Bacterial antibiotic new resistance: mechanism found (Introduction)

by David Turell , Tuesday, December 10, 2019, 00:36 (1811 days ago) @ David Turell

This is in a very dangerous enterococcus in immune depleted patients but lives in us normally without problem. It has automatic responses to drugs and our immune system:

https://phys.org/news/2019-12-achilles-heel-drug-resistant-superbug.html

"The research, published in the December issue of the Proceedings of the National Academy of Sciences of the United States of America, revealed that a protein called LiaX is released by bacteria into the environment to sense the presence of antibiotics, causing restructuring of the bacterial cell that prevents the drug from destroying it. VRE is on the Centers for Disease Control's latest threat report and is most commonly associated with health care settings. It can lead to serious complications, causing nearly 5,400 deaths in 2017 in the U.S.

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"Enterococci and other bacteria have a stress response system, called LiaFSR, which helps germs build drug resistance and adapt to many environmental stressors. LiaX, they discovered, is a major player in that system.

"'We call LiaX the master modulator of resistance, and it basically tells the bacteria to remodel their protective cell envelope, causing daptomycin to bind away from the septum and allowing the cell to survive," Khan said.

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"'We observed high levels of the protein outside of the cell that was binding to the antibiotic and signaling back to the cell to activate the stress response," Khan said.
In essence, the LiaX protein behaves like Paul Revere alerting the bacteria that the antibiotics are coming. However, the researchers discovered it's not just antibiotics that the protein can sense, it also signals when an immune response is happening.

"The immune system produces antimicrobial peptides, which are molecules that help fight infections caused by germs like bacteria or fungi. They work by destroying the cell envelope, much like daptomycin does.

"'What we revealed is that not only is LiaX acting as a sentinel protein that latches on to daptomycin, but it can sense the antimicrobial peptides created by our immune systems and elicit the same cell restructuring response," Khan said.

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"According to the researchers, a major takeaway from their study is not just that VRE produces a sentinel protein that can protect bacteria against antibiotics and the immune system, but that its protection inherently makes the bacteria more lethal during infection."

Comment: No thinking on the part of the enterococcus. Just automatically deploy the protein molecules