Natures wonders: predatory bacteria (Introduction)

by David Turell , Tuesday, August 25, 2020, 15:29 (1549 days ago) @ David Turell

Bacteria have two main enemies, bacteriophages and predatory bacteria. Both can help control disease:

https://www.nytimes.com/2020/08/25/science/bacteria-bdellovibrio-predator-prey.html?cam...

"Predatory bacteria carry immense promise in an extraordinarily small package. Deployed under the right circumstances, they could help people beat back harmful microbes in the environment, or purge pathogens from the food supply. Some experts think they could someday serve as a sort of living therapeutic that could help clear drug-resistant germs from ailing patients in whom all other treatments have failed.

"But even the small community of researchers who study predatory bacteria have not fully figured out how these cells select and slaughter their hosts. Teasing out those answers could reveal a range of ways to tackle stubborn infections, and provide a window onto predator-prey dynamics at their most microscopic.

"To potentially use this group of microbes as “a living antibiotic, we need to know how it grows,” said Terrens Saaki, a microbiologist studying predatory bacteria at the de Duve Institute in Belgium. “We can’t use it if we don’t understand it.”

"Predatory bacteria were discovered by accident. Scientists stumbled upon them more than a half-century ago while hunting for another type of murderous microbe called a bacteriophage, or phage, a virus that can infect and kill bacteria. Before then, Dr. Williams said, “it was not known that a bacterium would prey on other bacteria in this fashion.”

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"But phages and predatory bacteria are very different beasts. Phages tend to target a narrow range of hosts, whereas many predatory bacteria are far less finicky. Some predatory bacteria are amenable to eating dozens, if not hundreds, of bacterial species, enabling them to thrive in most habitats. And whereas phages work quickly, massacring entire populations within hours, predatory bacteria are plodding, sometimes taking weeks to grow in the lab.

"And while other microbes are content to feast on nutrient-rich broth, predatory bacteria demand a steady supply of live prey.

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"Once a bacterial predator has homed in on its prey, little can stop it. Whereas antibiotics and bacteriophages tend to target very specific parts of a bacterium’s anatomy bacterial predators are blunt agents of gluttony: A microbe can no more easily evolve resistance to them than a rabbit can evolve resistance to a wolf.

"Even before latching onto their prey, BALOs are formidable foes, capable of chemical sensing that allows them to “sniff” out their prey and then give chase, propelling themselves forward by rotating a corkscrew-like tail called a flagellum. “They can swim 100 times their body lengths in a second,” Dr. Kadouri said. “Pound for pound, that’s faster than a cheetah.”

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"Some evidence suggests that “healthy human beings usually have predatory bacteria as part of their microbiome,” she said. Little is understood about their role, she added. But they likely maintain order in the gut and ensure that no single species runs amok."

Comment: It follows the usual rule. Everyone has to eat something. But we humans have the smarts to make them into a good therapeutic agent.