Mary Parker:
I'm Mary Parker, and welcome to this episode of Eureka's Sounds of Science. Two years ago, I was joined by someone who became one of my favorite guests ever, Ziva Abraham, CEO and founder of Microrite. She is an expert on mycology, or the study of fungi. In a rare occurrence, this expertise is a hot topic in both the scientific and popular entertainment fields right now. In real life, scientists are battling the ever-present threat of fungal contamination in the lab, including hard to identify organisms like bacillus cereus. On television, Pedro Pascal is battling the fictional threat of fungal zombies in the series, The Last of Us. Ziva's here to talk to us about the real dangers of fungi. We might not need to be afraid of zombies, but we should still respect the spores. Welcome Ziva.
Ziva Abraham:
Thank you, Mary.
Mary Parker:
So I'm dying to know, did you overcome your squeamishness to watch some of this show? It wasn't that bad violence wise.
Ziva Abraham:
I have to be honest with you, I watched the show in parts. You may laugh if I tell you I ask my husband to watch the scary parts, and I open my eyes only for the non-scary parts.
Mary Parker:
That's fair.
Ziva Abraham:
Then I got the gist of it, watched some parts with the fungus where the fungus infects humans and then spreads. Looking back, I should not have been scared as I dealt with zombies during my PhD research.
Mary Parker:
Really?
Ziva Abraham:
Yep. For four years, my job was finding the zombies in the field, and you'll be surprised, I rode motorbikes, isolating the organisms, growing them, identifying them, and then developing mass spore production methods, and taking the spores to the fields to make more zombies. Never had I dreamt that these entomogenous fungi would become talk of the town.
Mary Parker:
Yeah. Well, I think the show is based on a video game that was quite popular. So I guess ever since the video game came out, people have gotten more interested in these fungi.
Ziva Abraham:
They sure have.
Mary Parker:
Well, we'll get into the zombies a little later, but let's start with the real world threats. So what are some of the dangers and undiscovered fungal contamination in a pharma lab?
Ziva Abraham:
So you know fungal contamination have been on the rise and are becoming more prevalent since the seventies. And I'm going to give you my personal experience. I was a clinical scientist in Israel and my job was to introduce new technologies. So in the seventies when we discovered HIV and we had a lot of patients, we used to get sputum samples. Normally, sputum samples will have gram-negative bacteria like pseudomonas or bacterial pneumonia. And we started seeing pneumocystis carinii. Pneumocystis carinii is a natural habitat of the lungs, but if the person is immunocompromised, even your normal flora becomes pathogenic.
Well, we had to develop media to grow it. But very fast, pneumocystis carinii subsided and we started seeing aspergillus fumigatus. Today, aspergillus fumigatus is the prevalent organism that kills people who are immunocompromised and who have fungal pneumonia.
So recently, last December, WHO released a list of 19 fungi in order of criticality. This has gotten the attention of the regulators and industry alike. And I hope everybody takes fungi seriously because there are more opportunistic fungi today than there were 50 years back. Just an example to see how opportunistic they are, people who survived COVID in India got mucormycosis, that is a pneumonia from mucor. Mucor belongs to the family of bread mold. This is how fungi infect. They see weak tissue, they have something to anchor to, and there they are, they anchor to it, proliferate. So I think the industry has to take mold seriously. Gone are the days of black mold, blue mold, so on, so forth.
Mary Parker:
So why is it important to know which species you're dealing with? Why is fungal identification important?
Ziva Abraham:
Let me tell you, you cannot catch a criminal without a name or with first name only. I think everybody should remember, unless you know what the isolate is, you cannot investigate. As I mentioned, knowing the mold or the criminal's name provides the information to investigate and then to remediate. Mold has various sporulation patterns. So in short, I'm going to tell you in layman's terms, zygomycota, ascomycota, deuteromycota are the main classes. Zygomycota has asexual and sexual spores, right? Asexual spores are easy to kill and sexual spores are hard to kill.
But the trick here is that many deuteromycota fungi, which create only asexual spores, may switch their sporulation pattern and go to sexual, right? And if you don't identify, you will never be able to know the information you need to remediate or even to assess the objectionability of the mold. So if you have a deuteromycota fungi, you have to know whether it has a sexual stage, that means it'll be difficult to kill. You might have to look into your disinfection program, right? Also, the ID will tell you if they're cellulose or non-cellulose. Cellulose are the ones that come from wood, paper, cardboard. So that information helps you to investigate.
Now some mold like colder climate, knowing the ID will lead you to your refrigerators and cold rooms. And examples of these are your cladosporium and your aureobasidium. Those are very predominant, right? Some mold proliferate fast, little food and little moisture, and they go off making millions of spores. You should know which are the fast proliferating ones so that they don't take over your clean rooms or your labs. Only if the ID is valid will you know the mold and its resistance to disinfection, radiation, or heat. So ID is very important.
Mary Parker:
So it's important to know what species it is, not only to know how to kill it, but also to figure out how it might have gotten in there in the first place.
Ziva Abraham:
Exactly. Because there are three parts to any investigation. It's ingress, transport, and proliferation. Ingress, where does the ingress happen, where does the mold come from? Mostly from the outside, rarely we see mold growing, only if we have leaks or conditions for it to grow. So you want to know upfront. And transport, you can transport it through your air flows, material flows, personal flows, waste flows. So if at the ingress point you know which mold is coming in, then you will be able to protect your critical areas and your product, but also either stop it from coming in or kill it as soon as you can.
Mary Parker:
Yeah. So you've written that fungal spores can live in the vacuum of space, in extreme heat and cold, and even in the soil contaminated by the Chernobyl disaster. So what are some of the ways to mitigate fungal contamination if they're so hardy? And would those methods work on fungal zombies?
Ziva Abraham:
Like the zombies a lot. In my mold contamination investigations, I'm talking about the zombies, I've seen cordyceps being isolated in the environment, which means they had insects coming into the corridors, either through the entrances or interstitial space. If you have broken tiles or leaks or you have air curtains, you are actually introducing these insects and they're there. The zombies are there. You won't believe me. I have gone to investigations, and I like to analyze the data and explain to people what the mold are, where they have come from. And many a times people are surprised how I know they had insects in the clean room. I said, I didn't see insects, I saw the zombies, right? Cordyceps.
These are called entomogenous fungi, the zombies that you call. Finding entomogeneous fungi in environmental moVnitoring is not uncommon, but due to the lack of mycology knowledge, QC personnel do not analyze these identified recoveries. So I highly encourage people to learn a little more and analyze what you have. Mold will give you clues. They will say, I am this person, I come from here, I'm hiding here. If you analyze it, you will be able to do your investigation more effectively and your remediation plans will be more effective too. Now cordyceps, for example, is an ascomycotas fungi, it has sexual stage, it's hard to kill. So you don't want those in your clean rooms. Now, like the other cellulose ascomycotas fungi, those that come from cardboard and all that, those are best kept away.
Mary Parker:
Can you tell me about cordyceps and why it might have been chosen as the zombie fungus in The Last of Us? Why'd they pick it?
Ziva Abraham:
I will tell you why, okay? Again, this is one visible, you can see with the naked eye, fruiting body of the fungus. Others are micro fungi, belonging to deuteromycota. And it's fascinating and it's been around for a long time. And I think the reason is that cordyceps seems to be all the rage right now. You see them in every adaptogen or pre-workout supplement, and they've been talked about extensively in the mushroom community and are considered as one of the top superfoods.
Now, there are other entomogenous fungi, which are highly adapted pathogens to the host. Have you heard the term flying salt shakers of demise?
Mary Parker:
No.
Ziva Abraham:
Okay. So the mold will initiate... It's in the cicadas, okay? It's where the mold will initiates sporulation within its cicada host, which is still alive. Eventually the abdomen is entirely consumed, leaving just the head and the thorax of the living insect. Then the cicada's ability to fly is retained increasing dispersion. So it eats up everything and it tells cicada, fly so I can spread everywhere. How intelligent, isn't it?
Mary Parker:
That's so gross, but also awesome.
Ziva Abraham:
Yep.
Mary Parker:
So is what they say in the show true about fungus not being able to live in human bodies? That doesn't sound true to me.
Ziva Abraham:
Okay. So the human body's average temperature is what? 98.6 Fahrenheit, and has long been too hot for most fungi to survive, right? That is what the infectious disease specialists say, but this is not an absolute. If you look at the various infections, including blood infection, yeast and mold, they happily live and replicate in the humans and even form biofilms. I don't know if you follow candida auris right now, it's hot topic in the medical industry. It is so well adapted to form biofilms, so we are really in the baby stages of understanding fungi right now. I think people will start paying attention.
Mary Parker:
Yeah. I mean, if the show does nothing else, but bring attention to how cool fungi is, I mean, that's a win for me.
Ziva Abraham:
Oh yeah, I'd love it. I'm glad.
Mary Parker:
Does transmission through cereal grain make sense? And why wouldn't an antifungal medication work for these infected people?
Ziva Abraham:
So many species of fungi called molding of the grain, right? Most becomes associated with the grain when it is still in the plant, in the field, but may continue to grow and reproduce if the grain is stored under wrong conditions of moisture and temperature in the bin. Now, you have to remember, not all grain mold fungi produce microtoxins. Now also, not all mold that grows on the grains will necessary in infect humans.
So again, not all cereal, grain mold will infect, but some are common, right? Now, the question about antibiotics, we don't have enough antifungals. So with the rare emerging infections and the tough to kill mold, I think it's a challenge in the medical field. Also, we don't do testing enough testing for fungal infections because we are so focused on bacterial infections, there's not much literature on fungal infections. I think the whole medical community, that is the doctors and clinicians, are waking up to the fact that they have to look not only for bacterial infections, but they have to also send tests for mold related infections.
Mary Parker:
Okay. Well, that is not comforting, but it's still good to have more information than less. So switching gears a little bit, there's a scene where one of the characters steps on a tendril of fungus and that alerts the zombies who are far away to their presence. And I've heard that there are fungal networks that can sort of communicate mycorrhizal network. So, is that a real thing?
Ziva Abraham:
Well, entomogenous fungi are not known to form such underground networks, if that helps you. But I think they have taken the concept of humongous fungi such as armillaria that has been incorporated into the episode, that they've taken two facts and combined them, right? Yeah, correct. So fungi, you know, they range from minute cells to the largest organisms alive. Honey fungus, if you have heard this, which is armillaria, whose underground network spans large areas covering vast forests. And you know where is the biggest one? In the Blue Mountains in Oregon.
Mary Parker:
Oh, wow.
Ziva Abraham:
A specific honey fungus measures over two miles and is thought to be the largest living organism on earth. So these networks are adaptive, they respond to the environment, allowing the fungi to send nutrients to where they are most required, explore resources, combat enemies, and make urgent repairs. They are the nature's most efficient and resilient network, and all without IT help. So that being said, fungi use many methods of communication in these fungal networks, okay? Quorum sensing, peptides, pheromones, oxylipins, volatile compounds, and gases as communication methods. Isn't that intriguing?
Mary Parker:
Yeah. They have as many ways to communicate as I have messaging apps on my phone, sounds like.
Ziva Abraham:
Exactly. Oh, they're so smart. They're so smart.
Mary Parker:
So, after Indiana Jones and other kind of similar adventure movies, there was a spike in college majors interested in archeology. So what would you say to any aspiring mycologists who are inspired by pop culture to study fungi?
Ziva Abraham:
So I have seen a little uptick in people getting interested in fungi. We have the Nextdoor app, I don't know whether you have it or not, Mary. But it's a great app, we share stuff, I give away my plants. And people have started going mushroom hunting, and people are talking about mushroom hunting. I think mushroom hunting is a lot of fun, but it is sort of a meditation too. You're so focused, right? You're so focused. If anybody has done morel hunting, they will know for hours you won't find and you get frustrated. This teaches you patience. So you don't find morels, you don't find morels, and then all of a sudden you find morel,one morel, and they're all there. And you say, "How come I didn't see them?" Right? So I hope this inspires QC microbiologist to learn fungi.
I've been teaching this hands on course for 30 years. I want them to touch feel, see, as I told you. I know they want to eradicate them, but they're sobeautiful. I hope these episodes will inspire more people to take the fungi as a hobby or as a career.
They've always inspired me. And I think, just read about them. Watch this. I mean, don't believe everything in this episode, as I told you how they've mixed two things together, but fungi are just fascinating. Just fascinating.
Mary Parker:
So what is the coolest fungus fact that you know? Yeah, pick just one.
Ziva Abraham:
Something that got me into trouble with my husband. It's a personal story. So I had a training center in Santa Clara. So I used to teach this hands-on fungal ID course that I'd been teaching for 30 years, and Olympus used to be very generous. They would loan me the Rolls Royce of microscopes. If you know what a Rolls Royce of microscopes is, that is what I want. People want fancy cars, I want that microscope. It's about $75,000 only.
It has the face contrast, it has DIC, it has dark field, and it has fluorescence. So on day three, after all the students left, I did a wet mount of the fast-growing fungi, paecilomyces being one, and aspergillus being another, and I started looking at it under the dark field, and I literally saw them forming spores. I had no idea, I was lost. I had no idea of time. 4:00 AM in the morning, I went, I said, "Oh, I must get some coffee." I went to the kitchenette and I saw my husband at the door, angry. And I opened the door and he said, "Do you know what time it is?" I said, "Absolutely not." He says, "We are all worried. I'm knocking at the door for half an hour." I was in trance, literal trance. If anybody gets a chance to watch this, it's fascinating, fascinating.
Mary Parker:
That does sound meditative.
Ziva Abraham:
That's the best thing. I wish I can do it every time, but-
Mary Parker:
But you'd get in more trouble.
Ziva Abraham:
Exactly.
Mary Parker:
That's fair, that's fair. Well, thank you so much for joining me, Ziva. This has been really fun.
Ziva Abraham:
I want to say one last thing, Mary.
Mary Parker:
By all means, yes.
Ziva Abraham:
I have a prayer. I say in gratitude to fungi for my daily bread. You know why?
Mary Parker:
Why?
Ziva Abraham:
If there were no fungi, there would be no soil, there will be no food for us. If we didn't have cellulose fungi, all the trees that have fallen would be still there, nobody would've broken down the trees to simple sugars, other fungi and bacteria would've come in and broke it down to soil. So we have to thank the fungi, the cellulose fungi for breaking down the trees so we can have our bread, our wine, our steaks. I hope this makes sense.
Mary Parker:
That does make sense. Thank you, fungi.