulla. Calculi appear 3 to 6 days after ureaplasma injection. We have studied the inhibitory effect of flurofamide, a potent inhibitor of Ureaplasma urealyticum urease, and doxycycline, on the formation of bladder stones. Flurofamide given orally in five doses (total 125 mg) over 3 days and doxycycline in seven doses (total 20 mg) over 4 days partially prevented stone formation only when given at the time of inoculation. Ureaplasmas disappeared rapidly from the urine. The inhibitory effect of flurofamide was higher than that of doxycycline. However, doxycycline seemed to be efficient when given for a long period (5 weeks).