New Study Sheds Light on How Antibiotic Resistance Spreads

Researchers at Umeå University have made a breakthrough in understanding how antibiotic resistance spreads among bacteria. Their study focused on an enzyme called PrgK, which plays a crucial role in breaking down bacterial cell walls, facilitating the transfer of antibiotic resistance genes.

The research team investigated Enterococcus faecalis, a bacterium notorious for causing hospital infections and developing antibiotic resistance. They discovered that E. faecalis uses type 4 secretion systems (T4SS) to spread resistance genes to other bacteria. PrgK, an essential component of T4SS, functions like scissors, cutting into the bacterial cell wall.

Contrary to previous assumptions, the study revealed that only one of PrgK's three domains, SLT, is active in breaking down the cell wall. The other two domains, LytM and CHAP, play a regulatory role. Additionally, the researchers identified another T4SS protein, PrgL, which ensures PrgK is correctly positioned within the protein machinery.

"You could say that we are adding a piece of the puzzle to the understanding of how antibiotic resistance spreads between bacteria," says Ronnie Berntsson, co-author on the paper published in mBio.

The research employed a combination of biochemical analyses, functional studies, X-ray crystallography, and AlphaFold modeling to reach these conclusions.

Josy ter Beek, another co-authored, emphasized the importance of these findings: "The findings are important for continued research into how to prevent T4SS from transferring properties such as resistance to antibiotics to other bacteria."