Created with Sketch.
Meet the Microbiologist
44 minutes | 6 months ago
Life Science and Earth Science and Biogeomicrobiology with Denise Akob
Denise Akob discusses her studies of microbial communities of contaminated and pristine environments using life science and earth science techniques. She discusses how to figure out “who’s there,” how to optimize select natural microbial activities, and her career path into government research. Julie’s Biggest Takeaways: Biogeomicrobiology straddles the life science and earth science fields. This is a growing area of research in the academic setting as well as in the private sector, where one can contribute to hydrogeology or bioremediation efforts. What happens on the surface when extracting resources like natural gases? Wastewater from hydraulic shale fracking, or fracking, can contaminate microbes. Preliminary data suggests that microbes that thrive in that wastewater can be a fingerprint for surface contamination, and this is one of the areas of active research in Akob’s lab. Additionally, microbes can respond to contaminants to remove that risk and remediate the spills. One trip to the field can provide samples for years of analysis. From one sample, scientists can conduct: Microbiome studies through amplicon sequencing to understand population structures. Metagenomics studies to understand functional potential. Biochemical studies to understand active metabolic processes. Akob asks how to make natural microbial degraders happy. For example: acetylene, a triple-bonded carbon compound, can inhibit degradation of chlorinated solvents, a potent groundwater contaminant. By studying the microbes that use acetylene as a primary energy source (acetylenotrophs), this removes this inhibition caused by acetylene and the chlorinated solvent-degraders can increase their activity. Akob studies pristine environments to understand natural microbial communities. A cave she studied in Germany was ‘ultra pristine,’ discovered while building a highway. Understanding natural processes, such as the biomineralization promoted during stalagmite and stalactite formation helps scientists imagine how to use tehse processes in other applications. Links for this Episode: Mumford AC et al. Common Hydraulic Fracturing Fluid Additives Alter the Structure and Function of Anaerobic Microbial Communities. Applied and Environmetnal Microbiology. 2018. Akob DM et al. Acetylenotrophy: a Hidden but Ubiquitous Microbial Metabolism? FEMS Microbial Ecology. 2018. Akob DM et al. Detection of Diazotrophy in the Acetylene-Fermenting Anaerobic Pelobacter sp. Strain SFB93. Applied and Environmental Microbiology. 2017. ASM Article: The Microbial World of Caves James J, Gunn AL, and Akob DM. Binning Singletons: Mentoring through Networking at ASM Microbe 2019. mSphere. 2020. HOM Tidbit: Scientists Find Ancient Cave Dwelling Resistant Bacteria ASM Press: Women in Microbiology
62 minutes | 10 months ago
131: Powassan virus and tick biology with Marshall Bloom
How does tick biology influence their ability to transmit disease? Marshall Bloom explains the role of the tick salivary glands in Powassan virus transmission and the experiments that led to this discovery. He also provides a historical background for the Rocky Mountain Labs in Hamilton, Montana, and talks about the 3 elements to consider when working with potentially harmful biological agents. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS or by email. Julie’s Biggest Takeaways There are 3 elements to consider when working with potentially harmful biological agents: Biosafety: protecting the laboratory workers from the infectious agents in the lab. Biocontainment: protecting the community by keeping the infectious agent contained within the facility. Bioassurity: protecting the individual by ensuring those working with infectious agents are capable to do so. You need 4 bites of an APPLE for full lab safety, for work in labs from high school level through biosafety level 4: A: Administration. Training, paperwork, etc. P: Personal protective equipment (PPE). Varies from gloves to positive pressure suits, depending on the microorganisms under study. PL: Laboratory procedures. Standard operating protocols. E: Engineering. Biosafety cabinets and labs that have protective features. Most of the vector-borne flaviviruses, including Powassan virus, don’t cause overt disease in the people they infect, so many people never know they’ve been infected. Without serological surveys, it’s difficult to know the full range of infected individuals versus those that develop serious disease. Serious disease often manifests in neurological symptoms such as encephalitis, with 10-15% mortality rate; half of those suffering neurological disease will continue to have serious sequelae for years. The Rocky Mountain Labs was once the world reference center for ticks: it held thousands of samples which represented the type species for the entire world. The tick salivary glands look like a bunch of grapes: the stem of the grapes is a series of branching ducts. The “grapes” at the end of the ducts are the acini, which is Latin for ‘little sac.’ These acini play a major role in tick feeding, and different types of acini play different functional roles: Type 1 acini: cells have no granules. Acini involved with fluid exchange. Type 2 and type 3 acini: cells with granules. Cells degranulate to release vasoactive compounds into tick saliva during feeding. Featured Quotes “The first isolation of Powassan virus was from a little boy in Powassan, Canada in 1958. If you look at the cases over the years, the numbers are going up, but compared to Lyme disease, they’re pretty low: there’s been less than 200 cases, all told.” “Amazingly, the Powassan virus can be transmitted in as little as 15 minutes….[and] a female tick can take days to get a full meal.” “I take a tick-centric view. If I can anthropomorphize, as my old friend Stanley Falkow used to say, he’d say ‘think like the microbe.’ The microbe doesn’t really care if we get sick or not. The microbe is just trying to make a living and survive.” “One of the really surprising things is that infected ticks can infect uninfected ticks, if they are feeding right next to each other. Ticks like to feed in groups: it’s called co-feeding. The virus can transferred really quickly, 15 min, which is way faster than the virus can go through a replication cycle. What that means to me is that the ticks are infecting each other….we want to investigate the role of co-feeding.” “If something sounds like fun or sounds important, and especially if something sounds fun AND important, then you should do it.” Links for this Episode: Paules CI et al. Tickborne Diseases--Confronting a Growing Threat. New England Journal of Medicine. August 2018. Amazon: Fighting Spotted Fever in the Rockies by Esther Gaskins Price New York Times: Kay Hagan obituary Grabowski JM et al. Dissecting Flavivirus Biology in Salivary Gland Cultures from Fed and Unfed Ixodes scapularis (Black-Legged Tick). mBio. January 2019. ASM on Instagram Grabowski JM, Offerdahl DK, and Bloom ME. The Use of Ex Vivo Organ Cultures in Tick-Borne Virus Research. ACS Infectious Disease. Marhc 2018. Twitter thread from @BugQuestions: Rocky Mountain Spotted Fever and Howard Ricketts History of Microbiology Tidbit: A Short History of the Screwworm Program
51 minutes | a year ago
130: Bioremediation of oil spills with Joel Kostka
What kinds of microorganisms can degrade oil? How do scientists prioritize ecosystems for bioremediation after an oil spill? Joel Kostka discusses his research and the lessons from the Deepwater Horizon oil spill that will help scientists be better prepared for oil spills of the future. Links for this Episode: Joel Kostka Lab Website Kostka J. et al. Hydrocarbon-Degrading Bacteria and the Bacterial Community Response in Gulf of Mexico Beach Sands Impacted by the Deepwater Horizon Oil Spill. Applied and Environmental Microbiology. 2011. Shin B. et al. Succession of Microbial Populations and Nitroget-Fixation Associated With the Biodegradation of Sediment-Oil-Agglomerates Buried in a Florida Sandy Beach. Scientific Reports. 2019. Bociu I. Decomposition of Sediment-Oil-Agglomerates in a Gulf of Mexico Sandy Beach. Scientific Reports. 2019. Overhold W.A. et al. Draft Genome Sequences for Oil-Degrading Bacterial Strains from Beach Sands Impacted by the Deepwater Horizon Oil Spill. Genome Announcements. 2013. Gulf of Mexico Research Initiative ASM Colloquia Report: Microbial Genomics of the Global Ocean System ASM Article: Microbiomes: An Origin Story Joyful Microbe Blog: How to make a Winogradsky column Small Things Considered: How to Build a Giant Winogradsky Column 20% off The Invisible ABCs for MTM listeners! Use promo code: ABC20 at checkout.
54 minutes | a year ago
129: Arbovirus evolution with Greg Ebel
How do arboviruses evolve as they pass between different hosts? Greg Ebel discusses his research on West Nile virus evolution and what it means for viral diversity. He also talks about using mosquitos’ most recent blood meal to survey human health in a process called xenosurveillance. Julie’s Biggest Takeaways: Mosquitoes and other arthropods have limited means of immune defense against infection. One major defense mechanism is RNA interference (RNAi). RNAi uses pieces of the West Nile viral genome to select against the viral genome, which helps select for broadly diverse viral sequences. The more rare a viral genotype, the more likely it is to escape negative selection inside the mosquito host, allowing this viral sequence to increase in frequency. West Nile virus passes largely between birds and mosquitos. Culex mosquitos tend to prefer birds, and this leads to an enzootic cycle for the virus passing between birds and mosquitos. The viral life cycle inside the mosquito has several important steps: The virus first enters as part of the mosquito blood meal. The virus infects epithelial cells of the mosquito midgut. After 3-5 days, the virus leaves the midgut (midgut escape) to enter the mosquito hemolymph. In the next mosquito blood meal, virus is expelled with saliva, which has anticoagulant activity. West Nile virus selection undergoes cycles of selection as it passes from vertebrates (mostly birds) to invertebrates (mosquitos): In vertebrates, the virus must escape to cause viremia in a short period of time for replication to occur before the immune system recognizes and eliminates the virus. This leads to purifying selection, or elimination of amino acid variation that decreases viral protein function. In mosquitos, the virus spends several days in the midgut epithelial cells and then hemolymph, leading to a longer selection time. This leads to more viral diversity in the mosquito host. RNAi further drives population diversity. Through stochasticity, a single viral population will often come to dominate a single infected mosquito. How do scientists know which virus replicates best? Competitive fitness tests measure which virus grows to a higher population in a given environment. A manipulated virus (one passaged in a mosquito or selectively mutated at distinct sequences) and its non-manipulated parent sequence are inoculated at known proportions, and given a certain amount of time to replicate. By measuring the final proportions, Greg and his team can determine which sequence was more fit in that given environment. Xenosurveillance uses mosquitoes to detect a wide array of pathogens at clinically relevant levels. Testing began with in vitro blood-bag feeding, and was validated with studies in Liberia and Senegal. The microorganism sequences are so diverse that the information was used to identify novel human viruses. These studies also provide insight into mosquito feeding habits, which helps in disease modeling. Links for this Episode: Greg Ebel Lab Website Rückert C. et al. Small RNA Responses of Culex Mosquitoes and Cell Lines during Acute and Persistent Virus Infection. Insect Biochemistry and Molecular Biology. 2019. Grubaugh N.D. et al. Mosquitoes Transmit Unique West Nile Virus Populations during Each Feeding Episode. Cell Reports. 2017. Grubaugh N.D. and Ebel G.D. Dynamics of West Nile Virus Evolution in Mosquito Vectors. Current Opinion in Virology. 2016. Fauver J.R. et al. Xenosurveillance Reflects Traditional Sampling Techniques for the Identification of Human Pathogens: A Comparative Study in West Africa. PLoS Neglected Tropical Diseases. 2018. Fauver J.R. The Use of Xenosurveillance to Detect Human Bacteria, Parasites, and Viruses in Mosquito Bloodmeals. American Journal of Tropical Medicine and Hygiene. 2017. Tracey McNamera: Canaries in the Coal Mine TEDxUCLA New York Times: Encephalitis Outbreak Teaches an Old Lesson. 1999. ASM Article: The One Health of Animals, Humans, and Our Planet: It’s All Microbially Connected
63 minutes | a year ago
128: Managing Plant Pathogens Using Streptomyces with Linda Kinkel
How can the intricate relationship between soil microbiota and plants be managed for improved plant health? Linda Kinkel discusses new insights into the plant rhizosphere and the ways that some Streptomyces isolates can protect agricultural crops against bacterial, fungal, oomycete, and nematode infections. Julie’s Biggest Takeaways: The soil microbiome is extremely dynamic, with boom-and-bust cycles driven by nutrient fluxes, microbial interactions, plant-driven microbial interactions, and signaling interactions. Finding the source of these boom-and-bust cycles can help people to manage the microbiome communities and produce plant-beneficial communities for agricultural purposes. Rhizosphere soil is soil closely associated with the root and is distinct from rhizoplane soil that directly touches the root. The endophytic rhizosphere are those microbes that get inside the root. Many scientists view these communities as a continuum rather than sharply delineated. Plants provide necessary carbon for the largely heterotrophic soil microbiota, and these microorganisms help the plants in several ways too: Microbes mediate plant growth by production of plant growth hormones. Microbes provide nutrients through mechanisms like nitrogen fixation or phosphorus solubilization. Microbes protect the plant from stress or drought conditions. Through a University of Minnesota plant pathology program, potatos were passaged in a field for over 2 decades to study potato diseases. Over time, researchers found fewer diseases in test crops, which led the plot to be abandoned in the late 1970s. In the 1980s, Dr. Neil Anderson planted potatoes to see if they would develop disease, but neither Verticillium wilt nor potato scab developed among the plants. Soil from the field (and on the potatoes) contained Streptomyces isolates that showed antimicrobial activity against bacteria, fungi, nematodes, and oomycetes. This discovery led Neil, new University of Minnesota professor Linda, and their collaborators to study the antimicrobial activity of natural Streptomyces isolates from around the world. Inoculation quickly adds specific microbial lineages to soil microbiome communities. Alternatively, land can be managed by providing nutrients to encourage the growth of specific species, like Streptomyces, within a given plot, but this takes longer to develop. How are soil microbiomes inoculated? Microbes can be: Added to the seed coating before planting. Placed in the furrow when the seed is planted. Distributed into the irrigation system. Links for this Episode: Linda Kinkel website at University of Minnesota Essarioui A. et al. Inhibitory and Nutrient Use Phenotypes Among Coexisting Fusarium and Streptomyces Populations Suggest Local Coevolutionary Interactions in Soil. Environmental Microbiology. 2020. Schlatter D.C. et al. Inhibitory Interaction Networks Among Coevolved Streptomyces Populations from Prairie Soils. PLoS One. 2019. Schlatter D.C. et al. Resource Use of Soilborne Streptomyces Varies with Location, Phylogeny, and Nitrogen Amendment. Microbial Ecology. 2013. Small Things Considered blog: Are Oomycetes Fungi or What? International Year of Plant Health HOM Tidbit: Austin-Bourke P.M. Emergence of Potato Blight, 1843-1846. Nature. 1965.
55 minutes | a year ago
127: E. coli and Burkholderia vaccines with Alfredo Torres
Pathogenic E. coli are different than lab-grown or commensal E. coli found in the gut microbiome. Alfredo Torres describes the difference between these, the method his lab is using the develop vaccines against pathogenic E. coli, and how this same method can be used to develop vaccines against Burkholderia infections. Julie’s Biggest Takeaways: coli plays many roles inside and outside the scientific laboratory: Laboratory E. coli strains used by scientists to study molecular biology. Commensal E. coli strains contribute to digestion and health as part of the intestinal microbiome. Pathogenic E. coli strains have acquired factors that allow them to cause disease in people The pathogenic E. coli associated with diarrheal disease are the ones named for their O-antigen and flagellar H-antigen, such as O157:H7. There are about 30 E. coli strains with various combinations of O-H factors known to cause diarrheal disease in people. The E. coli Shiga toxin (though not the bacterium itself) can pass through the epithelial cell layer to become systemic, and eventually the toxin will accumulate in the kidneys. This can lead to patients experiencing hemolytic uremic syndrome (HUS) and kidney failure, leading to lifelong dialysis or need for a transplant. An immune response that prevents the E. coli from attaching will prevent the bacterium from secreting toxin in close proximity to the epithelial cells and decrease likelihood of HUS development. Burkholderia is a bacterial genus whose member species have been weaponized in the past, and which remain potent disease-causing agents around the world. B. mallei causes glanders, a disease mostly of horses and their handlers. It is a respiratory infection that can become systemic if not treated. B. pseudomallei causes melioidosis, a disease that can manifest in many ways. It is endemic in many tropical regions around the world, found in over 79 countries so far. Coating gold nanoparticles with antigens against which the immune response will be protective is a method Alfredo has used for a number of candidate vaccines, including one against E. coli and one against B. pseudomallei. The nanoparticles can have the gold cleaved off to provide different functional variants of the same vaccine. Links for this Episode: Alfredo Torres webpage at University of Texas Medical Branch McWilliams BD and Torres AG. Enterohemorrhagic Escherichia coli Adhesins. Microbiology Spectrum. 2013. Sanchez-Villamil JI et al. Development of a Gold Nanoparticle Vaccine against Enterohemorrhagic Escherichia coli O157:H7. mBio. 2019. Wiersinga WJ et al. Melioidosis. Nature Reviews Disease Primers. 2018. Khakhum N. et al. Evaluation of Burkholderia mallei ΔtonB Δhcp1 (CLH001) as a live attenuated vaccine in murine models of glanders and melioidosis. PLOS Neglected Tropical Diseases. 2019. Torres AG. Common Sense Can Keep You Safe in E. coli Outbreak. Galveston County Daily News. 2020. ABRCMS: Annual Biomedical Research Conference for Minority Students MTM: Burkholderia pseudomallei & the neglected tropical disease melioidosis with Direk Limmathurotsakul HOM Tidbit: Kiyoshi Shiga Biography in Clinical Infectious Diseases
60 minutes | a year ago
126: Placental biology, infection and immunity with Carolyn Coyne
Does the fetus have a microbiome? How does the placenta prevent infection? Carolyn Coyne talks about placental structure and biology, and why studying the maternal-fetal interface remains a critical area of research. Julie’s Biggest Takeaways: The placenta forms within 3-5 days post conception as a single layer of cells surrounding the fertilized embryo. These cells differentiate and develop into more complex structures. Very few microbes cause fetal disease. Of those that do, the disease-causing microorganisms are diverse and can lead to serious congenital defects or even death of a developing fetus. These microbes are largely grouped into the TORCH (now TORCH-Z) microorganisms: Toxoplasma gondii Other (a variety of different bacteria and viruses) Rubella Cytomegalovirus Herpesviruses Zika virus The fetus is immunologically immature and unable to protect itself. Some of the maternal immunological molecules (such as maternal antibodies) cross the placenta to protect the fetus, but that only happens during later stages of fetal development. Between the first and second trimesters, the maternal vasculature reorganizes and maternal antibodies can begin to reach the fetus. This increases over time, until the end of the third trimester, when there is a higher concentration of maternal antibodies in fetal blood than in maternal blood. In the later stages of development, the placenta is coated in a layer of fused cells, leading to a shared cytoplasm that covers the entire surface area of the placenta. This fused-cell layer is formed from syncytiotrophoblasts, and the fusion is facilitated by the activity of an endogenous retrovirus fusion protein. Syncytiotrophoblasts are extremely resistant to infection with a number of different pathogens, and pathogen types. In initial tests experiments, Carolyn and her research team discovered that these cells releasing certain antimicrobial molecules to share protective properties. Syncytiotrophoblasts secrete type III interferons, which play a big role at barrier surfaces such as the airway and the gut—but unlike these barriers, the syncytiotrophoblast cells secrete type III interferons constitutively. Links for this Episode: Carolyn Coyne Website on the University of Pittsburgh School of Medicine Arora N. et al. Microbial Vertical Transmission during Human Pregnancy. Cell Host & Microbe. May 2017. Coyne C.B. The Tree(s) of Life: The Human Placenta and My Journey to Learn More About It. PLoS Pathogens. April 2016. Ander S.E. et al. Human Placental Syncytiotrophoblasts Restrict Toxoplasma gondii Attachment and Replication and Respond to Infection by Producing Immunomodulatory Chemokines. mBio. January 2018. Wells A.I. and Coyne C.B. Type III Interferons in Antiviral Defenses at Barrier Surfaces. Trends in Immunology. October 2018. Ander S.E. Diamond M.S. and Coyne C.B. Immune Responses at the Materna-Fetal Interface. Science Immunology. January 2019. HOM Tidbit: Women in Microbiology HOM Tidbit: Small Things Considered blog post: Retroviruses, the Placenta, and the Genomic Junk Drawer
53 minutes | a year ago
125: Coronavirus Antiviral Drug Discovery with Timothy Sheahan
Are there drugs that can treat coronaviruses? Timothy Sheahan talks about his drug discovery work on a compound that can inhibit all coronaviruses tested so far, and tells how his career path took him to pharmaceutical antiviral research and then back to academia. Julie’s Biggest Takeaways: Even though the MERS-CoV was discovered as a human pathogen in 2012, it was likely percolating as a disease agent for a long time before that. Banked camel serum provides evidence that the virus had been circulating in camels for several decades prior. Differentiated ex vivo lung cultures allow study of virus infection in a 3D model representation for studying viral infection, including target cell types of both MERS-CoV and SARS-CoV. SARS-CoV prefers ciliated epithelial cells Ace2 MERS-CoV prefers nonciliated epithelial cells DPP4 Coronavirus disease in people takes place over a course of about 2 weeks. In mice, the disease is similar, but progression is faster, taking about 1 week. The drug remdesivir (RDV) is a nucleoside analog that inhibits the coronavirus RNA-dependent RNA polymerase (RDRP). Remdesivir activity has not been tested against nCoV2019, but similarity to other viruses is promising. Bioinformatic approaches show that the nCoV2019 RDRP is 99% similar and 96% identical to SARS-CoV RDRP. Remdesivir works against every coronavirus tested so far, including viruses with highly divergent RDRP sequences, so remdesivir is likely to be effective again nCoV2019. Experiments must still be performed before reaching this conclusion, of course. Tim also hopes to discover the genetic determinants that will allow a chronic hepatitis C virus (HCV) infection in mice, but not standard inbred mice. He uses outbred mice meant to mimic the diversity of the human population, and strengthen the results. Understanding these determinants would inform human studies to better understand chronic HCV infection. Links for this Episode: MTM Listener Survey, only takes 3 minutes. Thanks! TWiV 584: Year of the Coronavirus Timothy Sheahan website at University of North Carolina Sheahan T.P. et al. Broad-Spectrum Antiviral GS-5734 Inhibits both Epidemic and Zoonotic Coronaviruses. Science Tranlational Medicine. 2017. Sheahan T.P. et al. Comparative Therapeutic Efficacy of Remdesivir and Combination Lopinavir, Ritonavir, and Interferon Beta against MERS-CoV. Nature Communications. 2020. Agostini M.L. et al. Coronavirus Susceptibility to the Antiviral Remdesivir (GS-5734) is Mediated by the Viral Polymerase and the Proofreading Exoribonuclease. mBio. 2018. ASM Coronavirus Resource Page HOM Tidbit: Baltimore D. In Vitro Synthesis of Viral RNA by the Poliovirus RNA Polymerase. PNAS. 1964.
55 minutes | a year ago
124: Gastroenteritis Viruses with Mary Estes
Viral gastroenteritis around the world causes 200,000 deaths globally each year. Mary Estes talks about her work on 2 gastroenteritis-causing viruses, rotavirus and norovirus, and tells the story of her discovery of the first viral enterotoxin. She also describes how noroviruses have changed from human volunteer studies to studies using “miniguts,” a system now used with many enteropathogenic microorganisms. Julie’s Biggest Takeaways: Rotaviruses and noroviruses kill 200,000 people annually, despite an available rotavirus vaccine and current anti-infective measures. Rotavirus is generally associated with gastrointestinal disease in the very young and the very old, while norovirus infects people at all life stages. Rotavirus is so stable that even when viral samples are extremely dessicated by lyophilization, the samples remain perfectly infectious. Rotavirus stability is largely due to 3 concentric capsid cells. NSP4 is a rotavirus enterotoxin, and the first viral enterotoxin to be discovered. It affects the concentration of the intracellular calcium pools. By activating the calcium chloride channel, NSP4 forces chloride and water to be excreted, directly leading to diarrhea. NSP4 is secreted from infected cells and can also disrupt calcium concentrations of neighboring cells, amplifying the effect of a single infected cell. Rotarix® and RotaTeq® are 2 different attenuated rotavirus vaccines. One contains a single attenuated viral strain while the other contains 5 attenuated viral strains; both vaccines have high efficacy in developed countries and slightly lower efficacy in developing countries. Why vaccine efficacy is lower in developing countries is uncertain, with many hypotheses including microbiome-based effects under study now. Human enteroids, or “miniguts,” offer insight into complex virus-cell interactions. These stem-cell derived miniguts can be generated from different types of animal stem cells, and the enteroids they become reflect the same host-barrier restriction as the animal of origin. The miniguts can be used to culture many sorts of viruses and other microorganisms, such as bacteria and protozoa. Links for this Episode: Mary Estes Website at Baylor College of Medicine Hyser J.M. et al. Rotavirus Disrupts Calcium Homeostasis by NSP4 Viroporin Activity. mBio. 2010. Crawford S.E. et al. COPII Vesicle Transport is Required for Rotavirus NSP4 Interaction with the Autophagy Protein LC3 II and Trafficking to Viroplasms. J Virology. 2019. Ettayebi K. et al. Replication of Human Noroviruses in Stem Cell-Derived Human Enteroids. Science. 2016. In J.G. et al. Human Mini-Guts: New Insignts into Intestinal Physiology and Host-Pathogen Interactions. Nat Rev Gastroenterol Hepatol. 2016. Finkbeiner S.R. et al. Stem Cell-Derived Human Intestinal Organoids as an Infection Model for Rotaviruses. mBio. 2012. Henning S.J. and Estes M.K. Women in Science: Hints for Success. Gastroenterology. 2015. Kapikian A.Z. et al. Visualization of a 27-nm Particle Associated with Acute Infectious Nonbacterial Gastroenteritis. Journal of Virology. 1972. HOM Tidbit: Smith K.N. The Iron Long was just an Engineer’s Side Project. Forbes. 2019. HOM Tidbit: Ramirez M. Living Inside a Canister: Dallas Polio Survivor is One of Few People Left in U.S. Using Iron Lung. Dallas Morning Star. 2018.
55 minutes | a year ago
123: SAR11 and Other Marine Microbes with Steve Giovannoni
The most abundant organism on Earth lives in its seas: the marine bacterium SAR11. Steve Giovannoni describes how the origins of SAR11 provided its name, and the ways that studying SAR11 have taught scientists about ocean ecology. He also discusses how the different depths of the ocean vary in their microbial compositions and what his big questions are in marine microbiology. Different depths of the ocean have different habitats, but the microbes vary continuously, based in part on light availability: Surface light facilitates photosynthesis by algal cells. These primary producers fix carbon for the entire ecosystem! Because nutrients are readily available, the cell concentration in surface waters can reach nearly 1,000,000 cells/ml. The twilight zone offers dim light. Microbes in this area mainly use carbon sources generated by the surface-dwelling microbes. Below a few hundred meters, cell concentrations drop to 10,000-100,000 cells/ml. The deep ocean has no light and the microbes that live here have significantly different biochemistries and metabolisms. SAR11 is small in both physical size and genome size (0.37–0.89 µm and 1.3 million base pairs, respectively). It is nevertheless the most abundant organism on the planet, with more than 1028 cells estimated to exist worldwide. These cells convert between 6-37% of the carbon fixed in the oceans daily. SAR11 in different niches have ecotypes with different specialties but look physically similar and have very similar genome sequences. Naturally, the most abundant cells in the ocean have the most abundant parasites: bacteriophages called pelagiphages infect SAR11 all over the world. SAR11 and pelagiphages are under constant evolution, though there doesn’t seem to be a CRISPR system in the Pelagibacter genome; these bacteria largely use other mechanisms to evade phage infection. SAR11 is like a house with the lights on all the time, in that the cells constitutively express most metabolic genes. For example, SAR11 metabolizes dimethylsulfoniopropionate (DMSP) into dimethyl sulfide (DMS) and methanethiol (MeSH), which can be produced as soon as the cells are exposed to DMSP. While this may seem energetically expensive, the cells must capitalize on their encounters with this transient resource, often found only at low concentrations, and this capitalization requires the investment of protein production. The cost of metabolic gene regulation outweighs the benefits in this particular case. SAR11 and SAR202 are the poles on the spectrum of heterotrophic marine bacteria. SAR11 is very efficient at accessing and using the organic compounds that come from the phytoplankton (also called the labile organic matter). SAR202, found in the deeper part of the ocean, specializes in hard-to-access carbon compounds that other bacteria can’t access. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Stephen Giovannoni website at Oregon State University OSU High Throughput Microbial Cultivation Lab Carini P. et al. Discovery of SAR11 Growth Requirement for Thiamin’s Pyrimidine Precursor and its Distribution in the Sargasso Sea. ISME J. 2014. Sun J. et al. The Abundant Marine Bacterium Pelagibacter Simultaneously Catabolizes Dimethylsulfoniopropionate to the Gases Dimethyl Sulfide and Methanethiol. Nature Microbiology. 2016. Moore E.R. et al. Pelagibacter Metabolism of Diatom-Derived Volatile Organic Compounds Imposes an Energetic Tax on Photosynthetic Carbon Fixation. Environmental Microbiology. 2019. HOM Tidbit: Sagan L. On the Origin of Mitosing Cells. 1967. HOM Tidbit: Cellmates (Radiolab podcast episode) ASM Article: The Origin of Eukaryotes: Where Science and Pop Culture Collide
50 minutes | a year ago
122: Prions and Chronic Wasting Disease with Jason Bartz
Can a protein be contagious? Jason Bartz discusses his work on prion proteins, which cause spongiform encephalopathy and can be transmitted by ingestion or inhalation among some animals. He further discusses how prions can exist as different strains, and what techniques may help improve diagnosis of subclinical infections. Links for this Episode: Jason Bartz Creighton University website Holec SAM, Yuan Q, and Bartz JC. Alteration of Prion Strain Emergence by Nonhost Factors. mSphere. 2019. Yuan Q et al. Dehydration of Prions on Environmentally Relevant Surfaces Protects Them from Inactivation by Freezing and Thawing. Journal of Virology. 2018. Bartz JC. Prion Strain Diversity. Cold Spring Harbor Perspectives in Medicine. 2016. Bartz JC. From Slow Viruses to Prions PLoS Pathogens. 2016. Deleault NR, Harris BT, Rees JR, Supattapone S. Formation of native prions from minimal components in vitro. Proceedings of the National Academy of Sciences. 2007. Planet Money Episode 952: Sperm Banks
54 minutes | a year ago
121: Microbial Interkingdom Interactions with Deb Hogan
Microbial interactions drive microbial evolution, and in a polymicrobial infection, these interactions can determine patient outcome. Deb Hogan talks about her research on interkingdom interactions between the bacterium Pseudomonas and the fungus Candida, 2 organisms that can cause serious illness in cystic fibrosis patients’ lung infections. Her research aims to better characterize these interactions and to develop better diagnostic tools for assessing disease progression and treatment. Links for this Episode: Deb Hogan Lab Website Demers EG et al. Evolution of Drug Resistance in an Antifungal-Naive Chronic Candida lusitaniae Infection. PNAS. 2018. Lewis KA et al. Ethanol Decreases Pseudomonas aeruginosa Flagella Motility through the Regulation of Flagellar Stators. Journal of Bacteriology. 2019. Gifford AH et al. Use of a Multiplex Transcript Method for Analysis of Pseudomonas aeruginosa Gene Expression Profiles in the Cystic Fibrosis Lung. Infection and Immunity. 2016. Grahl N et al. Profiling of Bacterial and Fungal Microbial Communities in Cystic Fibrosis Sputum Using RNA. mSphere. 2018. Microbiology Resource of the Month: The Aeminium ludgeri Genome Sequence HOM Tidbit: https://www.sciencedirect.com/science/article/pii/S0065216408705628 HOM Tidbit: The Frozen Potential of Microbial Collections
12 minutes | a year ago
Bonus: 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?
61 minutes | 2 years ago
120: 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 email@example.com.
55 minutes | 2 years ago
119: 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
64 minutes | 2 years ago
118: 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 website at 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.
52 minutes | 2 years ago
117: 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.
40 minutes | 2 years ago
116: 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.
42 minutes | 2 years ago
115: 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
46 minutes | 2 years ago
114: 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
Terms of Service
Do Not Sell My Personal Information
© Stitcher 2021