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Nicole Dubilier, Ph.D., Director and head of the Symbiosis Department at the Max Planck Institute for Marine Microbiology, has led numerous reserach cruises and expeditions around the world studying the symbiotic relationships of bacteria and marine invertebrates. She discusses how the use of various methods, including deep-sea in situ tools, molecular, 'omic' and imaging analyses, have illuminated remarkable geographic, species and habitat diversity amongst symbionts and emphasizes the importance of discovery-driven research over hypothesis-driven methods.
Watch this episode: https://www.youtube.com/watch?v=OC9vqE1visc
Ashley's Biggest Takeaways: In 1878, German surgeon, botanist and microbiologist, Heinrich Anton de Bary, first described symbiosis as the living together of two or more different organisms in close physical intimacy for a longer period of time. These relationships can be beneficial, detrimental or commensal, depending on the organisms involved. Microbial symbiosis research holds great potential to contribute to sustainable energy production and environmental health. Links for This Episode: Learn more about one of Dubilier's research vessels and see videos from the expidition. Functional diversity enables multiple symbiont strains to coexist in deep-sea mussels. Chemosynthetic symbioses: Primer. Take the MTM listener survey! -
From Bovine Spongiform Encephalopathy (BSE) to Creutzfeldt-Jakob disease (CJD), Neil Mabbott, Ph.D., has worked for nearly 2 decades on understanding the mechanisms by which prion proteins become infectious and cause neurological disease in humans and animals. He discusses the remarkable properties of prions and addresses complexities surrounding symptoms, transmission and diagnosis of prion disease.
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Episodi mancanti?
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Episode Summary Timothy Donohue, Ph.D.—ASM Past President, University of Wisconsin Foundation Fetzer Professor of Bacteriologyand Director of the Great Lakes Bioenergy Research Center (GLBRC) calls genomics a game-changer when it comes the potential of microbes to create renewable resources and products that can sustain the environment, economy and supply chain around the world. He also shares some exciting new advances in the field and discusses ways his research team is using microorganisms as nanofactories to degrade lignocellulose and make a smorgasbord of products with high economic value.
Take the MTM listener survey! Ashley's Biggest Takeaways: The bioeconomy can be broadly defined as the use of renewable resources, including microorganisms, to produce valuable goods, products and services. Microbes have the potential to create products that cannot be made by existing synthetic chemistry routes. Using raw, renewable resources to create a circular bioeconomy is beneficial to the environmental footprint, economic footprint and supply chain security around the globe. Links for This Episode: The theme of our Spring 2024 Issue of Microcosm, our flagship member magazine is Microbes and the Bioeconomy: Greasing the Gears of Sustainability, launches this week and features an article based on this MTM conversation. If you are an ASM Member, check back on Wed., June 30 for the newly published content! Not a member? Consider renewing or signing up today, and begin exploring endless potential to boulster your career and network with professionals, like Donohue, in your field. Get Bioeconomy Policy Updates. Heading to ASM Microbe 2024? Check out this curated itinerary of sessions on the bioeconomy, including those discussing the use of algae for bioproduction and synthetic biology for natural product discovery. Learn more about the Great Lakes Bioenergy Research Center. MTM listener survey! -
Rodney Rohde, Ph.D., Regents’ Professor and Chair of the Medical Laboratory Science Program at Texas State University discusses the many variants, mammalian hosts and diverse neurological symptoms of rabies virus.
Ashley’s Biggest Takeaways: Prior to his academic career, Rohde spent a decade as a public health microbiologist and molecular epidemiologist with the Texas Department of State Health Services Bureau of Laboratories and Zoonosis Control Division, and over 30 years researching rabies virus. While at the Department of Health Lab, Rohde worked on virus isolation using what he described as “old school” cell culture techniques, including immunoassays and hemagglutinin inhibition assays. He also identified different variants of rabies virus, using molecular biology techniques. Rohde spent time in the field shepherding oral vaccination programs that, according to passive surveillance methods have completely eliminated canine rabies in Texas. In the last 30-40 years, most rabies deaths in the U.S. have been caused by bats. Approximately 98% of the time rabies is transmitted through the saliva via a bite from a rabid animal. Post-exposure vaccination must take place before symptoms develop in order to be protective. Links for This Episode: Molecular epidemiology of rabies epizootics in Texas. Bat Rabies, Texas, 1996–2000. The Conversation: Rabies is an ancient, unpredictable and potentially fatal disease. Rohde and Charles Rupprecht, 2 rabies researchers, explain how to protect yourself. The One Health of Rabies: It’s Not Just for Animals. MTM listener survey!
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ASM's Young Ambassador, Aureliana Chambal, discusses the high incidence of tuberculosis in Mozambique and how improved surveillance can help block disease transmission in low resource settings.
Ashley's Biggest Takeaways: Mozambique is severely impacted by the TB epidemic, with one of the highest incidences in Africa (368 cases/ 100,000 people in the population). Human-adapted members of the Mycobacterium tuberculosis complex (MTBC) belong to 7 different phylogenetic lineages. These 7 lineages may vary in geographic distribution, and have varying impacts on infection and disease outcome. For decades, 2 reference strains have been used for TB lab research, H37Rv, which Chambal mentions, and Erdman. Both of these belong to TB Lineage 4. According to Chambal, the reference strains that we use for whole genome sequencing (worldwide) may be missing genes that are related the virulence (and/or resistance) of strains that are circulating in a given population and detected in clinical settings. Chambal is endeavoring to employ a new strain to control these analyses and better understand transmission dynamics in the community setting. Featured Quotes:The Schlumberger Foundation Faculty for the Future Fellowship is one of my proudest accomplishments for the 2023. I applied for this fellowship last year to pursue my Ph.D. It is a program that supports women coming from emerging and developing economies to pursue advanced research qualifications in science, technology, engineering and mathematics. I applied because I was looking to get more skills in microbiology, specifically tuberculosis, to pursue my Ph.D. at Nottingham Trent University.
Pathway to Microbiology ResearchMy trajectory is different because I have a bachelor’s in veterinary medicine. And during my undergrad, I always had more interest in the lab practice modules or disciplines. For the end of the [bachelor’s] project, I was looking to understand the anthelmintic effectiveness against the gastrointestinal parasites in goats. After I finished this project, I was looking to continue a related project, but unfortunately, I couldn't get work related to that..
Tuberculosis Genomic Diversity and Transmission Dynamics
In 2016, I applied for the National Institutes of Health of Mozambique, which is one of the biggest research institutions in my home country. That's when I was selected to work at the north region of Mozambique, specifically at the Nampula Tuberculosis Reference Laboratory. And then I moved to the public health laboratory as well, where I had the opportunity to work in the microbiology section. So, to be honest, my passion for microbiology started when I had the first contact with the TB lab, and then I couldn't separate myself from this area, tuberculosis.
In 2016, I had the opportunity to receive a mentorship. Our lab, the TB lab of Nampula, received mentorship from the American Society for Microbiology. And we worked with Dr. Shirematee Baboolal; she was the mentor of our lab. The main idea of the program was to get the lab accredited and to build technical capacity in the lab. And to be honest, at the time, I didn't have much experience in lab techniques to detect or diagnosis tuberculosis.
And I said to Dr. Shirematee, “I don't have much experience in this area, so, I don't know if I will be able to help you to accomplish these goals.” And she said, “If you want to learn, I can teach you, and you can be one of the best in this area.”
And then we started training with her. It was very interesting. The passion she passed to us about microbiology—and tuberculosis, in particular—was one of the triggers for my passion in this area. So, to be honest, Dr. Shirematee Baboolal was one of the persons that triggered my interest from tuberculosis. So, I have to say thank you to her!Mozambique is one of the higher burden countries of tuberculosis. So, our population is about 33 million people. And the case rate is high, it is approximately 360 per 100,000 people in the population, which is equivalent to over 110,000, which is equivalent 211,000 cases in the population. So, while I was working for the TB lab, I always had the desire to understand more about the transmission of the disease in the community.
Involvement with ASM Young Ambassador Program
And I felt like I didn't have enough skills to do that; I didn't the tools to do that. And I said, “Okay, let me try to look to improve the skills.” That's why for my master's degree I tried to understand the genomic diversity of M. tuberculosis and see how we can see the gene content diversity within the lineage for which is the most spread lineage worldwide, and is predominant in Mozambique. Afterwards, I tried to expand to the other lineages.
When I finished my master's degree, I felt that it was still missing something. I had the information about [TB] diversity, but I didn't get the point about transmission itself. That's why, when I went back and applied for my Ph.D., I structured my current project to specifically look at transmission and transmission clusters in the community.
I'm trying to see how we can expand the gold standard of whole genome sequencing to try to make it applicable for all settings, including the low resources settings where most TB cases happen.
So, M. tuberculosis itself doesn't have a lot of diversity between strains and within strains, because [strains] are very monomorphic. But you can find some genes that are different, specifically from the reference strain that we use, which is H37Rv. In the reference strain for M. tuberculosis, we saw is that many genes are missing—genes that are related to virulence. So, this information can be tricky, because it's the reference that we use worldwide to analyze our samples that come from whole genome sequencing. If we have genes missing, we are not [seeing] the complete information about the virulence of the bacterial strain that is circulating. So, my analysis was trying to understand how we can employ a new strain (that has at least most of the genes that are present in the other screens of the lineage) to control our analysis.
Whole genome sequencing requires a lot of computational resources. So, the main idea is to try to extend that pipeline to make applicable to use in all settings.
In Mozambique, we have whole genome sequencing equipment at the central level of the country, and the demand is high. But there is a queue for processing the samples. So, if we have a pipeline that [makes it so] anyone is able to analyze the data, we can have the results quick, and we can have more information for the public health sector.
And with transmission studies, you can have a clearer idea of where the recent infection happened. We can see how many cases we have and when the transmission started. And then we can [try to] track and block the transmission.So, I had the opportunity to hear about ASM’s Young Ambassador Program while I was working at the TB lab, in 2018. I spoke to Dr. Shirematee Baboolal and Dr. Maritza Urrego. And they told me about this position. Then, once I finished my masters [program], I applied for that position. I saw the requirements, and I felt like it was the right position for what I wanted to do for my community—to support the youth community and engage with my community back in Mozambique. I applied in 2020, and I got the position.
Links for the Episode: ASM Ambassador Program. ASM Global Public Health Program.
And I have to say, it is one of the best things I have done so far. Because since the implementation of this program in Mozambique, I have interacted with students in schools and universities. We have developed a lot of workshops. I feel like I can contribute scientifically to improve their lives, to improve their academic lives. And recently, we launched a program called Microbiology Kids Club. We go to schools, in church, and we teach children about science, specifically microbiology. We use cartoons and paint microbes to explain the importance of the microbes for the community for our daily activities. And it's very interesting how they are engaged. I can feel that it's a way to develop the taste for science in the children. So, I'm very happy with this accomplishment. In this role of young ambassador, I feel like I can contribute to my community back home.
I have so many ideas, so many dreams. I don't even know where to start! Because I have the ambitions to support my country back home. After I finish my Ph.D., I would like to create a robust technique that will help us to properly understand the [TB] transmission studies. So hopefully, with my Ph.D., I will be able to do that, or at least contribute something to support not only my country, but all low resources settings.
And I would also like to be like to support some public health policies that can help us. Because we don't have like a strong component that involves the lab, the public health sector—I feel like everything is separated. We need to combine everything if we want to fight against tuberculosis. So, my desire is also to create a link between all these specific sites so we can make our fight against TB stronger. I want to continue [to drive] awareness about the support we need in low resource settings to control the fight against tuberculosis. -
The scientific process has the power to deliver a better world and may be the most monumental human achievement. But when it is unethically performed or miscommunicated, it can cause confusion and division. Drs. Fang and Casadevall discuss what is good science, what is bad science and how to make it better.
Get the book! Thinking about Science: Good Science, Bad Science, and How to Make It Better
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Dr. James Morton discusses how the gut microbiome modulates brain development and function with specific emphasis on how the gut-brain axis points to functional architecture of autism.
Watch James' talk from ASM Microbe 2023: Using AI to Glean Insights From Microbiome Data https://youtu.be/hUQls359Spo
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Dr. Michael ginger, Dean of the School of Applied Sciences in the Department of Biological and geographical Science at the University of Huddersfield, in West Yorkshire, England discusses the atypical metabolism and evolutionary cell biology of parasitic and free-living protists, including Leishmania, Naegleria and even euglinids.
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Dr. Maria Eugenia Inda-Webb, Pew Postdoctoral Fellow working in the Synthetic Biology Center at MIT builds biosensors to diagnose and treat inflammatory disorders in the gut, like inflammatory bowel disease and celiac disease. She discusses how “wearables,” like diagnostic diapers and nursing pads could help monitor microbiome development to treat the diseases of tomorrow.
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Ashley's Biggest Takeaways Biosensors devices that engineer living organisms or biomolocules to detect and report the presence of certain biomarkers. The device consists of a bioreceptor (bacteria) and a reporter (fluorescent protein or light). Inda-Webb’s lab recently published a paper in Nature about using biosensors (Sub-1.4 cm3 capsule) to detect inflammatory biomarkers in the gut. The work is focused on diagnosing and treating inflammatory bowel disease, but Inda-Webb acknowledged that that is a large research umbrella. The next step for this research is to monitor the use of the biosensor in humans to determine what chemical concentrations are biologically relevant and to show that it is safe for humans to ingest the device. It is believed that the gut microbiome in humans develops in the first 1000 days to 3 years of life. Early dysbiosis in the gut has been linked to disease in adulthood. However, we do not have a good way to monitor (and/or influence) microbiome development. Inda-Webb hopes to use biosensors in diapers (wearables) to monitor microbiome development and prevent common diseases in adulthood. In 2015, Inda-Webb became ASM’s first Agar Art Contest winner for her piece, “Harvest System.” Inda-Webb is the 2023 winner of the ASM Award for Early Career Environmental Research, which recognizes an early career investigator with distinguished research achievements that have improved our understanding of microbes in the environment, including aquatic, terrestrial and atmospheric settings. Learn More About ASM’s Awards Program Featured Quotes:We engineer bacteria to sense particular molecules of interest—what we call biomarkers—if they are associated with a disease. And then, we engineer a way that the bacteria will produce some kind of molecule that we can measure—what we call reporter—so that could be a fluorescent protein or light, like the one that we have in this device.
Links for the Episode: Inda-Webb, et al. recent Nature publication: Sub-1.4 cm3 capsule for detecting labile inflammatory biomarkers in situ. Bacterial Biosensors: The Future of Analyte Detection.
The issue is that inflammation in the gut is really very difficult to track. There are no real current technologies to do that. That is like a black box. And so, most of what we measure is what comes out from the gut, and has its limitations. It doesn't really represent the chemical environment that you have inside, especially in areas where you're inflamed. So, we really needed technologies to be able to open a window in these areas.
The final device that I am actually bringing here is a little pill that the patient would swallow and get into the gut. And then they engineer bacteria that the biosensors, will detect, let's say, nitrous oxide, which is a very transient molecule. And the bacteria are engineered to respond to that in some way—to communicate with the electronics that will wirelessly transmit to your cell phone. And from there, to the gastroenterologist.
We make the bacteria produce light. If they sense nitrous oxide, they produce light, the electronics read that, and the [information] finally gets into your phone.
Part of the challenge was that we needed to make the electronics very very tiny to be able to fit inside the capsule. And also, the amount of bacteria that we use also is only one microliter. And so, imagine one microliter of bacteria producing a tiny amount of light. Finally, the electronics need to be able to read it. So that has been also part of the challenge.
In this case, you have 4 different channels. One is a reference, and then the other 3 are the molecule of your choice. So, for example, what we show in the paper here is that we can even follow a metabolic pathway. So, you can see one more molecule turn into the other one, then into the other one. I'm really excited about that. Because normally we kind of guess as things are happening, you know, but here you can see in real time how the different molecules are changing over time. I think that's pretty exciting for microbiologist.
The immediate application would be for a follow up. Let's say the patient is going to have a flare, and so you could predict it more much earlier. Or there's a particular treatment, and you want to see what is happening [inside the gut]. But for me, as a microbiologist, one of the things I'm most excited about will be more in the longer term.
One of my favorite experiments that I do with the students is the Winogradsky column, and everyone gets super excited. So, we all have nice feelings for that. And it’s basically a column where we asked the students to bring mud from a lake, for example, and then some sources of nutrients. And then, after 6months, you will see all the layers, which is super pretty—beautiful, nice colors. But actually, that gives the concept of how the microenvironment helps to define where, or how, bacteria build communities.
And so, what I think this device is going to do is to help us identify what is this microenvironment and to characterize that. And then, from there, to know if [an individual’s] microbiome is leaning towards the disease state, or if it's already in a serious or dangerous situation, to think about treatments that can lead to a more healthy state. So, I would just say it's really to have a window into the gut, and to be able to give personalized treatment for the patient.
So, one application: I was thinking, I'm from the Boston area. So, one problem we have is getting a tick bite, right? After that, you could actually have to go through a very traumatic, antibiotic regime. I would imagine, in that case, you could [use the biosensor to] get the baseline [measurement], and then if you need to take these antibiotics, the doctors can follow how your microbiome is responding to that. Because one of the problems is that antibiotics changed the oxidation level [in the gut], and that really affects a lot the microbiome. To that point, for example, I get to know patients that they were athletes, and then, after antibiotic treatment, they have serious problems with obesity. Their life gets really messed up in many ways.
And so, what I'm thinking is, if we could monitor earlier, there are a lot of ways that we could prevent that. We could give antioxidants; we could change the antibiotic. There are things that I think the doctor could be able to do and still do the treatment that we know.
And of course, [although] we talk a lot about how much trouble antibiotics are, for certain things, we still need [them].
[The multi-diagnostic diaper] is one of my pet projects. I really love it. So yeah, basically, the issue is that the microbiome develops in the first 3 years. People even say like, 1000 days, you know. But there's really no way to monitor that. And now we're seeing that actually, if the microbiome gets affected, there are a lot of diseases that you will see in adult life. So, if we will be able to monitor the microbiome development, I really believe that we'll be able to prevent many of the diseases of tomorrow.
What happens is that babies wear diapers. So, I thought it was really a very good overlap. We call that “wearables,” you know, like devices that you can wear, and then from there, measure something connected with health.
So, in the diaper, I was excited because—different from the challenge with the ingested device, which was so tiny—here, we don't have the limitation of space. So, we could measure maybe 1000 different biomarkers and see how that builds over time.
We can measure so many things. One could be just toxic elements that could be in the environment. I try to do very grounded science, and so, my question is always, ‘what’s the actionable thing to do?’ So, I'm thinking if there was a lot of toxicity, for example, in the carpet, or in the environment where you live, those are the easiest things to change, right?
Then also, other things connecting more with the metabolism. [Often] the parents don't know that the kid has metabolic issues. So, before that starts to build and bring disease, it would be best if you could detect it as early as possible. From there, with symbiotics, we are thinking there are a lot of therapies that could engineer bacteria to produce the enzymes that the kid can’t produce.
We could also [develop] other products, like for example, a t-shirt to measure the sweat. I'm also thinking more of the milk. I'm very excited about how the milk helps to build the microbiome in the right way. And that that's a huge, very exciting area for microbiologists. And so, we could also have nursing pads that also measure [whether] the mother has the right nutrients.
My family, my grandparents were farmers, and in Argentina, really the time for harvest is very important. You can see how the city and really the whole country gets very active. And at that time [during a course Inda-Webb was taking at Cold Spring Harbor] in this course, I could see that with yeast we were having a lot of tools that would allow us to be much more productive in the field. And I thought, ‘Oh, this feels like a harvest system for yeast.’ Yes. So that was how it [Inda-Webb’s winning agar artwork, ‘Harvest System’] came out.
I really love the people. Here, [at ASM Microbe 2023], I really found that how people are bringing so much energy and really wanted to engage and understand and just connect to this idea of human flourishing, right, giving value to something, and saying, ‘okay, we can actually push the limits of what we know.’ How beautiful is that? And you know, we can learn from that. That was very exciting.
ASM Agar Art Contest
Have you ever seen art created in a petri dish using living, growing microorganisms? That's agar art! ASM's annual Agar Art Contest is a chance for you to use science to show off your creative skills.
Submissions Are Now Being Accepted!
This year's contest theme is "Microbiology in Space." Head over to our Contest Details page to get all of the information about what you need to submit your entry. Submissions will be accepted until Oct. 28!
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. -
Dr. Gary Procop, CEO of the American Board of pathology and professor of pathology at the Cleveland Clinic, Lerner School of Medicine discusses the importance of early detection and diagnosis in order to prevent fungal invasion leading to poor outcomes, particularly in immunocompromised patients. He emphasizes the importance of thinking fungus early, shares his passion for mentoring and talks about key updates in the recently released 7th Edition of Larone’s Medically Important Fungi.
Ashley's Biggest Takeaways Many invasive fungal infections are angiotrophic, meaning they actually grow toward, and into, blood vessels. Once the fungus has penetrated the blood vessel, the blood essentially clots, causing tissue downstream from the blood clot to die (infarction). When tissues that have been excised are viewed under the microscope, hyphal elements can be seen streaming toward or invading through the wall of the blood vessels. Once the clot forms, those hyphal elements can be seen in the center of the blood vessel where only blood should be. Antifungals cannot be delivered to areas where the blood supply has stopped. Therefore, treatment requires a combined surgical and medical approach, and the process is very invasive. Early detection can prevent these bad outcomes by allowing antifungal treatment to be administered before angioinvasion occurs. Links for the Episode: Expand your clinical mycology knowledge with the recently released 7th edition of Larone's Medically Important Fungi: A Guide to Identification. Written by a new team of authors, Lars F. Westblade, Eileen M. Burd, Shawn R. Lockhart and Gary W. Procop, this updated edition continues the legacy of excellence established by founding author, Davise H. Larone.
Since its first edition, this seminal text has been treasured by clinicians and medical laboratory scientists worldwide. The 7th edition carries forward the longstanding tradition of providing high-quality content to educate and support the identification of more than 150 of the most encountered fungi in clinical mycology laboratories.
Get your copy today with $1 flat rate shipping within the U.S. or order the e-book! ASM members enjoy 20% off at checkout using the member promo code.Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.
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From antifungal resistance to disaster microbiology and tales of visible mold growing across the skin of patients following a tornado in Joplin, Missouri, Dr. Shawn Lockhart, Senior Clinical Laboratory Advisor in the Mycotic Diseases Branch at the CDC talks all things fungi—complete with references to pop TV shows and the recently released 7th Edition of Larone’s Medically Important Fungi.
Links mentioned:
Larone's Medically Important Fungi: A Guide to Identification, 7th Edition (Use code: MCR20 at checkout for 20% off) CDC’s Mycotic Diseases Branch conducts an annual training course on the identification of pathogenic molds. -
Dr. Kate Howell, Associate Professor of Food Chemistry at the University of Melbourne, Australia discusses how microbes impact the flavor and aroma of food and beverages and shares how microbial interactions can be used to enhance nutritional properties of food and beverage sources. Ashley's Biggest Takeaways Saccharomyces means sugar-loving fungus. Humans have similar olfactory structures and mechanisms as insects and are similarly attracted to fermenting or rotting fruits produced by Saccharomyces. Research has shown that insects (and humans) prefer yeasts that produce more esters and aromatic compounds. Palm wine is a product that is made from sap collected from palm trees (palm sap) across the tropical band of the world. Fruity flavors appear to be less important to persistence of Saccharomyces strains in an Indonesian palm wine fermentation. This may be because palm wine fermentation is very quick, generally 1-3 days often, with a maximum of 5 days for fermentation to be conducted. Wineries, on the other hand, ferment annually (one fermentation per year/vintage), when the grapes are right. Grape wine fermentations can take 7 days to 2 weeks to complete. So different selections likely take place between the 2 fermentation products. Featured Quotes:
When we start drawing our lens on how microbes produce food for humans, we're coopting a process that happens quite naturally. Here I'll start off talking about Saccharomyces cerevisiae, the main fermenting yeast in food and beverage production, because it's one of the most studied organisms and was the first eukaryote to be sequenced.
Links for the Episode: LC-ESI-QTOF/MS Characterisation of Phenolic Acids and Flavonoids in Polyphenol-Rich Fruits and Vegetables and Their Potential Antioxidant Activities. Frozen, canned or fermented: when you can't shop often for fresh vegetables, what are the best alternatives? Early Prediction of Shiraz Wine Quality Based on Small Volatile Compounds in Grapes. Building the climate resilience of Melbourne's Food System.
Saccharomyces cerevisiae, as the name implies, loves sugar, and it flourishes when there's a lot of sugar in the environment. Where is sugar found? In fruits, and that's done quite deliberately, because fruits develop sugars and flavors and aromas to attract a birds or insects or anything else that can carry their seeds elsewhere for dispersal.
Now, Saccharomyces lies dormant in the environment in a spore before it encounters a sugar-loving environment. And then it replicates very quickly and tends to dominate fermentation. Humans have coopted that into our kitchens, into our meals, into our lives, and we use that process to produce food.
As Saccharomyces starts to use this sugar, it balances up its metabolism. And as it does this, it produces aromas. These aromas have a lot of important characteristics. Humans love them, but insects also love them too.
I've been interested in the yeasts that are found naturally in sourdough starters. Sourdough is a really interesting system. Because you've got yeast and bacteria interacting with one another.
One of the things we are collaborating on with colleagues in France at Inrae, Dr. Delphine Sicard, is to understand some of the non-Saccharomyces yeasts that are naturally occurring in sourdough starters. So here we're looking at a collection of a yeast called Kazachstania humilis and trying to understand how it has adapted to the sourdough environment, how its sustained over time and how different global populations differ to one another.
And this, of course, is of interest to the baking industry because not only do artisanal bakers have sort of an undiscovered wealth of biodiversity in their starters, baking companies also have an interest in using different sorts of flavors and bread for the commercial markets.
The connection between a chemical profile and a person’s sensory preference isn't something that's complete and direct. So, in every method that we use, there's always caveats, but we try to correlate it. Let's start off with the chemical characterization. We use headspace sampling, analytical chemistry, separation with gas chromatography and identification with mass spectrometry.
And we use different 2-dimensional methods to be able to understand what the very small compounds are, and to be able to identify them. We can semi-quantify these to be able to make comparisons between different fermentations.
We know from wine fermentations and understanding preferences of wine that, in some cases, a particular increase, or an abundance of a particular compound, can be extremely attractive. And that might depend on the style of wine.
What we've discovered through this process is that different people prefer different flavors. Makes sense, doesn't it? We like different things. But some really interesting results from our lab, show that people from different cultural backgrounds have different preferences. And here we're using here in Melbourne, I'm very lucky to work with some very talented postdocs and Ph.D. students from China, who have very different preferences for wine than an Australian does. Of course, Australians are quite heterogeneous in their in their cultural diversity as well. But there's certain flavors that our Chinese colleagues tend to prefer. So we decided to investigate this a little bit more.
So for this study, we recruited wine experts from Australia, actively working in the wine industry, and also wine experts from China, working in the wine industry, and brought them to campus and ask them to rate their preferences on particular aromas and flavor characteristics that they noted in a panel of wines. These were very high-quality wines. We knew with wine experts, we couldn't just give them our loved wines, for example, which can be a little bit patchy quality wise. We asked them to rate their preferences, and then we collected saliva samples.
The saliva samples were really interesting. We looked at 2 different aspects. We looked at the proteins that were present in the saliva samples. And we also looked at the oral microbiome. So the salivary microbiome—the bacteria, in particular—that are present. We found some really interesting things. And this has sparked a big area in our lab.
So while the main enzymatic activities in the different groups of participants were quite similar—so esterase activity, Alpha amylase activity were similar—we found that there was a difference in the abundance of proline rich proteins and other potential flavor carrying compounds. Now, this is quite speculative. We'd like to know why this is the case. And so we're delving a little bit further into this area.
What we do know though is that the abundances, especially if these proline rich proteins, is correlated with how people perceive the stringency. Now stringency is one of those characteristics in wine which is quite difficult to appreciate. It’s a lack of drying characteristic on the tongue and in the mouth and oral cavity. Some people find it quite attractive, others don't.
But we found that the abundance of these polyproline-rich proteins correlates with stringency. This is, in fact, found in other studies because proline-rich proteins interact with polyphenols in the wine, and precipitate, which changes the sensation of astringency in the oral cavity. So here we've got a nice link to protein abundance and how people perceive flavor. But we're talking about microbiology, so maybe I should delve into the microbiological aspects of these studies as well.
In that particular study that I'm referring to, we used wines that were naturally fermented, and that's the other variability that we need to consider when we think about wines from different areas. So, a natural fermentation, in a wine sense, is the grapes are harvested, and whatever microflora is present on the grapes will just ferment, and we often don't know what the main fermenting parties are. But if you contrast that with a majority of commercial wine that's produced, mainly in Australia, but also worldwide, it's inoculated with a selected strain of Saccharomyces or maybe 2 selected strains of Saccharomyces, and that tends to produce a fairly similar flavor profile, regardless of region.
So, you can flatten out geographical characteristics and indications of flavor by inoculating a particular strain of yeast to ferment. That's not true with a natural fermentation, because that's conducted by the yeasts, and also the bacteria which just happened to be in the environment. So, I agree with you there is a lot of regional variation with wine flavor. And we can correlate that with regional diversity of yeast, but only if the wines are naturally fermented not if they're inoculated with a selected strain.
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. -
Dr. Steve Diggle, ASM Distinguished Lecturer and Microbiology Professor at the Georgia Institute of Technology in Atlanta, Georgia and Dr. Freya Harrison, Associate Microbiology Professor at the University of Warwick in Coventry, U.K., discuss the science behind medieval medical treatments and the benefits of interdisciplinary research.
Ashley's Biggest Takeaways Diggle and Harrison met in Oxford, where Harrison was finishing up her Ph.D. and Diggle was doing background research for his work studying evolutionary questions about quorum sensing. When Diggle began searching for a postdoc, Harrison, who had been conducting an independent fellowship at Oxford and studying social evolution, applied. The AncientBiotics Consortium is a group of experts from the sciences, arts and humanities, who are digging through medieval medical books in hopes of finding ancient solutions to today’s growing threat of antibiotic resistance. The group’s first undertaking was recreation and investigation of the antimicrobial properties of an ancient eyesalve described in Bald’s Leechbook, one of the earliest known medical textbooks, which contains recipes for medications, salves and treatments. The consortium found that the eyesalve was capable of killing MRSA, a discovery that generated a lot of media attention and sparked expanded research efforts. The group brought data scientists and mathematicians into the consortium (work driven by Dr. Erin Connelly from the University of Warwick). Together, the researchers began scouring early modern and medieval texts and turning them into databases. The goal? To mathematically data mine these recipes see which ingredients were very often or non-randomly combined in ancient medical remedies. The group recently published work showing synergistic antimicrobial effects of acetic acid and honey. They are also working to pull out the active compounds from Bald’s eyesalve and make a synthetic cocktail that could be added to a wound dressings. A 1,000-Year-Old Antimicrobial Remedy with Antistaphylococcal Activity. Medieval medicine: the return to maggots and leeches to treat ailments. A case study of the Ancientbiotics collaboration. Phase 1 safety trial of a natural product cocktail with antibacterial activity in human volunteers. Sweet and sour synergy: exploring the antibacterial and antibiofilm activity of acetic acid and vinegar combined with medical-grade honeys.
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. -
Dr. Jessica Lee, scientist for the Space Biosciences Research Branch at NASA’s AIMS Research Center in Silicon Valley uses both wet-lab experimentation and computational modeling to understand what microbes really experience when they come to space with humans. She discusses space microbiology, food safety and microbial food production in space and the impacts of microgravity and extreme radiation when sending Saccharomyces cerevisiae to the moon. Ashley's Biggest Takeaways Lee applied for her job at NASA in 2020. Prior to her current position, she completed 2 postdocs and spent time researching how microbes respond to stress at a population level and understanding diversity in microbial populations. She has a background in microbial ecology, evolution and bioinformatics. Model organisms are favored for space research because they reduce risk, maximize the science return and organisms that are well understood are more easily funded. Unsurprisingly, most space research does not actually take place in space, because it is difficult to experiment in space. Which means space conditions must be replicated on Earth. This may be accomplished using creative experimental designs in the wet-lab, as well as using computational modeling. Links for the Episode: Out of This World: Microbes in Space. Register for ASM Microbe 2023. Add “The Math of Microbes: Computational and Mathematical Modeling of Microbial Systems,” to your ASM Microbe agenda.
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.
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Dr. Maria Gloria Dominguez-Bello, Henry Rutgers Professor of Microbiome and Health and director of the Rutgers-based New Jersey Institute for Food, Nutrition and Health, and Dr. Martin Blaser, Professor of Medicine and Pathology and Laboratory Medicine and director of the Center for Advanced Biotechnology and Medicine at Rutgers (NJ) discuss the importance of preserving microbial diversity in the human microbiome.
The pair, whose research was recently featured in a documentary The Invisible Extinction, are on a race to prevent the loss of ancestral microbes and save the bacteria that contribute to human health and well-being.
Links for the Episode: The Invisible Extinction (documentary) Missing Microbes (book) Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues (article) (YouTube) Missing Microbes with Dr. Martin Blaser -
Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for the 3rd , and final, episode in a unique 3-part segment, in which we share stories about the life and work of medial pioneers in infectious diseases. Here we discuss the career of Dr. Barry Marshall, the Australian physician who is best known for demonstrating in a rather unorthodox way that peptic ulcers are caused by the bacterium, Helicobacter pylori.
Gaynes is author of Germ Theory: Medical Pioneers in Infectious Diseases, the 2nd edition of which will publish in Spring 2023. All 3 scientists highlighted in this special MTM segment are also featured in the upcoming edition of the book. -
Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for the 2nd episode in a unique 3-part series, in which we share the impact of scientists at the heart of various paradigm shifts throughout scientific history. Here we discuss the life and career of Tony Fauci, the scientist who has been recognized as America’s Top Infectious Diseases Doctor and “voice of science” during the COVID-19 pandemic.
Ashley's Biggest Takeaways Fauci was born in Brooklyn, New York. He was a 2nd generation American whose parents came from Italy. Fauci’s father was a pharmacist in Brooklyn and was very influential in his life. During high school, Fauci worked behind the counter at the family pharmacy and even delivered prescriptions by bicycle. He attended a Jesuit high school in Manhattan, and attended the College of Holy Cross. After college, Fauci attended Cornell Medical School in Manhattan, which was his first choice of medical school. Fauci graduated first in his class in medical school in the mid 1960’s, right in the midst of the Vietnam War. During that time, after completing their initial residency training, virtually all doctors were drafted into one of the military services or the U.S. Public Health Service. Fauci accepted into the NIH program within the U.S. Public Health Service, where he acquired training and a fellowship in Clinical Immunology and Infectious Diseases. Fauci became the Director of the National Institute of Allergy and Infectious Disease (NIAID) in 1984. Fauci served as advisor to 7 U.S. presidents, including Ronald Regan, George H.W. Bush, Bill Clinton, George W. Bush, Barack Obama, Donald Trump and Joe Biden. 15 years after the creation of PEPFAR, Fauci reported, in the New England Journal of Medicine, that PEPFAR funded programs had provided antiretroviral therapy to 13.3 M people, averted 2.2 M perinatal HIV infections and provided care for more than 6.4 M orphans and vulnerable children.The first edition of "Germ Theory: Medical Pioneers in Infectious Diseases" is available now. The 2nd edition will publish in the spring of 2023.
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Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for a unique episode, in which we share the story of Françoise Barré-Sinoussi, the French, female scientist who discovered HIV and found herself at the heart of one of the most bitter scientific disputes in recent history.
Ashley's Biggest Takeaways The U.S. Centers for Disease Control and Prevention (CDC)’s Morbidity and Mortality Weekly Report first reported on a cluster of unusual infections in June of 1981, which would become known as AIDS. Evidence suggested that the disease was sexually transmitted and could be transferred via contaminated blood supply and products, as well as contaminated needles, and could be passed from mother to child. All hemophiliacs of this generation acquired AIDS (15,000 in the U.S. alone). The fact that the microbe was small enough to evade filters used to screen the clotting factor given to hemophiliacs indicated that the etiologic agent was a virus. AIDS patients had low counts of T-lymphocytes called CD4 cells. By 1993, the most likely virus candidates included, a relative of hepatitis B virus, some kind of herpes virus or a retrovirus. Howard Temin discovered reverse transcriptase, working with Rous sarcoma in the 50s and 60s. His work upset the Central Dogma of Genetics, and at first people not only did not believe him, but also ridiculed him for this claim. Research conducted by David Baltimore validated Temin’s work, and Temin, Baltimore and Renato Dulbecco shared the Nobel Prize for the discovery in 1975. Robert Gallo of the U.S. National Institute of Health (NIH), discovered the first example of a human retrovirus—human T-cell lymphotropic virus (HTLV-1). Françoise Barré-Sinoussi worked on murine retroviruses in a laboratory unit run by Luc Montagnier, where she became very good at isolating retroviruses from culture. In 1982, doctors gave lab Montagnier’s lab a sample taken from a with generalized adenopathy, a syndrome that was a precursor to AIDS. Barré-Sinoussi began to detect evidence of reverse transcriptase in cell culture 2 days after the samples were brought to her lab. Barré-Sinoussi and Luc Montagnier were recognized for the discovery of HIV with the 2008 Nobel Prize in Physiology or Medicine. Links for the Episode:
Subscribe (free) on Apple Podcasts, Spotify, Google Podcasts, Android, RSS or by email.From the ancient worlds of Hippocrates and Avicenna to the early 20th century hospitals of Paul Ehrlich and Lillian Wald to the modern-day laboratories of François Barré-Sinoussi and Barry Marshall, Germ Theory brings to life the inspiring stories of medical pioneers whose work helped change the very fabric of our understanding of how we think about and treat infectious diseases.
Germ Theory: Medical Pioneers in Infectious Diseases
The second edition of Germ Theory, which will include chapters on Françoise Barré-Sinoussi, Barry Marshall and Tony Fauci, will publish in Spring 2023. -
Episode Summary Dr. Devin Drown, associate professor of biology and faculty director of the Institute of Arctic Biology Genomics Core at the University of Alaska Fairbanks, discusses how soil disturbance gradients in the permafrost layer impact microbial communities. He also explains the larger impacts of his research on local plant, animal and human populations, and shares his experience surveilling SARS-CoV-2 variants in Alaska, where he and colleagues have observed a repeat pattern of founder events in the state. Ashley's Biggest Takeaways Permafrost is loosely defined as soil that has been frozen for 2 or more years in a row. Some permafrost can be quite young, but a lot of it is much older—1000s of years old. This frozen soil possesses large storage capacity for walking carbon and other kinds of nutrients that can be metabolized by microbes as well as other organisms living above the frozen ground. About 85% of the landmass in Alaska is underlined by permafrost. Some is continuous permafrost, while other areas of landmass are discontinuous permafrost—locations where both unfrozen soil and frozen soil are present. As this frozen resource is thawing as a result of climate change, it is releasing carbon and changing soil hydrology and nutrient composition, in the active layer in the soil surrounding it. Changes in the nutrients and availability of those nutrients are also likely changing the structure of the microbial communities. Drown and team are using a combination of traditional (amplicon sequencing) and 3rd generation (nanopore) next sequencing (NGS) techniques to characterize the microbes and genes that are in thawing permafrost soil. Featured Quotes: “Globally, we've seen temperatures increase here in the Arctic. Changes in global temperatures are rising even faster, 2-3 times, and I've heard recent estimates that are even higher than that.”
“These large changes in temperatures are causing direct impacts on the thaw of the permafrost. But they're also generating changes in other patterns, like increases in wildfires. We just had a substantial wildfire season here in Alaska, and those wildfires certainly contribute to additional permafrost thaw by sometimes removing that insulating layer of soil that might keep that ground frozen, as well as directly adding heat to the to the soil.”
“There are other changes that might be causing permafrost thaw, like anthropogenic changes, changes in land use patterns. As we build and develop roads into areas that haven't been touched by humans in a long time. We're seeing changes in disruption to permafrost.”
“Some people are quite interested in what might be coming out of the permafrost. We might see nutrients, as well as microorganisms that are moving from this frozen bank of soil into the active layer.”
“We're using next generation sequencing techniques to characterize not only who is in these soils, but also what they're doing.”
“I started as a faculty member in 2015. As I moved up to Alaska, I got some really great advice from a postdoctoral mentor that said, make sure you choose something local. I'm fortunate enough that I have access to permafrost thaw gradient, that's effectively in the backyard of my office.”
“Just a few miles from campus, we have access to a site that's managed by the Army Corps of Engineers. They have a cold regions group up here that runs a more famous permafrost tunnel. So they've dug a deep tunnel into the side of a hill that stretches back about 40,000 years into permafrost. They also have a great field site that has an artificially induced permafrost thaw gradient, and a majority of our published work has been generated by taking soil cores from that field site.”
“Maintaining that cold chain, whether it’s experimental reagents or experimental samples, is a challenge for everyone. We're collecting active layer soil—the soil directly beneath our feet—so that's not at terribly extreme temperatures. But we do put it in coolers immediately upon extracting from the from the environment. Then we can bring it back to our lab where we can freeze it if we're going to use it for later analysis, or we can keep it at appropriately cool temperatures, if we're going to be working with the microbial community directly.”
“We were most interested in looking for microbes that might have impacts on the above ground. ecosystem. So when we were characterizing the microbial community, we were doing that because we also wanted to link it to above ground changes.”
“Changes in vegetation that might be driven by changes in microorganisms would certainly have an impact on the wildlife that are that are present at the site. So, just as an example, if we see a decrease in berries that might be present, that might decrease the interest from animals that rely on that [food source]. And so we might see changes in who's there.”
“Outside of my research, we've seen changes in the types of plants present across northern latitudes. So different willows, for instance, are moving farther north, and that is leading animals, like moose, to move farther north. And so we might see changes in those kinds of patterns directly as a result of the microorganisms as well.”
“We're really working to expand our efforts to move to other kinds of disturbances. I mentioned wildfires before, these are an important source of disturbance for boreal forest ecosystems. We have a project here in the interior, looking at the impacts of wildfires on microbial communities and how [these disturbances] might be changing the functional potential of microbial communities.”
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. -
Dr. Marie Landry, Professor of Laboratory medicine and Infectious Diseases at Yale University School of Medicine and Dr. John Booss, former National Director of Neurology for the Department of Veteran’s Affairs discuss the past, present and future of diagnostic virology. These proclaimed coauthors walk us through the impact of some of the most significant pathogens of our time in preparation for the launch of their 2nd edition of “To Catch a Virus,” a book that recounts the history of viral epidemics from the late 1800s to present in a gripping storytelling fashion. Ashley's Biggest Takeaways Coauthoring a book requires having great respect for the opinions of the person you are working with. The first human disease shown to be viral in nature was yellow fever, but for quite some time, the mode of disease transmission remained mysterious. In early 1881, Carlos Finlay of Cuba suggested that the disease could be spread by mosquitoes and significantly advanced the field. It wasn’t until polio was discovered in the early 1900s that scientists determined that viruses could also be transmitted by and animals. The ability to grow virus in tissue culture was another huge advancement in the field of diagnostic virology, which eventually led to the development of the Salk inactivated polio vaccine (IPV). Although he did not seek the spotlight for his work, Walter Roe, was a bright, hardworking (and one of John’s favorite) virologist, who made important advances in tissue culture, researched the role of retroviruses in animal cancer and discovered adenoviruses. As a result of the COVID-19 pandemic, the clinical laboratory played a central role in public health. The importance of a laboratory diagnosis became more evident and next generation sequencing moved further into the clinical lab. Featured Quotes: “Advice that was given to me way back when I started on my first book is that you have to write about something you're passionate about. You have to really believe in the topic because otherwise it'll come across as superficial and artificial. So the very first step is do you really believe in, [and in the case of writing a book, that means] believe in what you're writing about.” – Booss.
“Science is often projected as a steady stream of advances one after the other. But there is a certain amount, I think, of arbitrary choice at each step. And it's also true for for writing a book.” – Booss
“In putting the book together, there are obviously major events that occurred in virology, major crises that move the field forward, an interplay, really, of the scientific advances, the clinical need of the crisis at hand and some very remarkable people. One highlight of this book is the way it does focus on individuals and their stories and how they contributed to that progress.” -Landry
“When [pathogens] spread from a local area to a larger area geopolitical area or even globally, they become pandemic.” Polio “The most compelling virus that I can think of in my youth was obviously polio. So when I was a small child, polio was causing epidemics every summer, at the end of which, between 20 and 30,000 children in the United States were left either paralyzed or dead. So this was it really struck fear into parents hearts.” – Landry
“And then came the oral polio vaccine. We lined up, and it was a very, very painless way to be immunized. So that was a tremendous success story, we've come very close to eliminating polio, because of a number of reasons it hasn't happened.” - Landry
“There was a case recently of paralytic polio in New York, in an unvaccinated person. And I hope this is a wake-up call, we really thought we were about to eliminate before COVID. And then with those disruptions and others, there's been a little resurgence, but I hope that it will be accomplished soon.” -Landry COVID-19 “It's amazing how much the world did change. International economies collapsed. whole societies shut down. The education and socialization of children came to a screeching halt. As schools close, whole chasms of inequality opened up or were revealed. And also the poor and marginalized people were the ones who suffered most. And the U.S. cultural divisions interfered with attempts to block the disease. So that by 2022, the U.S. was unique in having over 1 million deaths. We lead unfortunately led the world in that regard.” – Booss
“Sometimes we need a crisis to move us forward. And we saw this with the new vaccine platforms, especially the mRNA vaccine.”
Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. Links From yellow fever and smallpox, to polio, AIDS and COVID-19, To Catch a Virus guides readers through the mysterious process of catching novel viruses and controlling deadly viral epidemics— and the detective work of those determined to identify the culprits and treat the infected.
The new edition will be released October 15, 2022, available at asm.org/books - Mostra di più
