MRSA bacteria can linger in homes for years

Once the MRSA bacteria enters a home, it can linger for years, spreading from person to person and evolving genetically to become unique to that household, new research reveals.

The methicillin-resistant Staphylococcus aureus (MRSA) are strains of the bacterium Staphylococcus aureus that are resistant to almost all antibiotics related to penicillin.

Since the 1990s, MRSA infections, mostly skin infections, have been seen in healthy people in the US.

The predominant community-associated strain of MRSA, called USA300, is virulent and easily transmissible.

The team found that USA300 MRSA strain within households were more similar to each other than those from different households.

It can hang out there for years, ping-ponging around from person to person. Our findings strongly suggest that unique USA300 MRSA strain is transmitted within households that contain an individual with a skin infection, said senior study author Michael Z. David, assistant professor of medicine at the University of Chicago.

For the study, researchers used a laboratory technique called whole genome sequencing on 146 USA300 MRSA samples collected during a previous study from 21 households in Chicago and Los Angeles.

"The study adds to the knowledge base of how USA300 MRSA has spread throughout the country," added study co-author Timothy D. Read from Emory University's School of Medicine in Atlanta.

Decolonisation of household members may be a critical component of prevention programmes to control USA300 MRSA spread," the authors said.

The study was published in the journal mBio.