Experimental acute pyelonephritis in grivet monkeys, provoked by Staphylococcus saprophyticus

Urinary tract infection by Staphylococcus saprophyticus was provoked in two female grivet monkeys. A non-hemagglutinating strain of S. saprophyticus was injected into the renal pelvis of one of the animals (monkey I), while in the other (monkey II), a hemagglutinating strain of the same species was inoculated into the bladder by suprapubic puncture. In monkey I, massive hematuria and proteinuria were demonstrated during the post-inoculation (p.i.) week, after which the monkey was killed. In monkey II, which was killed after 2 weeks, hematuria and proteinuria were present during the first 5 p.i. days. In both monkeys, S. saprophyticus was isolated in numbers < 10(5) bacteria/ml bladder urine on each p.i. day. Autopsy of monkey I revealed acute pyelonephritis and inflammatory changes in the ureter on the same side on which S. saprophyticus had been inoculated. In monkey II, both kidneys were enlarged and there were signs of acute pyelonephritis. The histopathological examination revealed microabscesses, interstitial infiltration and numerous leukocytes in the tubules. Both the ureters of monkey II were congested and microscopically an acute inflammatory reaction was found. Inflammatory signs were also present in the bladder. Scanning electron microscopy revealed cocci adhering to the epithelial lining of the urinary tract.