Superbug Invades Homes

Commonly spread by skin-to-skin contact or through sharing supplies such as towels or razors, and capable of causing pneumonia and bloodstream infections, methicillin-resistant Staphylococcus aureus (MRSA) is not only a problem in hospitals and nursing homes, but is now invading private homes.  Anne-Catrin Uhlemann, from Columbia University Medical Center (New York, USA), and colleagues analyzed the genetic makeup of MRSA samples collected from 161 New York City residents who contracted MRSA infections between 2009 and 2011, comparing against samples from a same-aged group who had not fallen ill to see if they harbored any kind of S. aureus bacteria. The researchers also tested other members of each patient’s household and their social contacts, and took samples from household surfaces to hunt for S. aureus contamination.  The team found evidence that people’s homes were “major reservoirs” of a MRSA strain called USA300—which is the chief cause of community MRSA infections across the United States.  Further, bacteria taken from people living in the same home, were genetically very similar, while there was more genetic variability between samples from different households.  Observing that their “analysis of [S. aureus sequence type 8] has documented the genomic changes associated with USA300 evolution and how some of its recent evolution has been shaped by antibiotic use,” the study authors warn of a “spread of USA300 and other emerging pathogens in large urban community populations.”