September 7, 2010

Gene Discovery Could Explain Why Some Get MRSA

(Ivanhoe Newswire) -- Two genes discovered in mice may help identify why some people are more likely to develop potentially deadly staph infections.

"If you know, up front, that a patient is at risk for developing a Staphylococcus aureus infection, then you will be better able to manage them clinically, give them preventive measures and treat them more aggressively if they become ill," Vance Fowler, M.D., MHS, an associate professor of infectious diseases in the Duke Department of Medicine, was quoted as saying. MRSA is a severe form of the infection.

Duke researchers discovered the two highly-promising susceptibility genes. Fowler said it's possible the genes they uncovered could play a role in other types of bacterial infections.

The scientists observed that two strains of lab mice had different courses of Staphylococcus aureus infection -- one that was susceptible to severe infections (A/J) and one that was resistant and had much milder infections (C57). Those two strains were further modified, so the more resistant C57 mice were bred to contain both versions of one chromosome from the A/J strain.

"This lucky break allowed us to narrow our search for genes governing susceptibility to S. aureus from 21 chromosomes to just three," Fowler said. "We finally narrowed the search to two genes on chromosome 18 and were able to show that each of these genes appears to influence the immune response to S. aureus."

Fowler said that genetic information could ultimately help to identify human populations that are susceptible to staph infections. "We're testing the importance of these candidate mouse genes in DNA from human patients with S. aureus infections that we have collected over the past 10 years," he said.

SOURCE: PLos Pathogens; September 2, 2010