Answer:
How does Group A Streptococcus Pyogenes enter
the host?
- S. pyogenes contains several
virulence factors (example Pyrogenic exotoxin A, B and C,
M-proteins, Streptococcal superantigen, lipoteichnoic acid) that
play an important role in evading the host immune response and
attachment to host tissue.
- S. pyogenes is present as a normal flora in the respiratory
tract of the individuals (~5-15%). However, in instances where the
individuals immune system is compromised or suppressed then these
organisms can penetrate the defense system and cause infection. It
can cause skin infections throat infections, suppurative and non
suppurative diseases.
- The primary site of invasion is the throat (pharynx) causing
pharyngitis or strep throat.