In natural environment, bacteria form communities, biofilms, on
surfaces. In biofilms, bacteria are more resistant than their planktonic
forms to antimicrobials and host defense factors. Reasons for biofilm
resistance to external forces include a protective extracellular matrix
and formation of non-dividing persister cells. In humans, bacterial
biofilms cause chronic infections. One of common biofilm diseases in
humans is periodontitis, a persistent multispecies infection triggering
chronic inflammation in tooth-supporting tissues. Periodontitis is
characterized by active and less active phases in inflammation and
tissue destruction suggesting that there might be certain type of
pathogen-host crosstalk. It has been suggested that bacteria growing in
biofilms could exploit proinflammatory cytokines produced by the host.
Thus cytokine network aimed to enhance the clearance of pathogens might
actually promote bacterial survival in protective biofilm.

 

Our research is focused on studying biofilm-host interaction in chronic infection, periodontitis. We use Aggregatibacter actinomycetemcomitans (Aa),
a major pathogen in aggressive periodontitis, as model bacterium. In
particular we are interested how the outer membrane proteins are
involved in sensing the host response in inflammation. The research
include molecular- and structural biology methods, flow cytometry and
electron microscopy. In addition, we study the
biofilm-host interaction by using cell culture model which mimics the gingival tissue.