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0:00
Hello. Today I will
be talking about
"Enteric
Pathogens-Microbiota-Host
Inter-Kingdom Chemical
Interactions".
My name is Vanessa
Sperandio and I'm in
the Department of Medical
Microbiology and Immunology
at the University of
Wisconsin-Madison.
0:20
I will be talking about
a specific enteric
pathogen Escherichia coli.
Usually, we think about E. coli
the predominant facultative
anaerobe commensal
of the human colonic flora.
But several strains
of E. coli can also
be pathogens causing meningitis,
urinary tract infections,
and there are several
clades that cause diarrhea.
0:45
The reason E. coli is a
versatile bacteria that can be
both a commensal
and a pathogen is
because it has a
very mosaic genome.
A comparison of the genomes
of E. coli even though.
E. coli genomes vary between
4,000 and 5,000 genes,
about only 2,000 of
these genes are shared
between all of the
E. colis and the genetic
repertoire of E. coli,
which we call the
pangenome can be
as large as 13,000 genes,
and several pathogens have
extra genes in
their genomes which
are encoded in
pathogenicity islands
which allow them to
become pathogenic.
1:26
The pathogen we're
discussing today is
enterohemorrhagic E.
coli (EHEC) O157:H7.
This is a food-borne pathogen
responsible for outbreaks
of bloody diarrhea in
many countries and
these outbreaks
are important because
the younger and the
older have a high probability
of developing hemolytic
uremic syndrome
which is a complication
that leads to
high levels of morbidity
and mortality.
You get infected by
contaminated food and
water and this is a very
professional pathogen with
a very low infectious dose,
so 50 bacterial cells can
make a human being sick and
it colonizes the
large intestine.
