421: Nucleocapsids Navigate Nano Nuggets

This episode: Using phages to target gold nanoparticles to
infecting bacteria, then using light to heat the nanoparticles
just enough to kill the bacteria!

Thanks to Raymond Borg and Huan Peng for contributing!


Download Episode (10.6 MB, 15.4 minutes)

Show notes:
Microbe of the episode: Pantoea agglomerans

News item

Takeaways
Viruses that infect bacteria, bacteriophages, are often very good
at overcoming bacterial defenses and killing them. This raises
the possibility, and many times actuality, of using phages to
treat bacterial infections that are no longer treatable with
antibiotics. But bacteria can evolve resistances to viruses as
well as drugs, and using multiplying, evolving entities as
treatments in people raises questions about the safety and
consistency of the treatment.

This study circumvents these questions by using phages for
delivery and targeting of bacteria rather than the therapeutic
agent itself. The actual treatment is done with tiny rods of
gold, gold nanorods, bound to the phage surface. When a certain
wavelength of light hits these nanorods, they vibrate enough to
generate enough heat in their immediate surroundings to render
nearby bacteria nonviable. Thus the infection is treated in a
very localized, targeted way that doesn't leave any active
bacteria or phages behind. The authors have plans to study this
approach as a topical treatment of wounds.

Journal Paper:
Peng H, Borg RE, Dow LP, Pruitt BL, Chen IA. 2020. Controlled
phage therapy by photothermal ablation of specific bacterial
species using gold nanorods targeted by chimeric phages. Proc
Natl Acad Sci 117:1951–1961.


Other interesting stories:



Two bacteria growing together on agar make pretty patterns

Marine bacteria kill and digest other bacteria (paper)




 


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com. Thanks for listening!


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