Related Experiment Videos
Survival of Streptococcus pyogenes within host phagocytic cells: a pathogenic mechanism for persistence and systemic
Eva Medina1, Oliver Goldmann, Antonia W Toppel
1Department of Microbial Pathogenesis and Vaccine Research, German Research Centre for Biotechnology, Braunschweig, Germany. eme@gbf.de
Abstract:
Streptococcus pyogenes is generally an extracellular pathogen that can survive and persist within the host by circumventing the host defense mechanisms. To achieve this, S. pyogenes has developed a number of strategies to circumvent the host immune system (e.g., virulence factors directed to prevent phagocytosis). By use of a murine model of skin infection, it was shown that survival within host phagocytic cells constitutes an additional strategy used by S. pyogenes to evade the host defenses and disseminate. Viable microorganisms were isolated from mouse phagocytic cells after in vitro or during in vivo infection. The capacity of intracellularly located bacteria to establish infection was demonstrated by the efficiency of gentamicin-treated neutrophils isolated from infected mice to transfer infection when injected intravenously into naive mice. The ability of S. pyogenes to exploit the inflammatory response of the host by surviving inside phagocytic cells may constitute an additional virulence mechanism of this pathogen.
Insights
Streptococcus pyogenes evades immune defenses by surviving inside host phagocytic cells. This intracellular survival strategy aids in pathogen dissemination and establishes infection, revealing a novel virulence mechanism.
Area of Science:
- Microbiology
- Immunology
- Pathogenesis
Background:
- Streptococcus pyogenes is a significant human pathogen.
- It typically exists extracellularly and employs strategies to evade host immune responses.
- Understanding evasion mechanisms is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the role of intracellular survival within phagocytic cells as a virulence strategy for Streptococcus pyogenes.
- To determine if Streptococcus pyogenes can evade host defenses by residing within phagocytes.
Main Methods:
- A murine model of skin infection was utilized.
- Isolation of viable Streptococcus pyogenes from phagocytic cells (in vitro and in vivo).
- Assessment of infection transfer using gentamicin-treated neutrophils from infected mice.
Main Results:
- Streptococcus pyogenes was successfully isolated from host phagocytic cells.
- Intracellular Streptococcus pyogenes demonstrated the capacity to establish infection.
- Neutrophils from infected mice transferred infection to naive mice.
Conclusions:
- Survival within host phagocytic cells is an additional immune evasion strategy for Streptococcus pyogenes.
- This intracellular survival contributes to pathogen dissemination.
- Exploiting the inflammatory response via intracellular persistence represents a novel virulence mechanism for Streptococcus pyogenes.