Gene discovery could provide relief for deadly staph infections

Up until now, most research on methicillin-resistant Staphylococcus aureus (MRSA) has focused on attributes like the amount of toxins or virulence factors that different strains make. A team of scientists at the University of North Carolina School of Medicine in Chapel Hill is taking a different approach.

The UNC researchers' attention is on the infection's sensitivity to polyamines--a novel target that could be key to developing new treatments against a particularly deadly strain of MRSA.

"Our work uncovers the molecular explanation for one strain's rapid and efficient spread to people outside of a crowded hospital setting," senior study author Anthony Richardson, assistant professor of microbiology and immunology at the UNC School of Medicine, said in a statement.

In the past 5 years, MRSA infections have been on the rise in places like hospitals, jails and schools where people come in close contact with one another. Staph infections account for a shocking 368,000 hospitalizations per year, according to government data, and their antibiotic-resistant nature makes them particularly difficult to treat, killing about 19,000 people annually.

Using a mouse model, researchers found a specific gene that causes one strain of the infection to stay on the skin longer than other strains, making it more contagious. This strain of MRSA--known as USA300--contains a chunk of genes that other staph strains don't have. In the past 10 years, USA300 has emerged outside of hospital walls as an extremely dangerous strain of MRSA because of its ability to progress rapidly and cause fatal disease like necrotizing pneumonia, severe sepsis and flesh-eating bacteria syndrome.  

The USA300 strain was the only strain out of hundreds tested that was not sensitive to polyamines, naturally occurring anti-inflammatory compounds that aid in wound repair by promoting tissue regeneration.

The study was published in the journal Host & Microbe.

- here's the study
- read UNC's news release