Microbiology
The Microbiology division, led by Prof. Dr. Michael Hensel, investigates molecular mechanisms of bacterial pathogenesis. Using the model organism Salmonella enterica, we unravel the pathogenic lifestyle in the host, host adaptation, and function of virulence factors.
What causes infectious diseases by bacteria, and what can we do against it?
Throughout our lives, the human body is colonised by a wide variety of bacteria that form our microbiome and interact symbiotically with us. However, there are also some species of bacteria that are not part of this microbiome and can cause infectious diseases after entering our bodies. Such pathogenic bacteria are largely responsible for disease burden and preventable deaths. Pathogenic bacteria have a variety of virulence factors, e.g. various adhesins for attaching to surfaces in the host organism, or secretion systems for injecting proteins into host cells. Bacterial infectious diseases can be treated with antibiotics, but increasingly frequent resistance is rendering such therapies ineffective. The search for new target structures for antimicrobial agents is an important alternative to the antibiotics currently available.
Pathogenic bacteria usually exhibit complex interactions with their host organisms and differ in their host specificity and the severity of the disease course in an infectious disease. The Microbiology division uses the model organism Salmonella enterica to unravel the molecular mechanisms of pathogenic lifestyle in the host, host adaptation, and the function of virulence factors.
Intracellular lifestyle of Salmonella in mammalian cells
Salmonella bacteria can invade cells in the intestinal wall as well as cells of the immune system, where they survive and multiply. Salmonella lives intracellular in a special compartment of the host cell called Salmonella-containing vacuole. We are investigating how Salmonella use a group of virulence proteins to establish this compartment and multiply within.
Host specificity of Salmonella
Some Salmonella strains are highly specialised in infecting humans and cause serious, sometimes life-threatening diseases, such as typhoid fever caused by Salmonella Typhi. The factors that determine host specificity and disease progression are only partially understood. The Microbiology division identifies new virulence factors of host-specific Salmonella strains and investigates their role in pathogen-host interactions.
High-resolution imaging of pathogen-host interactions
Microscopy is an important method for understanding the effects of pathogenic bacteria on their hosts. The Microbiology division uses various light microscopy and electron microscopy techniques for time-resolved or high-resolution imaging of infection processes. Furthermore, improved methods of live cell microscopy and correlation of different microscopy techniques are being developed.
Mechanisms of adhesion
Salmonella use a large number of adhesive proteins to bind to various surfaces inside and outside host organisms. The Microbiology division has identified numerous new adhesins in Salmonella and is investigating their structure and binding specificity.
