MRSA Notes

To infect, bacteria must first stick. Several proteins on their cell
wall surface are there simply to attach themselves to the surrounding
tissues of their hosts, such as the warm, moist, inviting ones at the
back of your throat.

Now new research from Sung Lee and Vincent Fischetti in
Rockefeller’s Fischetti Lab has identified an enzyme essential to
these proteins’ stickiness, and the scientists say their
discovery could lead to drugs that prevent some of our most dangerous
bacteria from gaining a foothold.

In addition to a cell membrane, bacteria also have a cell wall made up
of peptides linked to sugars, called peptidoglycans. Numerous proteins
are attached on the outside of the cell wall, and the one thing most
have in common is that when they are first made, the proteins have the
same five amino acids at the attachment end, termed LPXTG. To attach
the proteins to the cell wall, an enzyme, named sortase, cuts in this
sequence, hooking the rest of the protein into the cell wall.

“Cell surface proteins are indispensable for disease-causing
bacteria trying to establish successful colonization and infection of
host tissue,” says Fischetti, who made the discovery along with
Sung Lee, a senior research associate, by studying Staphylococcus aureus,
the bacteria that is responsible for many hospital infections and is
rapidly becoming resistant to existing antibiotics. “The surface
proteins play a part not only in adhesion to host cells and invasion,
but in the bacteria’s ability to evade the immune system.”

Read the rest at The Rockefeller University Newswire

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