BioTechMed Flagship Lecture
Prof. Bäumler (Department of Medical Microbiology and Immunology, University of California Davis School of Medicine): “Healthy guts exclude oxygen”
Where: Stremayrgasse 16, Hörsaal BMT, TU Graz
When: 17.04.2019, 5 p.m.
An imbalance in the colonic microbiota might underlie many human diseases, but the mechanisms maintaining homeostasis remain elusive. Recent insights suggest that colonocyte metabolism functions as a control switch, mediating a shift between homeostatic and dysbiotic communities. During homeostasis, colonocyte metabolism is directed towards oxidative phosphorylation, resulting in high epithelial oxygen consumption. The consequent epithelial hypoxia helps maintain a microbial community dominated by obligate anaerobic bacteria, which provide benefit by converting fiber into fermentation products absorbed by the host. Conditions that alter the metabolism of the colonic epithelium increase epithelial oxygenation, thereby driving an expansion of facultative anaerobic bacteria, a hallmark of dysbiosis in the colon. Enteric pathogens subvert colonocyte metabolism to escape niche protection conferred by the gut microbiota. The reverse strategy, a metabolic reprogramming to restore colonocyte hypoxia, represents a promising new therapeutic approach for rebalancing the colonic microbiota in a broad spectrum of human diseases.
Talk Prof. Tsolis (Department of Medical Microbiology and Immunology, University of California Davis School of Medicine):
„Disseminated Salmonella infections: a neglected tropical disease“
Where: SR 44.31, Humboldtstraße 48, 8010 Graz, ZMB Ex-Usu-Gebäude, 3rd floor
When: 16.04.2019, 5 p.m.
In the developed world, infection with Salmonella comes mostly from food, and infected individuals develop diarrheal disease. Usually, the immune system contains these infections to the intestinal tract and people recover on their own. However, in children in sub-Saharan Africa, Salmonellamore frequently is able to spread from the intestine to the bloodstream, causing life-threatening disease. To understand why these children are less able to control Salmonella infection, we developed mouse models to study how epidemiologic risk factors for bloodstream infection such as malaria and malnutrition affect immunity to infection. Our results are showing that malaria and malnutrition suppress multiple host defenses at different body sites that are needed to resist or control infection with Salmonella. By understanding how pre-existing health conditions or infections compromise resistance to Salmonella, we hope to discover new features of the immune system involved in defending against infection.
