Microbiologist Answers Microbiology Questions From Twitter | Tech Support | WIRED

Microbiology Support (0s)

• Dan Buckley studies microbes. (0s)
• Buckley will answer microbiology questions from the internet. (2s)
• A Twitter user with the name "culture pulp" asks a question. (9s)

Brain-eating amoebas? (13s)

• Brain-eating amoebas, such as Naegleria fowleri, exist and can be lethal. (13s)
• Infections are rare, with only a few cases reported annually in North America. (16s)
• One way infection can occur is by warm, freshwater entering the nose forcefully, potentially carrying the amoeba to the brain. (32s)

Flatulence and gut health (59s)

• Farts are entirely produced by microbes in the gut that aid in food digestion. (1m4s)
• An imbalance in the gut, potentially caused by consuming something detrimental, can lead to the release of volatile fatty acids, resulting in foul-smelling farts. (1m33s)
• The consumption of protein can result in the production of hydrogen sulfide by gut bacteria, leading to a rotten egg smell. (2m5s)

The Dancing Pinhead Microbes (2m27s)

• The head of a pin is estimated to be two microns in size. (2m32s)
• A bacterium is typically two microns in size. (2m34s)
• One or two microbes could fit on the head of a pin. (2m40s)

Are we human or are we microbe? (2m46s)

• The number of microbial cells in the human body is roughly equivalent to the number of human cells. (2m56s)
• Bacteria are significantly smaller than human cells, approximately one thousand times smaller. (3m0s)
• The total mass of bacterial cells in the human body can range from two to six pounds, which can fluctuate throughout the day, particularly due to bowel movements. (3m8s)

The fastest bacteria (3m27s)

• Delrio vibrio, also known as "the wiggly leech that eats bacteria", is the fastest bacteria. (3m32s)
• Delrio vibrio can reach speeds of approximately 150 microns per second, which is equivalent to 600 miles per hour when scaled to human size. (3m39s)
• This bacterium is commonly found in freshwater habitats where it preys on other bacteria. (3m51s)

Predatory bacteria (4m15s)

• Predatory bacteria are bacteria that consume other bacteria and exhibit diverse hunting mechanisms. (4m19s)
• Myxobacteria, for example, operate as a collective, communicating through molecular signals to locate, encircle, and break down their prey using secreted enzymes. (4m25s)
• Bdellovibrio, another type of predatory bacteria, inhabits aquatic environments and hunts by attaching to its prey, penetrating the cell wall, and replicating inside until the host cell bursts. (4m48s)

Bacteria on the move (5m17s)

• Bacteria move through a process called chemotaxis, which involves a "biased random walk" where they constantly sample their environment to determine if conditions are improving or worsening. (5m22s)
• Many bacteria use flagella, which are stiff, helical structures that spin to propel them forward, to move. (5m55s)
• Some bacteria move by gliding, using suction cup-like mechanisms to propel themselves along surfaces. (6m10s)

The Last Of Us fungi: Real or No (6m31s)

• The Ophiocordyceps fungus infects a variety of insects, invading their brains and manipulating their behavior to spread the fungus. (6m47s)
• Insects, being cold-blooded, are physiologically different from humans, making it improbable for the Ophiocordyceps fungus to infect humans. (7m0s)
• Rabies, a viral infection that affects the brain and can be transmitted through bites, is a more realistic example of a "zombie infection" in humans, although effective vaccines are available. (7m5s)

The microbe that scares this expert the most (7m26s)

• Avian influenza has been present for decades but is currently a problem due to a pandemic affecting birds, particularly in North America, leading to illness in chickens and turkeys. (7m31s)
• Avian influenza is a concern for humans because it has the potential to infect humans and combine with human influenza strains, creating a novel virus that could lead to a pandemic. (7m44s)
• This new virus would be problematic because it would be entirely unfamiliar to human immune systems, rendering prior vaccinations ineffective. (8m8s)

Metal eating bacteria (8m18s)

• There are many types of bacteria that can consume metals, including chrome and uranium. (8m22s)
• These bacteria essentially "breathe" the metal, using it as a form of respiration to obtain energy. (8m31s)
• Some of these bacteria possess nanowires that facilitate the transfer of electrons, allowing them to either deposit or extract electrons from the metal surface. (8m39s)

Antibiotic-resistant bacteria (9m23s)

• Microbes, including bacteria and fungi, constantly adapt to environmental changes to thrive. (9m26s)
• The discovery of antibiotics originated from observing soil-dwelling bacteria and fungi that produce substances to kill competing microbes. (9m35s)
• The widespread use of antibiotics since the 1930s and 1940s has created selective pressure, leading to the emergence of antibiotic-resistant bacteria. (9m54s)
• Bacteria can acquire antibiotic resistance genes from other organisms through horizontal gene transfer, accelerating the spread of resistance. (10m31s)
• Addressing antibiotic resistance requires understanding the evolutionary mechanisms of resistance and implementing strategies to slow down the evolution of resistant strains. (10m43s)

Microwaves and bacteria (10m55s)

• The primary reason to clean a microwave is to remove food debris, not necessarily to eliminate bacteria. (11m0s)
• While some microbes can survive high temperatures, the ones typically found in microwaves are similar to those on sponges and are likely to die. (11m18s)
• Deinococcus radiodurans is an extremophile capable of withstanding high levels of radiation, far exceeding the lethal dose for humans, and has even survived in space. (11m45s)

Extremophiles (11m59s)

• Extremophiles are microbes that thrive in conditions that are lethal to most other organisms. (12m3s)
• Thermophiles, a type of extremophile, thrive in extremely high temperatures, such as Pyrococcus furiosus, which lives in temperatures above the boiling point of water. (12m10s)
• Acidophiles are extremophiles that live in highly acidic environments, such as acid mine drainage with a pH of 0.5. (12m33s)

Bacteria vs. Virus vs. Fungus (12m58s)

• Microorganisms are defined as anything too small to be seen. (13m4s)
• Prokaryotes, which include bacteria, are single-celled organisms that lack a nucleus and first evolved 4 billion years ago. (13m13s)
• Eukaryotes, which include fungi, plants, and animals, are organisms that have a nucleus and evolved after prokaryotes. (13m22s)

Magnet bacteria, how do they work? (13m50s)

• Some bacteria species have magnets inside their cytoplasm. (13m56s)
• These bacteria use the magnets to orient themselves within the Earth's magnetic field, allowing them to navigate up and down to find the optimal oxygen levels in their environment. (14m0s)
• Researchers have used magnets to control the movement of these bacteria. (14m40s)

Subway poles and you: Partners in cleanliness (14m57s)

• Subway poles are relatively dry surfaces, which are not ideal environments for microbes to thrive. (15m4s)
• Microbes found on subway poles likely originate from human skin, which constantly sheds cells and associated microbes. (15m12s)
• One common skin microbe is Staphylococcus aureus, which is generally harmless but can pose risks if it carries antibiotic resistance genes or toxin genes. (15m29s)

We Love Tardigrades (16m30s)

• Tardigrades are eukaryotic, multicellular microorganisms. (16m36s)
• They can survive harsh conditions by dehydrating themselves. (16m51s)
• Rehydrating a tardigrade allows it to become active again. (16m55s)

Why cat poop is dangerous for pregnant people (17m3s)

• Toxoplasma gondii is a parasite that can be found in cat feces and can be harmful to developing embryos or fetuses, potentially leading to miscarriage. (17m5s)
• The parasite infects mice, affecting their brains and making them more susceptible to being preyed upon by cats; this allows the parasite to spread further through the cats' feces. (17m32s)
• Pregnant individuals are advised to avoid contact with cat feces, consider indoor cats that are less likely to be exposed to the parasite, or have someone else clean the litter box. (17m50s)

Romantic Music playing (18m1s)

• Amoebas reproduce asexually through binary fission, a process in which a single cell divides into two identical cells. (18m5s)
• Amoebas belong to a group of organisms called protists. (18m10s)
• Protists, including amoebas, can exchange genetic material through horizontal gene transfer, a process that involves the transfer of DNA between organisms. (18m21s)

Horizontal gene transfer (18m28s)

• Horizontal gene transfer is the transfer of DNA between organisms that are not related through descent, contrasting with vertical transfer which occurs from parent to offspring. (18m35s)
• Viruses can mediate horizontal gene transfer by picking up DNA from one host cell and transferring it to another. (19m7s)
• Horizontal gene transfer is a significant factor in the evolution of microorganisms, potentially increasing the pathogenicity of bacteria. (19m21s)

The biggest bacteria (19m29s)

• Thiomargarita magnifica is the largest bacteria discovered so far. (19m32s)
• Thiomargarita magnifica can grow to be 2 cm long and 50 microns in diameter, which is comparable to the size of a human hair. (19m34s)
• Thiomargarita magnifica was discovered approximately two years ago in mangroves. (19m43s)

Gut creature cravings (19m54s)

• Microbes in the human gut assist in the breakdown of food, particularly plant material, into usable nutrients. (20m10s)
• Some chemicals produced by gut microbes during digestion can enter the bloodstream and act similarly to hormones, potentially influencing feelings of hunger, fullness, and mood. (20m20s)
• Research, primarily conducted on mice, suggests a potential link between gut microbiome composition and behavior, though studying this in humans presents challenges. (20m34s)

Fecal transplants, sure (20m48s)

• Antibiotics, while used to treat infections, can kill beneficial microbes in the gut, sometimes leading to diarrhea. (20m53s)
• C. diff, a harmful organism, can proliferate in the gut after antibiotic use, potentially causing severe infection and death. (21m7s)
• Fecal transplants, involving the transfer of fecal matter from a healthy donor, are currently the most effective treatment for C. diff infections. (21m29s)

What is it that you do here (21m56s)

• Microbes are the most diverse organisms on the planet, with only about 10,000-20,000 described and most yet to be discovered and named. (22m1s)
• Microbiologists also work to predict the next pandemic, with coronaviruses already identified as a potential threat 20 years ago. (22m11s)
• The rapid development of a COVID-19 vaccine in a year demonstrates the significant amount of prior research conducted by microbiologists. (22m33s)

Martian microbes (22m41s)

• The Perseverance Rover discovered a rock on Mars with features resembling those left by microbes, suggesting the possibility of past life on the planet. (22m42s)
• The rocks found are sedimentary, indicating formation underwater, and contain organic molecules, which are associated with living organisms. (23m0s)
• While Mars is currently dry, it was wet in the past, raising the question of whether microbes existed then and if they might still exist underground. (23m27s)

Phone screens vs toilets (23m42s)

• Mobile phone screens and toilet seats are both dry, smooth surfaces that are frequently cleaned, so they do not harbor a significant amount of bacteria. (23m58s)
• Keyboards, kitchen sponges, and washrags tend to have more bacteria because they collect dust, trap moisture, and are exposed to food particles, creating an environment where microbes can thrive. (24m20s)
• Fish tank filters contain a large amount of microbes, similar to a rainforest ecosystem. (24m31s)

Beneficial microbes (24m35s)

• There are more beneficial microbes in 10 square meters of healthy soil than all other animal and plant species on the planet. (24m36s)
• A 10 square meter section of soil, 10 cm deep, contains approximately 12 million grams of soil and 1 billion bacteria per gram of soil. (24m49s)
• Lining up the 1.2 x 10^16 bacteria found in this patch of soil end-to-end would create a chain spanning 10 billion meters, enough to reach the moon and back approximately 30 times. (25m27s)

knowing what they know (25m33s)

• Microbiologists are aware that everything people interact with, including food, drinks, and surfaces, is covered in microbes. (25m35s)
• The majority of cells on Earth are microbial, and most of them are not harmful. (25m49s)
• Microbes are responsible for producing most of the oxygen on Earth, making the planet habitable for humans. (26m4s)

Unanswered questions about microbes (26m20s)

• The vast majority of microbes are unknown because they are difficult to identify under a microscope and do not grow on petri dishes. (26m28s)
• Genomic technologies, such as metagenomics, allow sequencing of DNA from all species in a sample, revealing that most do not match any described species. (26m41s)
• This vast, uncharacterized portion of the microbial world is referred to as "microbial dark matter." (27m7s)

Do bacteria mostly smell the same? (27m23s)

• Microbiologists can identify certain bacteria by their smell, such as Pseudomonas, which often smell like grapes. (27m40s)
• Streptomyces, a soil-dwelling bacteria, produces a compound called geosmin, which gives off an earthy scent, particularly noticeable after rain. (28m4s)
• Specific scents can be associated with particular organisms or biological processes, aiding in their identification. (27m37s)