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Meet the Microbiologist

Julie Wolf

9
Followers
10
Plays
Meet the Microbiologist
Meet the Microbiologist

Meet the Microbiologist

Julie Wolf

9
Followers
10
Plays
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About Us

Revealing more about microbiologists, the work they do, and what makes them tick. We ask them what they're up to now and what's next? How is the science moving forward to solve some of the intractable problems of our times? What keeps them going in a tough, competitive field? What do they see for the future of research, education, and training? We hope to show you a glimpse of what scientists are really like and what's going on in cutting-edge research today.

Latest Episodes

Diagnosing C. diff Infections for Optimal Patient Outcomes with Colleen Kraft

Why is C. diff such a serious disease and what are clinical microbiologists doing to improve patient outcomes with better diagnostic tools?

11 MIN2 d ago
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Diagnosing C. diff Infections for Optimal Patient Outcomes with Colleen Kraft

Antibiotic-Resistant Infections in Hospital Sinks with Amy Mathers

Many hospital-acquired bacterial infections are also drug-resistant. Amy Mathers describes her work tracking these bacteria to their reservoir in hospital sinks, and what tools allowed her team to make these discoveries. Mathers also discusses her work on Klebsiella, a bacterial pathogen for the modern era. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Nosocomial infections are a type of opportunistic infection: one that wouldn’t normally cause disease in healthy individuals. Once the immune system is compromised due to other infection or treatment, the opportunist bacteria take advantage of the conditions to grow to higher numbers and cause disease. How are different pathogens transmitted in the hospital? Previously, transmission was considered to occur from one patient to a second patient, perhaps via a healthcare worker. When patients from very different parts of the hospital began to come down with the same resistant strain of bacteria, without interacting through the same space or staff, researchers began to look at a different reservoir: the hospital wastewater. How does the bacteria get from the sink to the patients? The bacteria, existing in a biofilm in the pipe right below the drain, can be transferred in droplets when the water is run. These droplets can fall as far as 36 inches from the drain plate and can contaminate the sink bowl or patient care items next to the sink. Some of the solutions to decrease bacterial dispersion from hospital sinks are very simple: for example, offsetting the drain from the tap, which keeps the water from directly running onto the drain, helps decrease the force with which the water hits the drain and therefore decreases bacterial dispersion. The Sink Lab at University of Virginia couldn’t replicate the bacterial growth patterns seen in the rest of the building; in particular, there were fewer protein nutrients that promoted bacterial growth. By setting up a camera observation of sink stations used in the hospital, the team realized that the waste thrown down the sink (extra soda, milk, soup, etc) was feeding the microbial biofilm. This helps the CRE in the biofilms in the sinks thrive. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Amy Mathers website at University of Virginia The Sink Lab at UVA Kotay SM et al. Droplet- Rather than Aerosol-Mediated Dispersion is the Primary Mechanism of Bacterial Transmission from Contaminated Hand-Washing Sink Traps. Applied and Environmental Microbiology. 2018. Mather AJ et al. Klebsiella quasipneumoniae Provides a Windo into Carbapenemase Gene Transfer, Plasmid Rearrangements, and Patient Interactions within the Hospital Environment. Antimicrobial Agents and Chemotherapy. 2018. Kotay S et al. Spread from the Sink to the Patient: in situ Study Using Green Fluorescent Protein (GFP)-Expressing Escherichia coli to Model Bacteral Dispersion from Hand-Washuing Sink-Trap Reservoirs. Applied and Environmental Microbiology. 2016. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. Send your stories about our guests and/or your comments to jwolf@asmusa.org.

60 MIN1 w ago
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Antibiotic-Resistant Infections in Hospital Sinks with Amy Mathers

Microbiome Diversity and Structural Variation with Ami Bhatt

How do medical professionals incorporate microbiome science into their patient care? Ami Bhatt discusses her research on the diversity within and between human gut microbiomes, and how this research is slowly and carefully being used to build new patient care recommendations. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Although these terms are often used interchangeably, microbiome and microbiota represent distinct samples types: Microbiotarepresents all the organisms that live within a community: archaea, bacteria, viruses, and fungi. Microbiomeis the genomes or transcriptomes of these organisms. The gut microbiota may often be referred to as a single entity, but the gastrointestinal tract has many different niches. Alterations in pH, cell type, and the available nutrients provide different selective pressures for the microorganisms that reside in these conditions. By clustering small proteins based on similarity, Ami’s group was able to identify over 4000 new families of small proteins from existing microbiome datasets. Some of these were found among all microbiome datasets while others were found only in human microbiomes, which provides a clue to their potential housekeeping versus host-microbe-interaction functionality, although the exact functions are still unknown. Outcomes for non-infectious diseases are affected by the gut microbiome. Ami and her colleagues have worked with transplant patients to understand what type of diversity and which strains play a role in best outcome for cancer therapy patients, such as patients receiving bone marrow transplants. Medical doctors are beginning to incorporate new patient care in light of new microbiome studies. Understanding the effects of the gut microbiome on human health have helped slowly change patient care in some settings. For example, doctors are reconsidering recommendations for immunocompromised people to stay away from fresh fruits and vegetables, a recommendation previously made due to the potential risk of patients exposure to pathogenic microbes. The benefit of a wide variety of fiber sources, which promote a diverse and robust microbiome, may turn out to outweigh this risk. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Ami Bhatt lab website Brewster R. et al. Surveying Gut Microbiome Research in Africans: Toward Improved Diversity and Representation. Trends in Microbiology. Oct 1 2019. Sberro H. et al. Large-Scale Analyses of Human Microbiomes Reveal Thousands of Small, Novel Genes. Cell August 22 2019. Andermann T. et al. The Microbiome and hematopoietic Cell Transplantation: Past, Present, and Future. Biol Blood Marrow Transplant. July 1 2019. Bloomberg: Superbugs Deadlier Than Cancer Put Chemotherapy into Question Clinical Guide to Probiotic Products Available in USA HOM Tidbit: Rous P. A Sarcoma of the Fowl Transmissible by an Agent Separable from the Tumor Cells. Journal of Experimental Medicine. April 1 1911. ASM Article: A Brief History of Cancer Virology

55 MIN3 w ago
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Microbiome Diversity and Structural Variation with Ami Bhatt

Lyme Disease and Other Tick-Borne Infections with Jorge Benach

Identified in the 1980s, Borrelia burgdorferi and other Lyme disease-associated spirochetes have since been found throughout the world. Jorge Benach answers questions about Lyme Disease symptoms, his role in identifying the causative bacterium, and his current research on multispecies pathogens carried by hard-bodied ticks. Julie’s Biggest Takeaways Erythema migrans (the classic bullseye rash) is the most common manifestation that drives people to go see the doctor to be diagnosed with Lyme disease, but only about 40% of people diagnosed with Lyme disease experience erythema migrans. Lyme disease can progress to serious secondary manifestations. Why some patients experience these additional disease manifestations, but others do not, is one of the heaviest areas of study in Lyme disease. Though Borreliadoesn’t have virulence factors that mediate tissue damage, it does avoid the immune system via antigenic variation. When the bacterium is first introduced into a new human host, that person’s immune system generates reactions to the outer membrane components. These bacterial components change over time, leaving the immune response lagging behind and unable to clear the infection. Ixodesticks are the vector for Lyme disease and there are 3 stages in the Ixodestick life: Larvae: the stage during which the tick is most likely to become infected by feeding on a rodent. Nymph: the stage most likely to infect a person (due to their small size, they are less likely to draw attention while feeding). Adult: the stage when the tick develops into a sexual adult; females are most likely to be infected but because female ticks are large, most people will detect and pull out a feeding adult. Ticks feed for 2-4 days; removing a tick in the first 48 hours of attachment decreases the chance for transmission to the patient. Long Island is seeing anecdotal increases of Ambliomaticks (the Lone Star tick), which can transmit the human pathogen Ehrlichia. These anecdotal increases were one of the motivations behind a recently published survey of ticks and the human pathogens they carry. Links for This Episode MTM Listener Survey, it only takes 3 minutes. Thanks! Jorge Benach websiteat Renaissance School of Medicine Stony Brook University Sanchez-Vicente S. et al. Polymicrobial Nature of Tick-Borne Diseases. mBio. September 10 2019. Monzón J.D. et al. Populaiton and Evolutionary Genomics of Amblyomma americanum, and Expanding Arthropod Disease Vector.Genome Biol Evol. May 2016. ASM Article: The Bulls-Eye Rash of Lyme Disease: Investigating the Cutaneous Host-Pathogen Dynamics of Erythema Migrans Patient Zero podcast HOM Tidbit: Barbour A.G. and Benach J.L. Discovery of the Lyme Disease Agent. mBio. September 17 2019.

63 MINOCT 12
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Lyme Disease and Other Tick-Borne Infections with Jorge Benach

Influenza Virus Evolution with Jesse Bloom

Influenza is famous for its ability to mutate and evolve but are mutations always the virus’ friend? Jesse Bloom discusses his work on influenza escape from serum through mutation and how mutations affect influenza virus function and transmission. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Influenza is famous for its ability to mutate and evolve through two major mechanisms: Antigenic drift occurs when a few mutations accumulate in the influenza genome and lead to seasonal changes. Antigenic shift occurs when two influenza strains recombine their genomes to form one previously unknown in human populations. Avian influenza has caused thousands of zoonotic cases, in which the virus is transmitted from birds to people. This causes serious disease but the virus doesn’t easily pass from person-to-person, limiting how many people are affected. When a zoonotic case becomes easily transmissible between people, as is suspected occurred in the 1918 influenza pandemic, the outcome can be very serious for many, many people. During antigenic drift, the virus accumulates mutations randomly throughout its genome. Mutations in the hemagglutinin (HA) glycoprotein gene are the mutations most likely to affect the ability of antibodies to attach and block HA during viral infection of a new host cell. The circulating human H3N2 influenza A virus accumulates approximately 3-4 mutations annually within its HA gene, representing a 0.5-1% change. On average, it takes 5-7 years of these mutations accumulating until a viral strain can reinfect a previously infected person. The changes in the influenza sequence are responsible for waning immunity against the annually circulating strain. This was demonstrated when a flu strain from the 1950s was inadvertently reintroduced in the 1970s; older people who had previously been infected were protected against this exact same strain. Influenza viruses can escape from sera, which contains many different antibodies, similar to how they can escape from a single monoclonal antibody: through mutations in major antibody binding sites. However, the mutations that allow escape from one person’s serum are different from the mutations that allow escape from another person’s serum. This means the strains that escape one person’s immune system may only be able to infect those with similar immunity. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Jesse Bloom’s lab website Guns Germs and Steel by Jared Diamond Lee J.M. et al. Mapping Person-to-Person Variation in Viral Mutations that Escape Polyclonal Serum Targeting Influenza Hemagglutinin.eLife. August 2019. Xue K.S. et al. Cooperating H3N2 Influenza Virus Variants are not Detectable in Primary Clinical Samples.mSphere. January 2018. Francis Arnold at ASM Microbe:Innovation by Evolution: Bringing New Chemistry to Life Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

52 MINSEP 27
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Influenza Virus Evolution with Jesse Bloom

Citrus Greening and the Microbiome in Diabetes with Graciela Lorca

Graciela Lorca studies genetic systems to find positive and negative microbial interactions that lead to disease. She talks about her discovery of chemical inhibitors for the citrus greening disease bacterium, Liberibacter asiaticus,and how a specific strain of Lactobacillus johnsoniimodulates the immune system and may help prevent development of diabetes in people. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Citrus greening disease, or huanglongbing, is a disease of citrus trees causing a major epidemic among citrus farmers around the world. The disease causes trees to sicken and eventually die, and is best diagnosed by PCR amplification of the bacterial DNA from the bacterium that causes the disease, Liberibacter asiaticus. Because the disease spreads through the tree at different rates, it’s important that many samples be tested for accurate diagnosis. Quarantining the disease has proved difficult, as undiagnosed roots can transmit the disease if they are used to hybridize with canopy plants. The disease becomes even harder to contain under bad weather conditions: the high winds of recent hurricanes can scatter the insect vector, the Asian citrus psyllid, leading to infection of new orchards. Although L. asiaticuscan’t be cultured, Graciela performed a screen on L. asiaticustranscription factors that were produced by E. coli. These were tested for inhibition by a chemical library, and discovered that a common treatment for gout, benzbromarone, inhibited protein activity. This discovery was confirmed using in vivoinfected plants and by expressing the gene in related bacterial species, Graciela and her team predict the protein plays a role in responding to osmotic stress. The protein target of the chemical differs widely between citrus greening disease and gout, but the protein-chemical interaction is similar enough to allow protein inhibition. Is there a link between the microbiome and diabetes? 10 years ago, Lactobacillus johnsoniican rescue animals that are predisposed to diabetes. L. johnsoniiinactivates a host enzyme, IDO, which regulates proinflammatory responses. Activated immune cells can travel to the pancreas and attack beta cells, leading to diabetes. Regulating the proinflammatory response by administering L. johnsoniias probiotics offers the opportunity to control development of diabetes in predisposed people. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Graciela Lorca’s lab website Pagliai F.A. et al. The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance. PLoS Pathogens. April 2014. Lai K.K., Lorca G.L. and Gonzalez C.F. Biochemical Properties of Two Cinnamoyl Esterases Purified from a Lactobacillus johnsonii Strain Isolated from Stool Samples of Diabetes-Resistant Rats. Applied and Environmental Microbiology. August 2009. Marcial G.E. et al. Lactobacillus johnsonii N6.2 Modulates the Host Immune Response: A Double-Blind, Randomized Trial in Healthy Adults. Frontiers in Immunology. June 2017. HOM Tidbit: Hartmann A., Rothballer M., and Schmid M. Lorenz Hiltner, a Pioneer in Rhisophere Microbial Ecology and Soil Bacteriology Research. Plant and Soil November 2008.

40 MINSEP 13
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Citrus Greening and the Microbiome in Diabetes with Graciela Lorca

20 Years of the Lab Response Network with Julie Villanueva

When a new biothreat or emerging infectious agent threatens, how are diagnostic protocols put into place? It’s up to the Laboratory Response Network (LRN), a multipartner network of public health, clinical and other labs, to generate and distribute reagents, and provide training to detect these threats. Julie Villanueva, Chief of the Laboratory Preparedness and Response Branch at the CDC, talks about the LRN and how no two weeks on the job are alike. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways In the mid-1990s, the CDC joined public health representatives along with the Departments of Defense and Justice to determine the best way to prepare and respond to potential bioterrorism threats. The result was the Laboratory Response Network (LRN), founded in 1999. The LRN provides infrastructure to detect potential pathogens. Though first put into place to detect and prevent bioterror events, the LRN has also been able to detect infectious diseases that have emerged through other means. When a new disease emerges, there are typically no widely available tests to diagnose the disease. The CDC works hard to quickly develop diagnostic tests, validate the tests, manufacture the necessary reagents, and ship these out to the reference labs that are part of the LRN. This ensures that each lab can accurately reach the same result with the same sample. The laboratory response network requires more than just developing and deploying diagnostic tests. The LRN must also provide Training for LRN scientists. Proficiency testing to test the network. Reporting protocols for sending results. What diseases keep Julie up at night? A viral hemorrhagic fever is one, and microorganisms that evolve quickly and have high pathogenic potential, like influenza virus, is another. Featured Quotes “Our collaborations across other federal agencies like the FDA and the USDA are really important for us to stay on the cutting edge of what could be emerging.” “Partnerships are so critical when managing an outbreak. There’s never an outbreak that only affects one group of people...there are lots of different facets of an outbreak that need to be addressed and partnerships are critical for managing and trying to mitigate as much as possible.” “The LRN primarily focuses on diagnostics, this is what the network really does. It’s made to be able to detect biothreats and emerging infectious diseases in both clinical and environmental samples.” “We’re always looking at new technologies for faster, more sensitive, and more specific tests.” “Every outbreak has been different in a different way, and I’ve learned something every time. I think that each outbreak has taught us a few things that work well within the network and a few things with which we can improve, and continued improvement is very important to us. For example, the Ebola outbreak in 2014-16 really highlighted the need for biosafety and biosecurity procedures all across not only the network but also our hospitals...we learn something different from every outbreak.” Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! The Laboratory Response Network(CDC website) HOM: The Origin of In Situ Hybridization- a Personal History

41 MINAUG 30
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20 Years of the Lab Response Network with Julie Villanueva

Global Public Health with George F. Gao

George F. Gao discusses how China CDC promotes global public health during outbreaks SARS and Ebola. He also talks about running a structural biology lab, the importance of both basic and translational research, and the most important discovery of the 20th century. Julie’s Biggest Takeaways: China CDC was founded in 2001. Its experience with the SARS outbreak informed its response to the western Africa Ebola outbreak in 2014-2016, having learned that viruses don’t care about national borders and can quickly become an international problem. Responding to any major outbreak serves both altruistic and selfish motives, since quelling the outbreak decreases the chance that the disease will continue to circulate, potentially reaching your country. Basic research is fundamental for many translational applications to improve human health. By measuring the mutation rate, for example, of a circulating virus, scientists can determine if previous isolates can be used to generate vaccines. The basic research that led to new nucleic acid sequencing techniques has many important applications! When asking other scientists what the most important discovery of the 20th century is, many biomedical scientists name the discovery of the double helix. George points out that bird migration patterns have influenced our understanding of avian diseases like the flu. This discovery led scientists to understand more about the annual transmission patterns of flu, highlighting the importance of interdisciplinary research. George has a foot in both basic and translational sciences and is an ardent supporter of both. The difficulty is in identifying basic research that has potential for application and providing opportunities to basic researchers to create companies and products based on their research. Another hurdles is collaborating and coordinating to ensure people talk to each other George lists the 4 Cs required to promote science, public health and societal development: Collaboration Cooperation Communication Competition Links for this Episode: George F. Gao Lab Website Gao GF and Feng Y. On the Ground in Sierra Leone. Science 2014. Carroll D et al. The Global Virome Project. Science 2018. Watts G. George F. Gao: Head of China CDC Signals a More Global Outlook. Lancet 2018. Forging the Path for Polio Vaccination: Isabel Morgan and Dorothy Horstmann

45 MINAUG 15
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Global Public Health with George F. Gao

Bacteriophage Interactions in the Gut with Jeremy Barr

Bacteriophage are viruses that infect specific bacteria. Jeremy Barr discusses his discovery that phage interact with (but don’t infect) mammalian epithelial cells. He explains how these different organisms: bacteria, bacteriophage, and the mammalian host, may exist in three-way symbioses. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Jeremy’s work as a postdoc focused on developing a protocol to clean phages for use in tissue culture. He and his advisor, Forest Rohwer, were asked to use this protocol to clean phages for a patient extremely sick with a multidrug-resistantAcinetobacter baumannii isolate. Within 24 hours, they used an experimental lab method to clean and purify phages that were used in an experimental procedure to treat a very sick person; phage therapy ultimately saved his life. Jeremy discovered that phages can pass through human epithelial cells by using a ...

45 MINAUG 3
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Bacteriophage Interactions in the Gut with Jeremy Barr

A Career in Salmonella with Stanley Maloy

Stanley Maloy discusses his career in Salmonella research, which started with developing molecular tools and is now focused on the role of Salmonella genome plasticity in niche development. He further talks about his role in science entrepreneurship, science education, and working with an international research community. Julie’s Biggest Takeaways: Stanley’s career began when transposon mutagenesis was a new, cutting-edge technique, and he found the best way to learn how to apply a new method was to jump in and try it. Antibiotic resistance has been a problem throughout Stanley’s career. The future may hold new antimicrobials that aren’t necessarily categorized as classical ‘antibiotics,’ but may offer precision therapy against specific infectious agents. Whatever the future holds, it won’t be a single answer: Stanley sees many innovations necessary to deal with the future of antibiotic-resistant infections. Stanley’s current research is in Salmonella genome plasticity and how genomic traits influence the bacterial niche. Where do traits like exotoxins or antibiotic resistance exist in the environment, and how are they transferred to new species to influence disease? Cases of Typhoid Fever in people without known exposure to another diseased person suggest there may be an environmental reservoir. What might it be? Stanley is a big proponent of scientist entrepreneurs and participates with the NSF Innovation Corps to promote early science start ups. In addition to creativity and the scientific process, one characteristic he encourages all entrepreneurs to develop is a good team spirit. Working collaboratively as a team is a very strong sign of success. Stanley believes in the importance of an international science communities, and he practices what he preaches: he works closely with the scientific community of Chile. He began in 1990 by teaching an intensive lab course about techniques, and has developed a decades-long relationship with this community. These relationships allow a dialog, and were the reason Stanley ultimately turned his focus to Salmonella Typhi from Salmonella Typhimurium. Links for this Episode: MTM Listener Survey, only takes 3 minutes! Thanks;) Stanley Maloy website at San Diego State University This Week in Microbiology #95: A Microbe Lover in San Diego National Science Foundation Innovation Corps Journal of Microbiology and Biology Education Call for Submissions for a Special Issue on diversity and inclusion. HOM Tidbit: A Large Community Outbreak of Salmonellosis Caused by Intentional Contamination of Restaurant Salad Bars

41 MINJUL 19
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A Career in Salmonella with Stanley Maloy

Latest Episodes

Diagnosing C. diff Infections for Optimal Patient Outcomes with Colleen Kraft

Why is C. diff such a serious disease and what are clinical microbiologists doing to improve patient outcomes with better diagnostic tools?

11 MIN2 d ago
Comments
Diagnosing C. diff Infections for Optimal Patient Outcomes with Colleen Kraft

Antibiotic-Resistant Infections in Hospital Sinks with Amy Mathers

Many hospital-acquired bacterial infections are also drug-resistant. Amy Mathers describes her work tracking these bacteria to their reservoir in hospital sinks, and what tools allowed her team to make these discoveries. Mathers also discusses her work on Klebsiella, a bacterial pathogen for the modern era. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Nosocomial infections are a type of opportunistic infection: one that wouldn’t normally cause disease in healthy individuals. Once the immune system is compromised due to other infection or treatment, the opportunist bacteria take advantage of the conditions to grow to higher numbers and cause disease. How are different pathogens transmitted in the hospital? Previously, transmission was considered to occur from one patient to a second patient, perhaps via a healthcare worker. When patients from very different parts of the hospital began to come down with the same resistant strain of bacteria, without interacting through the same space or staff, researchers began to look at a different reservoir: the hospital wastewater. How does the bacteria get from the sink to the patients? The bacteria, existing in a biofilm in the pipe right below the drain, can be transferred in droplets when the water is run. These droplets can fall as far as 36 inches from the drain plate and can contaminate the sink bowl or patient care items next to the sink. Some of the solutions to decrease bacterial dispersion from hospital sinks are very simple: for example, offsetting the drain from the tap, which keeps the water from directly running onto the drain, helps decrease the force with which the water hits the drain and therefore decreases bacterial dispersion. The Sink Lab at University of Virginia couldn’t replicate the bacterial growth patterns seen in the rest of the building; in particular, there were fewer protein nutrients that promoted bacterial growth. By setting up a camera observation of sink stations used in the hospital, the team realized that the waste thrown down the sink (extra soda, milk, soup, etc) was feeding the microbial biofilm. This helps the CRE in the biofilms in the sinks thrive. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Amy Mathers website at University of Virginia The Sink Lab at UVA Kotay SM et al. Droplet- Rather than Aerosol-Mediated Dispersion is the Primary Mechanism of Bacterial Transmission from Contaminated Hand-Washing Sink Traps. Applied and Environmental Microbiology. 2018. Mather AJ et al. Klebsiella quasipneumoniae Provides a Windo into Carbapenemase Gene Transfer, Plasmid Rearrangements, and Patient Interactions within the Hospital Environment. Antimicrobial Agents and Chemotherapy. 2018. Kotay S et al. Spread from the Sink to the Patient: in situ Study Using Green Fluorescent Protein (GFP)-Expressing Escherichia coli to Model Bacteral Dispersion from Hand-Washuing Sink-Trap Reservoirs. Applied and Environmental Microbiology. 2016. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. Send your stories about our guests and/or your comments to jwolf@asmusa.org.

60 MIN1 w ago
Comments
Antibiotic-Resistant Infections in Hospital Sinks with Amy Mathers

Microbiome Diversity and Structural Variation with Ami Bhatt

How do medical professionals incorporate microbiome science into their patient care? Ami Bhatt discusses her research on the diversity within and between human gut microbiomes, and how this research is slowly and carefully being used to build new patient care recommendations. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Although these terms are often used interchangeably, microbiome and microbiota represent distinct samples types: Microbiotarepresents all the organisms that live within a community: archaea, bacteria, viruses, and fungi. Microbiomeis the genomes or transcriptomes of these organisms. The gut microbiota may often be referred to as a single entity, but the gastrointestinal tract has many different niches. Alterations in pH, cell type, and the available nutrients provide different selective pressures for the microorganisms that reside in these conditions. By clustering small proteins based on similarity, Ami’s group was able to identify over 4000 new families of small proteins from existing microbiome datasets. Some of these were found among all microbiome datasets while others were found only in human microbiomes, which provides a clue to their potential housekeeping versus host-microbe-interaction functionality, although the exact functions are still unknown. Outcomes for non-infectious diseases are affected by the gut microbiome. Ami and her colleagues have worked with transplant patients to understand what type of diversity and which strains play a role in best outcome for cancer therapy patients, such as patients receiving bone marrow transplants. Medical doctors are beginning to incorporate new patient care in light of new microbiome studies. Understanding the effects of the gut microbiome on human health have helped slowly change patient care in some settings. For example, doctors are reconsidering recommendations for immunocompromised people to stay away from fresh fruits and vegetables, a recommendation previously made due to the potential risk of patients exposure to pathogenic microbes. The benefit of a wide variety of fiber sources, which promote a diverse and robust microbiome, may turn out to outweigh this risk. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Ami Bhatt lab website Brewster R. et al. Surveying Gut Microbiome Research in Africans: Toward Improved Diversity and Representation. Trends in Microbiology. Oct 1 2019. Sberro H. et al. Large-Scale Analyses of Human Microbiomes Reveal Thousands of Small, Novel Genes. Cell August 22 2019. Andermann T. et al. The Microbiome and hematopoietic Cell Transplantation: Past, Present, and Future. Biol Blood Marrow Transplant. July 1 2019. Bloomberg: Superbugs Deadlier Than Cancer Put Chemotherapy into Question Clinical Guide to Probiotic Products Available in USA HOM Tidbit: Rous P. A Sarcoma of the Fowl Transmissible by an Agent Separable from the Tumor Cells. Journal of Experimental Medicine. April 1 1911. ASM Article: A Brief History of Cancer Virology

55 MIN3 w ago
Comments
Microbiome Diversity and Structural Variation with Ami Bhatt

Lyme Disease and Other Tick-Borne Infections with Jorge Benach

Identified in the 1980s, Borrelia burgdorferi and other Lyme disease-associated spirochetes have since been found throughout the world. Jorge Benach answers questions about Lyme Disease symptoms, his role in identifying the causative bacterium, and his current research on multispecies pathogens carried by hard-bodied ticks. Julie’s Biggest Takeaways Erythema migrans (the classic bullseye rash) is the most common manifestation that drives people to go see the doctor to be diagnosed with Lyme disease, but only about 40% of people diagnosed with Lyme disease experience erythema migrans. Lyme disease can progress to serious secondary manifestations. Why some patients experience these additional disease manifestations, but others do not, is one of the heaviest areas of study in Lyme disease. Though Borreliadoesn’t have virulence factors that mediate tissue damage, it does avoid the immune system via antigenic variation. When the bacterium is first introduced into a new human host, that person’s immune system generates reactions to the outer membrane components. These bacterial components change over time, leaving the immune response lagging behind and unable to clear the infection. Ixodesticks are the vector for Lyme disease and there are 3 stages in the Ixodestick life: Larvae: the stage during which the tick is most likely to become infected by feeding on a rodent. Nymph: the stage most likely to infect a person (due to their small size, they are less likely to draw attention while feeding). Adult: the stage when the tick develops into a sexual adult; females are most likely to be infected but because female ticks are large, most people will detect and pull out a feeding adult. Ticks feed for 2-4 days; removing a tick in the first 48 hours of attachment decreases the chance for transmission to the patient. Long Island is seeing anecdotal increases of Ambliomaticks (the Lone Star tick), which can transmit the human pathogen Ehrlichia. These anecdotal increases were one of the motivations behind a recently published survey of ticks and the human pathogens they carry. Links for This Episode MTM Listener Survey, it only takes 3 minutes. Thanks! Jorge Benach websiteat Renaissance School of Medicine Stony Brook University Sanchez-Vicente S. et al. Polymicrobial Nature of Tick-Borne Diseases. mBio. September 10 2019. Monzón J.D. et al. Populaiton and Evolutionary Genomics of Amblyomma americanum, and Expanding Arthropod Disease Vector.Genome Biol Evol. May 2016. ASM Article: The Bulls-Eye Rash of Lyme Disease: Investigating the Cutaneous Host-Pathogen Dynamics of Erythema Migrans Patient Zero podcast HOM Tidbit: Barbour A.G. and Benach J.L. Discovery of the Lyme Disease Agent. mBio. September 17 2019.

63 MINOCT 12
Comments
Lyme Disease and Other Tick-Borne Infections with Jorge Benach

Influenza Virus Evolution with Jesse Bloom

Influenza is famous for its ability to mutate and evolve but are mutations always the virus’ friend? Jesse Bloom discusses his work on influenza escape from serum through mutation and how mutations affect influenza virus function and transmission. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Influenza is famous for its ability to mutate and evolve through two major mechanisms: Antigenic drift occurs when a few mutations accumulate in the influenza genome and lead to seasonal changes. Antigenic shift occurs when two influenza strains recombine their genomes to form one previously unknown in human populations. Avian influenza has caused thousands of zoonotic cases, in which the virus is transmitted from birds to people. This causes serious disease but the virus doesn’t easily pass from person-to-person, limiting how many people are affected. When a zoonotic case becomes easily transmissible between people, as is suspected occurred in the 1918 influenza pandemic, the outcome can be very serious for many, many people. During antigenic drift, the virus accumulates mutations randomly throughout its genome. Mutations in the hemagglutinin (HA) glycoprotein gene are the mutations most likely to affect the ability of antibodies to attach and block HA during viral infection of a new host cell. The circulating human H3N2 influenza A virus accumulates approximately 3-4 mutations annually within its HA gene, representing a 0.5-1% change. On average, it takes 5-7 years of these mutations accumulating until a viral strain can reinfect a previously infected person. The changes in the influenza sequence are responsible for waning immunity against the annually circulating strain. This was demonstrated when a flu strain from the 1950s was inadvertently reintroduced in the 1970s; older people who had previously been infected were protected against this exact same strain. Influenza viruses can escape from sera, which contains many different antibodies, similar to how they can escape from a single monoclonal antibody: through mutations in major antibody binding sites. However, the mutations that allow escape from one person’s serum are different from the mutations that allow escape from another person’s serum. This means the strains that escape one person’s immune system may only be able to infect those with similar immunity. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Jesse Bloom’s lab website Guns Germs and Steel by Jared Diamond Lee J.M. et al. Mapping Person-to-Person Variation in Viral Mutations that Escape Polyclonal Serum Targeting Influenza Hemagglutinin.eLife. August 2019. Xue K.S. et al. Cooperating H3N2 Influenza Virus Variants are not Detectable in Primary Clinical Samples.mSphere. January 2018. Francis Arnold at ASM Microbe:Innovation by Evolution: Bringing New Chemistry to Life Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

52 MINSEP 27
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Influenza Virus Evolution with Jesse Bloom

Citrus Greening and the Microbiome in Diabetes with Graciela Lorca

Graciela Lorca studies genetic systems to find positive and negative microbial interactions that lead to disease. She talks about her discovery of chemical inhibitors for the citrus greening disease bacterium, Liberibacter asiaticus,and how a specific strain of Lactobacillus johnsoniimodulates the immune system and may help prevent development of diabetes in people. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Citrus greening disease, or huanglongbing, is a disease of citrus trees causing a major epidemic among citrus farmers around the world. The disease causes trees to sicken and eventually die, and is best diagnosed by PCR amplification of the bacterial DNA from the bacterium that causes the disease, Liberibacter asiaticus. Because the disease spreads through the tree at different rates, it’s important that many samples be tested for accurate diagnosis. Quarantining the disease has proved difficult, as undiagnosed roots can transmit the disease if they are used to hybridize with canopy plants. The disease becomes even harder to contain under bad weather conditions: the high winds of recent hurricanes can scatter the insect vector, the Asian citrus psyllid, leading to infection of new orchards. Although L. asiaticuscan’t be cultured, Graciela performed a screen on L. asiaticustranscription factors that were produced by E. coli. These were tested for inhibition by a chemical library, and discovered that a common treatment for gout, benzbromarone, inhibited protein activity. This discovery was confirmed using in vivoinfected plants and by expressing the gene in related bacterial species, Graciela and her team predict the protein plays a role in responding to osmotic stress. The protein target of the chemical differs widely between citrus greening disease and gout, but the protein-chemical interaction is similar enough to allow protein inhibition. Is there a link between the microbiome and diabetes? 10 years ago, Lactobacillus johnsoniican rescue animals that are predisposed to diabetes. L. johnsoniiinactivates a host enzyme, IDO, which regulates proinflammatory responses. Activated immune cells can travel to the pancreas and attack beta cells, leading to diabetes. Regulating the proinflammatory response by administering L. johnsoniias probiotics offers the opportunity to control development of diabetes in predisposed people. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Graciela Lorca’s lab website Pagliai F.A. et al. The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance. PLoS Pathogens. April 2014. Lai K.K., Lorca G.L. and Gonzalez C.F. Biochemical Properties of Two Cinnamoyl Esterases Purified from a Lactobacillus johnsonii Strain Isolated from Stool Samples of Diabetes-Resistant Rats. Applied and Environmental Microbiology. August 2009. Marcial G.E. et al. Lactobacillus johnsonii N6.2 Modulates the Host Immune Response: A Double-Blind, Randomized Trial in Healthy Adults. Frontiers in Immunology. June 2017. HOM Tidbit: Hartmann A., Rothballer M., and Schmid M. Lorenz Hiltner, a Pioneer in Rhisophere Microbial Ecology and Soil Bacteriology Research. Plant and Soil November 2008.

40 MINSEP 13
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Citrus Greening and the Microbiome in Diabetes with Graciela Lorca

20 Years of the Lab Response Network with Julie Villanueva

When a new biothreat or emerging infectious agent threatens, how are diagnostic protocols put into place? It’s up to the Laboratory Response Network (LRN), a multipartner network of public health, clinical and other labs, to generate and distribute reagents, and provide training to detect these threats. Julie Villanueva, Chief of the Laboratory Preparedness and Response Branch at the CDC, talks about the LRN and how no two weeks on the job are alike. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways In the mid-1990s, the CDC joined public health representatives along with the Departments of Defense and Justice to determine the best way to prepare and respond to potential bioterrorism threats. The result was the Laboratory Response Network (LRN), founded in 1999. The LRN provides infrastructure to detect potential pathogens. Though first put into place to detect and prevent bioterror events, the LRN has also been able to detect infectious diseases that have emerged through other means. When a new disease emerges, there are typically no widely available tests to diagnose the disease. The CDC works hard to quickly develop diagnostic tests, validate the tests, manufacture the necessary reagents, and ship these out to the reference labs that are part of the LRN. This ensures that each lab can accurately reach the same result with the same sample. The laboratory response network requires more than just developing and deploying diagnostic tests. The LRN must also provide Training for LRN scientists. Proficiency testing to test the network. Reporting protocols for sending results. What diseases keep Julie up at night? A viral hemorrhagic fever is one, and microorganisms that evolve quickly and have high pathogenic potential, like influenza virus, is another. Featured Quotes “Our collaborations across other federal agencies like the FDA and the USDA are really important for us to stay on the cutting edge of what could be emerging.” “Partnerships are so critical when managing an outbreak. There’s never an outbreak that only affects one group of people...there are lots of different facets of an outbreak that need to be addressed and partnerships are critical for managing and trying to mitigate as much as possible.” “The LRN primarily focuses on diagnostics, this is what the network really does. It’s made to be able to detect biothreats and emerging infectious diseases in both clinical and environmental samples.” “We’re always looking at new technologies for faster, more sensitive, and more specific tests.” “Every outbreak has been different in a different way, and I’ve learned something every time. I think that each outbreak has taught us a few things that work well within the network and a few things with which we can improve, and continued improvement is very important to us. For example, the Ebola outbreak in 2014-16 really highlighted the need for biosafety and biosecurity procedures all across not only the network but also our hospitals...we learn something different from every outbreak.” Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! The Laboratory Response Network(CDC website) HOM: The Origin of In Situ Hybridization- a Personal History

41 MINAUG 30
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20 Years of the Lab Response Network with Julie Villanueva

Global Public Health with George F. Gao

George F. Gao discusses how China CDC promotes global public health during outbreaks SARS and Ebola. He also talks about running a structural biology lab, the importance of both basic and translational research, and the most important discovery of the 20th century. Julie’s Biggest Takeaways: China CDC was founded in 2001. Its experience with the SARS outbreak informed its response to the western Africa Ebola outbreak in 2014-2016, having learned that viruses don’t care about national borders and can quickly become an international problem. Responding to any major outbreak serves both altruistic and selfish motives, since quelling the outbreak decreases the chance that the disease will continue to circulate, potentially reaching your country. Basic research is fundamental for many translational applications to improve human health. By measuring the mutation rate, for example, of a circulating virus, scientists can determine if previous isolates can be used to generate vaccines. The basic research that led to new nucleic acid sequencing techniques has many important applications! When asking other scientists what the most important discovery of the 20th century is, many biomedical scientists name the discovery of the double helix. George points out that bird migration patterns have influenced our understanding of avian diseases like the flu. This discovery led scientists to understand more about the annual transmission patterns of flu, highlighting the importance of interdisciplinary research. George has a foot in both basic and translational sciences and is an ardent supporter of both. The difficulty is in identifying basic research that has potential for application and providing opportunities to basic researchers to create companies and products based on their research. Another hurdles is collaborating and coordinating to ensure people talk to each other George lists the 4 Cs required to promote science, public health and societal development: Collaboration Cooperation Communication Competition Links for this Episode: George F. Gao Lab Website Gao GF and Feng Y. On the Ground in Sierra Leone. Science 2014. Carroll D et al. The Global Virome Project. Science 2018. Watts G. George F. Gao: Head of China CDC Signals a More Global Outlook. Lancet 2018. Forging the Path for Polio Vaccination: Isabel Morgan and Dorothy Horstmann

45 MINAUG 15
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Global Public Health with George F. Gao

Bacteriophage Interactions in the Gut with Jeremy Barr

Bacteriophage are viruses that infect specific bacteria. Jeremy Barr discusses his discovery that phage interact with (but don’t infect) mammalian epithelial cells. He explains how these different organisms: bacteria, bacteriophage, and the mammalian host, may exist in three-way symbioses. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Jeremy’s work as a postdoc focused on developing a protocol to clean phages for use in tissue culture. He and his advisor, Forest Rohwer, were asked to use this protocol to clean phages for a patient extremely sick with a multidrug-resistantAcinetobacter baumannii isolate. Within 24 hours, they used an experimental lab method to clean and purify phages that were used in an experimental procedure to treat a very sick person; phage therapy ultimately saved his life. Jeremy discovered that phages can pass through human epithelial cells by using a ...

45 MINAUG 3
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Bacteriophage Interactions in the Gut with Jeremy Barr

A Career in Salmonella with Stanley Maloy

Stanley Maloy discusses his career in Salmonella research, which started with developing molecular tools and is now focused on the role of Salmonella genome plasticity in niche development. He further talks about his role in science entrepreneurship, science education, and working with an international research community. Julie’s Biggest Takeaways: Stanley’s career began when transposon mutagenesis was a new, cutting-edge technique, and he found the best way to learn how to apply a new method was to jump in and try it. Antibiotic resistance has been a problem throughout Stanley’s career. The future may hold new antimicrobials that aren’t necessarily categorized as classical ‘antibiotics,’ but may offer precision therapy against specific infectious agents. Whatever the future holds, it won’t be a single answer: Stanley sees many innovations necessary to deal with the future of antibiotic-resistant infections. Stanley’s current research is in Salmonella genome plasticity and how genomic traits influence the bacterial niche. Where do traits like exotoxins or antibiotic resistance exist in the environment, and how are they transferred to new species to influence disease? Cases of Typhoid Fever in people without known exposure to another diseased person suggest there may be an environmental reservoir. What might it be? Stanley is a big proponent of scientist entrepreneurs and participates with the NSF Innovation Corps to promote early science start ups. In addition to creativity and the scientific process, one characteristic he encourages all entrepreneurs to develop is a good team spirit. Working collaboratively as a team is a very strong sign of success. Stanley believes in the importance of an international science communities, and he practices what he preaches: he works closely with the scientific community of Chile. He began in 1990 by teaching an intensive lab course about techniques, and has developed a decades-long relationship with this community. These relationships allow a dialog, and were the reason Stanley ultimately turned his focus to Salmonella Typhi from Salmonella Typhimurium. Links for this Episode: MTM Listener Survey, only takes 3 minutes! Thanks;) Stanley Maloy website at San Diego State University This Week in Microbiology #95: A Microbe Lover in San Diego National Science Foundation Innovation Corps Journal of Microbiology and Biology Education Call for Submissions for a Special Issue on diversity and inclusion. HOM Tidbit: A Large Community Outbreak of Salmonellosis Caused by Intentional Contamination of Restaurant Salad Bars

41 MINJUL 19
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A Career in Salmonella with Stanley Maloy
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