Related Experiment Videos
Confirmation of destruction of salmonellae within murine peritoneal exudate cells by immunocytochemical technique
1Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
Abstract:
A procedure was developed with which peritoneal exudate cell (PEC) preparations were fixed in a glutaraldehyde-picric acid mixture, post-fixed with osmium tetroxide, embedded in LR White resin and then stained with immunogold probe. It provided tissue sections showing both well-defined ultrastructures as well as specifically labelled Salmonella O antigens by electron microscopy. Inbred, male C57BL/6 mice were injected intraperitoneally with 2 x 10(7) virulent Salmonella typhimurium. Peritoneal exudate cells were harvested at 16 and 20 hr after infection. Disintegrating intracellular bacteria were identified as salmonellae by the immunogold markers. Deposition of gold particles in the cytoplasm of phagocytes also indicated that intracellular debris contained digested pathogen. This investigation therefore confirms previous findings of the destruction of salmonellae within inflammatory polymorphs and macrophages.
Insights
Researchers developed a new electron microscopy technique to visualize Salmonella O antigens in mouse cells. This method confirms Salmonella destruction within macrophages and polymorphs, advancing our understanding of bacterial clearance.
Area of Science:
- Immunology
- Microbiology
- Electron Microscopy
Background:
- Salmonella typhimurium infection triggers an immune response involving peritoneal exudate cells (PECs).
- Understanding the intracellular fate of Salmonella within host cells is crucial for developing effective treatments.
Purpose of the Study:
- To develop and validate an electron microscopy technique for visualizing Salmonella O antigens within PECs.
- To confirm the intracellular destruction of Salmonella by host immune cells.
Main Methods:
- PECs from infected C57BL/6 mice were processed using glutaraldehyde-picric acid fixation, osmium tetroxide postfixation, and LR White resin embedding.
- Immunogold staining with a probe specific for Salmonella O antigens was employed.
- Electron microscopy was used to examine ultrastructure and antigen localization.
Main Results:
- The technique provided well-defined ultrastructures of PECs and specifically labeled Salmonella O antigens.
- Intracellular bacteria were identified as Salmonella using immunogold markers.
- Gold particle deposition in phagocyte cytoplasm indicated digested Salmonella, confirming intracellular degradation.
Conclusions:
- The developed electron microscopy procedure effectively visualizes Salmonella O antigens within host cells.
- This study confirms the destruction of Salmonella within inflammatory polymorphs and macrophages.
- The findings support previous research on the intracellular clearance mechanisms against Salmonella infection.