Pyelonephritis. I. Observations on the Course of Chronic Non-Obstructed Enterococcal Infection in the Kidney of the Rat ‡

Studies of the pathogenesis of experimental pyelonephritis have been limited because of lack of a suitable model. Although several types of renal and extra-renal manipulations have been shown to predispose the kidneys of experimental animals to pyelonephritis, the investigator is frequently unable to distinguish between the effects of the predisposing injury and the induced infection. The few micro-organisms capable of initiating pyelonephritis in the "non-manipulated" kidney usually cause rapid death of the experimental animal or the renal lesion becomes bacteriologically sterile and the disease does not progress. The present data describes the course of chronic pyelonephritis produced by the intravenous injection of enterococci into the normal rat.