Meet the Microbiologist – Détails, épisodes et analyse

Moon Nahm, M.D., professor emeritus at UAB Department of Medicine and Director of the World Health Organization's Pneumococcal Serology Reference Laboratory at UAB, discusses his career in pneumococcal immunology. From uncovering the WU2 reference strain and other hidden serotypes to pioneering Multiplexed Opsono-Phagocytosis Assay (MOPA) to measure the functional activity of anti-pneumococcal antibodies, Nahm's contributions have facilitated development of advanced vaccines with broader protection and accessibility.

• UAB Spotlight on Moon Nahm.
• Discovery and Characterization of Pneumococcal Serogroup 36 Capsule Subtypes, Serotypes 36A and 36B. Journal of Clinical Microbiology paper, March 27, 2003.
• A New Pneumococcal Capsule Type, 10D, is the 100th Serotype and Has a Large cpsFragment from an Oral Streptococcus. mBio, May 19, 2020.
• 50 years—and change. WashU Magazine.
• MTM Listener Survey

From leading R&D at a biotech startup company to conducting environmental monitoring for NASA, Veronica Garcia, Ph.D., Scientific Director of the ASM Applied and Environmental Microbiology unit shares how experiences throughout her career have informed her appreciation for microbes and their real-world applications. She also discusses how the ASM AEM unit will support scientists around the globe by fostering collaboration and advocating for scientific advancements in areas like climate change, water systems and food production.

• Prior to her role as Scientific Director for ASM Applied and Environmental Microbiology unit, Garcia was Senior Director of R&D at Boost Biomes, a biotech startup focused on bio-pesticides and bio-fertilizers.
• Garcia's passion for microbiology began studying soil remediation at Texas A&M University.
• Seeing microbes under the microscope for the first time felt like discovering "another world," sparking a lifelong fascination with what microbes are and can do.
• Driven by a desire to see her science make an immediate impact, Garcia was drawn to industry after completing her Ph.D.
• At Boost Biomes, a biotech startup company, Veronica helped transform diverse microbial isolates into bio-pesticides, bio-fertilizers and bio-stimulants for agriculture and food. She progressed from bench scientist to senior Director of R&D, overseeing discovery, genomics, bioinformatics and product development, and learned the realities of scale-up, cost, regulation and end-user needs.
• She also monitored air, water and surfaces for the shuttle and ISS and NASA, ensuring astronaut safety by tracking microbial loads and potential pathogens.
• ASM is organizing around 3 scientific units, ASM Applied and Environmental Microbiology (AEM), ASM Health and ASM Mechanism Discovery.
• These units will equip researchers to translate discovery into impact while providing a forum to collectively shape the future of the field.
• The AEM unit provides the space and unique expertise for microbial scientists and partners to directly contribute to a healthier, more sustainable world through applied and environmental innovation and brings together experts whose work connects microbial processes to outcomes in ecosystems, infrastructure, food systems and planetary health.

• Learn More About ASM's Scientific Units.
• Join the Conversation on ASM Connect, our online community platform.
• Browse Volunteer Opportunities.
• Become an ASM Member.
• Take the MTM listener survey! 

• Dynamics surrounding the AMR crisis are complex and require an understanding of many different perspectives, including those of the farmers, health care professionals, pharmaceutical companies and individuals, in order to foster true and lasting global collaboration on the issue.
• Point-of-care diagnostics are critical to improving treatment decisions and reducing hospital costs.
• Better communication and education are needed in order to rebuild trust in scientists and institutions.
• Continuous research is necessary, as AMR will continue to evolve.
• Citizens are a key piece of the puzzle when it comes to pushing for change and supporting solutions to AMR.

Wilson: "I'll start with actually my Ph.D., which is talking about bacterial antibiotic biosynthesis. And so, I did some work in that arena, but since then, I've actually been working on bacterial protein toxins. These are very potent eukaryotic modulators that when bacteria get into the host, they release these proteins that are very large, that are able to interact with very specific cells. They actually get inside the cells—into the cytosol—and then they affect various signaling pathways in the host that can go anywhere from killing the cell to modulating some of the processes that the cell undertakes, even differentiating them and causing cancer.

So, one of my main focuses in my lab has always been to understand the structure and function of these toxins, to understand how they affect the eukaryotic cell system. And then now that we know a lot about them, we're actually moving more into the direction of trying to basically use them as biologics. We have some platforms that we call bacterial toxin inspired drug delivery, where we're using the mechanisms of how they work and their exquisite specificities to be able to actually use them for therapeutic applications."

Ho: "I got my start doing molecular genetics, actually, with John Mekalanos at Harvard, and I was kind of at the ground floor of the seminal work looking at the Type VI secretion system. And so, I got a front row seat to the kind of discovery and a lot of the initial understanding of the system. And I've kind of taken that work and expanded beyond it to look at kind of the ways different bacteria interact with each other within microbial communities. So my current work is looking at both DNA conjugation as well as the type six antagonism, and how the bacterial interactions kind of work together to build a larger population dynamics and interface with like the hosts that kind of house a your microbial communities."

Antimicrobial Resistance

Wilson: "In 2005 [when the first edition of Revenge of the Microbes was written], there was very little activity or understanding about antibiotic resistance and how important it was. Outside of the field, doctors were encountering it. But oftentimes what was happening is they just said, 'Oh, well, we'll just find another drug, you know.' And pharmaceutical companies, they were recognizing that there was a problem, and they would go off trying to hunt for new ones. And then right around the late 90s, there was a big impetus, because they thought, 'Oh, we, we have a miracle here, because we now do complete genomes. We can get out the comparative genomics and all the high throughput things, all the animations,' and that this would lead to many more new discoveries. And I think the pharmaceutical companies were very disappointed, and they started backing out of what they deemed a huge commitment.

Two decades later, people already were starting to get aware, at least in the field, and even the industry and the physicians. People were getting aware, but I think that they were stumbling, because of their silos, in trying to get interactions with each other. And I think part of it was that they felt that, 'Oh, we can try to solve it ourselves.' And in reality, this is a problem that that is concerning everyone, and everyone is contributing to it. Everyone has to find a solution to help, and we need to have more synergy. There have to be more interactions, and we have to do this at a much more global scale. And so that was sort of what, what we thought when we first started the [2nd edition of the book, Revenge of the Microbes]."

Ho: "At that point, I was just starting my new faculty position, and so I started having to teach students directly. And a lot of students were coming in and giving their presentation on their research proposal or project that they have, and they very adamantly declared the reason why we have antibiotic resistance. 'The problem is because doctors are over prescribing antibiotics.' And I'm scratching my head—a little like, 'Hmm, that's a really confident statement that you're making.' Next student comes in and they're talking about, 'Oh, it's all the farmers that are overusing antibiotics and causing the problem.' And then the next student comes in like, "Oh, the greedy corporations or pharmaceutical industry is trying to milk us for everything, and antibiotics are not profitable enough.' And, and I'm sitting here listening to the students who have a very narrow perspective. And clearly, they're getting it from whoever is teaching their classes.

And so, it feels like every single perspective at every single stage, they only see things through their own eyes, and can't understand what the broader perspective is and why you have all these various different problems, and I guess we call them stakeholders in the thing. It is that that every different angle has its own personal motivations. Corporations do need to have money and persist to exist. Doctors, if you encounter a patient that is dying, well, you have a moral compulsion to actually treat them. And farmers having their livestock, well, their livelihood is at stake if they don't have their animals survive, right?
And so, what I think was really important that we wanted to do is present the problem of antibiotic resistance and the way it works and why it's an issue, but also convey different perspectives on it, so that if people can kind of understand where everybody else is coming from, we can come together and have a more unified perspective, or understanding, at least, so that you're not thinking that everybody is this malicious actor, and you can actually work together to come with up with a complete solution."

Wilson: "The first book, was very important, because you needed to get people's attention right, right? But we got the attention. So, now let's come up with a plan! And we don't have a good plan. People are making progress. People are moving in the directions that need to be moved, coming up with alternatives, coming up with, you know, even financial solutions, to some extent.

They're not enough, still, and it's going to take a global community to come forward and buy in to the problem. And I think we still have a large sector of our whole global community that are not really fully aware of what really this problem entails. They hear on the media and the news, 'Oh, the crisis is here. We're in danger.' And then a year later, they say, 'Well, what happened? Nothing's happened.' It hasn't impacted their lives yet, right? Or at least not in a way that they've noticed. And I think this is why we need more awareness. We need to get the word out there. We need to actually start having folks that make some of the big decisions, both financially, regulatory and other types of things, like education."

Ho: "One really big problem I think that COVID introduced us to, is that it's not just that we have to convince everybody it's important, but we have to also get people, in general, the population, to trust us. You know, that there is a problem. There's been a kind of an erosion in the trustworthiness, or trust in the institutions that we relied upon that are responsible for keeping everybody safe and healthy. And I think a big part of that is also communication education, that the populace needs to be better educated, but the communication level of people in charge, as well as researchers like us—we need to speak to the people in a way that people can understand."

Wilson: "We're not saying that we have a solution, but we do have some directions that, in many areas, have started, and we feel that they need more support. And we're hoping that folks that are reading the book actually appreciate that aspect of it, and then start realizing that, 'Hey, I'm part of this solution too.' It can be very little—being mindful of making sure that we have clean water, making sure that we have food security, making sure that we stay healthy and, therefore, we don't have as many infections, right? Just little things like that that we can actually do as individuals, that as a whole population, will actually contribute to improving the situation.

Then, of course, we have to support our leaders in making some of the decisions. We have to let them know that we care about this. And I think at this stage, what we're hoping is that we can maybe encourage some folks to take a citizen stand on this, to ask questions, to start going and probing and saying, 'Hey, congress person, what are you doing about this?' And maybe just start the dialog. This is all we're doing, is starting a dialog."

• The 2nd Edition of Revenge of the Microbes, details the intricacies of the antibiotic-microbe arms race. Beginning with a historical perspective on antibiotics and their profound impact on both modern medicine and present-day society. It also examines the practices and policies driving the discovery and development of new antibiotics, what happens to antibiotics once they are released into the environment, how antibiotic-resistant bacteria evolve and spread and the urgency for finding alternative approaches to combating infections. For anyone interested in antimicrobial resistance (AMR), this is a completely approachable 360-degree view of a very complex topic. Get your copy of Revenge of the Microbes today!
• Want to get involved and spread the word about AMR? Become an ASM Advocate
• Bacterial Pathogenesis: a Molecular Approach
• Take the MTM listener survey!

Sabra Klein addresses the question: how does biological sex influence influenza infection and vaccination? She explains her findings on inflammation differences between males and females, and how these differences can affect the outcome of disease. Klein also discusses her advocacy for inclusion of biological sex in method reporting as a means to improve scientific rigor.

Host: Julie Wolf

Subscribe (free) on iPhone, Android, RSS, or by email. You can also listen on your mobile device with the ASM Podcast app.

Julie's biggest takeaways:

• Information from the 1918 influenza pandemic suggested males died at a higher rate than females, which could be due to a gender fator or a biological factor. In 1918, men lived in close quarters of military barracks while women didn't, representing a cultural difference of gender norms (women were exempted from military duty). But males are more susceptible to secondary bacterial infections that often accompany flu, which may represent a biological difference in infection outcome. In Klein's studies, female mice suffer influenza more severely than males. Women who contracted the H1N1 flu epidemic in 2009 were more likely to be hospitalized with severe influenza than men. These data have yet to be aligned and leave many variables yet to explore!

• Influenza infection disrupts the female menstrual cycle, causing lowered estrogen and progesterone levels. Providing exogenous progesterone can dampen inflammation and stimulate repair mechanisms needed to fix the damaged lung tissue. This type of host treatment is less likely to lead to the evolution of resistance than using antiviral compounds.

• Females and males respond differently to vaccination; females mount a higher antibody response and have greater cross-protection than males.

• Many diseases in addition to influenza show these sex-specific differences. The sex differences observed are specific to age; with older age, the differences are lost.

• In several other countries, epidemiological and clinical data are analyzed for differences between sexes. With greater awareness, the United States may incorporate this practice too.

   

Featured Quotes (in order of appearance):

"Both genes as well as the hormones define the biological construct of sex."

"There's an ample amount of data that suggest men are less likely to wash their hands than women. We all know handwashing is probably one of the best ways to avoid contact with viruses - really anything infectious. We always have to question if we do things that influence our exposure; but in our mice studies, we can control their exposure."

"We really have a love-hate relationship with inflammation. We need it to recognize the presence of the virus, but then we need it to dissipate. Our data suggest hormones are integral to regulating inflammation and the repair following inflammation."

"The immune responses to the influenza vaccine - and this extends to many vaccines - are often higher in females as compared with males. This has been shown in humans as well as animal models."

"I don't know that I think that man flu is real. I think a lot can depend on both your age as well as your vaccine status that can influence whether you're going to land in the hospital with severe influenza. Much like we were talking about with individuals who don't have a vaccine, such as during a pandemic, females may be suffering a bit more, but once vaccinated females seem to do better than males. There are some nuances we shouldn't lose sight of."
 

Links for this episode

• Sabra Klein website
• Klein speaking on heart disease differences in men and women
• Klein editorial in mBio: Sex reporting in microbiological and immunological research
• Smithsonian exhibit notification
• HOM Tidbit: Smithsonian article: How the horrific 1918 flu spread across America
  
• HOM Tidbit: Aeon article: Who names diseases?

Send your stories about our guests and/or your comments to jwolf@asmusa.org.

Jennifer Martiny describes the incredible microbial biodiversity of natural ecosystems such as soils and waterways. She explains how to add a bit of control in experiments with so many variables, and why categorizing microbial types is important for quantifying patterns.

Host: Julie Wolf

Subscribe (free) on iPhone, Android, RSS, or by email. You can also listen on your mobile device with the ASM Podcast app.

Julie's biggest takeaways:

• Studying microbial community functions in their natural environment are harder to understand, but help us to parse the complexity of the natural world, in part because these experiments also include local flora and fauna that are often omitted in the controlled lab environment. Microbial cages - an actual physical barrier that contains a soil-based community - can help to disentangle the effects of the microbial community from those of the surrounding environment by adding a level of control by limiting interaction of microbes inside the nylon mesh cage with those outside of it.

• Are microbial functions redundant? It depends on what function you look at - respiration is a very common function, so it's less likely to be affected by a change in microbiome composition. Other functions, such as degrading particular compounds, may have a stronger relationship between the microbes present and those functions.

• Microbes are hugely diverse! Jennifer's comparison of all the diversity of the birds on Earth to a single bacterial taxon is mind-blowing!

• Microbial categorization may be hard, but the ability to group similar organisms is necessary to formulate hypotheses and conduct experiments. It's important to remember the groupings are manmade and sometimes have to be reconstructed!

Featured Quotes (in order of appearance)

"One of the hardest things we study is not on the microbiology side but is on the ecosystem side, measuring those biochemical functions in the environment." (10:05)

"It's not as if we are ever going to be able to study every particular organism out there and build a model with thousands of equations; instead what we really need to do is go after trade-offs and overall relationships that may hold across large groups, and in that way have some simple rules under different conditions like drought or temperature." (16:45)

"Modern birds evolved about 100, 125 million years ago. Two sequences that share the 16S gene, if it's roughly 97% identical, probably diverged 150 million years ago. That means we are lumping in all the diversity within the bacteria group within one taxon, calling it a species, which is the equivalent of lumping all birds together!" (18:47)

"It's a bit overwhelming to imagine that for each 16S rRNA taxon, you could have as much functional, morphological, and behavioral diversity as what we see in all of birds!" (19:39)

"In biology, we're always using an operational definition but we don't want to get too hung up on the definition and miss all the interesting patterns going on!" (20:49)

"If you can start to quantify patterns, then you can start to ask ecological and even evolutionary questions about why we see those patterns." (33:04)
 

Links for this episode

• Jennifer Martiny Lab Home Page

• University of California Irvine Microbiome Initiative

• HOM Tidbit: TWIM 50: These things aren't even bacteria!

• Carl Woese Obituary (New York Times)

• Carl Woese 1996 Feature (New York Times)

Send your stories about our guests and/or your comments to jwolf@asmusa.org.

Peter Hotez talks about neglected tropical diseases: what are they, where are they found, and where did the term "neglected tropical disease" come from, anyway? Hotez discusses some of the strategies his and other groups are using for vaccine development, and his work as an advocate for childhood vaccines and global health.

Host: Julie Wolf

Subscribe (free) on iPhone, Android, RSS, or by email. You can also listen on your mobile device with the ASM Podcast app.

Julie's biggest takeaways:

• Renaming "other diseases" - a large collection of disparate diseases such as schistosomiasis, leishmaniasis, and onchocerciasis (also called river blindness) - as "neglected tropical diseases" by Hotez and colleagues was integral to bringing attention to the diseases of the bottom billion, people that live on less than one U.S. Dollar per day.

• Neglected tropical diseases are often chronic and debilitating without high mortality. These diseases trap people in poverty due to their long-term effects. The NTDs are often associated with terrible stigma that can lead to additional challenges for affected populations.

• Neglected tropical diseases are found worldwide, in rich and poor countries. The poorest peoples living in the G20 countries (and Nigeria) now account for most of the world's NTDs.

• Parasitic infections present challenges for vaccine design, but reverse vaccinology may be a useful strategy. Reverse vaccinology mines genomes to identify promising vaccine candidates in silico, which are then narrowed sequentially for those that are expressed on the bacterial surface, immunogenic, and ultimately protective against disease. This strategy has worked for Neisseria meningitidis, and Hotez is hopeful that it will produce effective vaccines for the parasitic infections he studies.

• The tradition of individual fields and departments, combined with the old-fashioned notion that scientists needn't spend their time engaging with the public, has led to flatlined budgets and the rise of anti-science movements. Scientists need to engage the public to ensure the future of science and science-based policy.

   

Featured Quotes (in order of appearance):

"The concept of 'neglected tropical diseases' was very much born out of the Millennium Development Goals launched in the year 2000."
 

"Treating NTDs in rich countries "is not a resource problem; it's an awareness problem."

"If you want to enter global health, we need as many people with a scientific background to go into business and law and international relations as we need to go into traditional scientific pathways"
 

"Many involved in the antivaccine movement disproportionately involve either parents who are affluent or educated, or both: those who know just enough to do a google search but without the background to separate the garbage from the important stuff. And of course the anti-vaccine groups are deliberately misleading."
 

"Research America found that 81% of Americans can't name a living scientist. That's our fault. We're so inward looking that we aren't taking the time to do public engagement."
 

Links for this episode

• Peter Hotez at Baylor College of Medicine
• Peter Hotez website
• Millennium Development Goals published by the World Health Organization in 2000
• WHO list of Neglected Tropical Diseases
• Forgotten People, Forgotten Diseases by Peter Hotez
• Blue Marble Health by Peter Hotez
• Public Health United episode featuring Hotez
  
• HOM Tidbit: Oncocerciasis now: 1986 British Medical Journal report

Send your stories about our guests and/or your comments to jwolf@asmusa.org.

Stacey Schultz-Cherry explains the selection process to choose the influenza virus strains to include in the annual influenza vaccine. Schultz-Cherry also discusses her research on the influence of obesity on the course of disease and vaccine efficacy.

Host: Julie Wolf

Subscribe (free) on iPhone, Android, RSS, or by email. You can also listen on your mobile device with the ASM Podcast app.

Julie's biggest takeaways:

• The WHO Collaborating Centers and National Influenza Centers around the world work with a humongous network of physicians, public health workers, and veterinarians to identify strains most likely to become part of the circulating influenza viruses.

• An influenza strain that makes birds very sick is not necessarily a strain that will make people sick.

• Predicting phenotype from genotype remains a challenge. Receptor binding to mammalian receptors, signatures in the genome that allow it to replicate in mammalian cells, and transmission between ferrets are the marks of potentially bad strains. Genetics can also tell you a little bit about the antiviral resistance characteristics of a strain.

• Why can't we incorporate all known influenza strains into a vaccine? It's an issue of immunodominance - having enough antibodies against an infectious agent that it will be neutralized should it cause infection. Researchers don't know how many HAs you can incorporate to generate proper immunity to each molecular version, and this is one area of influenza vaccine research.

• Obesity appears to decrease the immune response to influenza, potentially affecting the ability to form memory response. This means the vaccine is less effective, the course of disease when infected is worse, and the likelihood of secondary bacterial infection is higher.

Featured Quotes (in order of appearance)

"People don't appreciate how much work goes into this. The importance of surveillance - if we lose our surveillance, it's going to be very difficult to know which strains to select for the vaccine, as well as diagnostics."
 

"Part of the trick is not just predicting which viral strain to use but understanding which of those strains will grow to the highest efficiency without changing when we grow it in eggs to make the vaccine."
 

"My bet is, whatever we find, it's going to end up being 10 times more complicated...which is great for my post-docs, because there's plenty of opportunities for them to find new things and build new labs, which is ultimately the most important thing you can do as a P.I."
 

"I did wound repair during my Ph.D. . . . with my background in wound repair, I said 'what is a virus but a great big wound" 
 

"When I was changing fields, my thesis committee asked me, 'what are you doing? I was told it would take five years just to read the literature. You can't change fields!' And I said, 'Yeah, I can.'" And I did!
 

"Whatever your decision is, you go for it you don't have regrets, but you put 110% into whatever you decide to do."
 

Links for this episode

• Stacey Schultz-Cherry
• St. Jude Graduate School of Biomedical Sciences
• CDC Flu Activity Map
• HOM Tidbit: Vaccination against Influenza (review)

Send your stories about our guests and/or your comments to jwolf@asmusa.org.

Gigi Kwik Gronvall talks to MTM about the importance of biopreparedness. Gronvall discusses her work in creating policies around potential natural, accidental, and man-made pandemics. She describes her experiences running pandemic thought exercises that help researchers, public health workers, and governmental officials apply preparedness ideas to real-world simulations.

Host: Julie Wolf

Julie's biggest takeaways:

• Thought exercises and scenarios work well for people to understand how technology, communications, human behaviors can affect the spread of infectious disease.

• Many after-action reports after major biosecurity breaches, such as the Dugway contamination event, where inactivated Bacillus anthracis was accidentally shipped without being inactivated. These involve reports on what went wrong, who made mistakes, and how to prevent repeats of these errors going forward.

• International groups such as the Global Health Security Alliance work with governments and institutions around the world to run dialogs and talk about biosecurity issues, safety issues, pathogen management issues. Comparing notes across countries helps to harmonize policies and find gaps that need addressing.

• Bringing scientists into the policy-making meetings is the best way to write regulations in a way to protect the public, the scientists, and the research itself. Crafting good recommendations for governance prevents writing regulations that can be hard to remove.

Featured Quotes (in order of appearance):

"There's a public health infrastructure that's needed to detect epidemics and respond to them appropriately. If you are lacking that infrastructure, it's like not having a fire department anywhere close when there's a fire. The fire gets bigger and bigger, it becomes much more difficult to be able to put out the fire, and a lot of lives are lost."

"The thinking behind the GHSA is to boost public health infrastructure in different parts of the world that need it and to focus donor attention on some of those areas so that the weakest links are made stronger."

"It's going to shock no one, but it's not always the case that the best scientific information is brought to bear on a policy issue."

"You have to do what you can to make things a little bit harder, a little bit more challenging but still allow real, legitimate, important science to continue. Everybody sees that balance a little bit differently."

"It's important to me that we have someone advocating for the science and making it so it's not onerous to be a scientist."

"Synthetic biology changes the way we think about what biology can do. Biology has a bigger potential to be involved in industrial processes than it used to have."

"The problem with a lot of these pathogens is that they exist in nature...you can't take care of all options, unfortunately."

"You can't ever be fully prepared, but you can be in the right mindset to be surprised."

Links for this episode

• Gigi Kwik Gronvall website at Johns Hopkins University
• SPARS epidemic pamphlet
• Preparing for Bioterrorism: The Alfred P Sloan Foundation's Leadership in Biosecurity: Book by Gronvall
• Synthetic Biology: Safety, Security, and Bioterrorism: Book by Gronvall
  
• The Global Health Security Alliance homepage

Send your stories about our guests and your comments (email or recorded audio) to jwolf@asmusa.org.

Jack Gilbert talks about his studies on microbiomes of all sorts. He describes the origin of the Earth Microbiome Project, which has ambitions to characterize all microbial life on the planet, and talks more specifically about the built microbiome of manmade ecosystems such as hospitals. Gilbert explains how advances in scientific techniques have driven past microbiome-related discoveries and will continue to do so in the future.

Host: Julie Wolf

Subscribe (free) on iPhone, Android, RSS, or by email. You can also listen on your mobile device with the ASM Podcast app.

Julie's biggest takeaways:

1. Insect-pathogenic fungi living in plant roots can pass nitrogen from killed insects to their plant hosts, receiving different carbon nutrients from the plants in return.

2. Fungi harvested after growth on inexpensive materials like chicken droppings are used in agriculture both as fertilizer and as insecticide.

3. Cyclosporine was first discovered in insect-pathogenic fungi.

4. Raymond St. Leger and other scientists working to introduce genetically modified microbes into the environment deeply consider the societal effects of their work, including collaboration with local communities, governmental regulatory bodies, and trusted leaders and tailor their efforts to the regional area.

Featured Quotes (in order of appearance):

"We really can apply ecological understanding of microbiomes and microbial ecosystems to any environment."

"I think basic research is absolutely essential but I always want to think about what that could lead to in the future."

"Reproducibility is key and extraordinarily difficult in all fields of science due to lack of appropriate funding and a zeitgeist in science that discourages scientists from reproducing one another's studies."

"We are forever striving to validate the predictions we derive from our descriptive work. We create SO MANY predictions!"

"No small dreams, no small goals - go big or go home! At the end of the day, we all want to feel like we're doing something that makes an impact."

"I love to collaborate. I love to work with other people, brilliant people in the microbiome field"

"I'm often accused of not being focused enough. What does Jack Gilbert do? Well, I do a little bit of everything - as long as there's a microbe involved! I like it like that; it keeps me energized."

Links for this episode

• Jack Gilbert website at University of Chicago
• Jack Gilbert TedxNaperville Talk
• Earth Microbiome Project home page
• Dirt is Good - new book by Gilbert and Rob Knight
• History of Microbiology Tidbit: Joshua Lederberg piece in The Scientist on 'microbiome' nomenclature in 2001.

Send your stories about our guests and your comments (email or recorded audio) to jwolf@asmusa.org.

Tara C. Smith discusses her work uncovering ties between agriculture and methicillin-resistant Staphylococcus aureus (MRSA). Her studies have found MRSA on and around pig farms, on animal handlers, and even in packaged meat in the grocery store. She also talks about using zombies as an allegory for infectious disease outbreak preparedness.

Links for this episode

Tara C. Smith website

Aetiology Blog on Science Blogs Network

Outbreak News Interview with Smith on her work communicating the science around vaccines and fighting anti-vaccine sentiments.

Smith's collected writings on Ebola and emerging infectious diseases

Zombie Infections: Epidemiology, Treatment, and Prevention in the British Medical Journal

History of Microbiology tidbit: Thomas Jukes' 1968 Letter to the British Medical Journal and 1997 Recollections in Protein Science.

Julie's biggest takeaways:

MRSA transitioned from primarily hospital-acquired to community-acquired infections in the 1990s. In the early 2000s, MRSA strains associated with livestock farming emerged in Europe. Smith's group was the first to identify agriculture-associated MRSA strains in the United States.

Tara found MRSA on the very first farm in which she and her colleagues looked for MRSA.

The MRSA strain ST398 appears to have originated in people as MSSA then moved to livestock, where the strain acquired some antibiotic resistance related genes. This is because zoonotic diseases are a two-way street and microbes can pass from people to animals, as well as passed from animals to people.

Many factors may contribute to MRSA contamination of consumer meat products: for one, MRSA in farms is aerosolized and the same may be true in meat processing facilities. People can also be colonized and spread from workers to products. It's likely a mixture of strains from farms and strains from people working in the packing plants.

Farms that raise animals without antibiotics were not positive for MRSA. Processing these animals at plants where conventional animals are raised creates potential for cross-contamination, however.

Prophylactic and treatment applications of antibiotics are still allowed for livestock, but antibiotics used for growth promotion purposes were phased out in January 2017.

Featured quotes:

"I was in Iowa, the #1 pig-producing state. We started looking for MRSA + found them on the very 1st farm we sampled"

"When we think of zoonotic diseases, usually we think of microbes that come from animals to people, but there can be bidirectional transmission. It's definitely not just a one-way street

"That it doesn't cause disease in pigs made S. aureus invisible to people studying its epidemiology for quite a while"

"Our biohazard people probably hated us because we had pounds and pounds of meat products we were checking" for MRSA

"S. aureus is definitely not the only one - there's lots of bacteria that are affected by use of antibiotics on farms"

"Everything zombies now is a virus!"