Plug-n-play in Staph adaptation

By comparing Staphylococcus aureus strains, British researchers this week highlighted the important role played by easily exchanged, mobile genetic elements in the organism's global success and in the havoc they sometimes wreak in hospitals.

Matthew Holden, at the Wellcome Trust Sanger Institute in Cambridge, and colleagues compared two pathogenic S. aureus strains: a recent hospital-acquired representative of the epidemic methicillin-resistant S. aureus EMRSA-16 clone (MRSA252), and an isolate of an invasive community-acquired methicillin-susceptible S. aureus clone (MSSA476). The authors sequenced the isolates and compared them with published S. aureus genome sequences.

A pool of virulence and antibiotic resistance genes in the form of large mobile "accessory elements" is available for transfer between strains, Holden and colleagues report in the PNAS Early Online Edition.

No single strain has all these elements, but the ease of exchange is probably why the organism is so globally successful, according to Mark Enright, a coauthor ...