PNAS: Secret weapon of "superbug" has been found

Researchers at the University of Texas Health Science Center (UTHealth) have identified the protein, which was recently published in the journal PNAS and is being revealed as a winning weapon for VRE, a finding that could provide new ideas for future treatment options for antibiotic resistancehttp://doi.org/10.1073/pnas.1916037116Datomycin (DAP) is commonly used in clinical treatment for the most serious stage of bacterial infection, it is a cational antibiotic acting on the cell membrane, targeting the gin ion phospholipids in the gap between bacterial divisionIts insertion into the cell membrane can lead to mislocation of membrane proteins involved in maintaining the dynamic balance of the cell membrane, leading to the death of bacterial cellsVAE and other bacteria have a stress response system called LiaFSR, which helps bacteria build resistance and adapt to many environmental stressors, but the mechanism of action is unclearThe researchers studied the Clinical Strain of VRE, which is resistant to DAP attack cell membranes, and found a special protein, LiaX, that senses the presence of antibiotics in the environment and then causes bacterial cell membranes to recombine to prevent the drug from destroying the bacteriaLiaX regulates the cell membrane remodeling of Efaecalis
LiaX is exposed to the cell surface, and in clinical strains resistant to DAP, the N-end domains of LiaX and LiaX alone are released into the extracellular environmentThe researchers observed high levels of protein symphoe in extracellular cells that bind to antibiotics and send signals to cells to activate stress responsesLiaX protein behaves like a sentinel, warning bacterial cells to be aware of the coming antibioticsAt the same time, researchers have found that LiaX can not only sense antibiotics, but also signal when the body responds to an immune responsethe immune system produces antimicrobial peptides (AMP), which help the body fight infections caused by bacteria or fungiSimilar to DAP, they also work by destroying bacterial cell membraneseach domain of LiaX plays a unique role in regulating DAP-R (DAP tolerance)LiaX's C-end domain inhibits liaFSR systems in wild strainsTherefore, the absence of the C-end structural domain relieves this inhibition and acts as a signal to trigger the stress response of the cell membrane The N-end domain acts as a sentinel and binds to DAP and AMP in the extracellular environment, leading to the activation of the LiaFSR system a mechanism model of DAP-R and AMP resistance mediated by LiaX (A) LiaFSR is in the OFF state of DAP-S (DAP susceptibility) strain under stress-free conditions (B) Due to the mutation in LiaFSR, the strain is resistant to DAP by activating the LiaFSR system or by truncating the C-side of LiaX, both the N-ends of LiaX and LiaX are released to the ECM (extracellular environment) the results show that the LiaX may be a potential target for the future development of adaptive molecules, thus restoring the efficacy of widely used antimicrobialagents and enhancing the body's inherent immune mechanism to remove the immune mechanism of multiple bacteria references: santinos s a gullad with cell cell ing mediatesand and resistance virulence in Enterococcusfaecalis