Scientists at the University of California, Irvine have discovered how the opportunistic bacterium *Enterococcus faecalis* defeats competing microbes in the gut. The findings, published in *Cell Host & Microbe*, could have important implications for the development of new treatments for infections caused by *E. faecalis* biofilms, in which microbial cells stick to surfaces and secrete a slimy matrix.

The researchers found that *E. faecalis* produces a molecule called gelatinase that breaks down the protective biofilm matrix of other bacteria. This allows *E. faecalis* to invade the biofilm and outcompete the other bacteria for nutrients.

"Our findings provide new insights into the mechanisms by which *E. faecalis* causes infections," said study leader Dr. Michael Glickman, professor of molecular biology and biochemistry at UCI. "This could lead to the development of new treatments that target the gelatinase molecule and prevent *E. faecalis* from forming biofilms."

*E. faecalis* is a Gram-positive bacterium that is found in the intestines of humans and other animals. It is usually harmless, but it can cause infections in people with weakened immune systems. *E. faecalis* infections are often difficult to treat because the bacterium is resistant to many antibiotics.

In this study, the researchers used a variety of techniques to investigate how *E. faecalis* produces and uses gelatinase. They found that the gelatinase is produced by a gene called *gelE*. The researchers also found that *E. faecalis* uses gelatinase to degrade the biofilm matrix of other bacteria, including *Pseudomonas aeruginosa* and *Staphylococcus aureus*.

"Our findings suggest that *E. faecalis* uses gelatinase to gain a competitive advantage over other bacteria in the gut," said Glickman. "This could have important implications for the development of new treatments for *E. faecalis* infections."