Bacterial phagocytosis in obstructive jaundice. A microbiologic and electron microscopic analysis. Reticuloendothelial system dysfunction has been suggested as an explanation for the increased susceptibility to infection in patients with obstructive jaundice. In the present study, the response of cholestatic rats to a bacterial challenge was investigated and the uptake of bacteria by their Kupffer cells was examined with the electron microscope. Rats underwent bile duct ligation (BDL, n = 8) of sham celiotomy (SC, n = 8) and were allowed to recover for 10 days. They were then injected with 10(9) Staphylococcus aureus IV and killed at intervals of 15, 30, 60, and 180 minutes after injection. Two from each group were killed at each interval. Quantitative blood cultures were performed, and specimens of liver and lung were obtained for quantitative bacterial culture and processed for electron microscopy. Bacteria were rapidly cleared from the bloodstream of SC animals but persisted in BDL rats. Electron microscopy consistently demonstrated bacteria within Kupffer cell phagocytic vesicles of both SC and BDL animals at each interval selected. There was no morphologic difference in these vesicles between the two groups. Bacteremia persists in BDL rats subjected to a bacterial challenge despite rapid uptake of bacteria in apparently normal phagocytic vesicles. This study suggests a defect in intracellular killing of bacteria, an impairment of delivery of bacteria to RE cells, or a combination of these factors. 