November 19, 2024 • 53 mins
We really don’t give fungi the credit they deserve. Over the years of this podcast, we’ve covered only a handful of fungal pathogens, and pathogenic fungi themselves represent a teeny tiny proportion of the incredible diversity of fungal life on this planet. But with this book club episode, we’re attempting to correct this oversight, at least a little bit. Toxicologist and science writer Dr. Emily Monosson joins us to discuss her book Blight: Fungi and the Coming Pandemic. We chat about how fungal epidemics have shaped entire ecosystems, altered economies, and invaded hospitals. Despite the devastating impact pathogenic fungi have made, we still underappreciate their potential to cause harm in the future, as our climate changes, as our land use changes, and as globalization continues. In Blight, Monosson delivers an important reminder that we should use what we have learned about these historical outbreaks to limit the harm fungi may cause in the future. Tune in today to gain a new appreciation for this incredible group of organisms.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:44):
Hi, I'm Aaron Welsh and this is this Podcast Will
Kill You. I am so excited to welcome you all
to another episode in our tp w K Y book
Club series this season, where we interview authors about their
wonderful books in science and medicine. The effects these books
have on us or the inspiration we draw from them,
(01:06):
can be as varied as the topics of the books themselves.
With the books just this season, I've been on the
edge of my seat, reading as fast as I can
to find out what happens next in a book about
an element essential to all of life. I've been absolutely
raging over a story of misogyny in academia. My jaw
(01:27):
fully dropped. I've been delighted to learn about the regenerative
power of the endometrium. And I've been moved in so
many other ways by the incredible things I've learned from
these authors. If you'd like to check out the books
that we've covered so far in this book Club, head
to our website This Podcast Will Kill You dot Com,
where you can find pages for each of our released
(01:48):
book club episodes. And if you, like me, were one
of those nerds always going past your assigned reading in
middle school and you want to sneak peek at the
rest of the books for this season. You can also
find that through our website under the Extras tab by
clicking on a link to our bookshop dot org affiliate account,
which will take you to a list of lists, including
(02:09):
a book club list which features all of the books
from this season and the one before. But now let's
turn back to the present and the book will be
chatting about today Blight Fungi and the Coming Pandemic by
author and environmental toxicologist doctor Emily Monison. Here at TPWKY,
we love talking about fungi, even if we don't do
(02:33):
it maybe as often as we should. We've covered kittrid fungus,
which affects amphibians, white nose syndrome, which has devastated some
bat populations, as well as a couple of fungal diseases
of public health relevance, cocidioidomycosis and blastomycosis, which was one
of my favorite topics to research last season because I
(02:55):
got to talk about dinosaurs. Go check it out if
you haven't already. This handful of fungal pathogens represents only
a teeny tiny proportion of fungi that can be pathogenic
to humans or animals, and that group itself is minuscule
compared to the mind boggling beautiful diversity of fungal species
(03:16):
that play so many crucial roles in ecosystems and make
life possible. Fungi truly are amazing, and all fungal species
are certainly worthy of appreciation and attention. But today we're
setting our sites on the select few that have the
power to do us and plants and other animals harm,
(03:39):
especially harm on what is an almost incomprehensible scale. Allow
me to take a quick trip down memory lane to
explain in part why I love this book Blight so
very much. When I was an undergrad at the University
of Kentucky, I spent many weekends escaping the end traffic
(04:01):
on Nicholasville Road on football game days, my teeny apartment
with the bright orange walls, and of course the homework
and studying that I probably should have been doing, and
I would head down to Red River Gorge.
Speaker 2 (04:14):
For some hiking and camping.
Speaker 1 (04:15):
It's an amazing place, and you should absolutely go if
you get the chance. But sometimes while I was driving
through the park to get to a trailhead, I would
stop at the visitor center, initially for the opportunity to
use a nice, clean bathroom rather than the pit toilet
at camp. Once I had luxuriated and washing my hands
with soap and warm water, I would wander around the
(04:37):
displays at the center, peeping at the photos showcasing its history,
the respectably done taxidermy of local fauna, and what quickly
became my favorite attraction and my reason for future pit stops.
At the center a massive cross section of a tree
whose label read something to the effect of This cross
(04:59):
section is of an American chestnut tree. The tree was
one hundred and eighty something years old when it was killed,
along with millions of other chestnut trees, by the chestnut
blight fungus in the early twentieth century. Next to this
cross section was a grainy black and white photo showing
a forest of living chestnut trees, whose colossal size was
(05:20):
made very clear by the tiny humans standing in their shade.
My mind was blown. I could not fathom, even with
the help of more old photographs, the sheer size of
these forests. How the forests that I walked in today
were so dramatically different than those of one hundred years before.
(05:41):
How it all changed so quickly and all due to
a fungus. That chestnut tree cross section has never left
my mind, and I admit to every month or two
googling historical chestnut forests out of this morbid fascination. The
story of the chestnut blight is only one of many
(06:01):
told in Emily Monisson's captivating book Blight, which delves into
the history of fungal epidemics and pandemics and asks what
these fungal pathogens may have in store for us in
the future, as our climate changes, as global movement and
travel increases, and as these notoriously hard to eliminate species
(06:22):
see the chestnut blight fungus establish strongholds in our hospitals
and across the world. So let's take a quick break
and then get into it. Doctor Monison, thank you so
(06:59):
very much for joining me today. Your book, Blight Fungui
in the Coming Pandemic was such a fascinating read, and
I loved learning more about this world of infectious disease
that we you know we on the podcast, but also
we as a general public, don't really give enough attention to.
And I'm super excited to dig into some of these
(07:20):
fungal pathogens and the patterns that we've been seeing lately.
But first, can you tell me where the idea for
this book first came about?
Speaker 3 (07:29):
Sure, And first I just want to say thank you
for having me, and I love your show, so I'm
excited to be So this is something that kind of
was running in the back of my mind for a
long time. So many years ago. My first kind of
experience with a fungus like pathogen was a thing called
(07:52):
late light in tomatoes. So people grow tomatoes, I think
they probably know about late light, especially if they're on
the East Coast, and that is an organism that I
think there was sort of an outbreak of it in
around two thousand and six or seven or something like that,
and it was a disease where you're growing tomatoes. They
look beautiful end of the summer, and all of a
(08:13):
sudden something just came and hit them and within a day,
the tomatoes and their leaves just were dead, hanging on
the stock, looking really pretty ugly. And what it turned
out was that that was a disease called pause by
an organism called phytophra infestins, and it was new to
(08:33):
the East Coast for tomatoes. And it turns out that
that disease was probably distributed by a big box distributor
who was growing tomatoes starts down in I think Florida
and then shipping them up the East Coast and infected
the Holy East Coast. And we are we have had
phytopha infestins infections pretty much every year or maybe every
(08:56):
other year ever since then, because once it you know,
So what I learned from that, that was just that
I was writing and I was trying to understand the disease,
and what I learned was that it's caused by phytopher infestins,
same organism that caused or contributed to the Great famine
in Ireland, the potato blight, same organism, that it could
(09:17):
be spread so easily through buying plants and being distributed
up the coast, and that once it got established, it's
very hard to get rid of, if not impossible. So
that was sort of an introduction to a sort of
new disease that just kind of came and you know,
caused havoc. And like I said, it's not a fungus,
(09:38):
but it behaves like a fungus. I think when it
was first discovered. They probably thought it was a fungus.
It's really something called a water mold. Then around that time,
there was a paper that came out in a scientific
publication a group of scientists who were across different disciplines
about the emerging fungal threats across species. And so what
(09:59):
they were saying was, hey, hey, people, you need to
take you know, be aware. And they actually included phytopher
infestins because it's fungus like in this paper. But they
were talking about frogs and bats and humans and crops
and that you know, there are fungal pathogens across all
of these species, and they weren't getting a whole lot
of attention. So together that seemed like a really good
(10:22):
topic for a book. I had just finished a book
about how all sorts of things were getting resistant to
all the chemicals we used to kill them, which was
a pretty depressing book, and then this would have been
a pretty depressing book. And I was talking with the
editor and I was like, this is kind of depressing,
and she agreed, and so I wrote a different book
that was kind of hopefully more hopeful. So I put
(10:43):
this off and I didn't really think about it, and
then in what was it whenever a fairly recently Canada orius.
So the yeast fungus that's been infecting people started infecting
people and it became a problem, and the CDC started
putting out alerts. I think that was twenty sixteen maybe,
(11:05):
So when that came about, that was sort of seemed like, Okay,
maybe it's time to revisit and write a book about
emergent fungal pathogens.
Speaker 1 (11:13):
Of which there are many, and not just in sort
of these big devastating epidemics that we have come across
the news, like in amphibians or in frogs, or in bats,
but also, as you mentioned, in humans. And so, what
are some of the unusual patterns that we've been seeing
(11:33):
lately in this rise in these human fungal infections that
have been observed over the past few decades.
Speaker 3 (11:41):
So I think the biggest one. I remember speaking to
an infectious disease doctor who specialized in fungal pathogens, and
he said he got his degree in the eighties, and
he said, and if somebody were to come to Rounds
with a heart to treat fungal problem, that would have
(12:01):
been news like that would have been a big deal,
and then came HIV human immune deficiency virus, and people
started becoming immunocompromised because of it, and fungal diseases started
to rise. So that was one of the things because
a lot of fungal pathogens. So I should say first
of all that there are a lot of fungi in
(12:22):
the world. Most of them are beneficial, some of them
don't do anything, and only a very small proportion of
them cause problems. So that's you know, important to keep
in mind that we really most we rarely rely on
fungus for a lot of things. So in most fungi,
you know, we're not really the target for a lot
of fungal pathogens, so there are very few compared to
(12:44):
viruses and bacteria. They're a small proportion of those kind
of pathogenic problems. But so it would would have been unusual.
And one of the reasons is we have a pretty
robust immune system, and when we do have a robust
immune system, we can you know, we're breathing in fungal
spores all the time, and most of us it's not
you know, for most of us, it's not a problem.
(13:05):
So when people are compromised, then fungi are ouptimistic and
they take advantage and they can start to infect you.
So back in the eighties they were rise. There was
a rise. There's also been there was some commentary that
I came across that in the fifties when we started
using antibiotics on a large scale, so that there was
(13:30):
had a quote somewhere where, you know, they fungal pathogens
were kind of a disease of the antibiotic age. And
the thinking there is in part because of our microbiome,
although back then they didn't really talk about that in
those terms because I don't think we you know, nobody
really realized how much of a part of us our
(13:51):
microbiome is. But so we have, you know, fungi and
bacteria that keep other fungi in bacteria in check. So
once we start using antibiotics, you wipe out the bacteria
they're not keeping the fungi in check.
Speaker 1 (14:04):
And we've been seeing some unusual cases in terms of
like person to person spread or outside of hospitals or
outside of people who are have immunal compromise of some kind.
Is it sort of a mix of all of these
things where we have overuse or potential overuse of antibiotics,
we have higher rates or higher detection of immunal compromise.
(14:25):
And is it just that we're better at finding and
isolating and treating, well maybe not treating, but finding an
isolating or detecting fungal infections period.
Speaker 3 (14:36):
You know, And it's not just you know, the other
thing is there's antibiotics, is immune compromise, and there's a
lot more tissue transplants, so just a lot of good
you know, medical advances have also contributed to this because
if you get you know, tissue t plant or an
organ transplant, I mean, you know, then you can be
on you know, suppressence to prevent rejection, that sort of thing.
(14:57):
So we have a large population people that are also
you know, transplant recipients and things like that. So there's
a lot of reasons why people can be imm compromised.
The part about are we detecting you know, what changed
and are we detecting it? So one difference in almost
all most fungal pathogens is that when we think about
bacteria viruses, we think about spreading it from one to another,
(15:19):
you know, where you sneeze on somebody and you spread
the virus. We all know that so fun I don't
spread like that. Usually it's there isn't that sort of
person to person contact. So that's one thing that was
raised sort of red flags with Canada Orus. So when
this was the yeast that you know, emerged somewhere around
(15:39):
twenty sixteen, at least came to recognition in twenty sixteen
as a problem. I think it was twenty sixteen. I
can't remember the year that the CDC issued their warning.
And part of it was because here we had a yeast,
and yeast is you know, it's the fungus we have
Canada albacans. That's very common use that a lot of us,
you know, we all have it on us and some
(16:01):
of us problems, some of it's not. Canada Orus is
another kind of yeast, and this one was one that
had a high mortality rate when it infected people in
the hospitals, and it seemed to spread person to person,
so it could spread around the hospital room and it
could spread, you know, they thought maybe health workers were
spreading Canada ors. It was very hard to clear from
(16:23):
the room. So there were a lot of problems with
Canada ors. And the other odd thing about Canada ors
was that it emerged here in the US and in
many other places around the world kind of at the
same time. So in twenty sixteen, there were these outbreaks
in you know, far flung places of this kind of
new pathogen, which was kind of frightening. And one of
(16:45):
the things that the scientists that I spoke to at
CDC had said was, we wondered, was it something we
just couldn't detect before and now we detected it, So
was it something that was just misdiagnosed and now we
know that it's something different? And so they could go
back into the archive. They'd had some programs running where
you know, physicians were taking samples of fungi from patients,
(17:06):
and it wasn't that case. It wasn't that they were
detecting it now and not before. They found a few
cases that had been misdiagnosed, but most of them were
really new cases, so it really was an emergent fungus
in that case. So it's a very rare thing to
have a new disease like that just sort of emerge.
And this one was so deadly, and it was resistant
(17:29):
to a lot of the anti fungal medications, and it
was hard to clear from a room, although they now
you know, have learned better how to you know, sterilize
a hospital room.
Speaker 1 (17:38):
Afterwards, let's take a quick break and when we get back,
there's still so much to discuss. Welcome back everyone. I've
(18:03):
been chatting with doctor Emily Monison about her book Blight
Fungui and the coming pandemic. Let's get back into things.
I do want to take a moment because I feel
like I have to ask, even though I'm sure you
get this question a lot since writing this book, to
go into the fictional.
Speaker 2 (18:19):
World a bit.
Speaker 1 (18:20):
Have you ever played The Last of Us or have
you watched the show? And if so, any thoughts.
Speaker 3 (18:27):
I have not played the game, but I did watch
the show. So because it came out right before the
book came out. So one thing was so it came
out in the in January twenty twenty three. So one
striking thing was right after that came out, there was
so much about fungal pathogens in the news, and in
(18:48):
the end of twenty twenty two, the World Health Organization
had just made this big announcement of these nineteen you know,
priority fungal pathogens, and so they were trying to get
it out there in the news. You know, here are
some fung guy that we want you all to be
aware of. And that didn't really make such a splash.
There was maybe a couple of weeks of the news
(19:09):
that you know, World Health Organization has these priority fungal pathogens.
Then Last of Us comes out, and you know, fungal
pathogens are everywhere. So it was sort of like that
show did an amazing thing for awareness of fungal pathogens.
The one thing that I just cringed from in the
show is only mostly that you know, they had no
(19:33):
concern about spores, you know, so they'd be going in
where they're dead zombies and you could see the you know,
my cilia or whatever all over the place, and you know,
nobody's worrying about breathing in the stuff. But you know so,
But I since read you know that they didn't want
to put masks on all the stars. Would you can
imagine why?
Speaker 2 (19:54):
But yep, yep, okay, that makes sense.
Speaker 1 (19:57):
And speaking of masks, I read that you worked on
this book a lot, or at least wrote a lot
of this book and researched for this book during the
COVID pandemic. What was that experience like compared to previous
books that you've worked on, and another two parter, how
did writing about pathogenic fungui during a pandemic shape this book?
Speaker 3 (20:20):
Yeah, So for this book, I had this, Like the
other books, I've just sat at home and read a
lot of papers, called up some scientists, and so for
this one, I'm like, I'm going to do a better book.
I'm going to go visit laboratories and I'm going to
go see bats and bat caves and frogs and the
you know. So I had this I was going to
travel and be right there with the scientists, and so
(20:42):
that's what didn't happen. I did get to Costa Rica
and we went to a banana plantation, which was really
cool and I'm glad I had that experience. But yeah,
the rest of it was sitting at home talking to
science except over zoom, so that was different. I also
felt that a lot of them were kind of more
relaxed because they're sitting in their living rooms talk to me.
And I think the other thing was once I realized
(21:05):
that we were really in a pandemic, I had this
book called Blake in the kind of pandemic, I asked
my editor, I'm like, do you really think people are
going to read this? Maybe I should stop writing it
because you know, And the last thing is that it
also since it's come out talking about the title, you know,
(21:27):
when I was before, when I proposed it and was
writing it, there hadn't been a pandemic like this, and
so the time, you know, pandemic wasn't such a hot
button word. I don't think, you know, And I chose
it because I was trying to say that, you know,
some of these funky are like, they're big outbreaks there,
not just an epidemic here. You know, small outbreaks here
(21:49):
and you're an epidemia. So you might have thoughts on
using the name a word like pandemic. But I wanted
people to think about it in a large way. But
then we had this global viral pandemic and I'm like,
but not like that.
Speaker 1 (22:03):
So right, right, right, no, And I think I think
it's a completely apt term. I think that we tend to,
maybe in part because of COVID, think about pandemics as
in happening to humans, especially very human centric ideas of
what a pandemic is.
Speaker 2 (22:21):
And that's not necessarily the case.
Speaker 1 (22:23):
But anyway, so all that is to say, is that
I love the title, and I think that it is
something that we are a little bit in part, have
this human bias where we don't think about fungi as
much as we do, you know, bacteria and viruses, things
that we're more familiar with, and humans represent of course,
(22:45):
only a small proportion of organisms impacted by fungal pathogens.
You know, some frog populations around the world have been
absolutely devastated by b D a cattrid fungus that we
did an episode on like years back. At this point,
can you talk about why frogs are so susceptible to
this pathogen and what the latest is on this fungal
(23:07):
pandemic and are there any glimmers of hope out there?
Speaker 3 (23:11):
Yeah, well, so I only know what I've learned from
the scientists, and I spoke to Karen Lips, who is
one of the lead scientists, and you know, she sort
of experienced this decline. It's a good question about why
frogs are so susceptible. So part of it is is
that their skin they you know, carotin and their skin
just like we do, and it's food for the Kittrids
(23:33):
are aquatic. So that's one thing is that they'll spread
their spores into the aquatic ecosystem and then that can
spread easily move her on. Frogs breathe, they're basically breathing
through their skin, and so this is a skin pathogen
and so once it infects the skin, it you know,
it will poke through and send out its spores and
(23:55):
when it does that, it's completely ripping apart the frog skin.
So you've got this skin that's very important for managing
electrolytes coming in and out, and then you've got all
these it's just being shredded by this fungus that's eating
the skin and then growing and sending out its spores
through the skin. And so that is what kills the frogs.
(24:18):
They're not I mean they are. So there's this obviously,
it's it's impacted a lot of different species. So that's
another thing is that it's not species specific. It's impact
a lot of different frog species. There's a very similar
fungus and I do think that VD I might misspeak,
but I think BD can also impact salamanders who have
(24:39):
a similar part of their lifestyle, but it's not as
problematic in salamanders. But there is another caterried fungus that
has become called B cell that does impact salamanders, and
that outbreak for that was in Europe, and there's a
(24:59):
lot of concern. We have some really biodiversity hotspots here
for salamanders, and there's a lot of concern that if
that B cell enters the US. You know, what happened
to frogs around the world could happen to the salamanders here.
Speaker 1 (25:13):
It's alarming, especially because there is so much global exchange,
global movement, global trade of thousands of species of plants
and animals. And in your book you use this great
term conveyor belt of disease. So what role has this
conveyor belt of disease played in fungal outbreaks?
Speaker 3 (25:35):
So just about every fungal pathogen that I wrote about
was an emergent disease, and it was emergent in large
part because of trade and travel. So every fungus you
know that became emergent pathogen is because it was brought
to a new place and it found something to infect
(25:56):
that had never seen it before. And that's how why
it became so devastating. Those organisms had no defense. So
the movement of plants and animals and us too, I
mean there are some outbreaks that you know, what happened
to the bats, which the white nose disease is thought
to have been kicked off by cavers bats living caves.
(26:20):
That's a pathogen that has killed bats across in the
East and is moving across the country. And it was
discovered also that that pathogen does infect bats in Europe,
but it doesn't kill them, and it's in the caves
in Europe, and so it's believed that you know, people
tramping around those caves then came here, tramped around in
(26:41):
caves here, left some spores disease.
Speaker 1 (26:44):
So yeah, movement, movement, I mean, it's a real driver
of the spread of pathogens and fun guy, especially because,
like you've talked about, the vast majority of the fungi
we encounter our or the pathogenic fungui that we encounter,
are stable in the environment, and so they're or long
(27:08):
lived in the environment, and they're there, they stay somewhere
for a very long time. They're they're very sticky in
terms of you know, not being able to get rid
of them, and that's I think one thing that makes
them so I don't want to say scary, but like
kind of alarming in that sense of like, once it's here,
it's here. But the other thing that I find really
(27:29):
both you know, fascinating and terrifying about some fungal pathogens
of humans, especially going back to the humans, is that
some of them can be incredibly deadly even with treatment.
And I know that our treatments are somewhat limited in
in you know, what they can do. But why are
some of these fungal pathogens so very deadly?
Speaker 3 (27:52):
Oh, that's a good question, and I'm not a physician,
and I don't really have a good answer for that,
except that when we're thinking about some of the people
who are infected, that they're immunocompromised, so that gives the
fungus some advantage. I think some fungi are also good
at evading the immune response, so there's that, And I
(28:15):
do think part of it is just that some of
them are hard to treat because there aren't that many
antifungal medications. There are very few classes of antifungal medications,
and so once of fungus can overcome all of them,
there aren't that many options after that for treatment. So
resistance to antifungal medications is a real problem.
Speaker 1 (28:37):
Most if not all countries have regulations or laws that
limit the importation of plants or animals into the countries
in part to try to prevent pathogens from coming in
and affecting these immunologically naive populations.
Speaker 2 (28:53):
But these laws aren't perfect.
Speaker 1 (28:55):
And you pointed out one gap with like humans just
not knowing that we're transporting the fungus responsible for white
nose syndrome on our boots. If we're cavers and we're
going from one airport to the next, and what a
cool cave. Let's pop in that one and then go
back home, pop in that one. So there are some
of these gaps that we see, but there's also seems
(29:17):
to be sometimes resistance to stricter laws or longer quarantine periods.
Why is there some resistance And that's kind of a
both a big and simplistic question at the same time.
Speaker 3 (29:30):
But yeah, to why there's resistance, I mean, I think
sometimes it's just such a big ask in many ways,
and then some people would say it's not a very
big ask, and I think what I wrote about was
sort of. So there were two things, and I have
to say right up front, regulation not my strong point.
I find them very complicated to even you know, to
(29:50):
try to dig into the history to understand the current regulations.
The biggest gap that I came across, and I think
that people would point out, is that for play plants
since the nineteen hundreds, because there were a lot of
outbreaks in plant diseases. The USDA, I think it was,
(30:10):
you know, there was a lot there was a big
fight between a couple of different factions of people who
want to bring in plants from all over the world
and people who said no, no, no, those are bringing
in pests and pathogens, and so there was a big fight.
But in the early part of the nineteen hundred they
actually did eventually come up with some regulations about quarantines
and you couldn't bring soil in and you couldn't do this
to protect plants. So plants there is, you know, there
(30:33):
is some healthy regulations. And we actually have a national mycologist,
we have two, so that's a position and their role
is to identify odd things that come in in plants
that can't be identified and that might be pathogenic. And
so they're sitting there in their labs constantly looking and
a lot of stuff comes in. They look at a
lot of different kinds of mostly fungal spores, because that's
(30:56):
how they can identify them. So we have these people
looking at for plants pretty much, and still we get
plant pathogens slipping in. Okay, we don't have the same
thing for animals that are pet trade animals, and you know,
so for food animals we do because we're worried about
humans and disease and her food. But for other kinds
(31:16):
of animals that are in trade, there is not. For
a lot of them, there is no you can't come
in with this disease. You know, they're not checked for disease.
Part of it is a capacity thing, and part of
it is you know, I can't tell you why not.
So now we're talking about millions of animals coming over
(31:37):
and crates of animals and things like that. How difficult
that is. So that's a big gap, and it was
almost shocking. I had to ask a lot of times.
I'm like, you mean, there's no national mycologists equivalent for
animals because this seems so important and there isn't. So
I will say one more thing, just about when I
mentioned the BD and the salamander, So this is something
(31:58):
that's kind of good that came out. I mean the
b seal in the salamander. So I mentioned that there's
concern that this cattrid fungus that's in Europe will come
across to the US. And so those scientists that were
working with frogs and knew how devastating the disease could
be of the kittred BD could be in frogs got
(32:20):
together and they first tried to have some new regulations
there's some enforcement about bringing disease frogs into the country,
and that really didn't go anywhere because the response was,
we already have the disease here, so how are we
going to stop it? But when the B sal came
along in the salamanders, they got together again and they said, hey,
it's not here, maybe we can stop it. And what
(32:44):
happened and they worked with it was you know, nonprofits
and federal agencies and you know, academics all working together
to do this. And what they did come up with
was in the end a list of I think two
hundred and maybe nine or something salamanders that cannot come
into the country because they are known carriers of B cell.
So it's not exactly what they wanted, which would have been,
(33:06):
you know, you just can't bring you have to be
tested for diseased or get a health certificate that says
you have no disease. But it's a it's a step
and so and so far we haven't had b cell here.
There is monitoring for it, but so that's kind of worked.
But that's really you know, when you ask about regulations,
how you do things, and you know that took a
(33:27):
lot of effort.
Speaker 1 (33:29):
On this podcast, we're mostly talking about animal diseases and
animal immune systems, but as you discuss in blight, plants
especially trees are incredibly impacted by fungal infections. How do
tree immune systems work? And like why are they so
susceptible to some fungi?
Speaker 3 (33:50):
So trees have they do multiple things. So they grow,
they have you know when you look at bark, that's
like our skin first line. But they also do this
thing where they grow, you know, in layers, right, so
when you sometimes see the inside a tree that looks
kind of there's nothing there, it's it's dead. And so
they grow and they can wall off pathogens. It's just
(34:14):
the way they grow. And so that's one defense is
that if you know, something gets infected, they can kind
of just grow around it wallet off and don't need
that part. They don't need a branch or like we
need our arm. So that's one thing. But the other
thing they do produce a lot of chemicals. I mean,
we know this in plants, right because we either use
a lot of plant chemicals for drugs or whatever, and
(34:34):
a lot of these sort of secondary chemicals that they're producing,
including things like alkaloids that might make foods bitter, are
defenses against pathogens. So that's another thing that they'll do
is they can produce, you know, different kinds of chemical
products to fend off disease and in pests too, insecte pests.
Speaker 1 (34:59):
When that doesn't go according to plan, it can be
incredibly dramatic and awful. So one of the most tragic
stories of a fungal epidemic is chestnut light And it's
just so hard to wrap my head around how different
some North American forests looked like before this epidemic struck.
(35:21):
So can you take us through this tragedy, you know,
how it was first recognized and then what led to
this dramatic and rapid change.
Speaker 3 (35:32):
Yeah, so chestnut trees the American Because a lot of
people around me are like, wow, but I just got
some chestnuts. I'm like, yeah, but they're not American chestnuts.
If you got them from you know, the farmer down
the road, they're probably some hybrid. So American chestnuts were
huge trees, beautiful trees, very productive. They ranged along sort
of the Appalachian Range and up along the East Coast.
(35:54):
There were really important trees in many ways, both to
humans and ecosystems. And so the story of the demise
of the American chestnut kind of begins at the Bronx Zoo.
So when they were first developing the zoo, the society
that wanted to bring these, you know, have these exotic
animals on show and everything, they were also very interested
(36:16):
in the trees on their property. So they had a
lot of acreage and they had a lot of old trees,
and so they thought that those trees were just as
important almost as the animals that they were going to
bring in, and so they hired a forester. He was
in charge of the trees and it was his job
to make sure that all the trees in the park
were good, healthy, whatever, and plant other stuff in the park.
(36:38):
And so he knew all the trees in that park,
and there were something like over a thousand chestnut trees,
and they were some of them were, you know, the big, old,
beautiful chestnuts. And so I think it was in nineteen
oh four that Merkel noticed on a couple of chestnut
trees some of the leaves were kind of curling and
looked like they kind of looked like it was fall.
They were sort of dying at a time when they
shouldn't have been. So thought, well, this seems like some
(37:01):
kind of disease. And he could see some little spots
on the trees, and he thought, you know, maybe it's
a fungal disease, but just a few trees, maybe won't
come back next year, so you didn't worry about it.
Nineteen oh five, almost every tree in the park was
infected with this fungus and their leaves were curling up
and dying, and so he at that point, you know,
(37:23):
got worried, called the USDA asked what to do. One
of the things that they did at the time what
to treat fungal pathogens, which I thought was interesting because
we still use this to treat them with copper. So
copper is an organic fungicide and it is effective against fungus,
but it's topical. And so the response to him was, well,
cut off the dead branches and you know, treat the
(37:45):
trees with copper. Well, you had a thousand you know,
big old trees that wasn't really in you know, in
early nineteen hundred that he tried to do that, but
that was not that effective and it was just overwhelming.
He brought in a colleague from down to the botanical
gardens and he identified as something different, and he identified
as what would become known as chestnut light. By the
(38:06):
time he figured out what it was, you know, within
that year and identified that it was in fact the
organism that's infecting and killing the chestnut trees, he predicted
that all the trees would probably be infected and dead
within a few years, and he was right. And what
happened from there is that the blight spread from New
York all the way down through the Appellachians, killing chestnuts
(38:30):
just about every single chestnut tree, millions of trees, maybe billions.
Within decades, there were no more American chestnut trees growing. Now.
People also cut down the trees in part to maybe
make a fire break of infection, you know, to stop
the infection, and also because chestnut wood was so valued,
and you know they were going to try to stop this,
(38:53):
and nothing stopped it. One thing we haven't talked about
is spores. So you know fungi makes except for Last
of Us, which didn't have spores, but it could have,
and I think maybe in the game it does. I'm
told that they actually wear masks in the game. So anyway,
you know, fungi spread by spores. They can put out
(39:14):
hundreds of thousands or millions of spores, and in the
case of the chestnut light, you know, these trees would
be infected the funguses putting out spores. The wind can
carry spores, and these spores can be carried by birds
and insects that you know go to the trees and
then go to the next tree, and so you know it,
it just it spread rapidly and it was unstoppable. As
(39:36):
that was happening, as they were realizing that they're losing
these valuable trees, they wanted to understand something about the
fungus and so there were these people called agricultural explorers
around nineteen hundreds, which was part of that fight. Remember
when I said there was the argument about you know,
collecting and bringing in stuff from all over the world,
but so wrong with that. So they had these and
(39:58):
there were you know, dedicated explorers who would do that.
They'd go all over the world looking for plants and
fruits and you know, crop plants and trees and bring
them back. And so they're happened to have an explorer
that was going to China or he was in China
at the time. They got in touch with him and said, hey,
you know, there's this fungus on the chestnut tree. We
know there's chestnuts in China. Can you see if this
(40:19):
fungus is there, you know, identify this fungus on those trees.
And he did, and what he also noticed is that
those trees weren't really impacted by the fungus. He got
word back and so you know, in the end, what
people figured is that some of those trees that had
been imported from either China or Japan people, you know,
they're very popular. There's still we have neighbors with Chinese
(40:41):
chestnut trees. Still that fungus probably came in on some
of those imports and then spread throughout the country. But
that understanding that now they know that the Chinese chestnut
trees have some kind of resistance against the fungus because
it co evolved with it, right, the two of all
over how many hundreds of thousands of years together, that
(41:04):
maybe there might be some way to use the resistance
of Chinese chestnutrees and breed it into the American chestnut trees.
So that started a whole new program to try to
bring back American chestnutrees. One thing that I haven't mentioned,
because we are so human centric, is that each time
you do this, you're changing the whole ecosystem. And so
(41:25):
you remove a key species like that, you remove a
frog or a bat, and it changes things and it's
not you know, it doesn't always have to. Sometimes it
is still relevant to us that the ecosystem has changed.
But you know, you can just imagine the changes that
happen when this occurs and you take a whole species
out of a.
Speaker 1 (41:45):
System, instant, huge transformation with unforseeable consequences. And there are
some consequences I think that are a bit more easily
seen when it comes to agriculture, and especially a lack
of biodiversity in agricultural practice, so monoculture basically, So, could
(42:07):
you take us through the story of bananas, This fruit
that we eat so much of all the time around
the world, and maybe we don't ever give a second
thought to the banana that we hold in our hands.
Speaker 3 (42:20):
Yeah, So the banana story which we did, you know,
like I mentioned before, it got to go to Costa Rica,
went to this place called Earth University, which is a
really cool place. They're growing bananas sustainably because it's difficult
to grow banana sustainably for a couple of reasons. One
of them is fungus no matter where you grow. But
(42:40):
the story that I focus on there is the story
of a fungus called tr ie. It's an oxysporum, some
kind of fungus. And so back in the thirties, forties
and fifties, banana's big business. They were grown on these
huge monocrop plantations in Costa Rica and Swear Honduras, and
(43:04):
they at that time there was this fungus that emerged
and it started killing those bananas. And the bananas that
we ate were called the gross Michelle banana, and so
they call them dessert banas, the bananas that we were
all eating. So I should also clarify that there are
many there are different kinds of bananas. We happened to
eat one, as you mentioned, that's grown in a big monocrop.
(43:27):
Basically clones, they're just clones of each other. They're not
even because banas don't have seeds, so they're really really clones.
A lot of people eat other kinds of bananas, So
this particular fungus impacted the banana that we were all eating,
the banana that was grown, the growmy shell that was imported,
(43:47):
and it was devastating to those crops. And interesting I
didn't bother the other kinds of bananas, but it was
the industry that got worried. And so basically at that time,
back in the fifties and sixties, there were concerns that
they might not have any more bananas because that's a
fungus that when you talk about scary spores, that's the
one that makes spores and it can make this kind
(44:09):
of spore that some scientists say has been detected in soil.
So it's a soil born fungus. Means that it's in
the soil, then it gets up through the banana from
the soil, makes spores. It can last in the soil
for ten years or more so decades. So this is
a kind of thing that once it impacted plantation, got
(44:29):
in the soil, you just can't grow bananas there anymore.
And so what the industry would do back then, because
it was not a great industry, would just be to
move to another place and grow their bananas there, leave
behind the other land that they you know, so they
just kept moving. But it became clear that they were
going to be out of bananas, and so around that time,
(44:51):
there was a you know, discovery that there was another
kind of banana called the cavendish that was not susceptible
to that fungus. So that was a very you know,
that fungus was very specific for the gro michell banana,
and so they replaced the gross michelle with cavendish, which
is what we eat. But they basically did the same thing.
So they just planted huge monocrops of banana, same kinds
(45:14):
and cloned banana everywhere wherever banas are grown for export.
I think it was in the seventies, maybe slowly, a
new kind of fungus emerged called TR four. So the
first one was called tier one. The second round, Tier four,
similar kind of fungus, causing the same kind of problem,
(45:36):
and it is frightening growers. It was believed to be
transported in soil, so that would have been in boots
of people or farm machinery that was transported from one
place to another. But one of the scientists I spoke
to said, you know, even though we know that, I
don't think that that's the only way it spreads, and
that that would really stuck, you know that, even if
we were totally hygienic about this, But there are you know,
(45:59):
you used to be able to go in Costa Rica.
I think if you went several years ago before TR
four became a problem, you could go take a tour
of banana plantation, which is just really it's fascinating to
see how much care the bananas that we eat. We
don't pay enough for our bananas. Let's just say that
they require a lot of care. And so used to
(46:20):
be able to go there and see how they do that,
and that you're not allowed to do that anymore because
there's too much concern about TR four. So we're kind
of fortunate to be able to get a tour of
this smaller plantation. But yeah, so there's TR fours out
there and there are concerns about you know what will
be next. And so some of the banana breeders and
(46:41):
people who work with bananas have said, you know, yeah,
we might lose this banana, but there are a lot
of other kind of bananas. And so one thing to
think about is that when we you know, when I
was growing up, there are a few different kinds of
apples and that was it. And now it's I'm boggling.
I think just in the last two years, how many
(47:04):
different kinds of apples there are out there. So there's
you know, that that different kinds. If we are open
to having some diversity in our banana, that would be great.
And another thing is is that growing these huge monocrops
with you know, so there are other ways. That was
one of the things that the scientists that I had
visited was doing was experimenting with how to grow large crops,
(47:28):
but not in these big monocrops, to have them in
blocks and have other stuff planted, you know, agro ecology
or grow forestry whatever, have other stuff growing in between,
other crops growing in between, so that the you know,
a disease can't spread so easily. So there are ways
of doing, you know, dealing with this, and it's just
that we you know, we we need to either change
what we want and what we accept and also how
(47:50):
we grow things diversity. You had mentioned diversity, So I'm
glad you said that biodiversity before because it reminded me
that that's one of the most important things for all
of this is the and that we need to understand
and do whatever we can to preserve biodiversity across species,
no matter what we're talking about.
Speaker 1 (48:09):
It's it's amazing to me that we are provided, you know,
learning opportunities all of the time, from fungal pathogens, from
other types of pathogens, from don't you know maybe giant
monoculture is not a great idea, and that we have
to keep relearning those lessons over and over again.
Speaker 3 (48:27):
That's that's a problem. It Meanswediam won't to learn them.
Speaker 1 (48:31):
Yeah, exactly, because if we're not, if we're learning them
over and over again, we never learned them in the
first place. But so for my last question, I want
to go back to the title of your book, blighte
Fungi and the Coming Pandemic, and I want to ask
you not about like why we should be wary of
fungal pathogens, because I feel like we did a pretty
(48:53):
good job covering that so far. But I want to
ask about what should give us hope in our ability
to detect or control or treat a possible fungal epidemic
in the future.
Speaker 3 (49:06):
So one start is awareness. So just being aware when
we talk about you know, you go to the airport
and they ask you to not take any plants or
plant bits or whatever, pay attention. There's a reason for that.
There's hope in new developments, like we talked about better analysis,
(49:28):
faster analysis. You know, if you can you know diagnosis,
if you can have rapid diagnosis that sorts of thing,
there is some hope there. You know, I would hope
that with trade and travel, but trade, that we can
be more aware of sort of what we want. There
are some people that say, well, why do we need
(49:49):
to plant, you know, plant plants from other countries. Why
don't we just you know, grow what's native. So that's
why not, you know, really and similarly, I think there
are people who would like to see less animal trade
or and you know, the flip side of that is
that some people say, but then when you do get
to have a salamander or some kind of odd lizard,
(50:12):
you develop an awareness for that animal and you know
some kind of you want to save that animal. So
there is you know, it goes both ways to this
kind of thing. I think that just having some greater
awareness grow things in different ways. I think, you know,
people in agriculture are beginning to understand and think about
(50:32):
how to grow crops differently so that they're not so
disease prone. Just diversity in what we eat and what
we want. You know, why do we just want one
type of wheat? Maybe we could be eating all sorts
of different grains, which we're just starting to do. But
you know, that's that's one way. So there are those
kinds of things. Is that we just have to be
(50:53):
open to more diversity in what we want. We also
have to be aware of protecting a diversity that's out there,
and just more cognizant of how we all live in
this one world. You know, plants, animals, humans, we're all
together in this one world and we all impact each other.
We're not in our little human bubble. Everything interacts with
(51:16):
each other and we really need to take that seriously.
And I think and if COVID didn't get that us
thinking that way, I don't know what will which is
kind of a sad note to end it on, because
I'm not sure, you know. I do think there's more
awareness of ecosystem health, how important that is for diseases
and things like that. So we just have such short memories.
(51:37):
That's the problem, you know.
Speaker 1 (51:58):
This conversation just rein forced how amazing and fascinating fungi are.
Doctor Monison, thank you so very much for taking the
time to chat with me. We covered so much ground
in this convo, but there is still so much more
to the world of fungal pathogens that I'm sure you
all want to learn about. If you find yourself craving
(52:19):
more fungi facts, check out our website this podcast will
kill You dot com. We're all post a link to
where you can find blighte Fungi and the Coming Pandemic,
as well as a link to doctor Monison's website. And
don't forget you can check out our website for all
sorts of other cool things, including but not limited to, transcripts,
quarantine and place be reader recipes, show notes and references
(52:41):
for all of our episodes, links to merch our bookshop
dot Org, affiliate account, our Goodreads list, a first hand
account form and music by Bloodmobile. Speaking of which, thank
you to Bloodmobile for providing the music for this episode
and all of our episodes. Thank you to Leana Squalatchi
and Tom Bryfogel for our audio mixing. And thanks to
(53:01):
you listeners for listening. I hope you liked this bonus
episode and our loving being part of the TPWKY book Club.
And a special thank you, as always to our fantastic patrons.
We really really appreciate your support so much. Well, until
next time, keep washing those hands.
Hi, I'm Aaron Welsh and this is this Podcast Will
Kill You. I am so excited to welcome you all
to another episode in our tp w K Y book
Club series this season, where we interview authors about their
wonderful books in science and medicine. The effects these books
have on us or the inspiration we draw from them,
(01:06):
can be as varied as the topics of the books themselves.
With the books just this season, I've been on the
edge of my seat, reading as fast as I can
to find out what happens next in a book about
an element essential to all of life. I've been absolutely
raging over a story of misogyny in academia. My jaw
(01:27):
fully dropped. I've been delighted to learn about the regenerative
power of the endometrium. And I've been moved in so
many other ways by the incredible things I've learned from
these authors. If you'd like to check out the books
that we've covered so far in this book Club, head
to our website This Podcast Will Kill You dot Com,
where you can find pages for each of our released
(01:48):
book club episodes. And if you, like me, were one
of those nerds always going past your assigned reading in
middle school and you want to sneak peek at the
rest of the books for this season. You can also
find that through our website under the Extras tab by
clicking on a link to our bookshop dot org affiliate account,
which will take you to a list of lists, including
(02:09):
a book club list which features all of the books
from this season and the one before. But now let's
turn back to the present and the book will be
chatting about today Blight Fungi and the Coming Pandemic by
author and environmental toxicologist doctor Emily Monison. Here at TPWKY,
we love talking about fungi, even if we don't do
(02:33):
it maybe as often as we should. We've covered kittrid fungus,
which affects amphibians, white nose syndrome, which has devastated some
bat populations, as well as a couple of fungal diseases
of public health relevance, cocidioidomycosis and blastomycosis, which was one
of my favorite topics to research last season because I
(02:55):
got to talk about dinosaurs. Go check it out if
you haven't already. This handful of fungal pathogens represents only
a teeny tiny proportion of fungi that can be pathogenic
to humans or animals, and that group itself is minuscule
compared to the mind boggling beautiful diversity of fungal species
(03:16):
that play so many crucial roles in ecosystems and make
life possible. Fungi truly are amazing, and all fungal species
are certainly worthy of appreciation and attention. But today we're
setting our sites on the select few that have the
power to do us and plants and other animals harm,
(03:39):
especially harm on what is an almost incomprehensible scale. Allow
me to take a quick trip down memory lane to
explain in part why I love this book Blight so
very much. When I was an undergrad at the University
of Kentucky, I spent many weekends escaping the end traffic
(04:01):
on Nicholasville Road on football game days, my teeny apartment
with the bright orange walls, and of course the homework
and studying that I probably should have been doing, and
I would head down to Red River Gorge.
Speaker 2 (04:14):
For some hiking and camping.
Speaker 1 (04:15):
It's an amazing place, and you should absolutely go if
you get the chance. But sometimes while I was driving
through the park to get to a trailhead, I would
stop at the visitor center, initially for the opportunity to
use a nice, clean bathroom rather than the pit toilet
at camp. Once I had luxuriated and washing my hands
with soap and warm water, I would wander around the
(04:37):
displays at the center, peeping at the photos showcasing its history,
the respectably done taxidermy of local fauna, and what quickly
became my favorite attraction and my reason for future pit stops.
At the center a massive cross section of a tree
whose label read something to the effect of This cross
(04:59):
section is of an American chestnut tree. The tree was
one hundred and eighty something years old when it was killed,
along with millions of other chestnut trees, by the chestnut
blight fungus in the early twentieth century. Next to this
cross section was a grainy black and white photo showing
a forest of living chestnut trees, whose colossal size was
(05:20):
made very clear by the tiny humans standing in their shade.
My mind was blown. I could not fathom, even with
the help of more old photographs, the sheer size of
these forests. How the forests that I walked in today
were so dramatically different than those of one hundred years before.
(05:41):
How it all changed so quickly and all due to
a fungus. That chestnut tree cross section has never left
my mind, and I admit to every month or two
googling historical chestnut forests out of this morbid fascination. The
story of the chestnut blight is only one of many
(06:01):
told in Emily Monisson's captivating book Blight, which delves into
the history of fungal epidemics and pandemics and asks what
these fungal pathogens may have in store for us in
the future, as our climate changes, as global movement and
travel increases, and as these notoriously hard to eliminate species
(06:22):
see the chestnut blight fungus establish strongholds in our hospitals
and across the world. So let's take a quick break
and then get into it. Doctor Monison, thank you so
(06:59):
very much for joining me today. Your book, Blight Fungui
in the Coming Pandemic was such a fascinating read, and
I loved learning more about this world of infectious disease
that we you know we on the podcast, but also
we as a general public, don't really give enough attention to.
And I'm super excited to dig into some of these
(07:20):
fungal pathogens and the patterns that we've been seeing lately.
But first, can you tell me where the idea for
this book first came about?
Speaker 3 (07:29):
Sure, And first I just want to say thank you
for having me, and I love your show, so I'm
excited to be So this is something that kind of
was running in the back of my mind for a
long time. So many years ago. My first kind of
experience with a fungus like pathogen was a thing called
(07:52):
late light in tomatoes. So people grow tomatoes, I think
they probably know about late light, especially if they're on
the East Coast, and that is an organism that I
think there was sort of an outbreak of it in
around two thousand and six or seven or something like that,
and it was a disease where you're growing tomatoes. They
look beautiful end of the summer, and all of a
(08:13):
sudden something just came and hit them and within a day,
the tomatoes and their leaves just were dead, hanging on
the stock, looking really pretty ugly. And what it turned
out was that that was a disease called pause by
an organism called phytophra infestins, and it was new to
(08:33):
the East Coast for tomatoes. And it turns out that
that disease was probably distributed by a big box distributor
who was growing tomatoes starts down in I think Florida
and then shipping them up the East Coast and infected
the Holy East Coast. And we are we have had
phytopha infestins infections pretty much every year or maybe every
(08:56):
other year ever since then, because once it you know,
So what I learned from that, that was just that
I was writing and I was trying to understand the disease,
and what I learned was that it's caused by phytopher infestins,
same organism that caused or contributed to the Great famine
in Ireland, the potato blight, same organism, that it could
(09:17):
be spread so easily through buying plants and being distributed
up the coast, and that once it got established, it's
very hard to get rid of, if not impossible. So
that was sort of an introduction to a sort of
new disease that just kind of came and you know,
caused havoc. And like I said, it's not a fungus,
(09:38):
but it behaves like a fungus. I think when it
was first discovered. They probably thought it was a fungus.
It's really something called a water mold. Then around that time,
there was a paper that came out in a scientific
publication a group of scientists who were across different disciplines
about the emerging fungal threats across species. And so what
(09:59):
they were saying was, hey, hey, people, you need to
take you know, be aware. And they actually included phytopher
infestins because it's fungus like in this paper. But they
were talking about frogs and bats and humans and crops
and that you know, there are fungal pathogens across all
of these species, and they weren't getting a whole lot
of attention. So together that seemed like a really good
(10:22):
topic for a book. I had just finished a book
about how all sorts of things were getting resistant to
all the chemicals we used to kill them, which was
a pretty depressing book, and then this would have been
a pretty depressing book. And I was talking with the
editor and I was like, this is kind of depressing,
and she agreed, and so I wrote a different book
that was kind of hopefully more hopeful. So I put
(10:43):
this off and I didn't really think about it, and
then in what was it whenever a fairly recently Canada orius.
So the yeast fungus that's been infecting people started infecting
people and it became a problem, and the CDC started
putting out alerts. I think that was twenty sixteen maybe,
(11:05):
So when that came about, that was sort of seemed like, Okay,
maybe it's time to revisit and write a book about
emergent fungal pathogens.
Speaker 1 (11:13):
Of which there are many, and not just in sort
of these big devastating epidemics that we have come across
the news, like in amphibians or in frogs, or in bats,
but also, as you mentioned, in humans. And so, what
are some of the unusual patterns that we've been seeing
(11:33):
lately in this rise in these human fungal infections that
have been observed over the past few decades.
Speaker 3 (11:41):
So I think the biggest one. I remember speaking to
an infectious disease doctor who specialized in fungal pathogens, and
he said he got his degree in the eighties, and
he said, and if somebody were to come to Rounds
with a heart to treat fungal problem, that would have
(12:01):
been news like that would have been a big deal,
and then came HIV human immune deficiency virus, and people
started becoming immunocompromised because of it, and fungal diseases started
to rise. So that was one of the things because
a lot of fungal pathogens. So I should say first
of all that there are a lot of fungi in
(12:22):
the world. Most of them are beneficial, some of them
don't do anything, and only a very small proportion of
them cause problems. So that's you know, important to keep
in mind that we really most we rarely rely on
fungus for a lot of things. So in most fungi,
you know, we're not really the target for a lot
of fungal pathogens, so there are very few compared to
(12:44):
viruses and bacteria. They're a small proportion of those kind
of pathogenic problems. But so it would would have been unusual.
And one of the reasons is we have a pretty
robust immune system, and when we do have a robust
immune system, we can you know, we're breathing in fungal
spores all the time, and most of us it's not
you know, for most of us, it's not a problem.
(13:05):
So when people are compromised, then fungi are ouptimistic and
they take advantage and they can start to infect you.
So back in the eighties they were rise. There was
a rise. There's also been there was some commentary that
I came across that in the fifties when we started
using antibiotics on a large scale, so that there was
(13:30):
had a quote somewhere where, you know, they fungal pathogens
were kind of a disease of the antibiotic age. And
the thinking there is in part because of our microbiome,
although back then they didn't really talk about that in
those terms because I don't think we you know, nobody
really realized how much of a part of us our
(13:51):
microbiome is. But so we have, you know, fungi and
bacteria that keep other fungi in bacteria in check. So
once we start using antibiotics, you wipe out the bacteria
they're not keeping the fungi in check.
Speaker 1 (14:04):
And we've been seeing some unusual cases in terms of
like person to person spread or outside of hospitals or
outside of people who are have immunal compromise of some kind.
Is it sort of a mix of all of these
things where we have overuse or potential overuse of antibiotics,
we have higher rates or higher detection of immunal compromise.
(14:25):
And is it just that we're better at finding and
isolating and treating, well maybe not treating, but finding an
isolating or detecting fungal infections period.
Speaker 3 (14:36):
You know, And it's not just you know, the other
thing is there's antibiotics, is immune compromise, and there's a
lot more tissue transplants, so just a lot of good
you know, medical advances have also contributed to this because
if you get you know, tissue t plant or an
organ transplant, I mean, you know, then you can be
on you know, suppressence to prevent rejection, that sort of thing.
(14:57):
So we have a large population people that are also
you know, transplant recipients and things like that. So there's
a lot of reasons why people can be imm compromised.
The part about are we detecting you know, what changed
and are we detecting it? So one difference in almost
all most fungal pathogens is that when we think about
bacteria viruses, we think about spreading it from one to another,
(15:19):
you know, where you sneeze on somebody and you spread
the virus. We all know that so fun I don't
spread like that. Usually it's there isn't that sort of
person to person contact. So that's one thing that was
raised sort of red flags with Canada Orus. So when
this was the yeast that you know, emerged somewhere around
(15:39):
twenty sixteen, at least came to recognition in twenty sixteen
as a problem. I think it was twenty sixteen. I
can't remember the year that the CDC issued their warning.
And part of it was because here we had a yeast,
and yeast is you know, it's the fungus we have
Canada albacans. That's very common use that a lot of us,
you know, we all have it on us and some
(16:01):
of us problems, some of it's not. Canada Orus is
another kind of yeast, and this one was one that
had a high mortality rate when it infected people in
the hospitals, and it seemed to spread person to person,
so it could spread around the hospital room and it
could spread, you know, they thought maybe health workers were
spreading Canada ors. It was very hard to clear from
(16:23):
the room. So there were a lot of problems with
Canada ors. And the other odd thing about Canada ors
was that it emerged here in the US and in
many other places around the world kind of at the
same time. So in twenty sixteen, there were these outbreaks
in you know, far flung places of this kind of
new pathogen, which was kind of frightening. And one of
(16:45):
the things that the scientists that I spoke to at
CDC had said was, we wondered, was it something we
just couldn't detect before and now we detected it, So
was it something that was just misdiagnosed and now we
know that it's something different? And so they could go
back into the archive. They'd had some programs running where
you know, physicians were taking samples of fungi from patients,
(17:06):
and it wasn't that case. It wasn't that they were
detecting it now and not before. They found a few
cases that had been misdiagnosed, but most of them were
really new cases, so it really was an emergent fungus
in that case. So it's a very rare thing to
have a new disease like that just sort of emerge.
And this one was so deadly, and it was resistant
(17:29):
to a lot of the anti fungal medications, and it
was hard to clear from a room, although they now
you know, have learned better how to you know, sterilize
a hospital room.
Speaker 1 (17:38):
Afterwards, let's take a quick break and when we get back,
there's still so much to discuss. Welcome back everyone. I've
(18:03):
been chatting with doctor Emily Monison about her book Blight
Fungui and the coming pandemic. Let's get back into things.
I do want to take a moment because I feel
like I have to ask, even though I'm sure you
get this question a lot since writing this book, to
go into the fictional.
Speaker 2 (18:19):
World a bit.
Speaker 1 (18:20):
Have you ever played The Last of Us or have
you watched the show? And if so, any thoughts.
Speaker 3 (18:27):
I have not played the game, but I did watch
the show. So because it came out right before the
book came out. So one thing was so it came
out in the in January twenty twenty three. So one
striking thing was right after that came out, there was
so much about fungal pathogens in the news, and in
(18:48):
the end of twenty twenty two, the World Health Organization
had just made this big announcement of these nineteen you know,
priority fungal pathogens, and so they were trying to get
it out there in the news. You know, here are
some fung guy that we want you all to be
aware of. And that didn't really make such a splash.
There was maybe a couple of weeks of the news
(19:09):
that you know, World Health Organization has these priority fungal pathogens.
Then Last of Us comes out, and you know, fungal
pathogens are everywhere. So it was sort of like that
show did an amazing thing for awareness of fungal pathogens.
The one thing that I just cringed from in the
show is only mostly that you know, they had no
(19:33):
concern about spores, you know, so they'd be going in
where they're dead zombies and you could see the you know,
my cilia or whatever all over the place, and you know,
nobody's worrying about breathing in the stuff. But you know so,
But I since read you know that they didn't want
to put masks on all the stars. Would you can
imagine why?
Speaker 2 (19:54):
But yep, yep, okay, that makes sense.
Speaker 1 (19:57):
And speaking of masks, I read that you worked on
this book a lot, or at least wrote a lot
of this book and researched for this book during the
COVID pandemic. What was that experience like compared to previous
books that you've worked on, and another two parter, how
did writing about pathogenic fungui during a pandemic shape this book?
Speaker 3 (20:20):
Yeah, So for this book, I had this, Like the
other books, I've just sat at home and read a
lot of papers, called up some scientists, and so for
this one, I'm like, I'm going to do a better book.
I'm going to go visit laboratories and I'm going to
go see bats and bat caves and frogs and the
you know. So I had this I was going to
travel and be right there with the scientists, and so
(20:42):
that's what didn't happen. I did get to Costa Rica
and we went to a banana plantation, which was really
cool and I'm glad I had that experience. But yeah,
the rest of it was sitting at home talking to
science except over zoom, so that was different. I also
felt that a lot of them were kind of more
relaxed because they're sitting in their living rooms talk to me.
And I think the other thing was once I realized
(21:05):
that we were really in a pandemic, I had this
book called Blake in the kind of pandemic, I asked
my editor, I'm like, do you really think people are
going to read this? Maybe I should stop writing it
because you know, And the last thing is that it
also since it's come out talking about the title, you know,
(21:27):
when I was before, when I proposed it and was
writing it, there hadn't been a pandemic like this, and
so the time, you know, pandemic wasn't such a hot
button word. I don't think, you know, And I chose
it because I was trying to say that, you know,
some of these funky are like, they're big outbreaks there,
not just an epidemic here. You know, small outbreaks here
(21:49):
and you're an epidemia. So you might have thoughts on
using the name a word like pandemic. But I wanted
people to think about it in a large way. But
then we had this global viral pandemic and I'm like,
but not like that.
Speaker 1 (22:03):
So right, right, right, no, And I think I think
it's a completely apt term. I think that we tend to,
maybe in part because of COVID, think about pandemics as
in happening to humans, especially very human centric ideas of
what a pandemic is.
Speaker 2 (22:21):
And that's not necessarily the case.
Speaker 1 (22:23):
But anyway, so all that is to say, is that
I love the title, and I think that it is
something that we are a little bit in part, have
this human bias where we don't think about fungi as
much as we do, you know, bacteria and viruses, things
that we're more familiar with, and humans represent of course,
(22:45):
only a small proportion of organisms impacted by fungal pathogens.
You know, some frog populations around the world have been
absolutely devastated by b D a cattrid fungus that we
did an episode on like years back. At this point,
can you talk about why frogs are so susceptible to
this pathogen and what the latest is on this fungal
(23:07):
pandemic and are there any glimmers of hope out there?
Speaker 3 (23:11):
Yeah, well, so I only know what I've learned from
the scientists, and I spoke to Karen Lips, who is
one of the lead scientists, and you know, she sort
of experienced this decline. It's a good question about why
frogs are so susceptible. So part of it is is
that their skin they you know, carotin and their skin
just like we do, and it's food for the Kittrids
(23:33):
are aquatic. So that's one thing is that they'll spread
their spores into the aquatic ecosystem and then that can
spread easily move her on. Frogs breathe, they're basically breathing
through their skin, and so this is a skin pathogen
and so once it infects the skin, it you know,
it will poke through and send out its spores and
(23:55):
when it does that, it's completely ripping apart the frog skin.
So you've got this skin that's very important for managing
electrolytes coming in and out, and then you've got all
these it's just being shredded by this fungus that's eating
the skin and then growing and sending out its spores
through the skin. And so that is what kills the frogs.
(24:18):
They're not I mean they are. So there's this obviously,
it's it's impacted a lot of different species. So that's
another thing is that it's not species specific. It's impact
a lot of different frog species. There's a very similar
fungus and I do think that VD I might misspeak,
but I think BD can also impact salamanders who have
(24:39):
a similar part of their lifestyle, but it's not as
problematic in salamanders. But there is another caterried fungus that
has become called B cell that does impact salamanders, and
that outbreak for that was in Europe, and there's a
(24:59):
lot of concern. We have some really biodiversity hotspots here
for salamanders, and there's a lot of concern that if
that B cell enters the US. You know, what happened
to frogs around the world could happen to the salamanders here.
Speaker 1 (25:13):
It's alarming, especially because there is so much global exchange,
global movement, global trade of thousands of species of plants
and animals. And in your book you use this great
term conveyor belt of disease. So what role has this
conveyor belt of disease played in fungal outbreaks?
Speaker 3 (25:35):
So just about every fungal pathogen that I wrote about
was an emergent disease, and it was emergent in large
part because of trade and travel. So every fungus you
know that became emergent pathogen is because it was brought
to a new place and it found something to infect
(25:56):
that had never seen it before. And that's how why
it became so devastating. Those organisms had no defense. So
the movement of plants and animals and us too, I
mean there are some outbreaks that you know, what happened
to the bats, which the white nose disease is thought
to have been kicked off by cavers bats living caves.
(26:20):
That's a pathogen that has killed bats across in the
East and is moving across the country. And it was
discovered also that that pathogen does infect bats in Europe,
but it doesn't kill them, and it's in the caves
in Europe, and so it's believed that you know, people
tramping around those caves then came here, tramped around in
(26:41):
caves here, left some spores disease.
Speaker 1 (26:44):
So yeah, movement, movement, I mean, it's a real driver
of the spread of pathogens and fun guy, especially because,
like you've talked about, the vast majority of the fungi
we encounter our or the pathogenic fungui that we encounter,
are stable in the environment, and so they're or long
(27:08):
lived in the environment, and they're there, they stay somewhere
for a very long time. They're they're very sticky in
terms of you know, not being able to get rid
of them, and that's I think one thing that makes
them so I don't want to say scary, but like
kind of alarming in that sense of like, once it's here,
it's here. But the other thing that I find really
(27:29):
both you know, fascinating and terrifying about some fungal pathogens
of humans, especially going back to the humans, is that
some of them can be incredibly deadly even with treatment.
And I know that our treatments are somewhat limited in
in you know, what they can do. But why are
some of these fungal pathogens so very deadly?
Speaker 3 (27:52):
Oh, that's a good question, and I'm not a physician,
and I don't really have a good answer for that,
except that when we're thinking about some of the people
who are infected, that they're immunocompromised, so that gives the
fungus some advantage. I think some fungi are also good
at evading the immune response, so there's that, And I
(28:15):
do think part of it is just that some of
them are hard to treat because there aren't that many
antifungal medications. There are very few classes of antifungal medications,
and so once of fungus can overcome all of them,
there aren't that many options after that for treatment. So
resistance to antifungal medications is a real problem.
Speaker 1 (28:37):
Most if not all countries have regulations or laws that
limit the importation of plants or animals into the countries
in part to try to prevent pathogens from coming in
and affecting these immunologically naive populations.
Speaker 2 (28:53):
But these laws aren't perfect.
Speaker 1 (28:55):
And you pointed out one gap with like humans just
not knowing that we're transporting the fungus responsible for white
nose syndrome on our boots. If we're cavers and we're
going from one airport to the next, and what a
cool cave. Let's pop in that one and then go
back home, pop in that one. So there are some
of these gaps that we see, but there's also seems
(29:17):
to be sometimes resistance to stricter laws or longer quarantine periods.
Why is there some resistance And that's kind of a
both a big and simplistic question at the same time.
Speaker 3 (29:30):
But yeah, to why there's resistance, I mean, I think
sometimes it's just such a big ask in many ways,
and then some people would say it's not a very
big ask, and I think what I wrote about was
sort of. So there were two things, and I have
to say right up front, regulation not my strong point.
I find them very complicated to even you know, to
(29:50):
try to dig into the history to understand the current regulations.
The biggest gap that I came across, and I think
that people would point out, is that for play plants
since the nineteen hundreds, because there were a lot of
outbreaks in plant diseases. The USDA, I think it was,
(30:10):
you know, there was a lot there was a big
fight between a couple of different factions of people who
want to bring in plants from all over the world
and people who said no, no, no, those are bringing
in pests and pathogens, and so there was a big fight.
But in the early part of the nineteen hundred they
actually did eventually come up with some regulations about quarantines
and you couldn't bring soil in and you couldn't do this
to protect plants. So plants there is, you know, there
(30:33):
is some healthy regulations. And we actually have a national mycologist,
we have two, so that's a position and their role
is to identify odd things that come in in plants
that can't be identified and that might be pathogenic. And
so they're sitting there in their labs constantly looking and
a lot of stuff comes in. They look at a
lot of different kinds of mostly fungal spores, because that's
(30:56):
how they can identify them. So we have these people
looking at for plants pretty much, and still we get
plant pathogens slipping in. Okay, we don't have the same
thing for animals that are pet trade animals, and you know,
so for food animals we do because we're worried about
humans and disease and her food. But for other kinds
(31:16):
of animals that are in trade, there is not. For
a lot of them, there is no you can't come
in with this disease. You know, they're not checked for disease.
Part of it is a capacity thing, and part of
it is you know, I can't tell you why not.
So now we're talking about millions of animals coming over
(31:37):
and crates of animals and things like that. How difficult
that is. So that's a big gap, and it was
almost shocking. I had to ask a lot of times.
I'm like, you mean, there's no national mycologists equivalent for
animals because this seems so important and there isn't. So
I will say one more thing, just about when I
mentioned the BD and the salamander, So this is something
(31:58):
that's kind of good that came out. I mean the
b seal in the salamander. So I mentioned that there's
concern that this cattrid fungus that's in Europe will come
across to the US. And so those scientists that were
working with frogs and knew how devastating the disease could
be of the kittred BD could be in frogs got
(32:20):
together and they first tried to have some new regulations
there's some enforcement about bringing disease frogs into the country,
and that really didn't go anywhere because the response was,
we already have the disease here, so how are we
going to stop it? But when the B sal came
along in the salamanders, they got together again and they said, hey,
it's not here, maybe we can stop it. And what
(32:44):
happened and they worked with it was you know, nonprofits
and federal agencies and you know, academics all working together
to do this. And what they did come up with
was in the end a list of I think two
hundred and maybe nine or something salamanders that cannot come
into the country because they are known carriers of B cell.
So it's not exactly what they wanted, which would have been,
(33:06):
you know, you just can't bring you have to be
tested for diseased or get a health certificate that says
you have no disease. But it's a it's a step
and so and so far we haven't had b cell here.
There is monitoring for it, but so that's kind of worked.
But that's really you know, when you ask about regulations,
how you do things, and you know that took a
(33:27):
lot of effort.
Speaker 1 (33:29):
On this podcast, we're mostly talking about animal diseases and
animal immune systems, but as you discuss in blight, plants
especially trees are incredibly impacted by fungal infections. How do
tree immune systems work? And like why are they so
susceptible to some fungi?
Speaker 3 (33:50):
So trees have they do multiple things. So they grow,
they have you know when you look at bark, that's
like our skin first line. But they also do this
thing where they grow, you know, in layers, right, so
when you sometimes see the inside a tree that looks
kind of there's nothing there, it's it's dead. And so
they grow and they can wall off pathogens. It's just
(34:14):
the way they grow. And so that's one defense is
that if you know, something gets infected, they can kind
of just grow around it wallet off and don't need
that part. They don't need a branch or like we
need our arm. So that's one thing. But the other
thing they do produce a lot of chemicals. I mean,
we know this in plants, right because we either use
a lot of plant chemicals for drugs or whatever, and
(34:34):
a lot of these sort of secondary chemicals that they're producing,
including things like alkaloids that might make foods bitter, are
defenses against pathogens. So that's another thing that they'll do
is they can produce, you know, different kinds of chemical
products to fend off disease and in pests too, insecte pests.
Speaker 1 (34:59):
When that doesn't go according to plan, it can be
incredibly dramatic and awful. So one of the most tragic
stories of a fungal epidemic is chestnut light And it's
just so hard to wrap my head around how different
some North American forests looked like before this epidemic struck.
(35:21):
So can you take us through this tragedy, you know,
how it was first recognized and then what led to
this dramatic and rapid change.
Speaker 3 (35:32):
Yeah, so chestnut trees the American Because a lot of
people around me are like, wow, but I just got
some chestnuts. I'm like, yeah, but they're not American chestnuts.
If you got them from you know, the farmer down
the road, they're probably some hybrid. So American chestnuts were
huge trees, beautiful trees, very productive. They ranged along sort
of the Appalachian Range and up along the East Coast.
(35:54):
There were really important trees in many ways, both to
humans and ecosystems. And so the story of the demise
of the American chestnut kind of begins at the Bronx Zoo.
So when they were first developing the zoo, the society
that wanted to bring these, you know, have these exotic
animals on show and everything, they were also very interested
(36:16):
in the trees on their property. So they had a
lot of acreage and they had a lot of old trees,
and so they thought that those trees were just as
important almost as the animals that they were going to
bring in, and so they hired a forester. He was
in charge of the trees and it was his job
to make sure that all the trees in the park
were good, healthy, whatever, and plant other stuff in the park.
(36:38):
And so he knew all the trees in that park,
and there were something like over a thousand chestnut trees,
and they were some of them were, you know, the big, old,
beautiful chestnuts. And so I think it was in nineteen
oh four that Merkel noticed on a couple of chestnut
trees some of the leaves were kind of curling and
looked like they kind of looked like it was fall.
They were sort of dying at a time when they
shouldn't have been. So thought, well, this seems like some
(37:01):
kind of disease. And he could see some little spots
on the trees, and he thought, you know, maybe it's
a fungal disease, but just a few trees, maybe won't
come back next year, so you didn't worry about it.
Nineteen oh five, almost every tree in the park was
infected with this fungus and their leaves were curling up
and dying, and so he at that point, you know,
(37:23):
got worried, called the USDA asked what to do. One
of the things that they did at the time what
to treat fungal pathogens, which I thought was interesting because
we still use this to treat them with copper. So
copper is an organic fungicide and it is effective against fungus,
but it's topical. And so the response to him was, well,
cut off the dead branches and you know, treat the
(37:45):
trees with copper. Well, you had a thousand you know,
big old trees that wasn't really in you know, in
early nineteen hundred that he tried to do that, but
that was not that effective and it was just overwhelming.
He brought in a colleague from down to the botanical
gardens and he identified as something different, and he identified
as what would become known as chestnut light. By the
(38:06):
time he figured out what it was, you know, within
that year and identified that it was in fact the
organism that's infecting and killing the chestnut trees, he predicted
that all the trees would probably be infected and dead
within a few years, and he was right. And what
happened from there is that the blight spread from New
York all the way down through the Appellachians, killing chestnuts
(38:30):
just about every single chestnut tree, millions of trees, maybe billions.
Within decades, there were no more American chestnut trees growing. Now.
People also cut down the trees in part to maybe
make a fire break of infection, you know, to stop
the infection, and also because chestnut wood was so valued,
and you know they were going to try to stop this,
(38:53):
and nothing stopped it. One thing we haven't talked about
is spores. So you know fungi makes except for Last
of Us, which didn't have spores, but it could have,
and I think maybe in the game it does. I'm
told that they actually wear masks in the game. So anyway,
you know, fungi spread by spores. They can put out
(39:14):
hundreds of thousands or millions of spores, and in the
case of the chestnut light, you know, these trees would
be infected the funguses putting out spores. The wind can
carry spores, and these spores can be carried by birds
and insects that you know go to the trees and
then go to the next tree, and so you know it,
it just it spread rapidly and it was unstoppable. As
(39:36):
that was happening, as they were realizing that they're losing
these valuable trees, they wanted to understand something about the
fungus and so there were these people called agricultural explorers
around nineteen hundreds, which was part of that fight. Remember
when I said there was the argument about you know,
collecting and bringing in stuff from all over the world,
but so wrong with that. So they had these and
(39:58):
there were you know, dedicated explorers who would do that.
They'd go all over the world looking for plants and
fruits and you know, crop plants and trees and bring
them back. And so they're happened to have an explorer
that was going to China or he was in China
at the time. They got in touch with him and said, hey,
you know, there's this fungus on the chestnut tree. We
know there's chestnuts in China. Can you see if this
(40:19):
fungus is there, you know, identify this fungus on those trees.
And he did, and what he also noticed is that
those trees weren't really impacted by the fungus. He got
word back and so you know, in the end, what
people figured is that some of those trees that had
been imported from either China or Japan people, you know,
they're very popular. There's still we have neighbors with Chinese
(40:41):
chestnut trees. Still that fungus probably came in on some
of those imports and then spread throughout the country. But
that understanding that now they know that the Chinese chestnut
trees have some kind of resistance against the fungus because
it co evolved with it, right, the two of all
over how many hundreds of thousands of years together, that
(41:04):
maybe there might be some way to use the resistance
of Chinese chestnutrees and breed it into the American chestnut trees.
So that started a whole new program to try to
bring back American chestnutrees. One thing that I haven't mentioned,
because we are so human centric, is that each time
you do this, you're changing the whole ecosystem. And so
(41:25):
you remove a key species like that, you remove a
frog or a bat, and it changes things and it's
not you know, it doesn't always have to. Sometimes it
is still relevant to us that the ecosystem has changed.
But you know, you can just imagine the changes that
happen when this occurs and you take a whole species
out of a.
Speaker 1 (41:45):
System, instant, huge transformation with unforseeable consequences. And there are
some consequences I think that are a bit more easily
seen when it comes to agriculture, and especially a lack
of biodiversity in agricultural practice, so monoculture basically, So, could
(42:07):
you take us through the story of bananas, This fruit
that we eat so much of all the time around
the world, and maybe we don't ever give a second
thought to the banana that we hold in our hands.
Speaker 3 (42:20):
Yeah, So the banana story which we did, you know,
like I mentioned before, it got to go to Costa Rica,
went to this place called Earth University, which is a
really cool place. They're growing bananas sustainably because it's difficult
to grow banana sustainably for a couple of reasons. One
of them is fungus no matter where you grow. But
(42:40):
the story that I focus on there is the story
of a fungus called tr ie. It's an oxysporum, some
kind of fungus. And so back in the thirties, forties
and fifties, banana's big business. They were grown on these
huge monocrop plantations in Costa Rica and Swear Honduras, and
(43:04):
they at that time there was this fungus that emerged
and it started killing those bananas. And the bananas that
we ate were called the gross Michelle banana, and so
they call them dessert banas, the bananas that we were
all eating. So I should also clarify that there are
many there are different kinds of bananas. We happened to
eat one, as you mentioned, that's grown in a big monocrop.
(43:27):
Basically clones, they're just clones of each other. They're not
even because banas don't have seeds, so they're really really clones.
A lot of people eat other kinds of bananas, So
this particular fungus impacted the banana that we were all eating,
the banana that was grown, the growmy shell that was imported,
(43:47):
and it was devastating to those crops. And interesting I
didn't bother the other kinds of bananas, but it was
the industry that got worried. And so basically at that time,
back in the fifties and sixties, there were concerns that
they might not have any more bananas because that's a
fungus that when you talk about scary spores, that's the
one that makes spores and it can make this kind
(44:09):
of spore that some scientists say has been detected in soil.
So it's a soil born fungus. Means that it's in
the soil, then it gets up through the banana from
the soil, makes spores. It can last in the soil
for ten years or more so decades. So this is
a kind of thing that once it impacted plantation, got
(44:29):
in the soil, you just can't grow bananas there anymore.
And so what the industry would do back then, because
it was not a great industry, would just be to
move to another place and grow their bananas there, leave
behind the other land that they you know, so they
just kept moving. But it became clear that they were
going to be out of bananas, and so around that time,
(44:51):
there was a you know, discovery that there was another
kind of banana called the cavendish that was not susceptible
to that fungus. So that was a very you know,
that fungus was very specific for the gro michell banana,
and so they replaced the gross michelle with cavendish, which
is what we eat. But they basically did the same thing.
So they just planted huge monocrops of banana, same kinds
(45:14):
and cloned banana everywhere wherever banas are grown for export.
I think it was in the seventies, maybe slowly, a
new kind of fungus emerged called TR four. So the
first one was called tier one. The second round, Tier four,
similar kind of fungus, causing the same kind of problem,
(45:36):
and it is frightening growers. It was believed to be
transported in soil, so that would have been in boots
of people or farm machinery that was transported from one
place to another. But one of the scientists I spoke
to said, you know, even though we know that, I
don't think that that's the only way it spreads, and
that that would really stuck, you know that, even if
we were totally hygienic about this, But there are you know,
(45:59):
you used to be able to go in Costa Rica.
I think if you went several years ago before TR
four became a problem, you could go take a tour
of banana plantation, which is just really it's fascinating to
see how much care the bananas that we eat. We
don't pay enough for our bananas. Let's just say that
they require a lot of care. And so used to
(46:20):
be able to go there and see how they do that,
and that you're not allowed to do that anymore because
there's too much concern about TR four. So we're kind
of fortunate to be able to get a tour of
this smaller plantation. But yeah, so there's TR fours out
there and there are concerns about you know what will
be next. And so some of the banana breeders and
(46:41):
people who work with bananas have said, you know, yeah,
we might lose this banana, but there are a lot
of other kind of bananas. And so one thing to
think about is that when we you know, when I
was growing up, there are a few different kinds of
apples and that was it. And now it's I'm boggling.
I think just in the last two years, how many
(47:04):
different kinds of apples there are out there. So there's
you know, that that different kinds. If we are open
to having some diversity in our banana, that would be great.
And another thing is is that growing these huge monocrops
with you know, so there are other ways. That was
one of the things that the scientists that I had
visited was doing was experimenting with how to grow large crops,
(47:28):
but not in these big monocrops, to have them in
blocks and have other stuff planted, you know, agro ecology
or grow forestry whatever, have other stuff growing in between,
other crops growing in between, so that the you know,
a disease can't spread so easily. So there are ways
of doing, you know, dealing with this, and it's just
that we you know, we we need to either change
what we want and what we accept and also how
(47:50):
we grow things diversity. You had mentioned diversity, So I'm
glad you said that biodiversity before because it reminded me
that that's one of the most important things for all
of this is the and that we need to understand
and do whatever we can to preserve biodiversity across species,
no matter what we're talking about.
Speaker 1 (48:09):
It's it's amazing to me that we are provided, you know,
learning opportunities all of the time, from fungal pathogens, from
other types of pathogens, from don't you know maybe giant
monoculture is not a great idea, and that we have
to keep relearning those lessons over and over again.
Speaker 3 (48:27):
That's that's a problem. It Meanswediam won't to learn them.
Speaker 1 (48:31):
Yeah, exactly, because if we're not, if we're learning them
over and over again, we never learned them in the
first place. But so for my last question, I want
to go back to the title of your book, blighte
Fungi and the Coming Pandemic, and I want to ask
you not about like why we should be wary of
fungal pathogens, because I feel like we did a pretty
(48:53):
good job covering that so far. But I want to
ask about what should give us hope in our ability
to detect or control or treat a possible fungal epidemic
in the future.
Speaker 3 (49:06):
So one start is awareness. So just being aware when
we talk about you know, you go to the airport
and they ask you to not take any plants or
plant bits or whatever, pay attention. There's a reason for that.
There's hope in new developments, like we talked about better analysis,
(49:28):
faster analysis. You know, if you can you know diagnosis,
if you can have rapid diagnosis that sorts of thing,
there is some hope there. You know, I would hope
that with trade and travel, but trade, that we can
be more aware of sort of what we want. There
are some people that say, well, why do we need
(49:49):
to plant, you know, plant plants from other countries. Why
don't we just you know, grow what's native. So that's
why not, you know, really and similarly, I think there
are people who would like to see less animal trade
or and you know, the flip side of that is
that some people say, but then when you do get
to have a salamander or some kind of odd lizard,
(50:12):
you develop an awareness for that animal and you know
some kind of you want to save that animal. So
there is you know, it goes both ways to this
kind of thing. I think that just having some greater
awareness grow things in different ways. I think, you know,
people in agriculture are beginning to understand and think about
(50:32):
how to grow crops differently so that they're not so
disease prone. Just diversity in what we eat and what
we want. You know, why do we just want one
type of wheat? Maybe we could be eating all sorts
of different grains, which we're just starting to do. But
you know, that's that's one way. So there are those
kinds of things. Is that we just have to be
(50:53):
open to more diversity in what we want. We also
have to be aware of protecting a diversity that's out there,
and just more cognizant of how we all live in
this one world. You know, plants, animals, humans, we're all
together in this one world and we all impact each other.
We're not in our little human bubble. Everything interacts with
(51:16):
each other and we really need to take that seriously.
And I think and if COVID didn't get that us
thinking that way, I don't know what will which is
kind of a sad note to end it on, because
I'm not sure, you know. I do think there's more
awareness of ecosystem health, how important that is for diseases
and things like that. So we just have such short memories.
(51:37):
That's the problem, you know.
Speaker 1 (51:58):
This conversation just rein forced how amazing and fascinating fungi are.
Doctor Monison, thank you so very much for taking the
time to chat with me. We covered so much ground
in this convo, but there is still so much more
to the world of fungal pathogens that I'm sure you
all want to learn about. If you find yourself craving
(52:19):
more fungi facts, check out our website this podcast will
kill You dot com. We're all post a link to
where you can find blighte Fungi and the Coming Pandemic,
as well as a link to doctor Monison's website. And
don't forget you can check out our website for all
sorts of other cool things, including but not limited to, transcripts,
quarantine and place be reader recipes, show notes and references
(52:41):
for all of our episodes, links to merch our bookshop
dot Org, affiliate account, our Goodreads list, a first hand
account form and music by Bloodmobile. Speaking of which, thank
you to Bloodmobile for providing the music for this episode
and all of our episodes. Thank you to Leana Squalatchi
and Tom Bryfogel for our audio mixing. And thanks to
(53:01):
you listeners for listening. I hope you liked this bonus
episode and our loving being part of the TPWKY book Club.
And a special thank you, as always to our fantastic patrons.
We really really appreciate your support so much. Well, until
next time, keep washing those hands.
Hosts And Creators
Erin Welsh
Erin Allmann Updyke
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