How Multi-Resistant Staphylococcus aureus cells (the infamous MRSA) outsmart an antibiotic


I use the adjective “fascinating” very often for my contributions, but the results that scientists bring to the world simply cannot be described more appropriately.

Imperial College London researcher led by Dr. Andrew Edwards showed in a study published in Nature Microbiology yesterday how MRSA cells can escape the effects of one of the most potent reserve antibiotics: daptomycin .

This antibiotic is used when hardly any other active substances have an effect on skin and soft tissue infections. Resistance can also occur in 20% of cases, which is an immense problem for a pathogen that is becoming resistant to more and more antibiotics. The daptomycin binds to the cell membrane (more precisely to the phospholipid double layer inside the membrane) of the MRSA cells, accumulates there and forms pores, so that important ions emerge from the cell and the cell is thus damaged. In order to escape this fate, the cells do something that pilots of an F22 Raptor (the fighter aircraft shown above) would also do with an approaching rocket (analogous to daptomycin): they release so-called “flares”, which are decoys that die Then deflect missiles. Membrane phospholipids are then secreted as decoys, which do exactly the same thing: intercept the daptomycin, since both have a fat-like structure and thus avoid death. There are dozens of other so-called immune evasion mechanisms, but they all have one thing in common: they are just awesome!

Image sources:

Left: F22 raptor
Right: MRSA cell that secretes membrane phospholipids

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