Tackling swine dysentery

Suzana Grazielli Cortiano Stubert, a USask PhD student based in the WCVM Department of Large Animal Clinical Sciences, joins us in the pilot episode of WCVM Next Gen Scientists.

Working in Dr. Matheus Costa's lab, Suzana's research focuses on swine health and infectious diseases, with a particular interest in swine dysentery caused by Brachyspira species. She is interested in understanding host-pathogen interactions and developing better tools for disease diagnosis and control. 

Transcript

SPEAKER_00 0:00

What's it like to be a graduate student in the sciences and how does their research shape the world around us? Welcome to WCBM Next Gen Scientist, the podcast where we share the stories behind the science. Join us as we dive into the research and experiences of graduate students at the Western College of Veterinary Medicine here at the University of Saskatchewan in Saskatoon. We aim to break down their work in clear, accessible ways for everyone to understand. I'm Kat Sens.

SPEAKER_01 0:39

And I'm Lucas Horseman.

SPEAKER_00 0:42

As we gather here today, we acknowledge that we are on Treaty 6 territory and the homeland of the Metis. We pay our respect to the First Nations and Metis ancestors of this place and reaffirm our relationship with one another. Today we're joined by Susanna Grazielli Cortiano Stuart, who is a PhD student working in Dr. Mateus Costa's lab in the Department of Large Animal Clinical Sciences here at the WCBM. Her research focuses on swine health and infectious diseases, with a particular interest in swine dysentery caused by the Brachy Spira species. She's interested in understanding host pathogen interactions and developing better tools for disease diagnosis and control. This work can not only improve swine health, but also save producers time and money. Welcome to the podcast, Susanna.

SPEAKER_02 1:30

Hi, thank you for having me today. So to get us started, could you introduce yourself to our listeners? I'm Susanna. Um I'm originally from Critiba, a large city in Southern Brazil. Just so you guys understand, it's like down south, so it's probably one of the coldest capitals in the country. And we even had snow there a few years ago, which was a pretty big deal for us. And I recently moved here. Um I started as a master's student, and pretty recently I transferred for the PhD program. Um as I said, my research focuses on swine health and more specifically, swine dysentery. How long have you been working on your current research? Nine months. I'm I'm in the beginning still.

Suzana's research

SPEAKER_01 2:16

I'm just gonna step in here and I'm gonna ask you a little bit more about the research project. So for someone who's never heard of swine dysentery before, what is it and why is it so important to have it treated?

SPEAKER_02 2:25

So swine dysentery is a disease caused by a bacteria called brachispira that leads to a severe form of diarrhea, often with blood, with mucus. Um, and this infection will cause a very intense inflammation in the large intestine, leaving it like red and damaged inside, which can be very painful for the animals. So, because of this, swine dentary is a major animal welfare concern, but it's also a big economic problem for pig producers, because sick pigs they will eat less, grow slowly, and they will lose a lot of weight, which can directly affect productivity. So, on top of that, farmers have to spend a lot of money on treatments, biosecurity measures, and all the extra labor needed to control outbreaks and remove the bacteria from their herds. So looking at the bigger picture, these production losses uh and control costs can contribute to higher pork prices for consumers. So swine dysentery is important not only because of its impact for the animals, but also because of all its economical consequences.

SPEAKER_01 3:30

As far as uh contagion goes, you mentioned outbreaks. How contagious is the uh disease?

SPEAKER_02 3:36

The disease is spread from animal to animal, so it can spread really fast in a barn. So if you have brack spira, it will be in the whole herd. That doesn't mean that all the animals will get sick, but all the animals we will very likely be positive.

SPEAKER_01 3:50

As far as uh I guess like fatality goes, is it uh lethal in many cases? Not so much?

SPEAKER_02 3:55

Uh not so much. Depends on the age of the animals. So for the younger pigs is more lethal than for the older pigs, but it can cause some mortality, yes.

SPEAKER_01 4:05

Well why does this work matter in uh the agriculture industry specifically?

SPEAKER_02 4:09

Uh it's mostly because of the causes of the disease, because the treatments are expensive, so you have to buy antibiotics in large amounts to mix with the water and with the food, and also because of the weight loss that the animals are going through. So at the end you get less money for your animals.

SPEAKER_01 4:29

How are you working to solve this problem? You know, are there certain techniques that you're using within the lab to address this?

SPEAKER_02 4:34

One of the biggest problems with swine dysentery is that we don't understand this disease that well, and that's a challenge when you want to find treatments and solutions. So what I'm doing here is that I have to start by thinking that Brack Spira is not a common bacteria. It has curious characteristics, so it does not tolerate a lot of oxygen. Um it chooses a very specific place in the intestine to live that is deep in the mucus layer in the intestinal crypts. And it's hard to understand why it causes so much damage to the animal's intestine. Because it just stays in the mucus layer near the tissue and it does not invade. So this lack of contact makes it hard for the immune system to create a response against it. Um, another challenge is that the intestine is an environment obligated to tolerate a lot of bacteria because us and animals have a natural microbiome. So having Brexpire there is not enough for the immune system to create a strong response against it. So I'm focusing on some recent clues we have about these mechanisms of disease and trying to find corresponding tools that we can use as a treatment. Um for this, we have animal trials, we culture the bacteria in the lab, we use cell culture, PCR, Western blood, and several lab techniques. So the point is really trying to understand the disease so we can target how to solve the problem.

SPEAKER_01 5:58

Now, I know you mentioned earlier on in our discussion just the ways that you're treating the disease and trying to figure out how to address it. When it comes to researching uh antibiotics for this disease, how is that coming along?

SPEAKER_02 6:09

Um so we have a very good and effective antibiotic right now for this disease, and it's called Tiamolin. And producers use it a lot. Um and also similar antibiotics in a class that we call the Pluromutilens class. But the problem is that the more you use an antibiotic, you kind of create a selective pressure for the bacteria, and at some point the bacteria start to develop antibiotic resistance genes. And in the past decades, um some papers have been published showing that Braxpira is starting to develop these genes against Yamolin. So if this antibiotics start stops working, we are just jumping to another one and then another one, and the problem is never over when you have antibiotics being used for animal production. So if we can find another strategy or at least something that helps reducing the use of antibiotics, we can also help protect the effectiveness of the antibiotics we already have today. So this will actually reduce the use of antibiotics and reduce the problem of resistance and allow that the antibiotics we use, they still work for a longer time. And we actually don't have to keep looking for new antibiotics all the time because actually it's not easy to find new antibiotic molecules. So we have to go for other solutions that can last longer.

SPEAKER_01 7:36

What's something uh in your research that's uh been unexpected? You know, something that hasn't gone as planned.

SPEAKER_02 7:41

Uh I guess in research a lot of things don't go as planned. So I think one of the biggest challenges is that many things can go wrong, and sometimes a small mistake can ruin weeks of work. So, an example is that that night we needed a fresh culture for an experiment the next day, and by pure coincidence I decided to check the cultures at night before going home. And I noticed that one of the steering machines has been accidentally set up to around 90 degrees. So instead of growing happily and normally, all the bacteria had become uh disgusting soup. And if I haven't checked that night and fixed the problem, me and my co-workers would have lost weeks of work and would have to restart the entire process. So I think all the time these things happen when you are doing um a research, an experiment, and you always depend on a little bit of luck and paying attention and everything all the time is very hard. So you have to handle this kind of situation and not panic and not cry, maybe just a bit of crying, but you have to really um have an emotional um strain to handle all the things that can go wrong. So yeah, I would say that a lot of small details go wrong. But if you look like in the long term, all these little mistakes, they ended up leading you to where you were supposed to be.

SPEAKER_01 9:05

What still needs to be done to advance this research?

SPEAKER_02 9:08

So I think the main point for me is to understand the factor that makes Bergspar cause disease. Like, since there is a trigger that makes one pig get very sick, while another pig is okay. And if we find out about this, like what exactly is the mechanism and how this bacteria works, will be way easier to fight disease and find new treatments, and maybe in the future even develop a vaccine, being optimistic here.

SPEAKER_01 9:36

Okay, very interesting, very interesting.

SPEAKER_00 9:38

Yes, this sounds like incredibly important work for both pigs and people. Thank you so much for sharing that with us, Susanna.

Life as a graduate student

SPEAKER_00 9:55

I'd love to talk a bit more about your journey. So, what did you study before coming to the WCBM?

SPEAKER_02 10:02

Um, I am a veterinarian. I graduated in Brazil last year.

SPEAKER_00 10:06

Nice. Um, so would you like to go back to veterinary work? What brought you into research?

SPEAKER_02 10:12

Yes, maybe. I did a few internships as like in clinics, and but I was always very interested in research. I don't know exactly why. I just fell in love with it.

SPEAKER_00 10:25

Nice. And how about pigs? Was there like a specific moment or experience where you realized you really wanted to work with pigs specifically?

SPEAKER_02 10:34

Not exactly. Um I've been interested in diseases and research since the beginning of my studies, but I don't think I was specifically swine directed at the beginning. Um, it's just that as a clinician, you're always focusing on helping a patient in front of you and using the tools available. And sometimes these tools, they are not ideal, the medications you have, they are not great, but you do the best you can and move on to the next case. But as a scientist, you are always bothered by the things that don't work and you want to fix the problem. Um, and I think now I have the opportunity to improve the studs and maybe help thousands of animals instead of just my patient. So to me, clinical practice and research, they they are different ways of achieving the same goal. And scientists are they're just more stubborn and won't let a problem go until they figure it out. So I think I'm still doing the same thing, but just in a different way.

SPEAKER_00 11:32

So, why did you decide to do your your graduate programs here at the WCBM? I understand you started as a master's student and now you're in a PhD program. So what inspired those decisions?

SPEAKER_02 11:44

Um so I ended up here because I did an internship here two years ago uh with the same advisor, Dr. Costa, um because I got this MyTex scholarship, and then I got to know double CVM, uh the research group, and the swine work. And luckily he invited me to come back. So the lab is really cool. Um, and the people I got to know, they are great, and I'm learning a lot from them, and I'm really enjoying the process here.

SPEAKER_00 12:11

And coming here from Brazil, what has been the biggest adjustment for you now that you're here in Saskatoon?

SPEAKER_02 12:18

Oh, I think there are a lot of things that are hard. Um, I think missing people is the hardest thing. Like sometimes you feel like crying just of remembering about someone, which is sad. But then there is another challenge, like the fact that you have to live in English, because before we have to know English to read papers and to write, but now I have to speak all the time too, which sometimes is not easy. And um, I don't know, being by myself, like completely by myself for the first time was really challenging, yes.

SPEAKER_00 12:54

And do you have any advice for aspiring graduate students in the veterinary sciences?

SPEAKER_02 13:00

Um, so I think that working with animals is hard, it's every day, and you get tired, and it's easy to forget what you're doing here. Um, but especially when the results they seem so far away. But I noticed that when you look back, it's always worth it and is a very rewarding career path.

SPEAKER_00 13:20

Amazing. Thanks so much for that insight, Susanna.

Rapid fire questions

SPEAKER_01 13:34

Just before we let you go, we have some quick rapid fire questions for you. Uh you're good to go? Yeah?

SPEAKER_00 13:39

Yes.

SPEAKER_01 13:40

Okay.

SPEAKER_00 13:40

So what's your favorite thing to do in your free time in Saskatoon? Oh, I would say biking. If it's not snowing, of course.

SPEAKER_01 13:48

If you weren't a scientist, which profession would you choose?

SPEAKER_02 13:50

Uh Finances. What's your go-to lunch on days that you're in the lab? My homemade food.

SPEAKER_01 13:57

What do you think is the cutest thing about pigs?

SPEAKER_02 13:59

Have you ever seen a pig like a baby pig with their snouts? They're super cute.

SPEAKER_00 14:06

What's your go-to study spot on campus? Um, Boray Library. And bonus question: what's your favorite type of ice cream? Guava. Thanks so much for joining us, Susanna. It was such a pleasure to have you as the very first guest of WCBM Next Gen Scientist. Thank you. What a fantastic conversation with Susanna Grazielli Cortiano Stuart, who is a PhD student in the Department of Large Animal Clinical Sciences. We're so excited to see how this important work continues to evolve. And thank you for listening to the very first episode of WCVM Next Gen Scientists, a podcast where we share the stories behind the science. Want to learn more about the research studies happening inside our college? Visit our news site at wcvmtoday.usask.ca for all the latest happenings, including an article that Susanna wrote about her own project.

SPEAKER_01 15:08

And be sure to follow WCVM today on all your favorite social media platforms, including but not limited to, Facebook, X, Instagram, and LinkedIn.

SPEAKER_00 15:17

I'm Kat Zenz.

SPEAKER_01 15:18

And I'm Lucas Horseman.

SPEAKER_00 15:20

And this has been the pilot episode of WCVM Next Gen Scientist. Thanks for listening.