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Hello, everybody. My
name is Dr. Sarah Fouch.
Welcome to this short talk
where we will be considering
group A streptococci or
Streptococcus pyogenes.
We will be considering
the conditions that this
organism is associated with
and the virulence factors that
this organism can produce to
make it such a
successful pathogen.
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When we consider
group A streptococci,
we carry this organism in low
numbers in our oropharynx.
Carriage tends to be seen
normally in children
and young adults.
However, some older adults
can also carry this
organism as well.
Sometimes we can have
transient carriage and
sometimes permanent carriage.
But the carriage will
depend on the antibodies
that are being
produced to the
particular M proteins
that are being expressed
by the organism.
Basically, an individual's
immune system is reducing
the number of organisms
that are being
carried to a low number.
When we think about
how strains are
transferred between
person to person,
this is through
droplet infection.
While I'm talking to you,
I have small droplets
coming out of my mouth.
I'm not spitting
all over the camera
because that would be
particularly unpleasant.
But small droplets are
actually coming out of
my mouth all the time,
particularly, when I say B or P.
If somebody is in
close proximity to me,
and they're able to breathe in
those droplets, and they don't
have antibodies to that
particular M protein
that's being expressed,
they will have an
increased risk of
obtaining an infection.
Group A streptococci
can also be part of
our normal skin flora so
we can have skin
colonisation as well.
Direct contact can also be
an issue with
susceptible individuals.
