Evasion Factors

Bacterial virulence factors that facilitate escape from antimicrobial extracellular traps (ETs) and other host immune defence mechanisms

Bacterial host immune evasion factors are studied in cooperation with Victor Nizet at UCSD in La Jolla, California, Alexander Horswill, University of Iowa, and Suzán Rooijakkers at UMC Utrecht, The Netherlands.

Selected bacterial mutant strains with known or putative virulence function are tested for resistance/susceptibility against intracellular and/or extracellular killing mechanisms by host immune cells (e.g. neutrophils, macrophages, mast cells). Animal models are used to confirm the in vivo role of selected host evasion factors during bacterial pathogenesis. Using this approach, it was recently discovered that the human pathogen Streptococcus pyogenes produces M1 protein to survive within mast cell and neutrophil extracellular traps, and thereby enhances its potential to cause invasive human infections. This study suggests that investigations of strain variation in cathelicidin and ET resistance/sensitivity may prove fruitful in understanding the epidemiology and pathogenesis of bacterial infections important in human as well as veterinary medicine.