Reveal the mechanism of Staphylococcus aureus tolerating high salt concentration

  Staphylococcus aureus is a common cause of food poisoning and can withstand the high temperatures and high salt concentrations used in cooking and storing food. Researchers hope to use this knowledge to develop treatments that will prevent food poisoning by ensuring that all cells in the food are killed. They are also investigating whether these findings can help develop non-antibiotic therapies for patients. Staphylococcus aureus is present on the skin or nose of one in four people.

  However, when these bacteria invade the human body, they can cause serious illness, sepsis, and even death. The "super bacteria" form of this bacteria, methicillin-resistant Staphylococcus aureus (MRSA), has developed resistance to the antibiotic methicillin. Staphylococcus aureus can cause food poisoning through contaminated meat products (such as ham) as well as sandwiches, salads, and dairy products. In this new study, researchers discovered how Staphylococcus aureus regulates its salt intake. Disrupting this mechanism means that the bacteria either absorb too much salt from the environment or lose too much water. In both cases, the bacteria will become dehydrated and die.

  The corresponding author of this paper, Professor Angelica Grundling from Imperial College London, said: “Staphylococcus aureus is an important pathogen that causes many serious infections in patients. This research now allows us to better understand this bacteria. How to deal with salt stress. Although this research is only in its infancy, we hope that this knowledge will one day help prevent food poisoning-transmitted staphylococcal infections and open up new possibilities for the development of non-antibiotic treatments. In the laboratory I studied MRSA cells and found that a signaling molecule called cyclic diadenylic acid (c-di-AMP) regulates their ability in this bacteria. Salt level plays an important role.

  Staphylococcus aureus is very resistant to high salt concentration, but until now scientists have not known why. Current research has detected that the signal molecule is in the high-salt environment of bacteria. The researchers then revealed that it attaches to some transporters and guides them to react and prevent bacteria. High salt content will cause cells to lose water, so eat salty food. You will be thirsty after eating. Therefore, in order to prevent water loss, these transport proteins transport molecular sponges into cells like tiny molecules, and absorb water into cells. Contain and prevent escape. These small sponge molecules prevent salt from entering the cell by preventing water loss.

  Researchers can disrupt this salt mechanism. We found that increasing the signal molecule c -di-AMP that binds to these transporters will significantly reduce the number of these small sponge molecules. Inhibition of this salt protection mechanism can cause MRSA cells to become salty. It becomes more sensitive to it, which will eventually lead to the destruction of these bacterial cells.