Internalization of Proteus mirabilis by human renal epithelial cells.

摘要: Proteus mirabilis, a common agent of bacteriuria in humans, causes acute pyelonephritis and bacteremia. Renal epithelium provides barrier between luminal organisms the renal interstitium. We have hypothesized that P. mirabilis may be internalized into epithelium. To test this hypothesis, we added suspensions three strains (10(8) CFU) to confluent monolayers primary cultures human proximal tubular epithelial cells (HRPTEC) and, after 3 h, found bacteria within membrane-bound vacuoles by light electron microscopy. Internalization HRPTEC was corroborated using gentamicin protection assay. Cytolysis HpmA hemolysin, however, confounding factor assay, therefore hemolysin-negative hpmA mutant used subsequent experiments. The nonhemolytic WPM111 did not disrupt monolayer recovered numbers were 10- 100-fold higher than those hemolytic parent BA6163. Cytochalasin D (20 micrograms/ml) inhibited internalization Salmonella typhimurium but suggesting latter species enters mechanism is dependent on actin polymerization. suggest hemolysin-mediated cytotoxicity play role development pyelonephritis.