• Adherence and invasion of streptococci to eukaryotic cells and their role in disease pathogenesis.

      Rohde, Manfred; Chhatwal, G Singh; Department of Medical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany. manfred.rohde@helmholtz-hzi.de (2013)
      Streptococcal adhesion, invasion, intracellular trafficking, dissemination, and persistence in eukaryotic cells have a variety of implications in the infection pathogenesis. While cell adhesion establishes the initial host contact, adhering bacteria exploit the host cell for their own benefit. Internalization into the host cell is an essential step for bacterial survival and subsequent dissemination and persistence, thus playing a key role in the course of infection. This chapter summarizes the current knowledge about the diverse mechanisms of streptococcal adhesion to and invasion into different eukaryotic cells and the impact on dissemination and persistence which is reflected by consequences for the pathogenesis of streptococcal infections.
    • Biological functions of GCS3, a novel plasminogen-binding protein of Streptococcus dysgalactiae ssp. equisimilis.

      Bergmann, René; Dinkla, Katrin; Nitsche-Schmitz, D Patric; Graham, Rikki M A; Lüttge, Melanie; Sanderson-Smith, Martina L; Nerlich, Andreas; Rohde, Manfred; Chhatwal, Gursharan S; Dept. of Medical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany. (2011-02)
      Increasing awareness of the relevance of Streptococcus dysgalactiae ssp. equisimilis as a human pathogen motivates the analysis of its pathomechanisms. One of the mechanisms that increases infectivity and dissemination of several streptococcal species is the recruitment and subsequent activation of host plasminogen on the streptococcal surface. This study identified GCS3 as a novel plasminogen-binding M protein of S. dysgalactiae ssp. equisimilis and revealed a difference in the mode of binding as compared to the plasminogen-binding protein PAM of S. pyogenes. In contrast to PAM, GCS3 did not bind to the kringle 1-3 region of plasminogen. Despite this difference, GCS3 exerts the same function of recruiting plasminogen to the streptococcal surface, which can be activated by streptokinase and host plasminogen activators to serve as a spreading factor. Moreover, we demonstrate a role of GCS3 in plasminogen-dependent streptococcal adherence to human pharyngeal cells (cell line Detroit 562) that indicates an additional function of the protein as an adhesin in the oral cavity.