August 28, 2023 • 34 mins
Welcome to an eye-opening episode of our podcast, where we uncover the hidden dangers lurking in our food. Join me and our guest, Dr. Alfredo Torres, as we embark on a journey through bacteriology. In our conversation, Dr. Torres shares his personal experiences and expertise, shedding light on the recent recall of 1.7 tons of beef contaminated with E. coli. Discover the impact of this bacterium on our health, from urinary tract infections to kidney damage, and gain insights into the measures taken for food safety. Get ready for a thought-provoking exploration that will leave you with a newfound appreciation for the importance of scientific research in safeguarding our well-being.
In this episode, we unravel the mysteries surrounding E. coli, diving deep into its existence in various animals, including humans. Dr. Alfredo Torres, a leading expert in the field, reveals how certain strains of E. coli have acquired virulence factors, allowing them to attach to cells and produce toxins that wreak havoc in our bodies. Learn about the severe consequences of these toxins entering our bloodstream, causing millions of illnesses and deaths worldwide. Join us as we journey through the intricate world of bacteria and its impact on our lives.
But that's not all - our conversation takes an unexpected turn as we explore the alarming connection between climate change and bacterial diseases. As the environment shifts, so do the conditions for bacterial growth, increasing the risk of contamination and infection. Join us as we delve into the effects of temperature on bacterial growth, the implications for food safety, and the urgent need for scientific research to address these changes. Learn something as we discuss the meaningful careers that await those passionate about unraveling mysteries and positively impacting the world. Don't miss out on this enlightening episode that will forever change the way you view the microscopic world around us.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:09):
This is a podcast about one health the idea that
the health of humans, animals,plants and the environment that
we all share are intrinsicallylinked.
Speaker 2 (00:17):
Coming to you from the University of Texas Medical
Branch in the Galveston NationalLaboratory.
Speaker 1 (00:21):
This is infectious science.
We're enthusiasm for science.
Speaker 2 (00:25):
This is contagious.
Summer wouldn't be summerwithout a little bit of barbecue
.
But not all barbecue is createdequal.
Take this past March, when 1.7tons of beef were recalled in
the US due to contamination withE coli.
On this installment of theinfectious science summer camp,
(00:47):
we're inviting Dr Alfredo Torres, associate provost at UTMB and
professor in the Department ofMicrobiology and Immunology, to
help us understand a little bitmore about this recall and learn
how to stay safe this summerwhile we're at the grill.
So when I think about bacteria,e coli is the first thing that
comes to my mind, because it'severywhere, it's in our bodies,
(01:07):
it's in the environment and it'salso a really important cause
of disease worldwide.
In fact, according to the WorldHealth Organization, it's
responsible for more than 300million illnesses and nearly
200,000 deaths worldwide.
So to talk about this, I'mDanielle and I've got Connie
here with me.
Hello, happy Friday.
And we also have Dr Torres here.
(01:27):
Alfredo Torres is a facultymember and a professor here at
UTMB, and also an assistantprovost.
Hi, dr Torres, hey how are youdoing?
Good.
Thanks so much for coming totalk to us about this Kind of
recently in the news, 1.7 tonsof beef were recalled due to
contamination with E coli.
So he's here to talk to ustoday about E coli, what it is,
(01:50):
how does that contaminationhappen and why do we care?
So, dr Torres, how did youfirst get interested in science?
Speaker 3 (01:56):
Well, I was born in California, but with my family
we went back to Mexico when Iwas five years old.
Oh, ok.
So growing up in Mexico I gotvery interested in infectious
diseases.
Because you see people gettingsick, you're sitting at the
street the traditional, whatthey call moctezuma revenge.
You go there, you eat the tacosat the street and then you got
(02:18):
sick.
So that got my attention and Istarted studying science in
college in Mexico and eventuallyI found my way to the
microbiology lab and since thenI got hooked to microbiology and
I was interested to figure outhow microbes cause disease.
And that's what I have beendoing for the past 20 years here
(02:40):
at UTMB and the past 40 years,I think, since I started college
.
Speaker 2 (02:45):
Yeah, so can you think of any key moments that
you just knew that this is, thisis what you wanted to do, or
any key early inspirations?
Speaker 3 (02:53):
Yeah, I think one of the things my career, my major,
is chemistry, pharmacology,biology.
Speaker 2 (02:59):
You might think what is that?
Speaker 1 (03:00):
What is that?
Speaker 3 (03:01):
And pieces of everything, but mainly in Mexico
.
These people that get thisdegree normally work in clinical
laboratories and they doclinical analysis.
So I have an uncle that alsohas the same major and he has
his lab in Mexico and he took mewhen I was 12, 13 years old to
go there and start learning andlook through the microscope and
(03:22):
figure out what was happeningand literally I recall that I
was the first hook to see cellsand potentially get bacteria and
see how they were acting,although it was a clinical lab
and we were just diagnosing.
Speaker 2 (03:35):
That was the yeah, that kind of like special really
interesting experience.
Yeah, I kind of had somethingreally similar when I was in
high school.
I got to hang out in amicrobiology lab and back when I
was in high school all thegirls had these trapper keepers
with clear covers and they wouldput pictures of movie stars and
like their friends in them andI got to take a picture of the
(03:55):
bacteria we were looking at inthe lab and I filled my trapper.
Speaker 3 (03:59):
Oh, that's super cool .
That's super cool.
Speaker 2 (04:02):
I was a little bit nerdy, but also really proud at
the same time.
So I can definitely relate howthose early introductions can
really impact you for the restof your career.
So you went to school, were youa good?
Speaker 3 (04:14):
student?
I think so that was you'regoing to call it nerd?
Yes, I was a nerd.
Speaker 2 (04:19):
Yeah, and how was it managing kind of that journey
and balancing your professionaland your nerdy self with your
regular, like personal life?
Speaker 3 (04:30):
Well, one of the things that happens to me when I
was in Mexico I was always kindof the outsider, so I was not
born there.
I came when I was a kid but Ialways felt that my place was
not there, so it was not anintrovert, but I was not a
really an extrovert.
And one of the things thathelped me and I really really
(04:53):
think being a boy scout I becamea boy scout that helped me to
learn some leadership skills andbeing outside in the field with
other kids that were nerdy likeme and enjoying things that I
was doing like me, that was aneye opening for me.
That part definitely changedhow I approach things and
(05:15):
approach life and how completelychanged the way I am now,
Because you had me as aprofessor.
I don't think you know this,that I'm an introvert.
Speaker 2 (05:24):
No, I would never called you an introvert.
Speaker 3 (05:25):
Yeah, so now I was able to change completely.
Yeah, you know the way I am.
Speaker 2 (05:30):
Oh, that's so interesting, how that kind of
early experience affected you.
So you went to grad school inMexico or in the US.
Speaker 3 (05:37):
So the story goes like this.
So I finished college in Mexicoand people had asked me this
question why do you decide tobecome a PhD, a doctor in
sciences?
And I don't have an answer.
I always was in college and Iwould say I want to finish as
soon as possible because I wantto go back to the United States
and get a PhD.
Oh, okay, I don't know wherethis came from and that was the
(05:59):
mission.
Yeah, even my wife my wife wasmy classmate.
She remembers.
I say like everybody hates youbecause you hate to skip classes
, you hate when they cancelexams because you wanted to
finish and then you want to moveon and do that.
So as soon as I finished college, I enrolled in a master degree
in Mexico.
At the time I didn't have moneyto travel or anything, so I was
(06:23):
very poor.
I was working as a high schoolprofessor and then doing
part-time master degree inmicrobiology.
I think in my second year inthe master's program I met a
professor that came to give atalk to my university.
I was parking in Mexico Puebloin central Mexico, and I don't
know how he found out that I wasan American that always wanted
(06:45):
to come back.
So he came talk to me and sayAlfredo, you're interested to do
research and do your masterthesis, potentially in the
United States.
And I say absolutely yeah.
So he came back.
He used to work in Dallas andthen at the time there was no
email or anything.
So he sent me a letter and hesaid I want you in the lab, I
want to see you here in a month.
(07:05):
So literally I droppedeverything, I grabbed my bags
and then I took a bus for 18hours or whatever, so many hours
from Puebla to all the way toDallas and I show up and I start
working in his lab in doingresearch.
Speaker 2 (07:19):
And what did your wife say?
Was she your wife?
Speaker 3 (07:21):
No, my wife was my.
My wife was my girlfriend atthe time.
Yeah.
And she said well, it's whatyou really want to do.
Yeah, Good luck.
And hopefully we'll see eachother again.
Then she became my wife.
Speaker 1 (07:33):
Yeah, that's the story.
Speaker 3 (07:34):
But, yeah, I came and I was doing a master's degree
and then, as you and everybodyworking in science, you know
that sometimes we have money todo research, sometimes we don't,
right?
So the professor basically oneday walks into the lab and he
says, well, I have money for youfor two more months.
Yeah, so you have to figure outwhether you go back to Mexico,
(07:55):
you find a job, or figure outwhere you are going.
I know you want to do a PhD, sothat was February, and then all
the applications were alreadydone.
Oh yeah, so I basically look,and the only school that was
still open was UT Austin.
Speaker 2 (08:12):
Yeah.
Speaker 3 (08:12):
So the only school I apply for a PhD was UT Austin.
I apply in March.
I haven't even take the GRE, soI took the GRE and then I
interview in July and bySeptember I was in doing my PhD
in UT Austin.
Speaker 2 (08:26):
Yeah, it's funny how that works out.
You don't even have to stressabout where you're going to go.
Speaker 3 (08:30):
No, I have no option, but I don't regret it.
Speaker 2 (08:34):
I end up with the best mentor somebody can ask OK,
good, and what did you study ingrad school?
Speaker 3 (08:39):
So I was working with E coli in Dallas.
So I went and when I end up inAustin, I look for the only
professor that was working withbacteria.
And she was working with sisterbacteria to E coli called
Shigala that also calls diarrhea, yeah, and she was working with
Bibrocholera, a causative agentof cholera.
Right, and I came and I saidwell, I want to work with E coli
(09:02):
.
She looked at me and said Idon't work with E coli, but
there was at the time a newcategory of E coli that was
producing outbreaks.
That's the reason we're talkingto this new E coli that was
associated with consumption ofundercooked beef.
And then she got interested andshe said OK, you are the only
(09:23):
one that is going to work with Ecoli in my laboratory.
So I did a PhD in this new Ecoli that was associated with
consumption of undercooked beef.
That's how I got my PhD.
Speaker 4 (09:34):
Yeah, I remember a situation back in probably the
early 90s with a jack in the boxand an undercooked hamburger.
I think it was just like asingular accident, but somebody
died.
That was E coli.
Is this this kind you studiedin grad school?
Speaker 3 (09:49):
That's it.
That's 1982.
Speaker 4 (09:51):
It was 82.
1982 is when you name the fastfood the fast food change I
remember it.
Speaker 3 (09:58):
But yeah, it was interesting because this fast
food change was located betweenthe United States and Canada.
So there were cases inMinnesota and in the other side
in Canada and the two groupsfrom the United States and
Canada are investigating andthey found out that this was new
isolate that has never beenreported before that was causing
(10:19):
these infections and in theUnited States the people that
investigated they call thisbacteria she got toxic,
producing E coli, so it produceda toxin.
In the Canadian side theydidn't like to use the American
designation so they call itneurotoxin E coli because they
isolated in bureau cells.
So in Canada it's calledtoxinic E coli, In the United
(10:40):
States called she got toxic Ecoli, but that's the same
bacteria.
Speaker 4 (10:43):
OK, but it was a sourdough jack.
Speaker 3 (10:45):
Yes.
Speaker 2 (10:48):
Well, it sounds like a super, like awesome project
for a grad student.
A new bacteria that's causingdisease that no one's ever
reported before.
So have you always beeninterested in bacteria that
causes diarrheal disease?
I think so.
Speaker 3 (11:00):
I guess that was my passion for many, many years.
And to continue the story, Ifinished my PhD and then I
looked for a lab that was alsostudying this bacteria.
Right, so I did a postdoctoraltraining in Baltimore where I
was studying this bacteria andtrying to figure out how this
bacteria was causing disease.
Yeah, and then I moved on tobecome an assistant professor
(11:22):
and we have continued workingwith this bacteria and I love
now develop vaccines and we haveeffective vaccines against
these bacteria.
Speaker 1 (11:30):
But they are still causing disease.
Speaker 3 (11:32):
Right, so we are.
We haven't done the job,correct I have a question about
that vaccine.
Speaker 4 (11:37):
So would the vaccine be for people who are working in
the beef industry or who have ahigher potential for exposure,
or would it be something thatwould become a childhood vaccine
, along with all of the ones wegive our children when they're
young?
Speaker 3 (11:52):
So the original vaccines that were developed.
We have to tell it with more ofa story.
So turns out that this bacteriais found in the
gastrointestinal tract of cows,and cattle do not develop
disease, they like to have thisbacteria in there.
The bacteria leaves, happily,is particularly close to the
rectum and the anum in the inthe in the cows.
(12:14):
And once we consume the cow andthey open the cow, the carcass
to to trade, to take the meterwe're going to consume, it gets
sometimes contaminated withintestinal tract bacteria and
that's how you contaminate themeat that we're going to consume
.
So the original idea was to tryto develop vaccines that were
used in cattle and then reducethe load of bacteria, especially
(12:37):
this E coli that we're talkingabout, and then when we consume
the meat, then we'll not havethis potential bacteria.
The problem is that ranchers andpeople that raise cattle we're
in Texas, so there is ranch thathave 100,000 heads of cattle
and the vaccine costs like two,three dollars each and you have
to give two doses.
The ranchers say, no way, I'mnot going to spend money in a
(13:00):
vaccine that does not causedisease in cattle, so it's not
going to do anything.
So there's two effectivevaccines against cattle that are
no use.
So the idea now to developvaccines against humans.
Potentially there is areas thatare endemic around the world
still with this bacteria, so theidea is to potentially give it
to those individuals that arenot susceptible.
Mainly the most susceptiblekids to this bacteria are kids
(13:24):
under age of five or elderlypeople.
So the idea is to target it andthen give it to them in those
countries that they suffer themajority of these cases.
Speaker 4 (13:32):
And it's foodborne.
I mean, if you're going to getE coli, you're going to get it
from food.
Speaker 3 (13:36):
Yes, absolutely, absolutely.
Speaker 2 (13:37):
So let's back up a little bit and talk about E coli
generally.
You kind of mentioned that it'sin cows, but it's not just in
cows, right?
We humans have E coli in ourintestines, yeah.
Speaker 3 (13:47):
All mammals have E coli in their intestines.
Speaker 2 (13:50):
Yeah.
Speaker 3 (13:51):
That doesn't mean that all E coli that we carry
are bad.
It's part of our microbiota.
Yeah, and we need it, we needbacteria.
So there is very small group ofthese E coli that through
evolution have acquired what iscalled virulence factors, so
those genetic components thatproduce either toxins or
adhesions or other factors thatallows the bacteria to.
(14:11):
You can imagine the bacteriawants to attach to something.
In this case we'll attach tothe intestinal and epithelial
cells the lumen.
They will attach because ifthey don't attach with the flow
going through the intestine theywill be washed away, right.
So they want to attach and thenthey want to use nutrients, so
they're attached to the cell.
So how do you get nutrients froma cell?
Well, you want to attack thecell, break the cell open and
(14:33):
get the nutrients from the wholecell and then the bacteria will
eat them.
So how do you kill the cell?
Well, you produce toxins or youproduce other factors that are
going to actually break open thewhole cell and then the
bacteria will eat them.
The problem is, when thosetoxins are produced they are not
just staying in that cell.
They can go to the bloodstream,to particular organs, and then
cause other problems.
Speaker 2 (14:54):
Right.
So I have a question If thebacteria is killing the cell
it's adhered to, does it thenget released to find another
cell to adhere to?
Or is it kind of only adheringto maybe a neighboring cell and
killing one of?
Speaker 3 (15:06):
the neighboring cells .
Yeah, there's a theory that Iuse when I try to teach my
students inparticoninobacteriology is that
sometimes many of these bacteriathey don't really want to kill
you.
You are killed because it's anaccident, Right Well, they
really want to go outsidebecause they like to live in the
environment, and I assume thisE coli likes to live in the
(15:27):
intestine of cattle.
They don't like to be in theintestine of humans.
Maybe it's not the rightenvironment for the bacteria.
Speaker 2 (15:33):
Right.
Speaker 3 (15:33):
So the bacteria is producing a toxin, getting the
nutrients and trying to get outIn the process.
Unfortunately, they can killyou yeah.
Speaker 2 (15:39):
I think this is such an interesting idea, that some
bacteria are good and some arebad and some are good in some
places.
E coli is fine in yourintestines as long as it's not
one of the burial strains, butit can cause UTIs and a lot of
other infections if it moves toa different part of your body.
And I think one thing thatpeople don't realize is in the
(16:00):
space that you occupy.
There's more bacteria cells inthe space you occupy than there
is human cells, which is, Ithink, just so amazing.
When we talk about themicrobiota and the microbiome,
it's something word that we justthrow out that, oh yeah, we
have a few bacteria living in us, but we're actually more
bacteria than human 85% of ourbody mass is bacteria.
Speaker 3 (16:22):
Yeah, microorganisms.
Speaker 2 (16:23):
Because there's viruses and phages.
Fages that live inside thebacteria.
Speaker 3 (16:28):
Exactly yeah.
Speaker 2 (16:29):
So I think for me that always is so amazing, I
agree.
Speaker 4 (16:33):
And when you were talking a few minutes ago and
you were saying, oh, e colidoesn't like living in humans,
it's like it has a mind of itsown.
And when you start to thinkabout bacteria as this living
thing that, like you said, itdoesn't mean to kill you, it
actually wants to be there andjust survive itself right.
Speaker 3 (16:52):
Absolutely.
And again the other example,thinking about that there is
some E coli in urine testingthat likes to live in urine
testing, those part of themicrobiota.
However, you might perhaps hearthat when you are growing up
especially females they mightdevelop urinary tract infections
and that's because a bacteriathat was in the intestine of
these individuals accidentallyfind their way to the urinary
(17:16):
tract and they cause aninfection.
So in one place the bacteria isnot causing an infection, but
in the wrong part of the bodythey become pathogenic.
So these individuals will havethis infection and then you can
treat it.
But sometimes it's reallydifficult to treat because it's
a bacteria that is adapted toyour body and knows how to live
in your body and that's how youget that.
(17:36):
So urinary tract infectionsnormally they don't come from
elsewhere, normally they comefrom inside us.
Yeah.
Speaker 4 (17:42):
So what kind of antibiotics would treat E coli?
Is that how you would treatsomething like that?
Speaker 3 (17:48):
Yeah, antibiotics normally treat all types of E
coli.
The majority the one that we'retalking about that is
associated with B, is the onlybacteria that cannot be treated
by antibiotics and there is anexplanation for that.
So you want to hear it?
Yeah, so the bacteria that isassociated with B contamination
and the one that we have beendescribing and now lately has
(18:11):
been associated with letals andspinous contamination, because
the bacteria now found their wayto survive in other
environments.
This bacteria, as I was tellingyou a few minutes ago, is
called Shiga toxin, producing Ecoli.
So the unique feature of thisbacteria is that it produces a
toxin and the toxin can killintestinal cells.
But the bad part of the storyis that the toxin can travel
(18:33):
through the bloodstream and goto the kidney and then this
toxin, as I told you before,find receptors, and the
receptors for the toxin arefound in the kidney cell.
So the toxin goes to the kidneycleaves, these receptors, and
there is a general malfunctionof the kidney because it cannot
process protein synthesis.
And then the individuals havingthe toxin in the kidneys
(18:54):
basically have kidneymalfunction.
They can die and from acomplication called hemolytic
urimic syndrome, which isbasically kidney malfunction,
and those surviving from theinfection.
Actually, they need dialysisfor the rest of their lives or
kidney transplant.
So I'm telling you all that forthe following reason you asked
me about antibiotics this toxin,the genes encoding for this
(19:15):
toxin, are found in a componentin the genome of these bacteria,
thisophage, and this phase ispart of the genome of this E
coli.
If you give antibiotics to abacteria, the bacteria starts
sensing that the antibiotic isin the environment.
So if you are a bacteria andthere is an antibiotic, the
bacteria doesn't want to die.
The bacteria has to activatewhat is called SOS mechanisms to
(19:37):
try to survive.
And one of the SOS mechanismsthat the bacteria activates is
start producing more toxin.
Instead of having one copies ofthe toxin, start getting
hundreds of copies of the toxin.
So if the bacteria dies becauseof the antibiotic, can you
imagine how many toxins arereleased?
So at the beginning, when theywere investigating this 1982
outbreak, the way they connectthe two things is that they
(20:00):
found these people eating inthis fast food chains with the
development of hemolytic urimicsyndrome, and years later they
found out that the reason therewere so many hemolytic urimic
syndrome cases is because thephysicians were treating with
antibiotics.
So if somebody is listening.
If you want to learn one lessonfrom this if you get E coli for
(20:23):
food contamination, it's theonly bacteria that physicians
should not treat withantibiotics.
Speaker 4 (20:28):
Yeah, for sure.
So it's almost like when yourbody mounts an immune response
and responds to a pathogen or abacteria or anything.
This is the flip side of that.
This is the bacteria reactingto something you thought might
be a cure and creating even moretoxin.
Speaker 3 (20:47):
Wow, yeah, but again, it don't want to give the
impression that antibiotics donot work.
Speaker 1 (20:51):
No.
Speaker 3 (20:51):
The antibiotics work perfectly against all E coli and
even this one will die withantibiotics.
But if the bacteria is carryingthe Siga toxins, that's
counterindicated.
Speaker 2 (21:02):
So I have a question.
There's more than one strain ofbacteria that produce
Shingatoxin In this outbreak.
I know it's a bacteria called O103, because we're just giving
bacteria numbers.
Now how is that different fromother Shingatoxin producing
bacteria?
Speaker 3 (21:17):
Okay, so within the family of Siga, toxin producing
E coli, we have a way in thelaboratory to identify some of
the features of these bacteriaand then we can classify them.
So we use Sira that has raysagainst components of these
bacteria on the surface and theyreact to different components.
So there is a component in thebacteria called
(21:37):
lipopolysaccharide that is acommon part of the structure of
the bacteria and different Ecoli carries different antigens
in that lipopolysaccharide thatif you use a Sira specific for
that O-antigen you can classifyit.
Speaker 2 (21:50):
So they're basically a little bit of a different
shape, right.
Speaker 3 (21:53):
Exactly, exactly.
The sugars are in a differentway so the antibody can
recognize that.
So we in the laboratory weassign numbers, so it's the
O-antigen, and then we assignnumbers so you can find that the
O-157 was the original bacteriathat was causing this disease.
So it has the O-antigen calledantigen 157.
But there is other ones nowthat we have found that also
(22:15):
carry the Siga toxin.
So the Siga toxin is in a phaseand can move to other E coli.
Speaker 2 (22:19):
And what's a phage?
Just remind us.
Speaker 3 (22:21):
The phage is a virus-like particle that infects
bacteria.
Speaker 2 (22:25):
Right.
The interesting thing aboutphages is it's a way that genes
can move from one bacteria toanother, because the virus or
virus-like particle isessentially bringing genes from
one bacteria another.
So it's not that the bacteriais inheriting it from its parent
bacteria, it's movinghorizontally to like its
neighboring bacteria, which issuper cool and interesting and
(22:48):
kind of special for bacteria.
Speaker 3 (22:50):
I'm so proud you were my student.
Very interesting.
So, if you can imagine,obviously there's 100 different
O-antigens.
Not all 100 bacteria that hasthese antigens cause disease in
humans.
So there is some O's thatactually associated with disease
.
So in those that carry Sigatoxin there is what is called
(23:12):
the big six.
The big six O-antigens, soO-157, o-26, o-113, o-103, those
are the ones that cause diseasein humans.
So there's the six.
In the United States we havesix of them and they are all
found in cattle.
They do not cause disease incattle.
I guess we can talk about theoutbreak and how this happened.
Speaker 2 (23:33):
Yeah, so I guess in this particular outbreak the
beef was recalled because theyfound evidence of O-103.
And it's interesting becauseapparently most laboratories
only test for O-157.
Is that true, correct?
Do you know why that is?
Speaker 3 (23:48):
Well, O-157, since the beginning, was the most
common O-antigens that wasidentified.
But what has been found?
And again, let me back up alittle bit to explain when the
first outbreaks happened in 1982, USDA and CDC start paying more
attention about what was goingaround and then they're
(24:10):
realizing that there were moreoutbreaks and every year we have
outbreaks in the United Statesthat we don't hear because they
are no major, because the USDAimplemented these rules and the
USDA indicated that when youhave a lot, millions of pounds
of beef, they sample and theylook for these big six and when
they identify one of them, therule is that you have to
(24:32):
basically eliminate everything.
Everything is gone.
So that's what happened in thiscase.
So normally, many places thatthey are looking for this,
normally they look for a 157because it's the most common one
.
But the rule, the law,indicates that they have to look
for these six.
Speaker 2 (24:49):
Yeah and gosh, they had to recall 1.7 tons of beef.
Just for you nerds out there,it's 3436 pounds of beef, which
is really incredible, and I wantto stress that no one actually
has gotten sick, so it's onlypossible contamination.
But still, that's just so muchso.
Speaker 4 (25:07):
This was found in a processing plant through testing
, but it was recalled, so it wasalready distributed, so it was
found after the fact.
Speaker 2 (25:16):
Yeah, so it was packed on February 16th and I
think at that time they had justchecked for the most common one
and I think, through thisrandom sampling that they do
when they randomly sample and doa more thorough look is when
they found the 0103.
I think that's how it workedout.
Speaker 3 (25:32):
Yeah and again.
The interesting part of thisrecall is two ways.
One is thanks to these newregulations that we have in the
United States and in manycountries, we normally do not
get sick for consuming beef inthe United States anymore.
Because they do this, they havethese massive recalls.
A lot of factories and packingimplants have gone bankrupt
(25:53):
Because when these recalls talkabout millions of pounds being
recalled, they cannot recoverfrom this.
And they know that this is goingto happen.
So what is happening lately isnow the bacteria doesn't cause
infection by the consumption ofbeef, because you don't hear it.
But perhaps you rememberseveral years ago that you walk
(26:13):
into any of your grocery storesand there was no bags of a
spinners of lettuce.
They were completely removed.
So that was in 2000,.
I think they figure out now thebacteria can actually survive
in the leaves of a spinners andlettuce.
And then we in the UnitedStates we'd a lot of bag pre
wash spinners and lettuce thatpotentially might be loaded with
(26:35):
these bacteria.
Speaker 2 (26:36):
Right.
Speaker 3 (26:36):
So that's another way we can actually get infected.
Speaker 2 (26:39):
I remember I've heard you recommend another thing
that your mother told you to dowhen you're growing up about how
to wash your lettuce, aboutletting it soak in a little bit
of bleach water just to becertain.
I remember that story and I'vebeen doing it ever since.
So yeah, just because it sayspre washed, you should rewash it
.
Speaker 3 (26:58):
The reason, Danielle, here some of my stories when
I'm teaching the class is thatwhen these cases were coming
along, when you look at the bags, you pay attention, you're
listening, and you go to therefrigerator open and look for a
bag, they say five time wash.
So I don't know how they wash aleaf five times.
They turn around and they washit five times, so literally they
(27:18):
just rinse it and if thebacteria is inside there's no
way to get out.
So what Danielle was tellingyou about is one thing that I
learned from my mom.
We never ate any salad that wascoming from a bag.
So she caught it, she get theleaves and she submerged it in a
water containing iodine.
And then they sell thesebottles of iodine.
You can put some drops and letit soak in there and then wash
(27:41):
it again with the idea ofpotentially eliminate any other
bacteria that might be attachedthere.
And always, always learn thatfrom my mom.
Speaker 4 (27:48):
Yeah, that's interesting.
I'm terrible.
I buy a bag and I open it upand I do have the salad spinner
so I wash it really good.
But yeah, I'm gonna have tothink about this.
So it's not bleach, it's iodine?
Speaker 3 (28:02):
No, I don't know, it's.
Speaker 2 (28:03):
I think I'm confusing your stories of your mother
with my stories of mygrandmother, that's why we,
that's why we clarify, that'swhy we clarify my grandmother
used to soak all of our dishesin bleach.
Speaker 3 (28:12):
In bleach yeah.
Speaker 2 (28:13):
That's how she did it , which I think iodine is
probably healthier.
Speaker 3 (28:17):
Yes, of course.
Speaker 2 (28:19):
Okay, so we've got this interesting story about the
contaminated beef and if you'relistening, I think we've gone
over a couple of ways for you toprotect yourself.
And what are they?
Wash your salad and if you'reconcerned, you can also just
cook your meat appropriately.
You're at risk here if you'reeating rare meat, which is
delicious I know rare steaks,everyone wants to eat rare
(28:41):
steaks but if you're everconcerned about the quality of
your beef, you just cook it allthe way through.
So is there anything else youthink you want to discuss about
E coli in general?
Speaker 3 (28:50):
Yeah, again, as we knew, technologies developing,
we are finding new things abouthow bacteria can cause disease.
So there was this recent storyin the news, just I think a week
ago.
They found out that themajority of UTIs that are being
happening comes from thegastrointestinal tract.
Speaker 1 (29:09):
Yeah some humans.
Speaker 3 (29:10):
So now there is a link, a distinct link, and they
can actually use in sequencingto identify what particular type
of E coli can be prone to causeurinary tract infections.
So we are learning more andmore about this.
One of the recommendations thatI do with my class is do not
eat rare meat anywhere you go,especially if you go to
countries where they have highprevalence of this bacteria.
(29:33):
South America has the largestnumber of a hemolytic umicases
400,000 individuals because inArgentina, chile mainly
Argentina they undercook themeat and there's a lot of kids
getting sick there.
And the United States.
The good thing is we do notmove meat around, so some areas
have outbreaks and then they areconcentrated in California and
(29:56):
Nebraska, for example.
Texas they never import meatfrom anybody else, so we're
pretty safe in Texas.
That doesn't mean that one daywe will get an outbreak.
Speaker 2 (30:04):
In the future, as we see more increasing temperatures
globally due to climate change,we can expect to see more
diarrheal disease, particularlybecause of more bacteria.
Why do you think that is?
Speaker 3 (30:15):
Well, if you want to think it as as simple as the
following so the bacteria likesto live in environments that
have higher temperatures, so youwant to grow bacteria, you put
37 degrees and sometimes theygrow faster.
Speaker 2 (30:28):
Is that 37 degrees Celsius?
Speaker 3 (30:30):
Celsius 37 degrees Celsius Instead of 30 degrees
Celsius then the bacteria growsfaster.
So as the climate changes, theenvironment is perfect for
potential bacteria that was notgrowing that fast to actually
start populating other areas andpotentially we get exposed to
these higher numbers of bacteriaand then getting disease.
Speaker 2 (30:52):
Right, and especially , I think, when you're thinking
about meat being processed andit being processed outside or
something like that beingprocessed in elevated
temperatures, lots more instancefor contamination and bacterial
growth and stuff like that.
And even not just E coli, butother kind of waterborne
bacterial pathogens as well.
Speaker 3 (31:10):
Yeah, that's a risk that we are going to have to
figure out and face astemperatures are going up.
Speaker 4 (31:15):
Yes, so does that mean that the study of E coli is
a growing science and that thiswould be the kind of thing that
you would encourage studentsthat might be interested in
careers in science?
Is there going to be a lot ofinteresting research in this
area?
Speaker 3 (31:29):
I think microbiology in general is an interesting
area to pursue as a career.
It could be bacteria, it couldbe parasites, it could be
viruses.
There's a lot of things to bedone and discover.
There's every day you findsomething new happening.
Potentially all depends on thefunding and where the funding is
going to these stories.
So somebody in a scientificfield has always said that the
(31:54):
best thing that can happen toyou as a scientist is that there
is an outbreak with yourfavorite pathogen, Because
potentially there is going to befunding that is going to be
supporting your research.
Speaker 2 (32:05):
So I've got one last question.
I don't know if Connie has anymore, but if any of our
listeners are interested ingetting into microbiology, do
you have any advice for them?
Speaker 3 (32:13):
Yeah.
So, being quicet, obviously youhave to like science.
Yeah, you're not getting intomicrobiology because you're
going to be rich, so don'texpect that, but you have to be
passionate about what you do.
And then if you are intriguedby mysteries, as we discussed,
and you're intrigued aboutpotentially connecting social
sciences with politics, withfast food chains and the federal
(32:38):
government, and just do goodfor human beings, then that's
your field.
Speaker 4 (32:44):
Right, right.
Well, I think this has been areally great discussion and I've
learned many things.
I've learned I've got to washmy lettuce better.
I've learned that the kind of Ecoli that we had this outbreak
in recently with this beef andthis recall is something that
cannot be treated withantibiotics.
I've learned that if you'reinterested in being somewhat of
(33:05):
a science detective, thatmicrobiology is a good way to go
, and that you had a very luckyexperience in getting into this
E coli study, just sort of by arandom meeting with a visiting
professor.
Correct, and so people shouldtake advantage, as they're going
to school and going to lecturesand you never know where your
(33:27):
opportunity that's going to leadyou on your career trajectory
may come from.
So this has been a greatdiscussion.
Speaker 3 (33:33):
Thank you.
Thank you for the Thank you somuch.
Thank you.
Speaker 2 (33:36):
Thanks for listening to the Infectious Science
podcast.
Be sure to hit subscribe andvisit infectiousscienceorg to
join the conversation, accessthe show notes and to sign up
for our newsletter and receiveour free materials.
Speaker 1 (33:47):
If you enjoyed this new episode of Infectious
Science, please leave us areview on Apple podcasts and
Spotify, and go ahead and sharethis episode with some of your
friends.
Speaker 2 (33:56):
Also, don't hesitate to ask questions and tell us
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To get in touch, drop a line inthe comments section or send us
a message on social media.
Speaker 1 (34:05):
So we'll see you next time for a new episode, and in
the meantime, stay happy stayhealthy, stay interested.
This is a podcast about one health the idea that
the health of humans, animals,plants and the environment that
we all share are intrinsicallylinked.
Speaker 2 (00:17):
Coming to you from the University of Texas Medical
Branch in the Galveston NationalLaboratory.
Speaker 1 (00:21):
This is infectious science.
We're enthusiasm for science.
Speaker 2 (00:25):
This is contagious.
Summer wouldn't be summerwithout a little bit of barbecue
.
But not all barbecue is createdequal.
Take this past March, when 1.7tons of beef were recalled in
the US due to contamination withE coli.
On this installment of theinfectious science summer camp,
(00:47):
we're inviting Dr Alfredo Torres, associate provost at UTMB and
professor in the Department ofMicrobiology and Immunology, to
help us understand a little bitmore about this recall and learn
how to stay safe this summerwhile we're at the grill.
So when I think about bacteria,e coli is the first thing that
comes to my mind, because it'severywhere, it's in our bodies,
(01:07):
it's in the environment and it'salso a really important cause
of disease worldwide.
In fact, according to the WorldHealth Organization, it's
responsible for more than 300million illnesses and nearly
200,000 deaths worldwide.
So to talk about this, I'mDanielle and I've got Connie
here with me.
Hello, happy Friday.
And we also have Dr Torres here.
(01:27):
Alfredo Torres is a facultymember and a professor here at
UTMB, and also an assistantprovost.
Hi, dr Torres, hey how are youdoing?
Good.
Thanks so much for coming totalk to us about this Kind of
recently in the news, 1.7 tonsof beef were recalled due to
contamination with E coli.
So he's here to talk to ustoday about E coli, what it is,
(01:50):
how does that contaminationhappen and why do we care?
So, dr Torres, how did youfirst get interested in science?
Speaker 3 (01:56):
Well, I was born in California, but with my family
we went back to Mexico when Iwas five years old.
Oh, ok.
So growing up in Mexico I gotvery interested in infectious
diseases.
Because you see people gettingsick, you're sitting at the
street the traditional, whatthey call moctezuma revenge.
You go there, you eat the tacosat the street and then you got
(02:18):
sick.
So that got my attention and Istarted studying science in
college in Mexico and eventuallyI found my way to the
microbiology lab and since thenI got hooked to microbiology and
I was interested to figure outhow microbes cause disease.
And that's what I have beendoing for the past 20 years here
(02:40):
at UTMB and the past 40 years,I think, since I started college
.
Speaker 2 (02:45):
Yeah, so can you think of any key moments that
you just knew that this is, thisis what you wanted to do, or
any key early inspirations?
Speaker 3 (02:53):
Yeah, I think one of the things my career, my major,
is chemistry, pharmacology,biology.
Speaker 2 (02:59):
You might think what is that?
Speaker 1 (03:00):
What is that?
Speaker 3 (03:01):
And pieces of everything, but mainly in Mexico
.
These people that get thisdegree normally work in clinical
laboratories and they doclinical analysis.
So I have an uncle that alsohas the same major and he has
his lab in Mexico and he took mewhen I was 12, 13 years old to
go there and start learning andlook through the microscope and
(03:22):
figure out what was happeningand literally I recall that I
was the first hook to see cellsand potentially get bacteria and
see how they were acting,although it was a clinical lab
and we were just diagnosing.
Speaker 2 (03:35):
That was the yeah, that kind of like special really
interesting experience.
Yeah, I kind of had somethingreally similar when I was in
high school.
I got to hang out in amicrobiology lab and back when I
was in high school all thegirls had these trapper keepers
with clear covers and they wouldput pictures of movie stars and
like their friends in them andI got to take a picture of the
(03:55):
bacteria we were looking at inthe lab and I filled my trapper.
Speaker 3 (03:59):
Oh, that's super cool .
That's super cool.
Speaker 2 (04:02):
I was a little bit nerdy, but also really proud at
the same time.
So I can definitely relate howthose early introductions can
really impact you for the restof your career.
So you went to school, were youa good?
Speaker 3 (04:14):
student?
I think so that was you'regoing to call it nerd?
Yes, I was a nerd.
Speaker 2 (04:19):
Yeah, and how was it managing kind of that journey
and balancing your professionaland your nerdy self with your
regular, like personal life?
Speaker 3 (04:30):
Well, one of the things that happens to me when I
was in Mexico I was always kindof the outsider, so I was not
born there.
I came when I was a kid but Ialways felt that my place was
not there, so it was not anintrovert, but I was not a
really an extrovert.
And one of the things thathelped me and I really really
(04:53):
think being a boy scout I becamea boy scout that helped me to
learn some leadership skills andbeing outside in the field with
other kids that were nerdy likeme and enjoying things that I
was doing like me, that was aneye opening for me.
That part definitely changedhow I approach things and
(05:15):
approach life and how completelychanged the way I am now,
Because you had me as aprofessor.
I don't think you know this,that I'm an introvert.
Speaker 2 (05:24):
No, I would never called you an introvert.
Speaker 3 (05:25):
Yeah, so now I was able to change completely.
Yeah, you know the way I am.
Speaker 2 (05:30):
Oh, that's so interesting, how that kind of
early experience affected you.
So you went to grad school inMexico or in the US.
Speaker 3 (05:37):
So the story goes like this.
So I finished college in Mexicoand people had asked me this
question why do you decide tobecome a PhD, a doctor in
sciences?
And I don't have an answer.
I always was in college and Iwould say I want to finish as
soon as possible because I wantto go back to the United States
and get a PhD.
Oh, okay, I don't know wherethis came from and that was the
(05:59):
mission.
Yeah, even my wife my wife wasmy classmate.
She remembers.
I say like everybody hates youbecause you hate to skip classes
, you hate when they cancelexams because you wanted to
finish and then you want to moveon and do that.
So as soon as I finished college, I enrolled in a master degree
in Mexico.
At the time I didn't have moneyto travel or anything, so I was
(06:23):
very poor.
I was working as a high schoolprofessor and then doing
part-time master degree inmicrobiology.
I think in my second year inthe master's program I met a
professor that came to give atalk to my university.
I was parking in Mexico Puebloin central Mexico, and I don't
know how he found out that I wasan American that always wanted
(06:45):
to come back.
So he came talk to me and sayAlfredo, you're interested to do
research and do your masterthesis, potentially in the
United States.
And I say absolutely yeah.
So he came back.
He used to work in Dallas andthen at the time there was no
email or anything.
So he sent me a letter and hesaid I want you in the lab, I
want to see you here in a month.
(07:05):
So literally I droppedeverything, I grabbed my bags
and then I took a bus for 18hours or whatever, so many hours
from Puebla to all the way toDallas and I show up and I start
working in his lab in doingresearch.
Speaker 2 (07:19):
And what did your wife say?
Was she your wife?
Speaker 3 (07:21):
No, my wife was my.
My wife was my girlfriend atthe time.
Yeah.
And she said well, it's whatyou really want to do.
Yeah, Good luck.
And hopefully we'll see eachother again.
Then she became my wife.
Speaker 1 (07:33):
Yeah, that's the story.
Speaker 3 (07:34):
But, yeah, I came and I was doing a master's degree
and then, as you and everybodyworking in science, you know
that sometimes we have money todo research, sometimes we don't,
right?
So the professor basically oneday walks into the lab and he
says, well, I have money for youfor two more months.
Yeah, so you have to figure outwhether you go back to Mexico,
(07:55):
you find a job, or figure outwhere you are going.
I know you want to do a PhD, sothat was February, and then all
the applications were alreadydone.
Oh yeah, so I basically look,and the only school that was
still open was UT Austin.
Speaker 2 (08:12):
Yeah.
Speaker 3 (08:12):
So the only school I apply for a PhD was UT Austin.
I apply in March.
I haven't even take the GRE, soI took the GRE and then I
interview in July and bySeptember I was in doing my PhD
in UT Austin.
Speaker 2 (08:26):
Yeah, it's funny how that works out.
You don't even have to stressabout where you're going to go.
Speaker 3 (08:30):
No, I have no option, but I don't regret it.
Speaker 2 (08:34):
I end up with the best mentor somebody can ask OK,
good, and what did you study ingrad school?
Speaker 3 (08:39):
So I was working with E coli in Dallas.
So I went and when I end up inAustin, I look for the only
professor that was working withbacteria.
And she was working with sisterbacteria to E coli called
Shigala that also calls diarrhea, yeah, and she was working with
Bibrocholera, a causative agentof cholera.
Right, and I came and I saidwell, I want to work with E coli
(09:02):
.
She looked at me and said Idon't work with E coli, but
there was at the time a newcategory of E coli that was
producing outbreaks.
That's the reason we're talkingto this new E coli that was
associated with consumption ofundercooked beef.
And then she got interested andshe said OK, you are the only
(09:23):
one that is going to work with Ecoli in my laboratory.
So I did a PhD in this new Ecoli that was associated with
consumption of undercooked beef.
That's how I got my PhD.
Speaker 4 (09:34):
Yeah, I remember a situation back in probably the
early 90s with a jack in the boxand an undercooked hamburger.
I think it was just like asingular accident, but somebody
died.
That was E coli.
Is this this kind you studiedin grad school?
Speaker 3 (09:49):
That's it.
That's 1982.
Speaker 4 (09:51):
It was 82.
1982 is when you name the fastfood the fast food change I
remember it.
Speaker 3 (09:58):
But yeah, it was interesting because this fast
food change was located betweenthe United States and Canada.
So there were cases inMinnesota and in the other side
in Canada and the two groupsfrom the United States and
Canada are investigating andthey found out that this was new
isolate that has never beenreported before that was causing
(10:19):
these infections and in theUnited States the people that
investigated they call thisbacteria she got toxic,
producing E coli, so it produceda toxin.
In the Canadian side theydidn't like to use the American
designation so they call itneurotoxin E coli because they
isolated in bureau cells.
So in Canada it's calledtoxinic E coli, In the United
(10:40):
States called she got toxic Ecoli, but that's the same
bacteria.
Speaker 4 (10:43):
OK, but it was a sourdough jack.
Speaker 3 (10:45):
Yes.
Speaker 2 (10:48):
Well, it sounds like a super, like awesome project
for a grad student.
A new bacteria that's causingdisease that no one's ever
reported before.
So have you always beeninterested in bacteria that
causes diarrheal disease?
I think so.
Speaker 3 (11:00):
I guess that was my passion for many, many years.
And to continue the story, Ifinished my PhD and then I
looked for a lab that was alsostudying this bacteria.
Right, so I did a postdoctoraltraining in Baltimore where I
was studying this bacteria andtrying to figure out how this
bacteria was causing disease.
Yeah, and then I moved on tobecome an assistant professor
(11:22):
and we have continued workingwith this bacteria and I love
now develop vaccines and we haveeffective vaccines against
these bacteria.
Speaker 1 (11:30):
But they are still causing disease.
Speaker 3 (11:32):
Right, so we are.
We haven't done the job,correct I have a question about
that vaccine.
Speaker 4 (11:37):
So would the vaccine be for people who are working in
the beef industry or who have ahigher potential for exposure,
or would it be something thatwould become a childhood vaccine
, along with all of the ones wegive our children when they're
young?
Speaker 3 (11:52):
So the original vaccines that were developed.
We have to tell it with more ofa story.
So turns out that this bacteriais found in the
gastrointestinal tract of cows,and cattle do not develop
disease, they like to have thisbacteria in there.
The bacteria leaves, happily,is particularly close to the
rectum and the anum in the inthe in the cows.
(12:14):
And once we consume the cow andthey open the cow, the carcass
to to trade, to take the meterwe're going to consume, it gets
sometimes contaminated withintestinal tract bacteria and
that's how you contaminate themeat that we're going to consume
.
So the original idea was to tryto develop vaccines that were
used in cattle and then reducethe load of bacteria, especially
(12:37):
this E coli that we're talkingabout, and then when we consume
the meat, then we'll not havethis potential bacteria.
The problem is that ranchers andpeople that raise cattle we're
in Texas, so there is ranch thathave 100,000 heads of cattle
and the vaccine costs like two,three dollars each and you have
to give two doses.
The ranchers say, no way, I'mnot going to spend money in a
(13:00):
vaccine that does not causedisease in cattle, so it's not
going to do anything.
So there's two effectivevaccines against cattle that are
no use.
So the idea now to developvaccines against humans.
Potentially there is areas thatare endemic around the world
still with this bacteria, so theidea is to potentially give it
to those individuals that arenot susceptible.
Mainly the most susceptiblekids to this bacteria are kids
(13:24):
under age of five or elderlypeople.
So the idea is to target it andthen give it to them in those
countries that they suffer themajority of these cases.
Speaker 4 (13:32):
And it's foodborne.
I mean, if you're going to getE coli, you're going to get it
from food.
Speaker 3 (13:36):
Yes, absolutely, absolutely.
Speaker 2 (13:37):
So let's back up a little bit and talk about E coli
generally.
You kind of mentioned that it'sin cows, but it's not just in
cows, right?
We humans have E coli in ourintestines, yeah.
Speaker 3 (13:47):
All mammals have E coli in their intestines.
Speaker 2 (13:50):
Yeah.
Speaker 3 (13:51):
That doesn't mean that all E coli that we carry
are bad.
It's part of our microbiota.
Yeah, and we need it, we needbacteria.
So there is very small group ofthese E coli that through
evolution have acquired what iscalled virulence factors, so
those genetic components thatproduce either toxins or
adhesions or other factors thatallows the bacteria to.
(14:11):
You can imagine the bacteriawants to attach to something.
In this case we'll attach tothe intestinal and epithelial
cells the lumen.
They will attach because ifthey don't attach with the flow
going through the intestine theywill be washed away, right.
So they want to attach and thenthey want to use nutrients, so
they're attached to the cell.
So how do you get nutrients froma cell?
Well, you want to attack thecell, break the cell open and
(14:33):
get the nutrients from the wholecell and then the bacteria will
eat them.
So how do you kill the cell?
Well, you produce toxins or youproduce other factors that are
going to actually break open thewhole cell and then the
bacteria will eat them.
The problem is, when thosetoxins are produced they are not
just staying in that cell.
They can go to the bloodstream,to particular organs, and then
cause other problems.
Speaker 2 (14:54):
Right.
So I have a question If thebacteria is killing the cell
it's adhered to, does it thenget released to find another
cell to adhere to?
Or is it kind of only adheringto maybe a neighboring cell and
killing one of?
Speaker 3 (15:06):
the neighboring cells .
Yeah, there's a theory that Iuse when I try to teach my
students inparticoninobacteriology is that
sometimes many of these bacteriathey don't really want to kill
you.
You are killed because it's anaccident, Right Well, they
really want to go outsidebecause they like to live in the
environment, and I assume thisE coli likes to live in the
(15:27):
intestine of cattle.
They don't like to be in theintestine of humans.
Maybe it's not the rightenvironment for the bacteria.
Speaker 2 (15:33):
Right.
Speaker 3 (15:33):
So the bacteria is producing a toxin, getting the
nutrients and trying to get outIn the process.
Unfortunately, they can killyou yeah.
Speaker 2 (15:39):
I think this is such an interesting idea, that some
bacteria are good and some arebad and some are good in some
places.
E coli is fine in yourintestines as long as it's not
one of the burial strains, butit can cause UTIs and a lot of
other infections if it moves toa different part of your body.
And I think one thing thatpeople don't realize is in the
(16:00):
space that you occupy.
There's more bacteria cells inthe space you occupy than there
is human cells, which is, Ithink, just so amazing.
When we talk about themicrobiota and the microbiome,
it's something word that we justthrow out that, oh yeah, we
have a few bacteria living in us, but we're actually more
bacteria than human 85% of ourbody mass is bacteria.
Speaker 3 (16:22):
Yeah, microorganisms.
Speaker 2 (16:23):
Because there's viruses and phages.
Fages that live inside thebacteria.
Speaker 3 (16:28):
Exactly yeah.
Speaker 2 (16:29):
So I think for me that always is so amazing, I
agree.
Speaker 4 (16:33):
And when you were talking a few minutes ago and
you were saying, oh, e colidoesn't like living in humans,
it's like it has a mind of itsown.
And when you start to thinkabout bacteria as this living
thing that, like you said, itdoesn't mean to kill you, it
actually wants to be there andjust survive itself right.
Speaker 3 (16:52):
Absolutely.
And again the other example,thinking about that there is
some E coli in urine testingthat likes to live in urine
testing, those part of themicrobiota.
However, you might perhaps hearthat when you are growing up
especially females they mightdevelop urinary tract infections
and that's because a bacteriathat was in the intestine of
these individuals accidentallyfind their way to the urinary
(17:16):
tract and they cause aninfection.
So in one place the bacteria isnot causing an infection, but
in the wrong part of the bodythey become pathogenic.
So these individuals will havethis infection and then you can
treat it.
But sometimes it's reallydifficult to treat because it's
a bacteria that is adapted toyour body and knows how to live
in your body and that's how youget that.
(17:36):
So urinary tract infectionsnormally they don't come from
elsewhere, normally they comefrom inside us.
Yeah.
Speaker 4 (17:42):
So what kind of antibiotics would treat E coli?
Is that how you would treatsomething like that?
Speaker 3 (17:48):
Yeah, antibiotics normally treat all types of E
coli.
The majority the one that we'retalking about that is
associated with B, is the onlybacteria that cannot be treated
by antibiotics and there is anexplanation for that.
So you want to hear it?
Yeah, so the bacteria that isassociated with B contamination
and the one that we have beendescribing and now lately has
(18:11):
been associated with letals andspinous contamination, because
the bacteria now found their wayto survive in other
environments.
This bacteria, as I was tellingyou a few minutes ago, is
called Shiga toxin, producing Ecoli.
So the unique feature of thisbacteria is that it produces a
toxin and the toxin can killintestinal cells.
But the bad part of the storyis that the toxin can travel
(18:33):
through the bloodstream and goto the kidney and then this
toxin, as I told you before,find receptors, and the
receptors for the toxin arefound in the kidney cell.
So the toxin goes to the kidneycleaves, these receptors, and
there is a general malfunctionof the kidney because it cannot
process protein synthesis.
And then the individuals havingthe toxin in the kidneys
(18:54):
basically have kidneymalfunction.
They can die and from acomplication called hemolytic
urimic syndrome, which isbasically kidney malfunction,
and those surviving from theinfection.
Actually, they need dialysisfor the rest of their lives or
kidney transplant.
So I'm telling you all that forthe following reason you asked
me about antibiotics this toxin,the genes encoding for this
(19:15):
toxin, are found in a componentin the genome of these bacteria,
thisophage, and this phase ispart of the genome of this E
coli.
If you give antibiotics to abacteria, the bacteria starts
sensing that the antibiotic isin the environment.
So if you are a bacteria andthere is an antibiotic, the
bacteria doesn't want to die.
The bacteria has to activatewhat is called SOS mechanisms to
(19:37):
try to survive.
And one of the SOS mechanismsthat the bacteria activates is
start producing more toxin.
Instead of having one copies ofthe toxin, start getting
hundreds of copies of the toxin.
So if the bacteria dies becauseof the antibiotic, can you
imagine how many toxins arereleased?
So at the beginning, when theywere investigating this 1982
outbreak, the way they connectthe two things is that they
(20:00):
found these people eating inthis fast food chains with the
development of hemolytic urimicsyndrome, and years later they
found out that the reason therewere so many hemolytic urimic
syndrome cases is because thephysicians were treating with
antibiotics.
So if somebody is listening.
If you want to learn one lessonfrom this if you get E coli for
(20:23):
food contamination, it's theonly bacteria that physicians
should not treat withantibiotics.
Speaker 4 (20:28):
Yeah, for sure.
So it's almost like when yourbody mounts an immune response
and responds to a pathogen or abacteria or anything.
This is the flip side of that.
This is the bacteria reactingto something you thought might
be a cure and creating even moretoxin.
Speaker 3 (20:47):
Wow, yeah, but again, it don't want to give the
impression that antibiotics donot work.
Speaker 1 (20:51):
No.
Speaker 3 (20:51):
The antibiotics work perfectly against all E coli and
even this one will die withantibiotics.
But if the bacteria is carryingthe Siga toxins, that's
counterindicated.
Speaker 2 (21:02):
So I have a question.
There's more than one strain ofbacteria that produce
Shingatoxin In this outbreak.
I know it's a bacteria called O103, because we're just giving
bacteria numbers.
Now how is that different fromother Shingatoxin producing
bacteria?
Speaker 3 (21:17):
Okay, so within the family of Siga, toxin producing
E coli, we have a way in thelaboratory to identify some of
the features of these bacteriaand then we can classify them.
So we use Sira that has raysagainst components of these
bacteria on the surface and theyreact to different components.
So there is a component in thebacteria called
(21:37):
lipopolysaccharide that is acommon part of the structure of
the bacteria and different Ecoli carries different antigens
in that lipopolysaccharide thatif you use a Sira specific for
that O-antigen you can classifyit.
Speaker 2 (21:50):
So they're basically a little bit of a different
shape, right.
Speaker 3 (21:53):
Exactly, exactly.
The sugars are in a differentway so the antibody can
recognize that.
So we in the laboratory weassign numbers, so it's the
O-antigen, and then we assignnumbers so you can find that the
O-157 was the original bacteriathat was causing this disease.
So it has the O-antigen calledantigen 157.
But there is other ones nowthat we have found that also
(22:15):
carry the Siga toxin.
So the Siga toxin is in a phaseand can move to other E coli.
Speaker 2 (22:19):
And what's a phage?
Just remind us.
Speaker 3 (22:21):
The phage is a virus-like particle that infects
bacteria.
Speaker 2 (22:25):
Right.
The interesting thing aboutphages is it's a way that genes
can move from one bacteria toanother, because the virus or
virus-like particle isessentially bringing genes from
one bacteria another.
So it's not that the bacteriais inheriting it from its parent
bacteria, it's movinghorizontally to like its
neighboring bacteria, which issuper cool and interesting and
(22:48):
kind of special for bacteria.
Speaker 3 (22:50):
I'm so proud you were my student.
Very interesting.
So, if you can imagine,obviously there's 100 different
O-antigens.
Not all 100 bacteria that hasthese antigens cause disease in
humans.
So there is some O's thatactually associated with disease
.
So in those that carry Sigatoxin there is what is called
(23:12):
the big six.
The big six O-antigens, soO-157, o-26, o-113, o-103, those
are the ones that cause diseasein humans.
So there's the six.
In the United States we havesix of them and they are all
found in cattle.
They do not cause disease incattle.
I guess we can talk about theoutbreak and how this happened.
Speaker 2 (23:33):
Yeah, so I guess in this particular outbreak the
beef was recalled because theyfound evidence of O-103.
And it's interesting becauseapparently most laboratories
only test for O-157.
Is that true, correct?
Do you know why that is?
Speaker 3 (23:48):
Well, O-157, since the beginning, was the most
common O-antigens that wasidentified.
But what has been found?
And again, let me back up alittle bit to explain when the
first outbreaks happened in 1982, USDA and CDC start paying more
attention about what was goingaround and then they're
(24:10):
realizing that there were moreoutbreaks and every year we have
outbreaks in the United Statesthat we don't hear because they
are no major, because the USDAimplemented these rules and the
USDA indicated that when youhave a lot, millions of pounds
of beef, they sample and theylook for these big six and when
they identify one of them, therule is that you have to
(24:32):
basically eliminate everything.
Everything is gone.
So that's what happened in thiscase.
So normally, many places thatthey are looking for this,
normally they look for a 157because it's the most common one
.
But the rule, the law,indicates that they have to look
for these six.
Speaker 2 (24:49):
Yeah and gosh, they had to recall 1.7 tons of beef.
Just for you nerds out there,it's 3436 pounds of beef, which
is really incredible, and I wantto stress that no one actually
has gotten sick, so it's onlypossible contamination.
But still, that's just so muchso.
Speaker 4 (25:07):
This was found in a processing plant through testing
, but it was recalled, so it wasalready distributed, so it was
found after the fact.
Speaker 2 (25:16):
Yeah, so it was packed on February 16th and I
think at that time they had justchecked for the most common one
and I think, through thisrandom sampling that they do
when they randomly sample and doa more thorough look is when
they found the 0103.
I think that's how it workedout.
Speaker 3 (25:32):
Yeah and again.
The interesting part of thisrecall is two ways.
One is thanks to these newregulations that we have in the
United States and in manycountries, we normally do not
get sick for consuming beef inthe United States anymore.
Because they do this, they havethese massive recalls.
A lot of factories and packingimplants have gone bankrupt
(25:53):
Because when these recalls talkabout millions of pounds being
recalled, they cannot recoverfrom this.
And they know that this is goingto happen.
So what is happening lately isnow the bacteria doesn't cause
infection by the consumption ofbeef, because you don't hear it.
But perhaps you rememberseveral years ago that you walk
(26:13):
into any of your grocery storesand there was no bags of a
spinners of lettuce.
They were completely removed.
So that was in 2000,.
I think they figure out now thebacteria can actually survive
in the leaves of a spinners andlettuce.
And then we in the UnitedStates we'd a lot of bag pre
wash spinners and lettuce thatpotentially might be loaded with
(26:35):
these bacteria.
Speaker 2 (26:36):
Right.
Speaker 3 (26:36):
So that's another way we can actually get infected.
Speaker 2 (26:39):
I remember I've heard you recommend another thing
that your mother told you to dowhen you're growing up about how
to wash your lettuce, aboutletting it soak in a little bit
of bleach water just to becertain.
I remember that story and I'vebeen doing it ever since.
So yeah, just because it sayspre washed, you should rewash it
.
Speaker 3 (26:58):
The reason, Danielle, here some of my stories when
I'm teaching the class is thatwhen these cases were coming
along, when you look at the bags, you pay attention, you're
listening, and you go to therefrigerator open and look for a
bag, they say five time wash.
So I don't know how they wash aleaf five times.
They turn around and they washit five times, so literally they
(27:18):
just rinse it and if thebacteria is inside there's no
way to get out.
So what Danielle was tellingyou about is one thing that I
learned from my mom.
We never ate any salad that wascoming from a bag.
So she caught it, she get theleaves and she submerged it in a
water containing iodine.
And then they sell thesebottles of iodine.
You can put some drops and letit soak in there and then wash
(27:41):
it again with the idea ofpotentially eliminate any other
bacteria that might be attachedthere.
And always, always learn thatfrom my mom.
Speaker 4 (27:48):
Yeah, that's interesting.
I'm terrible.
I buy a bag and I open it upand I do have the salad spinner
so I wash it really good.
But yeah, I'm gonna have tothink about this.
So it's not bleach, it's iodine?
Speaker 3 (28:02):
No, I don't know, it's.
Speaker 2 (28:03):
I think I'm confusing your stories of your mother
with my stories of mygrandmother, that's why we,
that's why we clarify, that'swhy we clarify my grandmother
used to soak all of our dishesin bleach.
Speaker 3 (28:12):
In bleach yeah.
Speaker 2 (28:13):
That's how she did it , which I think iodine is
probably healthier.
Speaker 3 (28:17):
Yes, of course.
Speaker 2 (28:19):
Okay, so we've got this interesting story about the
contaminated beef and if you'relistening, I think we've gone
over a couple of ways for you toprotect yourself.
And what are they?
Wash your salad and if you'reconcerned, you can also just
cook your meat appropriately.
You're at risk here if you'reeating rare meat, which is
delicious I know rare steaks,everyone wants to eat rare
(28:41):
steaks but if you're everconcerned about the quality of
your beef, you just cook it allthe way through.
So is there anything else youthink you want to discuss about
E coli in general?
Speaker 3 (28:50):
Yeah, again, as we knew, technologies developing,
we are finding new things abouthow bacteria can cause disease.
So there was this recent storyin the news, just I think a week
ago.
They found out that themajority of UTIs that are being
happening comes from thegastrointestinal tract.
Speaker 1 (29:09):
Yeah some humans.
Speaker 3 (29:10):
So now there is a link, a distinct link, and they
can actually use in sequencingto identify what particular type
of E coli can be prone to causeurinary tract infections.
So we are learning more andmore about this.
One of the recommendations thatI do with my class is do not
eat rare meat anywhere you go,especially if you go to
countries where they have highprevalence of this bacteria.
(29:33):
South America has the largestnumber of a hemolytic umicases
400,000 individuals because inArgentina, chile mainly
Argentina they undercook themeat and there's a lot of kids
getting sick there.
And the United States.
The good thing is we do notmove meat around, so some areas
have outbreaks and then they areconcentrated in California and
(29:56):
Nebraska, for example.
Texas they never import meatfrom anybody else, so we're
pretty safe in Texas.
That doesn't mean that one daywe will get an outbreak.
Speaker 2 (30:04):
In the future, as we see more increasing temperatures
globally due to climate change,we can expect to see more
diarrheal disease, particularlybecause of more bacteria.
Why do you think that is?
Speaker 3 (30:15):
Well, if you want to think it as as simple as the
following so the bacteria likesto live in environments that
have higher temperatures, so youwant to grow bacteria, you put
37 degrees and sometimes theygrow faster.
Speaker 2 (30:28):
Is that 37 degrees Celsius?
Speaker 3 (30:30):
Celsius 37 degrees Celsius Instead of 30 degrees
Celsius then the bacteria growsfaster.
So as the climate changes, theenvironment is perfect for
potential bacteria that was notgrowing that fast to actually
start populating other areas andpotentially we get exposed to
these higher numbers of bacteriaand then getting disease.
Speaker 2 (30:52):
Right, and especially , I think, when you're thinking
about meat being processed andit being processed outside or
something like that beingprocessed in elevated
temperatures, lots more instancefor contamination and bacterial
growth and stuff like that.
And even not just E coli, butother kind of waterborne
bacterial pathogens as well.
Speaker 3 (31:10):
Yeah, that's a risk that we are going to have to
figure out and face astemperatures are going up.
Speaker 4 (31:15):
Yes, so does that mean that the study of E coli is
a growing science and that thiswould be the kind of thing that
you would encourage studentsthat might be interested in
careers in science?
Is there going to be a lot ofinteresting research in this
area?
Speaker 3 (31:29):
I think microbiology in general is an interesting
area to pursue as a career.
It could be bacteria, it couldbe parasites, it could be
viruses.
There's a lot of things to bedone and discover.
There's every day you findsomething new happening.
Potentially all depends on thefunding and where the funding is
going to these stories.
So somebody in a scientificfield has always said that the
(31:54):
best thing that can happen toyou as a scientist is that there
is an outbreak with yourfavorite pathogen, Because
potentially there is going to befunding that is going to be
supporting your research.
Speaker 2 (32:05):
So I've got one last question.
I don't know if Connie has anymore, but if any of our
listeners are interested ingetting into microbiology, do
you have any advice for them?
Speaker 3 (32:13):
Yeah.
So, being quicet, obviously youhave to like science.
Yeah, you're not getting intomicrobiology because you're
going to be rich, so don'texpect that, but you have to be
passionate about what you do.
And then if you are intriguedby mysteries, as we discussed,
and you're intrigued aboutpotentially connecting social
sciences with politics, withfast food chains and the federal
(32:38):
government, and just do goodfor human beings, then that's
your field.
Speaker 4 (32:44):
Right, right.
Well, I think this has been areally great discussion and I've
learned many things.
I've learned I've got to washmy lettuce better.
I've learned that the kind of Ecoli that we had this outbreak
in recently with this beef andthis recall is something that
cannot be treated withantibiotics.
I've learned that if you'reinterested in being somewhat of
(33:05):
a science detective, thatmicrobiology is a good way to go
, and that you had a very luckyexperience in getting into this
E coli study, just sort of by arandom meeting with a visiting
professor.
Correct, and so people shouldtake advantage, as they're going
to school and going to lecturesand you never know where your
(33:27):
opportunity that's going to leadyou on your career trajectory
may come from.
So this has been a greatdiscussion.
Speaker 3 (33:33):
Thank you.
Thank you for the Thank you somuch.
Thank you.
Speaker 2 (33:36):
Thanks for listening to the Infectious Science
podcast.
Be sure to hit subscribe andvisit infectiousscienceorg to
join the conversation, accessthe show notes and to sign up
for our newsletter and receiveour free materials.
Speaker 1 (33:47):
If you enjoyed this new episode of Infectious
Science, please leave us areview on Apple podcasts and
Spotify, and go ahead and sharethis episode with some of your
friends.
Speaker 2 (33:56):
Also, don't hesitate to ask questions and tell us
what topics you'd like us tocover for future episodes.
To get in touch, drop a line inthe comments section or send us
a message on social media.
Speaker 1 (34:05):
So we'll see you next time for a new episode, and in
the meantime, stay happy stayhealthy, stay interested.
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