Induction of Necrosis in Human Macrophage Cell Lines by and Strains Isolated from Fatal Cases of Systemic Infections.

When infecting a human host, and are able to impair macrophage maturation and induce cell death. However, the underlying molecular mechanisms are not well understood. As a framework for this project, a combination of fluorescence microscopy, cytotoxicity assays, live cell imaging, and fluorescence-activated cell sorting was applied to understand the pathogenicity of two strains isolated from fatal cases of systemic infections. The results showed a clear cytotoxic effect of the bacteria. The observed survival of the pathogens in macrophages and, subsequent, necrotic lysis of cells may be mechanisms explaining dissemination of and to distant organs in the body.