Thursday, May 20, 2010

S. epidermidis vs. S. aureus: Who's the winner?

Wow! There's a very exciting paper in this week's Nature. Investigators in Japan have found that some strains of Staph epidermidis secrete a protease that destroys S. aureus biofilm, including those biofilms produced by MRSA and VISA strains. They used multivariate analysis to demonstrate that persons naturally colonized with the protease producing S. epi strain were protected against S. aureus nasal colonization. But they took it a step further and showed that when this S. epi strain was inoculated into the nose of S. aureus carriers it eliminated colonization, whereas a mutant that lacked the protease gene did not. The implications of this work are potentially huge. We've always thought of S. epi as the wimpy cousin of the big, bad S. aureus. Now the story seems to be changing. Who'da thunk it?


  1. There is so much we don't know and it is very exciting when we get a piece of the puzzle like this. The immune system and its interaction with commensals (which both of these organisms are) is relatively unexplored. Why are some people colonized with aureus and some not? Could this be the missing piece? Very cool.

  2. Mike, thanks for posting this. Eli comments on the interaction of of the host with commensals, but Im fascinated by the microbe-microbe interaction, and how certain strains develop capacity to compete with other organisms that allow them to thrive in a niche... not unlike animals... or humans!