MRSA: scientists discover a genetic mutation that protects against infection

A particular genetic mutation of hereditary origin seems to protect certain people from antibiotic-resistant staphylococcus infections, including that caused by methicillin-resistant Staphylococcus aureus (MRSA). This is the discovery made by a group of researchers at the Duke University Medical Center.

There is now an urgent need to find new methods to combat staphylococcal infections as these bacteria are proving increasingly resistant to antibiotics. “This study provides strong evidence of a genetic variant that appears to help people with MRSA resolve bloodstream infections,” reports Vance Fowler, professor at Duke and senior author of the study.

The researchers analyzed 68 patients divided into two groups of related people regarding age, gender, health status and other risk factors. Half of the people tested had had persistent MRSA infection while the other half had been able to eliminate the infection.

By performing the entire sequencing of the exome of all patients, the researchers identified a particular genetic variation that was evident in 62% of the patients who had eliminated the infection against only 9% of those patients in whom the infection had developed.

The genetic mutation, located in chromosome 2p, seems to affect an immune component called IL-10, an anti-inflammatory cytokine. Too large a presence of this component was associated with increased tissue damage during MRSA infection.

Researchers also performed experiments on animal models inhibiting this regulatory gene and this led to increased susceptibility to staphylococcal infection.