Junior Research Group Holtfreter

Analysis of the murine antibody and T cell response against S. aureus during colonization and infection.

The bacterium Staphylococcus aureus ranks No. 2 in nosocomial infection. The rapid spread of multi-resistant bacteria (so-called MRSA) both in the hospitals and the community has spurred efforts to develop vaccines; however, so far, no vaccine candidate passed the clinical phase. A better understanding of the adaptive immune response against S. aureus is mandatory for the development of effective vaccines. Therefore, our research aims at characterizing the antibody and T cell response directed against S. aureus in murine colonization and infection models.

Molecular epidemiology and host adaptation of S. aureus isolates from laboratory and wild mice.

Vaccine development relies on animal infection models that closely mimic the ‘real’ S. aureus infections. So far, researchers use human-adapted S. aureus strains to infect mice, bringing two organisms together that rarely meet in real life. We have observed that laboratory and wild mice are frequently colonized with specialized mouse-adapted S. aureus strains. These S. aureus strains have adapted to their murine host over decades, and probably have developed means to evade and block the attack of the murine immune system. We want to test whether these strains can be utilized for the investigation of host pathogen interactions in the mouse model.

Molecular epidemiology of S. aureus in the general Pomeranian population.

Apart from causing dangerous nosocomial infections, S. aureus is also a common colonizer of the human skin and mucosa. We are monitoring the S. aureus population that colonizes the Pomeranian population within the population-based study SHIP (Study of Health in Pomerania). We characterize the highly diverse S. aureus population by various genotyping methods (spa typing, DNA microarrays, multiplex-PCRs, next generation sequencing) and monitor the spread of MRSA strains, originating from hospitals or livestock farming, in the community. The SHIP study also gives us the unique opportunity to answer one of the long-standing questions in S. aureus research: What makes an S. aureus carrier a carrier?