Antibiotics, Antivirals, and the Fungus Among Us

Antibiotics, antivirals, and antifungals have revolutionized modern medicine, saving countless lives and transforming our approach to infectious diseases. In this episode of our podcast, we delve into the differences between these powerful tools of modern medicine. We explore their discovery, impacts, and the pressing issue of evolving resistance. 

We dive into where we get antibiotics, how they work and why responsible antibiotic use is so important to prevent antibiotic resistance. We highlight the critical role of accurate diagnosis and appropriate treatment of bacterial infections to prevent resistance from developing. 

We also dive in to the intricate interactions between microorganisms and our immune system. For instance, certain fungi and bacteria are essential for maintaining a healthy balance, but under specific conditions, they can cause infections. We discuss fungal pathogens like rose gardener's disease and aspergillus, emphasizing the importance of understanding fungal infections, especially in the context of rising global temperatures and their impact on fungal behavior. 

Antivirals, another critical class of antimicrobials, target viral infections by preventing viruses from replicating. This episode explores the challenges in developing effective antivirals, such as the rapid mutation rates of viruses and the difficulty of targeting viral components without harming host cells. Effective antiviral treatment often requires early administration, and the episode discusses the various forms these medications can take, from pills to intravenous injections. 

This episode provides a comprehensive guide to the world of antimicrobials, blending historical insights and scientific knowledge. We underscore the importance of responsible antibiotic use, the challenges of treating evolving and emerging diseases, and the critical role of the human microbiome. Listeners are encouraged to rethink their interactions with these microscopic beings and appreciate the delicate balance required to maintain health in the face of evolving pathogens. Whether you're a healthcare professional, a science enthusiast, or someone interested in the history or future of medicine, this episode offers valuable insights into the complex and fascinating world of antimicrobials. Tune in to learn more about how these powerful drugs have shaped our past, present, and future in the fight against infectious diseases.

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Transcript

Speaker 2 0:09

This is a podcast about One Health the idea that the health of humans, animals, plants and the environment that we all share are intrinsically linked.

Speaker 1 0:17

Coming to you from the University of Texas Medical Branch and the Galveston National Laboratory.

Speaker 2 0:21

This is Infectious Science, where enthusiasm for science is contagious.

Speaker 3 0:30

All right, hello everyone and welcome to this episode of Infectious Science. We are so excited to be here with you today. My name is Camilla Du and we're going to be talking about antivirals, antifungals and antibiotics and the difference between all of these. So when we get an infection, the drugs to treat it fall into those three main categories and each of them treats a different type of infection. So viruses like COVID-19 or the flu are treated with antivirals, bacterial infections like strep or Lyme are treated with antibiotics, and then fungal infections like yeast infections or ringworm are treated with antifungals. So in this episode we're going to break down the difference between these categories of drugs.

Speaker 4 1:07

Rock on and I guess we can go ahead and we can start with antibiotics, because I feel like that's probably the medication that most people are Everybody's probably taking antibiotics. Exactly. Most people are aware That'd be an interesting study.

Speaker 3 1:18

Are there populations that haven't taken antibiotics? And then what does that look like?

Speaker 5 1:22

And then now studies that show that even species or animals that have not taken antibiotics, that they pick up the antibiotic resistance from humans. Oh, that's pretty wild, right I?

Speaker 3 1:32

wonder too, with like amphibians and stuff, does that affect them? Because if it's in our water supply, so if it's in like wastewater, if you have antibiotic residue, it'd be really interesting. There's been other studies on things that are in our wastewater that are affecting amphibians.

Speaker 4 1:44

That's really interesting. I didn't even think about that. Well, let's get into the general idea of what antibiotics are, and then we'll discuss the effects on amphibian populations. What are antibiotics? A lot of people probably don't know, but antibiotics actually originate from fungi and from soil bacteria, and it kind of makes sense when you think about it, right. So these fungi have been around, and also bacteria have been around for thousands and thousands of years before us, and they were each other's competition when it comes down to it. And what do you have to do in order to survive amongst your competition? You got to have a way to kill them.

Speaker 3 2:19

That's all I'm going to say, especially because it's close quarters, right Like a lot of our antibiotics are from soil bacteria, right, exactly so they're very densely packed together, so if you aren't really moving around a bunch, you got to compete with your neighbors for nutrients.

Speaker 4 2:33

Yeah, exactly, and so the way that most of these antibiotics work. Well, let's be real, a lot of different antibiotics have different mechanisms, right, but some common ways that they work are, for example, by attacking the bacterial cell wall or the bacterial cell membrane, and so it's basically attacking the skin of the bacteria, let's say, and getting rid of the bacteria skin. And if you get rid of a human skin, a human's not going to survive. It's the same thing with the bacteria. So that's one way the antibiotics work. Maybe another way that we can talk about is just interfering with the actual bacterial replication in general. It's definitely a way that we can talk about is just interfering with the actual bacterial replication in general. It's definitely a way that antibiotics can work and that they are effective. And then also by blocking some protein production.

Speaker 4 3:12

But that's kind of getting into the nitty gritty of things. So I did want to talk a little bit about how antibiotics were originally found, though, because that's always a really fun story, and you guys actually corrected me on this when I first told you guys. So in 1928, I believe, alexander Fleming was a scientist, he was working with bacteria, and I think you said that he had tossed his plates with cultures into the trash. And then he came back. He was frustrated, I guess, left the lab, tossed the cultures, came back and noticed that there were these clear spots, so clear zones, where the bacteria was actually not able to grow Around the fungus that had grown Around, fungus that had contaminated the plates, and that fungus came from whatever was in the trash, right?

Speaker 3 3:56

Well, I think as we'll get to later. Yeah we're going to talk about. There's fungus everywhere. So if you're taking a deep breath right now, you're inhaling fungus, I guarantee it. It's really cool to see clearing zones. I used to work at a bacteriology lab and we would treat with different antibiotics on these little discs and then you set them on the plate and I just thought they looked really cool. It's like modern art.

Speaker 4 4:15

Yeah, exactly Because you have this plate. Imagine a plate, guys like full of fuzz or a growth or something right, and then what is a clear zone? It's literally a zone where that growth cannot form. So there are these clear spots on a plate. For those who don't know what a clear zone is or what a petri dish is or what an auger plate is, that's what it looks like, and so you can really make art with it.

Speaker 3 4:39

Yes, also, that's a fun thing to do if you have bacteria that'll fluoresce.

Speaker 1 4:42

Yeah, that was always a thing we would like.

Speaker 3 4:44

I did something. It was not an actual lab activity, it was just a fun science thing. It was very benign bacteria and they were like yeah, like just make your little art Someone made like a. It was like the ocean and a surfboard and it was very well done. It was impressive. Mine was like squiggles, but it still of them.

Speaker 5 5:01

They're so cool, very interesting. Did you go to a Waldorf school or Montessori?

Speaker 4 5:07

It's actually at.

Speaker 3 5:07

Cornell, where I did this Montessori.

Speaker 4 5:09

Dennis, are we like playing with bacteria in kindergarten? Is that what we're doing?

Speaker 5 5:13

I don't know. It's free thinking, free spirit. I've never heard of a Waldorf school. No.

Speaker 4 5:18

Yeah, they're Kind of a Montessori.

Speaker 3 5:26

Isn't it the self-teach?

Speaker 4 5:28

Yeah, they have a lot of pre-thinking. Teach yourself.

Speaker 5 5:30

Do they use antibiotics in the Waldorf school? I don't know.

Speaker 3 5:35

Isn't the antibiotic free zone?

Speaker 5 5:36

It's a clear zone. It's a clear zone.

Speaker 3 5:38

It's a clear zone. Oh my gosh, making me think of those signs I see of slow down. This is a school zone. This is a clear zone.

Speaker 4 5:47

Oh no. So just going back to the history of antibiotics in general, one event that I did want to talk about is the Coconut Grove Fire.

Speaker 5 5:59

So that was a fire that happened in. Is it a club somewhere in Houston?

Speaker 4 6:02

It's a club somewhere in Boston. It was a club in Houston. It's a club somewhere in Boston.

Speaker 1 6:05

It was a club in 1942.

Antibiotic Resistance and Proper Usage

Speaker 4 6:08

And it was the place to go to if you were an athlete, if you were a politician, if you were a celebrity. Everyone was going to Coconut Grove. However, coconut Grove only had one main entrance, one main exit. It was the same door and it was a revolving door and, of course, this was back in 1942. They still had lots of candlelit things and they had, of course, electricity, but that electricity was shoddy, let's be real. So there was a light bulb that went out in Coconut Grove and apparently the story goes that a worker was sent to change the light bulb but because there was no light there, he couldn't see what he was doing. So he lit a match and you guys know what happened.

Speaker 4 6:50

And with only one main exit, with fire exits jammed and with the other exits only known to people who actually worked at the club, there was a huge amount of injuries and also casualties from the actual incident and, of course, many of those injuries were serious burns. As we all know, burns are incredibly susceptible to infection because you're, as I said previously, taking out the skin of a human. The skin is our protection from so much and it also side note has a lot of bacteria on it that are really good for us. But when you get rid of that epidermal layer, you expose the body to a lot of bacteria, fungi and potential infections that your body normally wouldn't be susceptible to, and so back in 1942, when this occurred, they didn't have antibiotics. So a lot of people who sustained really serious burns ended up getting not only injured but also sustaining really serious infections that could potentially lead to death.

Speaker 4 7:51

However, our lovely little friend penicillin had recently been not only discovered but somewhat developed just not in the mainstream labs, and it wasn't heavily funded until the scientists managed to get the opportunity to treat the patients with penicillin. I have a stat here Merck and Company was the company that was working with penicillin. They were allowed to rush a 32 liter supply of penicillin to Boston to treat the patients with these serious birds 32 liters of liquid penicillin.

Speaker 5 8:27

Wasn't probably super potent back then, though right Probably not Probably not. When did Fleming discover the stuff? Do you remember In?

Speaker 4 8:34

1928.

Speaker 5 8:36

Oh wow, and this was in 1942.

Speaker 4 8:38

Yeah, okay, several years between the two events. And it was only after the penicillin was proven to keep these patients from developing infections that penicillin was then funded. The research into penicillin and the mass development of penicillin was actually funded by the US government.

Speaker 3 8:57

It's really wild. I always assumed it was the Second World War was where we got penicillin from.

Speaker 5 9:02

I think it was also used during the Second World War, which was right around that time, right.

Speaker 3 9:06

Right. Okay, so maybe this was a civilian population that got tested on, but I wonder you're making me think now. I think you brought up a great point that I want to highlight, in that, as much as we're talking about antibiotics and wanting to kill bacteria that are harming us, we do have a fabulous amount of bacteria on our skin, living inside of us. The world would not do well as a sterile place without bacteria. We need them for so many processes. I think microbiome is really fascinating.

Speaker 4 9:31

Microbiome is incredible. Microbiome is all over.

Speaker 3 9:33

But back to your history. I definitely would have died in the coconut grove fire because I struggle with revolving doors when I'm not under duress and I actually actively avoid them.

Speaker 5 9:42

Do you think you would have gone to a club back then?

Speaker 3 9:44

Probably not. No, I'm going to read a book and drink, you know, a nice Earl Grey tea.

Speaker 4 9:52

On a.

Speaker 3 9:52

Friday night, my Friday nights yeah, they're wild.

Speaker 4 10:02

Hey, kudos to you, though, and I just looked it up. Actually, it says that the success of penicillin in treating these burn victims from the coconut grill fire led to the US government to support the production and distribution to the armed forces, so that was probably what allowed you know.

Speaker 5 10:12

So, Mrs Stats, do you have some stats on how many people died of bacterial diseases before penicillin and then after penicillin?

Speaker 4 10:21

That I don't A lot. Yeah, I could imagine a lot, because I'm almost certain that the number one cause of death was these common pathogens that now we can fight with a simple antifungal or an antibiotic. And I know that was the number one cause of death before these medications were invented. And that actually is a nice little segue into. What I did want to talk about was antibiotic resistance.

Speaker 4 10:44

So antibiotic resistance is a serious global health problem for sure, and it occurs when bacteria evolve to resist the effects of antibiotics. And there are several ways that this can happen. One of the ways is to where bacteria themselves, just when they're replicating, mutations happen, as they always do, and then they just develop these means of resistance to an antibiotic. Another way is when antibiotics aren't taken correctly, whether they're taken for a viral infection that they did not need the antibiotics for, whether someone's given a course of antibiotics and they don't finish the course of antibiotics or they don't take the antibiotic as properly prescribed. That introduces the medication to bacterial populations and it also gives the bacteria who are resistant to the medication the opportunity to pass these genes on from themselves to other bacteria and also to proliferate in the face of this antibiotics. And then there's also sexual transmission between bacteria.

Speaker 1 11:44

Conjugation Conjugation there you go.

Speaker 4 11:47

The good old conjugation. It's weird. They just kind of like they literally pass their DNA to each other. They're like here, mate, here you go.

Speaker 3 11:56

Yeah, and some bacteria can just pick it up from the environment, just you know, like eating DNA kind of stuff. It's really weird. Bacteria are fun little creatures, yeah, but I think also what you're talking about is if someone hasn't finished their course of antibiotics, like you take it every 12 hours or whatever. It's meant to keep a certain level present in your body.

Speaker 3 12:14

And so then, if you are like, oh, I feel good you drop off, you might not continue taking it, then that potentially allows the populations that haven't died to then kind of rebound or just sort of continue to thrive, and that's you know, Camille, it's so difficult.

Speaker 5 12:30

You feel really bad. You go to the doctor, they prescribe you antibiotics and you feel much better. Within like two, three days the pain is gone. So you're not reminded to take the antibiotics. So isn't it super tricky to keep on taking?

Speaker 3 12:46

your stuff. I think that's a really good point. That's with any medication, right, Like even if you're diabetic and taking insulin or something. But yeah, especially for something like antibiotics, it can, I think, be very hard for people to remember to take them, or just that there's this feeling that the effects upon you have passed. But also our health is globally interconnected, right, and so the effects of my health affect everyone else, right, and I think that that's something to keep in mind and I think that that is something that everyone kind of struggles with. But it's worth it to put the reminder on your phone or get a pill case, you know, if you took it today. I always do. I'm like did I take?

Speaker 4 13:16

this today. Yeah, that's fair. Whatever works for you, honestly, and I think it's also important. Obviously. This is why we're doing this show right. I don't think a lot of people are actually educated on what antibiotics are, how to take antibiotics, why it's important to take antibiotics, the way that you should take them. So don't feel embarrassed to all of our listeners If you haven't in the past taken a course of antibiotics properly. I think we've all been there, done that. But, moving forward, do your best and just know that doctors prescribe medications in a certain way, because sometimes you need to take them in that certain way to help not only yourself, but also your friends, your family and those around you.

Speaker 3 13:52

And antibiotic-resistant infections are nasty, nasty things to treat.

Speaker 4 13:56

They are really nasty, they are expensive to treat and they are not fun to have.

Speaker 3 14:01

And it's sometimes they can throw everything at it that they can, and I think that that's also an aspect of you may have never taken antibiotics in your life, but you can still pick up an antibiotic-resistant infection because we have them in our environment. Someone else might have it, it might be in something that you're exposed to and so, keeping this in mind, it's not just your personal use of something, but it affects everyone around you.

Speaker 5 14:21

Absolutely so. Can we just quickly summarize for our listeners why should you continue taking your antibiotics, although you feel better? Just in a few sentences, what would you say? What's your slogan?

Speaker 3 14:33

Continue taking your antibiotics even though you feel better. Because it keeps the medication at a level in your body that's going to ensure that there's no bacteria that are persisting that might then cause the infection to resurge, but also because just out of respect for everyone else around you.

Speaker 5 14:51

In a sense that we don't want to generate resistance.

Speaker 3 14:53

That we don't want to generate resistance. We have a lot of bugs that are already resistant and we're really struggling to treat many of them, and we only have so many antibiotics, and some of the antibiotics that work against resistant infections are incredibly expensive, expensive, yes, incredibly expensive.

Speaker 4 15:11

And just so you guys know we're not making any of this up. You know E coli has a 42% resistance to third-generation cephalosporins. Staphylococcus aureus I'm sure everyone in the healthcare system has heard of MRSA Methicillin-resistant Staphylococcus aureus. That is a nasty bugger. Okay, this is actually a thing. We're not making this up.

Speaker 3 15:31

Yeah, there's so many infections that people get that they might have compromised immune systems, so they're like diabetic or something. They pick up an infection and they end up having to get things like amputation Because that's the last recourse. It's not treatable with antibiotics and that's a very grim reality that we are talking in 2024.

Speaker 3 15:48

And that's how we deal with some infections to this day is like amputation is the only option because if it's between your leg or your life and that's really scary yeah, I'd rather give my leg and we also don't want that to be a reality for ourselves in the future you know, if you want to be able to get a hip replacement or a knee replacement in the future because you might need one. You know you don't want more antibiotic resistant bugs just kind of hanging around and there's ways to treat them, but a lot of it's also very long courses of antibiotics and that's not great for your microbiome.

Speaker 4 16:18

I was going to say and then that has other effects. Right, it's like rippling side effects. So it's great to maintain this level of antibiotic effectiveness as long as we can. But anyway.

Speaker 5 16:31

So for you as a future physician, christina, yeah, what can you do?

Speaker 4 16:36

I think educating your patients is going to be the best way possible to for you as a doctor and, as a physician, definitely not over prescribing antibiotics.

Speaker 4 16:45

I mean, I personally have been prescribed antibiotics for what is more than likely a viral infection. Right so, like for the common, there's definitely multiple cases in which patients also will ask for antibiotics, even though maybe a physician says, hey, I'm pretty sure this is a viral infection, let's just write it out, treat your symptoms. Patients will persist. So there's kind of that fine balance between wanting to respect your patients and their autonomy but also wanting to respect the global health, the broader community and the health of the broader community. I think it's just being diligent about making those decisions with education, right. You just want to understand the processes behind the things that you're prescribing and understand why you're prescribing things and educate your patients on why you're prescribing things, and that's the best you can do.

Speaker 3 17:29

Yeah, and I think it's totally fair for people who are patients to, if their doctor's like hey, I want to prescribe you antibiotics, ask oh, did you take a throat culture, like if it's something like a sinus infection, are you really sure it's bacterial? Or, you know, has that person been tested for COVID, that kind of stuff? Because the symptoms can look very similar when it's like an uspiro-respiratory thing.

Speaker 4 17:46

Absolutely, absolutely. Camille, you want to let us know about antifungals.

Speaker 3 17:55

Yes, let's, let's, let's talk about fungus among us.

Speaker 4 17:57

I love I think. Oh my gosh. I need to do an episode just on fungus and call it the fungus among us.

Speaker 3 18:05

I think fungi are so cool. So just to start off again kind of with a broad definition basically, antifungals are medicines that kill or stop the growth of fungi that cause infections. But what exactly are fungi? Fungi include yeast, molds, basically things that reproduce through these really, really tiny spores, and so, as we were talking about, you know, with bacteria, we also have a naturally occurring microbiome of, you know, fungi and viruses that exist on our body as well, which is pretty cool that we've just evolved to live with them. Right, they live on our skin, in our gut, in the female reproductive system, and so there's definitely some really common fungal infections that most people have probably heard of, things like yeast infections or even, because she and I were really surprised to discover that dandruff might be caused by fungi.

Speaker 3 18:51

I had no idea, which I think is really wild. I always thought it was just like that's how people's scalp are yeah, like maybe you just had more sensitive skin.

Speaker 3 18:58

Yeah but apparently it's possible that it's like an overgrowth of normal fungal flora, which is exactly what a yeast infection is. So I think that that's really interesting that these things exist on our bodies. This is always a really cool interaction for me that these things exist in our bodies and we've evolved to live with them because in some way these things are beneficial or, at the very least, not harmful to us. But in certain conditions, like when there's stress or maybe someone's super over shampooing their scalp or something like, maybe you end up developing kind of an overgrowth of these things that naturally occur on or within our bodies.

Speaker 4 19:29

And isn't that a testament to like how incredible the body is? So you just have this perfect balance of these microbes that if that balance is thrown off, even by hair, you're in trouble.

Speaker 3 19:40

You know what I mean.

Microbial Infections in Humans

Speaker 4 19:40

So it's incredible. The body really is amazing, absolutely yeah.

Speaker 3 19:44

I've been listening to I Contain Multitudes by Ed Yong. I don't know if either of you have listened to that, but it's about the microbiome. It's really interesting because we're not really just human. Right, our genomes contain all this viral stuff and then, like on and within our bodies is like so much bacteria and so many viruses and fungi, and so that's an interesting way to put it yeah, we have more bacteria in our guts than we have cells in our bodies.

Speaker 3 20:08

Yeah, that's crazy and I've also seen that just references that it might be actually like pounds of our body weight. It's just not human cells, yeah, and that's so cool to me that just kind of exists with us. But I do want to talk about two really cool fungal pathogens. Yeah, so the first one I want to jump into. So when?

Speaker 5 20:25

you say cool.

Speaker 3 20:26

Cool in that they're in our environment, and so the one that I think is really cool is rose gardener's disease. So it's a fungi that lives on soil and plants and rose bushes. So if you're out there, if you're an avid gardener, and you are out there clipping and like picking roses, and you get a cut or a scrape or things like that, the fungi can sort of get within the epidermis, so within the skin, and especially if you're not wearing gloves, you get a cut, you scrape and then you can get this fungal infection, and I think that that's so wild. We've cultivated these rose bushes which are.

Speaker 3 21:01

I don't even know what roses are native to, but probably not wherever most people are growing. I'm assuming they're added in, but it can just kind of be like living on them and then we come in contact with them and so it's just normally there in our environment. But then it can become an infection in the right circumstances, and I think that that's always what I think about with pathogens is that maybe not necessarily with viruses, but a lot of times with something like fungi, it's there in the environment and it's completely fine. I guarantee all of us are breathing in fungi right now. Whoever's listening to this, even if you're in like ultra purified no-transcript really, really fascinating that these tiny little things that we can't see are just there. But speaking of breathing it in and I know this is also one that Christina finds fascinating is aspergillus. Do you want to talk about why you find it?

Speaker 4 21:49

so interesting? Yeah, so I worked in veterinary medicine for several years. I think I've already said that. So aspergillus, at least in Texas, is a fungal infection that predominantly infects German shepherds and everything. So if you see a German shepherd that is really sick like really sick, this infection is no joke. This German Shepherd is on the brink of death. Aspergillus is probably like your number one on the differential because of how vicious this infection is, and I know that humans can also get Aspergillus and I know that you have some information on the little Aspergillus balls in your lungs. So you want to talk about that.

Speaker 5 22:26

Hey, I have a question for you, christina. So what's the clinical presentation in those German Shepherds, and why is it only a German Shepherd thing?

Speaker 4 22:34

So it's not only a German Shepherd thing. Other dogs can have it, but it just particularly likes German Shepherds. I'm not sure why.

Speaker 5 22:41

So genetic predisposition or something like that Potentially yeah.

Speaker 4 22:43

But that's definitely an infection that favors German Shepherds and the presentation can be so diverse. So you can have a dog that can't even walk. They're so lethargic, they're so weak, hypotensive, they are panting up a storm. Their heart rate, their bradycardic heart rate, is super low and they have aspergillus. Or you can have a patient that is blind and you don't know why they're blind. Turns out it's aspergus. Aspergillus can affect the nervous system. It can affect so many different systems and cause sepsis. It is wild.

Speaker 3 23:17

That makes me think of like the last of us. Yeah, I don't know if you've seen the last of us, but I really love pathogen horror. I just think it's a great genre, but it's based on a video game, the idea that a fungal pathogen gets distributed all over the world and then, in this case, it's really infecting the brain and making people fungus zombies.

Speaker 5 23:34

So how do you diagnose the disease? So the spores are found, or the vegetative states are found in the eyes, if it's in the eye, or it's found in the lungs, if it's a systemic infection.

Speaker 4 23:44

So you would do a serology testing, essentially. So you pull blood and you send it to a lab.

Speaker 4 23:49

And you my dear scientists know more about this than I do. It's a fungal culture, essentially that you grow. So that's how we officially diagnose Aspergillus. But you want to preemptively treat for Aspergillus while the patient's there, if you really suspect Aspergillus, because if that dog goes the week that the serology results take to come back without treatment, they're more than likely not going to make it. It depending on, of course, the way the dog presents. There can be dogs that are, like I said, doing just fine. They just maybe have a limp or they're like holding their paw up or something that can be aspergillus. There can be a dog that's about to pass away, unfortunately, aspergillus, a blind patient Aspergillus it presents in so many different ways.

Speaker 5 24:31

That's really wild. It sounds a little fear-mongering.

Speaker 3 24:33

A little fear-mongering. Well, in humans it's a little different. So for my PhD program we take a year in med school and it is one of the wildest things. It's stuck with me ever since. It's called aspergilloma, so it's also caused by aspergillus. This fungi is literally everywhere. So you know, you talk and dogs, but this is something that's just everywhere.

Speaker 3 24:57

And what you see in people is that those with like chronic lung conditions, like people have emphysema or tuberculosis, they can end up with fungus balls in their lungs, so like we're all breathing it in right now, but there's not necessarily a good space for it to grow in healthy lung tissue. And at first they're not having a lot of symptoms. They might have like a mild cough or something like that, but they might already have that, and so then they'll start coughing up blood, feeling fatigue, really having shortness of breath, and these mold balls can just continue to grow and grow and grow within the lung tissue and sometimes they actually have to be taken out surgically, which is really wild. And that's because in this case antifungal medications don't penetrate them very well because it's like a solid ball of fungus. And so how a really common antifungal works, the azole class of antifungals, which most people can probably pick up at like a drugstore or something honestly they're there.

Speaker 3 25:44

How that works is that it basically prevents the synthesis of what's known as an ergosterol, which is just basically part of the fungal cell membrane, so kind of interrupting that. But if you have something that's just very densely packed or how do you even really get it just into the lungs, and so being able to treat that is really really difficult. So yeah, it's definitely something that's seen in humans as well, but I don't know that it's necessarily the first thought, like kind of how you were describing it with dogs. It's like the first oh, we're in Texas.

Speaker 3 26:16

And people can also get these in their sinuses, and so I was wondering, if you got one in your sinuses like, would you just smell mold? All the time, um, but it turns out the cleveland clinic doesn't say so, like it doesn't say like, oh, you'll smell mold. That would be a sign, right, I guess it smells really bad, which makes sense. You have like a ball of fungus in your sinuses.

Speaker 4 26:33

I guess it would be a very gradual smell change too, so you probably wouldn't even notice.

Speaker 3 26:37

Yeah, but like I think it would cause pressure, right your sinuses like can expand a bit if anyone's ever had a sinus infection?

Speaker 5 26:44

Yeah, and your body will probably try to wall it off as well, right? So it's not just free growing. That's true. That's true, yeah.

Fungal and Bacterial Interactions in Health

Speaker 4 26:51

But touch a little bit, camille. I know you kind of skipped over it, but why do aspergillomas form in patients with pre-existing conditions Again?

Speaker 3 26:58

TB. So I think, again, it's not something that it's necessarily going to take root in healthy lung tissue and I believe what I read about it is it's like the space that it has. So if there's damage, I think it's almost like there's not like pockets of air, but kind of like that, and that's what is allowing it to like take

Speaker 4 27:14

root and then start to grow Exactly Like little tissues within the pockets, and that damaged tissue is for some reason sought out by this fungi and that's where the aspergillum was. Yeah, at least that was my understanding of it.

Speaker 3 27:27

Yeah, yeah, yeah, and I think I want to end the fungal section with just talking about why this is so important right now. And what I think is interesting is that most people have heard of bacterial and viral infections. Right, they're, you know, very, very common, but you very rarely hear about like serious fungal infection. I mean, I can count on one hand the amount of people I've heard of with a fungal pneumonia or something. It's just not as common, and what's interesting about that is that's changing.

Speaker 3 27:52

And so why that's changing is that a lot of fungi don't love to live at human body temperature. We run pretty warm, but as we see the temperature of the planet increasing, fungi are having to adapt to that and begin to live at temperatures that are getting closer and closer to human body temperature, and that's going to be bad news for us, right, we've kind of given the planet a fever, and so, as that global temperature increases, fungi are adapting and we might possibly see an increase in the cases that we see, or even in fungal pathogens that we just previously didn't really struggle with, like a ton of cases, just because we've changed our environment, and so these things are already naturally there, they're everywhere, and I think that that's a really cool One Health tie-in that I just want to emphasize, because these things are just adapting to live and the environment we've given them to live in is getting closer and closer to our own body temperature, which is bad news for us from a health perspective.

Speaker 5 28:47

So do you think people should watch the Last of Us to prepare themselves for the future?

Speaker 3 28:52

No, no, no, not necessarily to prepare themselves. I hope we're not heading toward like a dystopian fungal zombie apocalypse. I watch it with other friends who are also like PhD students. I was watching it with a friend of mine who studies plague and we watch these things because we're like how accurate is this? That's always our question. And it's wild because I think the idea that there's a global distribution of a fungi is you know, it's not too far off. I think the effects the fungi had the way it grew inside the body, maybe not.

Speaker 4 29:23

Yeah, I mean, you're not going to turn to a fungus zombie, you're not going to cut open someone's leg and have the actual plant.

Speaker 3 29:28

Obviously it's horror Right, and so much of it is taken sort of beyond into the realm of science fiction.

Speaker 3 29:34

Right but the idea that we might have to deal with fungal pathogens I think is very real, and especially there in so much of our environment. We're talking about the Rose Gardner's disease. That's in soil. What else do we grow in soil, right? We have all kinds of? You know so much of our food and stuff like that, so I think it's worth thinking about. There's certainly beneficial fungi, right. People eat fungi too. It's something to consider that things are changing and we don't always know what that means, but everyone's health is interconnected and that's something that the Last of Us, I think, does get accurate, nothing else.

Speaker 4 30:04

Yeah, so does this mean I have to stop eating mushrooms, because I love mushrooms, I hate mushrooms.

Speaker 3 30:10

I mean, I've researched this whole thing and I eat mushrooms. Oh, I'm joking, I love mushrooms Also, like just come across mold and I can't say I'm scared of mold, I don't love it, but like I've seen it and I've not been like ah.

Speaker 5 30:21

Well, I think one thing we should also mention is that we haven't talked about antivirals yet, but the thing that we should also point out is that under the microscope, all of the three different categories look very different, right, and they also have subcategories. So you talked about mold, you talked about yeast, right and bacteria. They're like gram negative and gram positive, and so they're not just names on the paper. If you look at them under the microscope, they're all very different.

Speaker 3 30:50

Yes, definitely worth the Google, for like cool images of viruses, bacteria, fungi.

Speaker 4 30:55

And I think that's probably a good point to make, dennis, because you may wonder oh, I have this antibiotic left over in my cabinet, I'm going to take it, and it doesn't work for a certain infection that you have. That's because, like Dennis said, it's not just every bacteria is the exact same bacteria. There's so many different bacteria, so many different morphologies of these bacterias, and not every medication works for every bacteria. That's why it's so important to go to the physician when you have an infection, because if you take an antibiotic that is not appropriate for the infection that you have. That's just another way to enforce.

Speaker 4 31:27

Or an antifungal, yeah, or an antifungal Exactly.

Speaker 3 31:29

And that's why cultures are so important. From a physician's office.

Speaker 4 31:32

That is a way that we avoid resistance.

Speaker 3 31:37

We're treating this with the appropriate medication that actually targets it in a way that's going to be effective.

Speaker 4 31:42

So it won't only benefit you in the time being, but also you in the future and others in the long run as well.

Speaker 3 31:52

Yeah, and we don't want to overuse any of these categories, right? Because, as we've been talking about, they naturally coexist with us and so we don't want to be sterile human beings with no microbiota. It was interesting because I always thought we would just be dead if we were sterile. I guess we're one of the few species that wouldn't be immediately dead if we were entirely sterile of bacteria and stuff.

Speaker 4 32:08

I wonder what our quality of life would be then.

Speaker 3 32:10

It would be very low, because from all of our food any animals that we use for any type of food production, and then also all kinds of plants.

Speaker 4 32:17

Like your nitrogen cycle is, really messed up One day about how much bacteria help you with digestion and stuff like that too.

Speaker 3 32:23

But some species, like cattle, rely so much they can't really break down grasses. It's the bacteria that's in their stomach. We at least are able to break down some things.

Speaker 4 32:32

I can't imagine our bodies without bacteria. I love bacteria.

Speaker 5 32:39

And I think we should also make sure that we're giving the listeners not the impression that there's so many fungi and bacteria and viruses out there that are just out there to kill us, right Surrounded by fungi and bacteria and so on. And they're everywhere and 99% of them are really really good and really helpful. Right, if you jump into the water on the beach, in one liter of water is tons of bacteriophages right.

Speaker 5 33:04

And they have a function they clean the water. So you know we like to focus on these bad things and because they cause interesting diseases. But I think there's much good out there, much more good than bad.

Speaker 3 33:19

Absolutely. Yeah, yeah, yeah, and they existed far before us, right, like bacteria and other small microorganisms. That was goes around and and is still continuing to perpetuate through all these other animals that have gone, extinct, you know surviving, and they're in an integral part of our environment. You're absolutely right.

Speaker 4 33:39

So on that note, Dennis, did you want to move on to talking about retrovirals?

Speaker 5 33:43

Retrovirals. I'm sorry, about antivirals.

Speaker 4 33:45

We don't have to get into retrovirals right now.

Speaker 5 33:49

That would take way too long.

Antivirals

Speaker 5 33:50

No, I'm going to talk about antivirals, and antivirals are special meds that can help your body fight off viruses.

Speaker 5 33:58

So if you get sick from a virus, like the flu or a cold, the virus sneaks into your body and infects the cells of your body and starts making copies of itself. This is how the virus spreads and this is also how the virus makes you feel bad. Antivirals work by stopping the virus from making those copies, from replicating, so your body's natural defenses or your immune system gets a better chance of fighting the disease right, so you're helping your immune system by stopping that virus replication, the virus making copies of itself. So I think, for the listeners out there, I think a good way of thinking of antivirals is that they are a shield that blocks the virus from spreading further in your body. And I think one interesting fact is that they don't kill the virus directly. So it's not like they touch the virus and then the virus explodes or something like that, but they just slow down the virus proliferating, copying itself, and that gives the body enough time to catch up, to ramp up the immune response and stop the virus.

Speaker 3 35:09

And I think that's why a lot of times it's important when we're prescribing antivirals, the earlier an infection you can get them, the better. Because then, especially for something like I think of, like Paxlovid, or even for COVID-19, or for people that are getting triple drug therapy for HIV, the faster those antivirals are in the system, the less replication has already gotten out of control. Yeah, absolutely.

Speaker 5 35:30

This is Camille. This is the perfect segue. I'd written down some key things, some key takeaways from antivirals, and actually the first thing that I had written down is they work best when you start taking them soon after you get sick Nailed it.

Speaker 5 35:44

You nailed it, gold star, yeah. So they help you to feel better faster and they keep you from getting really, really sick. So the sooner the better. Then doctors prescribe them for specific viruses, so not all viruses can be treated with antivirals. So not every virus that's out there has a specific antiviral. So at this point in time we have antivirals only for certain types of viruses.

Speaker 4 36:09

And can you tell us a little bit about why that's the case? Because I know we have so many antibiotics that we pull from. I know that we don't have a lot of antifungals, but we have more than we have antivirals.

Speaker 3 36:19

We also don't have a ton of antifungal pathogens.

Speaker 4 36:21

Right, exactly, but how come it's so hard to make antivirals?

Speaker 5 36:34

them. But you're right, there are far less antivirals than there are antibiotics, and antivirals typically, just like antibiotics, intervene somewhere in the biology of the virus, in the replication. So they maybe work with an enzyme or they work and stop the virus from forming a virus particle or something like that. But you need specific targets and not every virus family will give you these specific targets and then often the virus is reproduced so quickly within hours that the antivirals have to be in every cell of the body and they have to reach that specific target quickly. So that's why that's one of the two things that I can think of, why we don't have enough antivirals.

Speaker 3 37:13

Yeah, and that's really interesting to think about. There's definitely places in the body that are immunoprivileged. So, as someone who works in a lab that studies HIV, originally the antivirals didn't cross the blood-brain barrier and so we weren't controlling HIV in the central nervous system. And now the antivirals are better and they do cross the blood-brain barrier and prevent the progression and the damage that can be caused. But it's difficult to get something everywhere in the body because the body is set up so that doesn't happen, because if there is some type of infection, you don't want it to go into places that are incredibly important, like the central nervous system.

Speaker 4 37:48

I was going to say the CNS specifically is really hard to get medications to if you're not giving it just like directly into the CNS. So that's yeah, those medications that can cross the blood-brain barrier. They're so rare because they do a lot of work and they're awesome.

Speaker 5 38:02

And maybe just coming back to what I said earlier about the specific targets that are so difficult to find for viruses, remember that viruses are obligate intracellular parasites, right? So they take hostage of the host cell and so for their replication they take good chunks from the cell. So if you're targeting the cell that the virus uses, you're targeting the rest of the cells in your body, and there's high toxicity.

Speaker 5 38:31

Yeah, that's fair, and you don't want to just be torching those, so you have to find something that is unique to the virus and not something that the virus stole from our body. And that's the huge difference to bacteria, where they grow on their own, they don't need parts of well, sometimes they need part of the cell, but most of the time they can grow and it's easier to target than something that runs 80% based on the stuff that's in the cell.

Speaker 4 38:57

Yeah, that's fair, yep.

Speaker 5 38:59

So then I have two more.

Speaker 4 39:02

Okay, let's hear it.

Speaker 5 39:03

A couple of key things left. So the antivirals are usually pills or liquids taken by mouth, but sometimes they're given through IV.

Speaker 4 39:13

I was going to say I don't really know of any IV antivirals, like off the top of my dome. You know what I mean. Versus antibiotics, I don't know either.

Speaker 5 39:20

Paxlovid is pills right.

Speaker 3 39:23

Actually. Well, it's not an IV, but I do know that there's a new HIV drug and it's an injectable, but it's not IV. But yeah, most antivirals.

Speaker 5 39:31

But I remember like in the beginning of covid remdesivir was given and that's an iv version, or the iv versions is more work, I thought it wasn't as effective. Not as effective as they. Yeah, yeah, okay. And then the last point is probably the most important one antivirals are different from antibiotics, which fight bacteria instead of viruses, so they are also different from vaccines, which help people prevent from getting sick in the first place.

Speaker 4 40:00

That's a good point.

Speaker 3 40:00

Yeah, absolutely, and I think, touching on vaccines, it's not always just prevention, right. If you do get sick, it lessens the severity and duration of the disease, and that's really the point. So if you get a COVID-19 vaccine or something like that, you won't necessarily not get COVID, but when you do get it, it is likely to be much less severe and won't last as long than if you hadn't been vaccinated at all Exactly.

Speaker 3 40:22

Which I think is always a point that I feel is kind of missed in the vaccine discourse that I always want to have.

Speaker 5 40:34

Yeah, that's a best to talk to your doctor.

Speaker 1 40:36

Yes, absolutely.

Speaker 5 40:38

If you feel sick, right, yes, please Don't take our advice here and just take antibiotics. Go to a doctor and they can decide what medicine.

Speaker 3 40:50

Yeah, don't just self-medicate with like over-the-counter items.

Speaker 4 40:53

Exactly Like please, if you're sick, go to the doctor.

Speaker 5 40:57

Okay, anything else we should talk about, you think?

Speaker 4 41:01

I think we did a pretty good job summarizing these three general topics. We hit on antibiotics, we hit on antifungals and we hit on antivirals and I hope, after hearing this episode, our listeners at least feel a little bit more educated on the three topics and a little bit more self-sufficient when it comes down to understanding what they need to do for themselves. Yeah, thanks for listening.

Speaker 5 41:23

Yeah, thank you, and if you have questions, send us a message. Absolutely.

Speaker 4 41:27

You know where to find us.

Speaker 1 41:30

Until next time.

Speaker 2 41:45

Thanks for listening to the Infectious Science Podcast. Until next time, and go ahead and share this episode with some of your friends.

Speaker 1 41:52

Also, don't hesitate to ask questions and tell us what topics you'd like us to cover for future episodes. To get in touch, drop a line in the comments section or send us a message on social media.

Speaker 2 42:01

So we'll see you next time for a new episode, and in the meantime, stay happy stay healthy, stay interested.

Speaker 4 42:16

Thank you.