Study of staph shows how bacteria evolve resistance

Antibacterial resistance doesn’t happen overnight. But until recently nobody knew exactly how long it took — or how it happened at all. Now, by studying blood taken from a single patient over a period of months, Rockefeller University researchers have been able to trace how a common strain of bacteria adapted its genes to counteract the antibiotics used to try to kill it, until it finally emerged into the kind of fully resistant microbe that is wreaking havoc in hospitals worldwide. Total elapsed time: 90 days.