Mar 24, 2020
This episode of Something to Chew On brings us a timely discussion, the current world-wide Coronavirus challenges the topics discussed with Dr. Megan Neiderwerder are not only timely, but instructional on helping us to understand what a virus is and how they impact the world around us. Megan’s teachings cover viral diseases in swine, equine, avian, bovine and canine species. Dr. Megan Niederwerder, Assistant Professor in the College of Veterinary Medicine here at K-State research investigates control strategies for endemic and foreign animal diseases of swine.
Welcome to the New Normal - What are Viruses and How do they Impact the Animal and Human World with Dr. Megan Niederwerder, Assistant Professor in the College of Veterinary Medicine here at K-State
Most people have been exposed to a Coronavirus. Of course, it's coronaviruses in general are probably the second leading cause of colds in humans, but it's a different Coronavirus. It's different than the one that's currently circulating and so we don't have that underlying immunity to the one that causes the common cold.
Something to Chew On is a podcast devoted to the exploration and discussion of Global Food Systems produced by the Office of Research Development at Kansas State University. I'm Maureen Olewnik, coordinator of Global Food Systems.
I’m Scott Tanona. I'm a Philosopher of Science.
And I'm Jon Faubion. I'm a Food Scientist.
Hello, everybody and welcome back to Something to Chew On. There are times when we take stock of our lives, try to better understand where we fit in the natural world, and to find ways where nature manages to provide us with some answers. today's podcast brings us a timely discussion with Dr. Megan Niederwerder, Assistant Professor in the College of Veterinary Medicine here at Kansas State University, with the current worldwide Coronavirus challenges. The topics discussed with Dr. Megan Niederwerder is not only timely, but instructional on helping us to understand what a virus is, and how they impact the world around us. Megan's teachings cover viral diseases in swine, equine, avian, bovine and canine species. Her research investigates control strategies for endemic and foreign animal diseases of swine. She is internationally recognized for her expertise in two primary areas of research, including the role of the gut microbiome on outcomes following viral respiratory infections, and the risk and mitigation of foreign animal disease introduction and transmission through feed and feed ingredients. today's podcast is being recorded in a manner that I certainly never anticipated. Jon, Scott, Megan and I are all in different locations. Courtney is recording via zoom at her home due to the spread of the Coronavirus. Our new normal is to stay connected in an unconnected environment. We've talked frequently about recording podcasts with someone that was off site. But I always figured that Jon and Scott would be in the same room with me chatting with someone else remotely. The time that we're in today is quite different, and the Coronavirus spreads and keep social distancing as part of the new normal. We are each in our own space and hoping for science to help bring a return to a healthy world. With that, I would like to welcome all and specifically welcome Megan to the podcast. The podcast is in this series is focused on the food system at Kansas State University. And certainly animals are a critical part of that system. This is actually the 20th recording in this series. And I was surprised to look back at the list and realize that this is the first podcast that we've done on animal related research between the College of Veterinary Medicine, the College of Agriculture, and the Department of Animal Science and Grain Science and Industry. There's a substantial amount of work being done in this area, whether it's through animal health, or food and feed and just a whole whole bunch of other areas that we touch on in the area of animal health. So, Megan, I've got a ton of questions for you as we go through this. I doubt that we'll get to all of them. But what I'd like to start off with is getting to know a bit about you and understanding how you got interested in this area. And then we can see where the discussion takes us. So Megan, could you tell us a little bit about yourself?
Sure. Well, thanks to everyone for the opportunity and invitation to speak with you and thank you for your work on the global food systems. I think it's really important and like he said, important to talk about animal health and animal diseases as part of the efforts for global food systems. So my name is Megan Neiderwerter and I am a veterinarian. I actually went to Kansas State or veterinary school I've been a veterinarian for about 10 years now. And as part of my veterinary practice, I worked with dogs and cat zoo animals as well as pigs. And when I decided to come back and pursue a career in academic research, it was really based on my desire to provide information or to research questions with regards to population health and livestock. And I've always had an interest in infectious diseases and the ability to ask questions. How do things work? How can we improve animal health? And the opportunities that research affords in an academic setting is to really understand how we can improve animal health at a population level. And even in my case, it's my research is focused on swine health. How do we improve the health of pigs around the world?
How long have you been on the faculty?
I've been on faculty now for almost five years at the College of Veterinary Medicine in the diagnostic medicine pathobiology department.
Great. Can you tell us a little bit about what your research is on swine health?
Sure. So there's I have really two main areas of research and both, again, focused on viral diseases and swine. One of the areas that I focus my research on is looking at the utilization of the gut microbiome to improve pig health in the face of respiratory disease. So when we think about pigs after they are weaned pigs are typically weaned about three weeks of age from their mothers. And they have a high incidence and high susceptibility to respiratory disease at that time. So we typically call that poor sign respiratory disease complex, because these respiratory diseases often have a viral component, a bacterial component, and often are due to environmental stressors as well. And so some of the respiratory diseases that are currently challenging pigs throughout the world, have been around for many decades. And so that means, you know, we're at a place where we want to look at alternative approaches for how do we improve the health of these pigs in the face of respiratory disease with alternative strategies. And so the focus of my work has been how do we utilize the DEP microbes, and the beneficial bacteria in the gut, to actually improve or enhance animal health in the face of the respiratory challenge environment. So, again, focused on the main virus that I have done is Porcine Reproductive and Respiratory Disease syndrome. It's really considered the most costly disease of swine production in the United States currently. And my work is really focused again on those gut microbes, and how do we improve disease. And the second area of research that I have is looking at foreign animal diseases, and the risk of foreign animal disease entry into the United States through feed and feed ingredients. And so that work has been focused on the fact that we import millions of feed ingredients, millions of kilograms of feed ingredients from all over the world that then are used to feed and provide nutrition for our pigs in the US. And so with the, with the introduction of porcine epidemic, diarrhea virus, we started to recognize that feed ingredients may be a potential route for transboundary, animal disease bred. And so my research is really focused on understanding the risk of other foreign animal diseases, such as African swine fever virus, and V.
Cool. I was interested. So I was going to ask just about the first set of things. So how is it that the gut microbiome for pigs actually affects their health? Does it prevent them from getting things? Are you talking about recovery time? Like, what's the relationship there? And it's curious, because that's not something we totally normally think of. Right? So this is a gut and you're talking about respiratory disease, right?
Yes, yes. It's not an inherent thought, to think about our diet, and the microbes in our gut affecting our health outside of the debt. It's more inherent to think about how those beneficial microbes may help resolve diarrheal disease. But in fact, they really play a role in systemic immunity throughout the whole body. And so what we think happens is that the gut is that really the largest immune organ in our bodies. And so the way that those gut microbes then communicate with the mucosal immune system in the lining of the gut, impacts how the immunity respond to the immune cells respond to pathogens and other areas of the body such as the lungs. So when we think about some of those beneficial microbes, not only stimulate the immune system, but they also communicate with the immune system in different areas of the body, through metabolic products of those microbes. And so we think there's a couple of different ways Oftentimes these, the exact mechanism by which these gut microbes impact disease outside of the gut, is not fully elucidated. But what we see is that pigs respond better to a respiratory challenge. So let's say they have fewer lung lesions, are they gain weight normally, or they replicate the virus to lower levels. So it almost creates a more resilient or resistant pig when they are exposed to these pathogens.
That's fascinating. I'm fortunate to be blissfully ignorant on most of this area, is that confined is that that phenomenon confined to monogastric? Or does it extrapolate to ruminants?
Well, we could assume that it extrapolates to ruminants, but they're really, this is really a new area of research. So a lot of the research that's been done has been done in my phone of respiratory disease. There's a great study with pneumococcal pneumonia, and a few other respiratory disease pathogens, where they will see that the presence of endogenous microbes or fecal microbial transplantation, or maybe those mice that did not receive antimicrobials, and have more diverse microbes actually respond in a better or more robust way when they're infected with respiratory pathogens. And so a lot of this research is fairly new. But you know, when people ask about what impacts the microbiome or what the microbiome impacts outside of the gut, it's sort of easy to go well, probably most things, we're just learning, and we're just at the cusp of learning exactly what those are.
Thanks. Yeah. Thank you new world of science here. And for all that, right. Are there particular strains, you said something about the diversity of the gut microbiome is important? Or what kinds of things in particular are you looking at? Right? So there are particular microbes? You're investigating? Are you your own work? Are you looking at the diversity? Tell us a little bit more about like, what's what's going on there?
Sure. Yeah. So that one of the most interesting things about some of these respiratory diseases in mice models, but also in pigs, is that a fairly common and consistent finding is that the more diverse the microbes are in the gut, the better the animal responds to respiratory disease challenge. So and that's been shown and some of the work that I've done with pig both, let's say, if the microbiome is more diverse prior to challenge, almost like there could be a prophylactic or preventative measure with regards to the microbiome on subsequent challenge, which is somewhat exciting, because it gives you the idea that microbiome modulation may be able to prevent or at least put a pig in a better place to respond to disease prophylacticly, but some of the microbes that we found that specifically seem to be beneficial, we found that a non pathogenic E coli seems to be beneficial in the pig gut, we found that increased in Ruminococcus seems to be beneficial when it's detected in the gut, and then also fecal microbial transplantation. So we've used fecal microbial transplants from older aged fowl that had high histories of health and, and great litter characteristics, took the feces from that those cells transplanted into younger pigs, and actually showed that fecal microbial transplant can provide benefits with regards to respiratory disease, when given prior to challenge.
Wow, that's, fascinating. Absolutely fascinating. And in the things that we're looking at, I hesitate even making this jump at this point in time. But the things that we're looking at going on in the world today with with Coronavirus and these viruses that are in humans, what are the chances that the kinds of things you're looking at now in swine and in animals is the same as what you're going to be seeing in humans is in helping to manage some of these things?
Yeah, I think some of the similar parallels that we've seen is when we talk about foreign animal disease such as porcine epidemic diarrhea virus, when that was introduced into the US swine herd in 2013, within eight weeks of its first identification in a pig herd, it had been detected in almost all of the major swine producing states. And the reason that is is because we have approximately 1 million pigs on the road every day being transported between different farms and everything is fast paced, pigs are moving, we see this you know, even within the country, let alone global distribution. Reach See that, you know, the movement of people and animals happens very quickly. And so we've seen that with the Coronavirus as well, and that the global movement of people makes it difficult to contain these viruses once they're introduced. The other sort of interesting parallels when we talk about African swine fever virus. The USDA released, I think, two years two weeks ago, that if African swine fever virus is introduced into the United States, which, of course, we're doing everything to prevent that, there will be a 72 hour standstill where no pigs will be moved. And so again, if you think about that, in parallel to what we're all currently doing, which is trying to stay in our homes and not be exposed to other humans, there are some similarities. And that just goes back to how these infectious diseases can be spread because of how rapidly humans and animals are moving throughout the world.
So even in cases, almost as though humans are a secondary vector, moving the pigs around
Well, so pig production in the US is fairly specialized. So when you think about the different age groups of pigs, there are certain farms that specialize in pregnant fouls or guilt, and farrowing. So that they have young piglets that they nursed. And then those piglets may be moved to a nursery facility where they live for several weeks prior to going to a grow finish facility. And then those pigs baby moved once they're ready to go to market. And so this has increased the efficiency by which we can produce pork in the US because of these specialized operations. But it also means that pigs are frequently moved, you know, during production?
Sure, do you have? Do you have an opinion on that trade off, right, between the efficiency and the basically the security of the food system there to an outside pathogen to a foreign pathogen?
Yeah, I think that you know, is the movement of pigs can sort of unveil the vulnerability of a pathogen being moved, but I think the the focus of course, one is prevention of any pathogen entering the second is rapid identification of pathogens, if they do become introduced, so that if a pathogen is introduced, there are protocols and procedures in place to stop pig movement. So that again, the pathogen can be contained, and eradicated as quickly as possible. So, you know, I think as these diseases are introduced, similarly, when I talk about P dv, it changes people's mindset, and again, can help us learn about the best way to prevent the spread of any virus or bacteria. If it's introduced.
we sort of moved off in one direction and you'd started to talk a bit about I think it was feed materials or feed ingredients. Yeah, animals as a source. What, what ingredients are the are we particularly concerned with?
Sure. So some of the research that we've done has looked at what's the stability of foreign animal diseases in feed and feed ingredients? Can viruses be transmitted through the natural consumption of plant based feed? And then how do we mitigate the risk of those viruses in feed? And so the first part of this research was really to understand if we inoculate feed ingredients, and subject those feed ingredients to temperature and humidity conditions that stimulate transoceanic shipment? Because is what we're concerned about, if feed ingredients are being imported, from China, or from other areas of the world that have different diseases or foreign animal diseases, could the virus survive? And would it be stable. And so we've looked at various ingredients such as soybean, organic soybean meal, conventional soybean meal, pork, sausage casings, and pet foods. And what we found is that it looks like soybean meal supports the stability of viruses such as African swine fever virus, classical swine fever virus and the rabies virus. And so it looks like there are certain ingredients and I think it has to do with the protein content of these feed ingredients, or the moisture content. But there are certain characteristics of individual feed ingredients that promote stability of these viruses. And of course, those are what were concerning high risk ingredients for import.
That's truly something that a lot of people wouldn't even think of, you know, when we think classically of viruses, we think that they need some kind of some kind of host to survive unless they're unless they're very, very dried down. low water activity. And yes, this really opens the window on something that needs to get to be figured out at least approaches to controlling it.
Yeah, and I think that goes back to understanding sort of the global distribution of many commodities. And that includes feed ingredients for our livestock here in the US. So certain feed ingredients that we put into the feed, some of which we do not manufacture in the US, we can only get from China. But there are other feed ingredients that we could locally sourced, that, of course, would reduce the risk with regards to introduction of viruses onto the farm. Right.
Interesting to the comment of only being able to source materials internationally is very true. And in human food consumption, as well. I recall some instances in the past where there were challenges in buying from certain areas, and we realized in the, in the food industry overall, that some of those were the only places you could buy those particular ingredients. And just the idea that those viruses can, can survive on some of these things. Is, is a little scary. And it's as John said, it's going to be something that we really need to better understand the how and why and how to control.
Yeah, I think we've operated with a lot of assumptions that were untested. And that the time was, I guess, the time now has come to really test those and get solutions.
Can we can we take this back probably as much for our listeners as anything to the to the basics of, quote A virus is Can you can you talk a little bit about what a virus is, and what makes it what makes it so special? What makes it different from other organisms in the characteristics that it imparts here?
Sure. So, a virus, one of the biggest differentials from other organisms that have virus recording, is that to replicate a virus requires a host cell. And so when we talk about replication of virus, let's say in a pig, for a pig virus, it requires the pig to actually replicate the virus particles so that there is more virus. There's a good, there's a, there's a important point there when we talk about contamination, because the virus is not replicating when there's no host cells. But if it's a highly stable virus, that's when we can see the virus essentially being maintained as infectious. There's a couple of different characteristics about viruses that I think are important to always think about. One is that viruses can either be made of the genetic material can be either RNA or DNA. And it can be single stranded or double stranded. And then another characteristic of viruses that we typically talk about is it viruses can either be envelope, or have a lipid membrane, or they can be non envelope. And so just general characteristics of viruses. If we talk about a non enveloped viruses, virus is typically much more stable in the environment. It's less sensitive to disinfectants. And then when we talk about an envelope virus, typically those viruses are more sensitive to disinfectants and less stable in the environment. And the other factor that we think about is when we talk about DNA versus RNA viruses, RNA viruses typically have higher mutation rates, because they have less proofreading when they replicate themselves. And so when we talk about RNA viruses, such as influenza, and of course, we know how much influenza changes every year. This is one of the reasons we have to get a new vaccine each flu season. When we compare that to, let's say, a DNA virus, DNA viruses are typically much more stable, less mutations. So there are certain things about different viruses. One of the characteristics of African swine fever virus is that it is a very large virus. So some viruses are, you know, maybe 10,000 faces, you know, we talk about African swine fever virus, it's much larger, much more complex. And when it has much more complexity with regards to the genome, that means it produces more proteins. And that's when we see challenges with regards to vaccine production. So one of the biggest challenges right now with African swine fever that I'm sure you've seen in the news is that there is no currently commercial vaccine that we can use to protect our pigs. Right, right.
In essence, the viruses takeover they hijack the host cells, enzyme and other systems to make more of themselves. And that's yeah, I think that right, so what are the envelopes made of? Those are those polymeric sugars or I would have expected them to be more resistant to cleaning solutions, for example.
Yeah, that was my thought as you were describing this.
Yeah, when we think about the envelope, it's mostly lipids, and then has proteins on it. Viruses typically use proteins on the surface glycoproteins on the surface, to actually bind to the host cell receptor, enter into the host cell and then replicate. But when it has that envelope, it often has those lipids that make it more susceptible. When we talk about non envelope, it's proteins that are surrounding the genetic information. And so it's more stable.
I'm just gonna say that one of the reasons so it's particularly effective is that like really just an on the envelope viruses attaching to the lipids and the protein, or as they were just so there's so as effective and non envelope viruses?
Well it depends on the virus, of course, but in general, a lot of the characteristics, of course, when we talk about hand washing, and the importance of handwashing, a lot of it is the mechanical, you know, cleaning of the hands, but of course, it depends. It depends on the different viruses. But yes, in general, these, these soaps are fairly effective against a broad range of viruses. But it again, sort of depends on the virus. Some viruses are very hardy and very difficult to eliminate from the environment.
So this is random. But here's a question. Are viruses alive? In your opinion? I mean, because they're, they're their own little strand, they can't replicate on their own right? When I was a kid, I was taught one of the things of one of the properties of life is that, you know, replication right? I know at the time, people disputed whether viruses are alive, right, because they can't replicate themselves, they you the host, do you have it?
That's sort of like the day one virology question for the students. So if you consider it if you consider alive or not alive, it's interesting, because when you actually talk about it, in, you know, when we talk about diagnostics, and what we think about with viruses, we more use the terminology infectious, versus non infectious, so weak, because one of the biggest diagnostics, one of the most widely used diagnostic tests to detect viruses is PCR polymerase chain reaction. But that test looks for viral genetic material. So it would look for the DNA or the RNA associated with the virus. But if you have a positive PCR test, it doesn't necessarily mean that the virus is infectious. So those are sort of the terminology when we think about infectious viruses, we think about can that virus if it was exposed to a susceptible cell, would it be able to gain entry into the cell and replicate and be infectious to that cell? So really, those are sort of the terminology at least in diagnostics that we think about, but the whole is the virus alive or not alive, I think people have different opinions, I suppose on that, which, which maybe makes it again, a good academic question for the students.
So here's just a random question. And in terms of terminology for disabling a virus, what, what's most often used to sort of kill wood, right?
Yeah, we usually say inactivation of the virus. So that because what could happen is, let's say, and we've done a lot of these experiments in feed, and let's say we expose the feed to heat treatment, or some sort of chemical, that inactivate the virus. If we take that seed and test it on PCR, it may still have viral genome. But if we tested on cells, it wouldn't be able to infect the cell. Maybe that's because lipid envelope has been disrupted. Maybe that's because the glyco proteins now can't find the host cell. There could be some different factors. But what we would talk about that is inactivation of a virus.
One of the areas of study that you had listed there is control strategies for endemic and foreign animal diseases. Can you speak to what some of those control strategies are or things maybe that you're researching?
Sure. So when we think about in general diseases in livestock, we first of course, we would like to eradicate or eliminate the disease from a herd. So we think About Coronavirus, you know, ideal scenario is that we would eliminate that from a herd. But then if you can't eliminate it, or if the herd is endemic for that disease, then you start thinking about can we use a vaccine strategy to improve the response of pigs to the virus? Which there are some vaccines available for the heard? And then sort of third is, Are there alternative strategies to actually improve the response of the pig to the virus when it's exposed? And so some of the strategies that have been looked at in that area is, are there certain genetic properties or genetic aspects of the pig that actually improve its ability to respond to viruses? Are there microbiome characteristics of the pig that improve its ability to respond to viruses? And so the focus of my work in that area goes back to that microbiome? Can we sort of set up the pigs gut health to help the pig respond to any pathogen? You know, it's really the goal. But you know, one of the largest sort of economic losses in pig production is the respiratory disease susceptibility of those young pigs three to five weeks of age, right after weaning. So we think about how do we improve gut health to improve respiratory health? And even as sort of a supplement to all of the other activities that are going on? How do we reduce the stress of the pig so that it can respond better to infection? How do we improve the nutrition of the pig so it can grow? Normally, even under disease challenge? So kind of think about some of those things? With regards to foreign animal disease? We really think about how would the virus be introduced into our country? And how do we mitigate that risk. So some of the big aspects of foreign animal diseases, particularly with African swine fever that we consider his contaminated pork products, we know that the virus survives for long periods in pork. And so that can be a risk factor for infection in pigs. And then, of course, we've talked about feed and feed ingredients, being a risk factor and understanding how we mitigate that risk for disease introduction.
So when you say pork, does that mean that humans are vector transferring the diseases back back to five pigs in the US possibly, or how? From pork?
So yeah, so importantly, African swine fever virus, humans are not susceptible to that virus. And pork is still safe to consume, even if pigs are infected. So that's an important point to highlight when we talk about pork products, and what we've seen in other areas of the world, is that oftentimes, people, you know, may bring sausage in with them through the airport, and not think about the risks that they are bringing in potentially contaminated pork products into the US. It's illegal. And you know, there have been illegal confiscations with regards to finding the pork products that should not be brought into the United States. And one of the big aspects with regards to foreign animal diseases is educating the public so that they understand that bringing in products from other countries into the US can be a huge risk factor for our animals here, as well as are our crops here.
Fascinating, why and explain the explain the impact on crops, for you just saying if they brought some other crop carrying disease into the US.
Right so, crop carrying disease. So when you talk about products, you have an apple or a banana, or any meat products? You know, the biggest reason for that is that there are certain agricultural diseases pests that we do not have in the United States that we want to maintain our crops are animals free from and so when people bring in agricultural products illegally from other countries, the risk is that those commodities of products could potentially have diseases that we do not have here. Sure.
So one of the kinds of fundamental differences in approach between scientists who wanted to go around the world finding new varieties of various and sundry crops versus people who wanted to keep them out by inspection. And actually the son of one of the first presidents of Kansas State was one of the folks that was critical in going around the world and bringing in new, new varieties of, of agricultural products.
And shipping them over.
Yeah, I think there's definitely a balance between, you know, learning from different agricultural products that could be beneficial, and then making sure that those agricultural products don't contain microbial pathogens that, yeah, impact the rest of the crop so.
Do we find that the contaminated materials are more frequently sourced in and maybe developing parts of the world? Are there differences in different areas around the world that cause specific problems in products that are moved into the United States? Or is this just kind of is different in different areas around the world, and you just have to be careful, regardless of where you're shipping from?
Yeah, I think you have to be careful regardless, because what we've seen oftentimes is that maybe a product is manufactured in one country, and maybe it's processed in another country. And then maybe it's shipped to a secondary, you know, a secondary country before. So there's all these steps. And again, that goes back to efficiency of the global trade that has been established over years to make these products available to people all over the world. But there's risks with regards to determining where the product came from. And if there was any risk upon its manufacturing or processing, that puts it at risk for contamination of the diseases that are in that country. We know, for instance, that there are crops that are grains and crops that are dried on the roadways in China. And those roadways are of course, shared with trucks and vehicles that could be transporting pigs. And so when you think about that, and the potential for those crops to become contaminated, because of the sort of risky agricultural practices with regards to drying on the roadways, you can imagine how those feed ingredients may become contaminated in the environment, and then could potentially maintain the virus during shipment. So it sort of depends on the ingredient. But it depends on where it's coming from to.
Sure. That makes total sense. Yeah. I've seen that in India.
Well, could ask a question back to gut microbiome. Are there any standard practices that you'd recommend if farmers to be putting into place to to improve the health of their herds? Or is there are there particular kinds of things that you would have to do like the fecal transplants? So other standard things that we do that actually that hurt our swine herds? Are there particular? Yeah, that would make it really easy to improve their gut microbiome so or is this something that would be actually kind of complicated to do or require new techniques?
Well, we're really still learning about how something like fecal microbial transplantation or microbiome modulation could be implemented in a broad scale and swine herds. But one of the biggest challenges with regards to fecal transplants, even on the human side when we talk about so in human fecal microbial transplants are most often used for recurrent Clostridium difficile infections that have been already treated with antimicrobials. And so this is somebody who's been treated with antibiotics probably multiple times and then gets the fecal transplant. And oftentimes, it has a fairly high success rate. When we talk about that in humans, and even in pigs and some of the work that I've done, we don't have sort of the foundational knowledge to say, let's take feces from 10 pigs or 10 humans, and based on the microbial characterization within that equal transplant, I can pick out the ideal donor, we don't really have that information. So when you think about is going to be your donor. For fecal transplants, oftentimes you go off of phenotype. So let's say the pig grew really well. The pig has had a great health history. The pig doesn't have certain pathogens circulating. It's very similar in humans, you know, you talk to the donors to say have you had any you know, history of diarrhea Have you had, you know, these infectious diseases we need to screen you for but sort of so you're sort of looking at the the phenotype of the person as opposed to, or the pig, as opposed to the genetic characterization or the microbial characterization of the actual transplant. And I think once we get there, then we'll be able to really sort of implement this more on a broad scale where we go, these are the characteristics of feet transplant, that really provide benefits under these circumstances, or in our, you know, modern day pig production.
Getting up in front of you. Exciting time. So what's the Chinese proverb for the Chinese curse? You should you should live in interesting times.
Yeah, well, in that, what were you gonna say there, Scott?
Oh, I was gonna ask more about the, the gut microbiome, but you know, I've got another question that's been floating around in the back of my head. And Megan, I was wondering if you could say something about what makes a virus like easily transferable? Right. So one of the things with the novel Coronavirus, right. So this came from a reservoir. And my understanding is that the think of the reservoir was bad, right? And that it was living in, that's then transferred through some other animal and then finally got to humans, right. And so there's something about these kinds of viruses that once they leave that, that reservoir where the animal reservoir where they were hanging out for a while, maybe without actually hurting that population, but they transfer to humans, and they're particularly problematic for us is a bad one, right now. What makes what makes a virus like, first of all, easily transferable like that, and what about that kind of thing makes it dangerous in a way that if some of the viruses that you're studying in swine are, you know, there's no risk of transfer, or infecting humans in a way that's going to hurt us?
Yeah, I think one of the important sort of components to what's going on with the Coronavirus is that, as you said, the way that it was the humans were exposed to it was this very close interaction between humans and wildlife, where we're seeing that maybe a virus that has been around in the wildlife population for decades, and has never caused the problem to that wildlife species or to humans, because of the the lack of close interaction, when a human is then exposed to that virus can become infected. And I think one of the important things about viruses is that they have this high ability to mutate into change. So of course, most people have been exposed to a Coronavirus. Of course, it's coronaviruses in general, are probably the second leading cause of colds in humans. But it's a different Coronavirus. It's different than the one that's currently circulating. And so we don't have that underlying immunity to the one that causes the common cold. And so one of the things that can make viruses transmissible is, of course, that oftentimes viruses are transmitted through the oral nasal route. If you think about respiratory diseases, those are ones that can make you cough can make you sneeze, that can create these aerosols that, again, oftentimes can contain large amounts of virus, if a person is in the acute phase of infection. The other thing about viruses is that even though they require cells to replicate, some of them can survive in the environment for an extended period. And again, that goes back to, you know, DNA versus RNA and versus non envelope. But when we think about touching, handle doors and touching our phones, and we want to be sure that, you know, we're taking the precautions to not only wash our hands, but think about the types of materials that our hands touched throughout the day, and make sure that we have those clean. So those are a couple of the characteristics with regards to viruses.
And those are there. I was just gonna say so is there anything particular about the type of virus or what it is that makes that makes it particularly harmful to humans? Right, sort of like so why is it that the viruses that you're studying that are caused a lot of disease in pigs strikes or don't happen to cause diseases in humans? Is it just kind of, you know, luck, or is there some particular characteristic about them that makes them not dangerous to humans, but something like the novel Coronavirus, right? Transferable and it's gonna infect us and make us sick.
Yeah, they're, they're typically the way that the virus is determined, you know, determines what host to that is susceptible is based on the proteins on the surface of the virus. So those proteins only recognize certain host cells. And then also on the host side, the host has to have the correct receptor, or it's often a protein, again on the host cell. So those interactions are what allow the virus to actually take it, you know, have the receptor bind to the, or the protein bind to the host cell receptor, and enter into the cell and cause infection. But viruses have a wide range of how they cause disease. When you think about a virus like HIV, people have HIV as lifelong infections, because that virus actually integrates itself into the host genome. Whereas you think about other viruses. And the infection is fairly short, maybe it's three to five days. And that's the only time period when you are shedding the virus, and then your immune system clears the virus. Some viruses cause chronic infections, some are very acute, some cause that like African swine fever, in pigs, causes extremely high mortality. So we see almost 100% mortality, whereas other viruses have mortality rates less than 1%. So really depends on the virus and the mechanisms by which that virus has evolved to cause disease. And also sort of this variation that we can see with regards to the length of time that the virus may infect the host. And, again, host susceptibility has a lot to do with the actual cells of the host, and then the proteins on the virus.
Interesting. That's very interesting. What I was going to ask we were going to be putting on a workshop global food systems is going to be putting on a workshop on microbiome in another month or two, and hopefully, it'll be face to face that if we're still in the situation we're in right now, we may, we may try and take it to a virtual level. But on the microbiome as I was putting the ideas together on this, and Megan, thank you for your help. And in working with me on it. There. There are a whole lot of different areas working on microbiome. And I wonder in my mind, how those things how those areas overlap, or if they do not overlap, what are the similarities and differences between, say, soil microbiome and what you're working on with swine gut or things that are being worked on in I know, in poultry gut? Or is that a fair question to ask you? I mean, it may be that the study areas are different enough?
No, I think I think it's an interesting, it's a good comment to have about the microbiome space. Because when we think about the research, really, it's been over the last decade that we've seen this expansion in microbiome work. And really, the vast majority, I mean, every year, the number of microbiome publications increases on both the human side, and let's say, the swine side, you know, there's probably over 50,000 Publications now on the human side. But the vast majority of those have been in the last three to five years. And even on the swine side, we talk about maybe 1000 publications on the swine side. So it's this, it's this new area of study that is very complex. And when we think about the microbial communities, in soil, or in our guts, or in the guts of pigs, or poultry, and we think about all the interactions of those microbes, it's very complicated. It's very difficult to replicate, let's say outside of the host, because you think about the immune cells of the host impact the microbial replication in the gut. And then the microbes within the gut interact and metabolic products impact what other microbes may do or make, may produce. So I think there's a couple of challenges with microbiome research that is probably fairly consistent in any microbiome research, one of which is replicating what happens in the natural environment in a laboratory setting, but also, how you actually analyze the microbiome. There's many different areas. You can use meta genomics, you can use whole genome sequencing, you can use 16 s ribosomal sequencing. One thing which is based on bacteria, you can use microarrays to look at populations of microbes, you can look at transcriptome, so maybe what the microbes produce? What, what does what's sort of the response between the host and the microbes. So I think it's such an exciting space, because we have so much to learn, and there's so many different areas. And really, if you look and see, you know, an aspect of the microbiome again, more than likely, it probably has an impact on some sort of disease in the host or in the, you know, in maintaining a healthy crop in the soil. And so I think it's really exciting. But again, it's important for people to sort of wrap their head around the complexity of, of how we research the microbiome true.
Another term I've heard used in that reference, the microbial ecology of the gut, is that correct?
Okay, good. Yes, Maureen.
Well, I was just gonna say, with what little life I've probably read and understood enough on the microbiome to be really dangerous in the area. But what I have read has absolutely fascinated me. And it seems, from my limited understanding that it's got the potential of changing the way we look at health in many ways, the way we are looking and understanding what's going on in our systems and how to manage and control healthful activities helpful. Is that a fair? Is that a fair assumption? On my part?
Absolutely, I think one of the most sort of fascinating and exciting things that I think about is, you know, in the future, are we going to be inoculating our young babies, and, you know, on my side, the young pigs with microbes that we know will improve the health of that person, or that animals throughout their lifetime, that's really exciting. Because you go, wow, we can if we learn about these microbes, what they do, and then on on the human side, or on the pig side, understand what diseases they're going to be susceptible to later on in life, and give them those microbes that are going to help them be resistant, or less susceptible to those diseases. That's a whole nother avenue to think about how we can prophylactically or preventatively provide health to people, or HIV or pigs. You know, prior to early on in life, I think it's really, really fascinating and exciting. And we think about, we are what we eat, you know, we haven't really talked about the diet. But you know, the other fascinating thing about the gut is that, you know, everything we eat in talks the microbes, so when we talk about learning about the connection between nutrition and microbes, and overall health and neurologic conditions that may even come in, later on in life. It's really, like you said, I think fascinating and exciting. I think, you know, it'll be very, very cool to see where we're at even, you know, five to 10 years from now in this in the microbiome world?
You know, what, what comes to mind with what you just stated was just some reading I did while that's been it's been a while ago, but on, on childbirth, and on the difference in the potential of the child with a vaginal birth, as opposed to a cesarean section and the number of microbes that that child was introduced to, during that process. And just thinking about all of those kinds of things, is, as I said, fascinating, I mean, it just it, it makes your mind kind of swim on all of the areas that those microorganisms are going to be touching and relating to how, how well we are in the long run.
Well, in nature, there's at least one example in nature for that. qualities are born without if they were if they were, there's a transfer of microbiome from the mother to the baby that allows them to eat and digest the eucalyptus, eucalyptus trees, which they wouldn't be able to do otherwise. So there are examples in nature of what we're trying to do.
Is there a feed of us swine, then studied in terms of the effects on the microbiome and their health right there? How much do we know about like, what the diversity are the type of feed that pigs get affects? affects their gut affects their health?
Yeah, so a lot of the focus of course in the nutrition side is what components of the pigs diet do we need to make the pig gain and have they to gain as much weight and as quickly as possible and maintain maintaining health? I think an area there As we should sort of bridge the gap is, as we understand the best nutritional outcomes with regards to grow. Also thinking about are those the best nutritional aspects is that pig is in certain health challenged conditions. And so oftentimes we do these, the research studies in, in herds that are fairly healthy, that maybe don't have a disease challenge. And then when we get into a disease challenge situation, we understand that pigs, not only eat differently, of course of a pig is not feeling well, they may not eat as much, but they're also able to they also metabolize, and take nutrients from the, from the feed in different ways based on their health challenge. And so I think that's another sort of exciting area where we can maybe bridge the gap in different disease settings, what sort of nutritional aspects of the seeds should we shift to, again, set the pig up for the best possible health outcome?
And does diversity of feed correspond to diversity of microbiome?
I don’t know off the top of my head. I don't know if we know that if we think about you mean, like, if a pig was that different threats throughout its lifetime, increase the diversity of the microbes? Right. Yeah, I think that's an interesting point, because you think about the feed at source, of course, in most high ball security operations is highly standardized, and right and changes as the pig ages. And so most pigs are not fed, you know, different diets, or, you know, a wide range of different diet that you think about maybe in developing world, when people hold pigs in their backyard. We talk about backyard operations. So we talked about this with regards to disease, oftentimes, those families may feed the pigs scraps from their meals. And so of course, I don't know if there's been a good study looking at, you know, if a pig is exposed to a wide range of foods throughout its life, what happens to the microbes? But my assumption would be yes, that the diversity would influence.
Because a lot of the work to this point has been more directed phenotypically, you're trying to change some
entire animal characteristic and improve it or keep it the same, as opposed to going at the genotypic level.
I think this has been a great conversation. very timely. I've learned a lot. It's been great. I've ever seen plastic work.
Yeah. Thank you for the discussion. It's been I've really enjoyed talking with you all. And hopefully we can all meet face to face soon and yeah, thanks for thanks again for the opportunity.
Well, we'll look forward to the face to face and thank you all for coming online. And yes, I learned a ton here today.
Likewise, likewise. Thanks again.
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Our music was adapted from Dr. Wayne Goins’s album Chronicles of Carmela. Special thanks to him for providing that to us. Something to Chew On is produced by the Office of Research Development at Kansas State University.