Dissemination of bacteria in multiple organs associated with apoptosis and macrophage activity in different stages of experimental sepsis

Abstract

Background: Gram negative sepsis is reported to induce massive translocation of bacteria into tissues, which associates with decreased macrophage function and increased macrophage apoptosis. Aims: The objective of this study was to detect the translocation of bacteria into different organs and to evaluate macrophage activity and the apoptosis of macrophages in the liver during different stages of sepsis and to correlate these parameters. Material: Wistar rats (n = 43) were inoculated intraperitoneally with an E. coli and divided into 5 groups, which were killed at different times. Methods: Counts of translocated bacteria in tissues were evaluated by using morphological and bacteriological methods. Macrophage activity and apoptotic cells in the liver were studied by applying immunohistochemical methods. Results: The counts of E. coli were the highest in the organs and blood 6 h after the onset of sepsis, being in correlation with the highest counts of apoptotic cells in the liver and the falling counts of activated macrophages. The counts of microbes show a new wave of elevation in tissues by 120th h. Conclusions: The massive penetration of bacteria, the depressed macrophage response in early sepsis following the increased rate of apoptotic macrophages, the different rate of bacterial multiplication in tissues and blood and the second wave of the multiplication of bacteria in tissues in late sepsis all refer to the significance of developing immune dysfunction.