The Effect of Water Diuresis on Spread of Bacteria through the Urinary Tract

After injection of 2−4 × 107Escherichia coli, enterococci, or Staphylococcus aureus into the left renal medulla of rats, titers of bacteria in the left kidneys gradually decreased from over 107 to between 105 and 106 during the first week. Diuresis produced by drinking 5 % glucose in water had no effect on titers of bacteria in the left kidney. Similarly, with enterococcal or S. aureus infections, titers in the right kidney were equivalent in diuresing and nondiuresing rats. In cases of infection due to E. coli, the right kidneys of rats drinking 5 % glucose in water had much higher titers of bacteria than those of rats drinking tap water. All three species of bacteria multiplied more rapidly in vitro in urine from diuresing rats than in urine from nondiuresing rats. Histological studies demonstrated marked pyelonephritis of all left kidneys. The right kidneys showed histological changes only in rats with titers of 105 or more per kidney. Many of these kidneys showed marked infiltration of polymorphonuclear leukocytes in the medulla just beneath the epithelium lining the papilla.