Streptococcus pyogenes is an exclusively human pathogen causing a wide variety of infections. Little is known about factors and environmental conditions involved in induction or inhibition of biofilm formation by S. pyogenes during the infection process. Hence, in the present thesis biofilm structures of S. pyogenes M2, M6, and M18 serotype strain were characterized under in vitro conditions.
A serotype dependent impact of factors like temperature, availability of nutrients or oxygen, and the presence of antimicrobial compounds on the formation and development of S. pyogenes biofilms were shown. For the first time proteins and nucleic acids were determined to be potential components of the extracellular biofilm matrix of S. pyogenes. Furthermore, investigations of S. pyogenes insertion mutants pointed at the involvement of several already known virulence factors in biofilm formation. Finally it was shown that S. pyogenes biofilm cells can enter a VBNC like status as persistence strategy during long term cultivation.