BacterioFiles 375 - Prepared Pathogen Preserves Perception

This episode: A cancer-killing virus could help increase success of treatment of a form of eye cancer in children!

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Show notes:
Microbe of the episode: Acanthamoeba polyphaga mimivirus

News item

Takeaways
Cancer obviously is a serious concern, and can be tricky to treat because there are endless varieties in all different places in the body, each of which can have its own expected progression, aggressiveness, and methods of treatment to take into account.

Even more serious is when the cancer is in very young children, as is often the case with a cancer of the eye called retinoblastoma. There are about 8000 cases of this disease per year, and when treatment is unsuccessful, it can lead to the loss of one or both eyes.

In this study, investigators looked into using a cancer-targeting, oncolytic virus to complement the normal treatment of chemotherapy. The virus for the most part remained localized to the eye where it should be, and targeted the cancer instead of healthy cells, and so seems promising. In the small trial with two patients included in this study, the virus didn't cause a complete recovery, but showed some modest promising results.

Journal Paper:
Pascual-Pasto G, Bazan-Peregrino M, Olaciregui NG, Restrepo-Perdomo CA, Mato-Berciano A, Ottaviani D, Weber K, Correa G, Paco S, Vila-Ubach M, Cuadrado-Vilanova M, Castillo-Ecija H, Botteri G, Garcia-Gerique L, Moreno-Gilabert H, Gimenez-Alejandre M, Alonso-Lopez P, Farrera-Sal M, Torres-Manjon S, Ramos-Lozano D, Moreno R, Aerts I, Doz F, Cassoux N, Chapeaublanc E, Torrebadell M, Roldan M, König A, Suñol M, Claverol J, Lavarino C, De TC, Fu L, Radvanyi F, Munier FL, Catalá-Mora J, Mora J, Alemany R, Cascalló M, Chantada GL, Carcaboso AM. 2019. Therapeutic targeting of the RB1 pathway in retinoblastoma with the oncolytic adenovirus VCN-01. Sci Transl Med 11:eaat9321.

Other interesting stories:

• Exploring how microbes can influence the flavor of coffee

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 374 - Microbes Muzzle Malicious Metal

Elemental arsenic
By Tomihahndorf
CC BY-SA 3.0

This episode: Mouse gut microbes, from mice or from human donors, can protect mice against arsenic toxicity!

Download Episode (6.3 MB, 6.9 minutes)

Show notes:
Microbe of the episode: Streptomyces griseus

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Takeaways
Our gut microbes benefit us in many ways, including nutritionally—by producing vitamins and helping to digest food—and by helping us in defense against pathogens and other immunological threats.

Many things we do can affect our gut microbes too, positively or negatively. What we eat, toxins we encounter, and other aspects of lifestyle can damage our microbial communities.

In this study, we see that the reverse could be true, that gut microbes, and specifically one called Faecalibacterium prausnitzii, can protect their host against toxins such as arsenic.

Journal Paper:
Coryell M, McAlpine M, Pinkham NV, McDermott TR, Walk ST. 2018. The gut microbiome is required for full protection against acute arsenic toxicity in mouse models. Nat Commun 9:5424.

Other interesting stories:

• Using bacteria to remediate rust on iron (paper)
• New large viruses discovered infecting bacteria in human gut
• Cool podcast about gardening that often mentions microbes

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 373 - Plant Pilots Prevent Parching

Emmer wheat

This episode: Beneficial fungi found inside wild grain plants help wheat plants grow better with less water!

Download Episode (7.1 MB, 7.75 minutes)

Show notes:
Microbe of the episode: Beijerinckia indica

Takeaways
As we have microbial communities in our guts, on our skin, and in various other places in and on our bodies, plants also have beneficial microbial symbionts around their roots, on their leaf surfaces, and even inside their tissues. These microbes can be bacteria, fungi, or other, and can help plants gather nutrients, resist diseases or pests, and other things.

In this study, some fungi living in grain plants—called endophytes, or "inside plants"—can help wheat tolerate drought and grow better with less water. Studying this system could lead to breakthroughs in wheat farming, all thanks to microbes.

Journal Paper:
Llorens E, Sharon O, Camañes G, García‐Agustín P, Sharon A. Endophytes from wild cereals protect wheat plants from drought by alteration of physiological responses of the plants to water stress. Environ Microbiol.

Other interesting stories:

• Searching bacterial metabolites for new insect repellants
• Antibiotic disruption of gut microbes can also mess with skeletal health
• Fibers derived from wood could encourage healthy gut microbes (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 372 - Roundworm Riders Repel Raiders

Nematode
By Bob Goldstein, UNC Chapel Hill
CC BY-SA 3.0

This episode: Bacteria that help nematodes prey on insects also help keep fungi from stealing their kills!

Download Episode (7.4 MB, 8.1 minutes)

Show notes:
Microbe of the episode: Artogeia rapae granulovirus

Takeaways
Soil is an incredibly complex ecosystem, with many different interactions constantly happening between plants, insects, bacteria, fungi, and other organisms, not to mention a large variety of shifting environmental conditions. All of these are competing with some and cooperating with others to try to survive and thrive the best they can.

One interesting interaction takes place between small roundworms in the soil, called nematodes, and bacteria they carry around that cause disease in insects. These nematodes prey on insects by injecting the bacteria into them, which kill and start digesting the insects. The nematodes then feed on the insects and the bacteria until the resources have been exhausted, and then move on to the next insect, taking some bacteria with them again.

In this study, the scientists wondered how these partners deal with competitors in the soil that might want to take advantage of their resources. They discover that the bacteria produce compounds that can repel and inhibit fungi that might otherwise steal their kills.

Journal Paper:
Shan S, Wang W, Song C, Wang M, Sun B, Li Y, Fu Y, Gu X, Ruan W, Rasmann S. The symbiotic bacteria Alcaligenes faecalis of the entomopathogenic nematodes Oscheius spp. exhibit potential biocontrol of plant- and entomopathogenic fungi. Microb Biotechnol.

Other interesting stories:

• Mice given gut microbes from healthy human babies don't get milk allergies
• New fungal species living in glaciers are losing their homes as glaciers disappear
• Toxins from cyanobacterial blooms can product tiny animals from pathogens

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 371 - Cell Stalker Senses Signals

Vibrio cholerae

This episode: Phages eavesdrop on bacterial communications to attack at the perfect moment!

Thanks to Justin Silpe and Dr. Bonnie Bassler for their contributions!

Download Episode (11.1 MB, 12.2 minutes)

Show notes:
Microbe of the episode: Artichoke Aegean ringspot virus

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Takeaways
Even organisms as small as bacteria can, and often do, communicate with each other through a process called quorum sensing, in which each cell releases a small amount of a certain chemical into their surroundings. When the population is large enough that the concentration of this chemical builds up to a certain level, the cells in the population change their behavior. The specifics of this change depend on the species and the situation.

But since this chemical signal is released into the environment, anything around that can sense it can listen in on the communications of a bacterial population. In this study, Justin Silpe and Dr. Bonnie Bassler find a type of virus that uses such a chemical communication as a signal to come out of stasis and hijack a whole population of bacteria at once!

Journal Paper:
Silpe JE, Bassler BL. 2019. A Host-Produced Quorum-Sensing Autoinducer Controls a Phage Lysis-Lysogeny Decision. Cell 176:268-280.E13.

Other interesting stories:

• Bacteria around plant roots can affect when they flower (paper)
• Certain respiratory microbe communities seem to protect against flu
• New process for finding better electric bacteria

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 370 - Magnets Make Messenger More Moveable

Baculoviruses in occlusion body

This episode: Enhancing a virus with magnetic nanoparticles and CRISPR-Cas gene editing abilities makes it a good vector for genetic therapies!

Download Episode (11.2 MB, 12.25 minutes)

Show notes:
Microbe of the episode: Staphylococcus virus S253

News item

Takeaways
Gene delivery, getting genetic content for gene therapy to the correct tissues in an organism, has long been a very tricky problem. And genetic modification, making specific changes at a specific place in a genome, is also difficult.

Viruses can help with both delivery and modification, but they're often not specific and targeted enough to be effective, or even safe. Off-target effects could be harmful or even deadly, potentially resulting in cancer.

In this study, a virus is modified with nanotechnology in the form of tiny magnets to allow humans to target it to specific tissues, and given the ability to modify specific genes using the bacterial CRISPR-Cas system. These modifications potentially make this gene delivery system much more safe and effective.

Journal Paper:
Zhu H, Zhang L, Tong S, Lee CM, Deshmukh H, Bao G. 2018. Spatial control of in vivo CRISPR–Cas9 genome editing via nanomagnets. Nat Biomed Eng.

Other interesting stories:

• Bacteria found in hot, dry areas could have potentially useful industrial enzymes (paper)
• Gut bacteria help regulate vitamin A activity in gut
• Confined swimming bacteria form shifting vortex like clothes washer (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 369 - Powering Purple Prokaryote Protonation

This episode: Purple phototrophic bacteria could use certain kinds of wastewater, along with electric current, to produce valuable products like hydrogen without much waste!

Thanks to Dr. Ioanna Vasiliadou for her contribution!

Download Episode (12.7 MB, 13.9 minutes)

Show notes:
Microbe of the episode: Streptomyces tendae

News item

Takeaways
Purple phototrophic bacteria can take light energy and use it to help power their metabolism. They're not dependent on it like plants, but can use light or other energy sources for their versatile metabolism.

This versatility makes them very interesting candidates for industrial biotechnology applications. These bacteria can take in various combinations of nutrients and produce a number of different valuable products, including protein-rich feed, bioplastics, and biofuels such as hydrogen gas.

Today's study shows they can also take up electrons directly to help make their biofuel production process even more environmentally sustainable.

Journal Paper:
Vasiliadou IA, Berná A, Manchon C, Melero JA, Martinez F, Esteve-Nuñez A, Puyol D. 2018. Biological and Bioelectrochemical Systems for Hydrogen Production and Carbon Fixation Using Purple Phototrophic Bacteria. Front Energy Res 6:107.

Other interesting stories:

• Looking at which microbes degrade classic paintings, and how
• Neurotransmitter-consuming gut microbes correlated with fewer signs of depression (paper)
• Phages don't always transfer the same way in fecal microbe transplants (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.