It all started with a crab apple tree.
Two years ago, a 71-year-old Indiana man impaled his hand on a branch after cutting down a dead tree. The wound caused an infection that led scientists to discover a new bacterium and solve a mystery about how bacteria came to live inside insects.
On Oct. 15, 2010, Thomas Fritz, a retired inventor, engineer and volunteer firefighter, cut down a dead, 10-foot-tall crab apple tree outside his home near Evansville, Ind.