premise: A lethal bacteria which surfaces in people being treated with antibiotics is spreading in North America and has grown resistant to drugs, according to two studies published Friday in the New England Journal of Medicine.
  According to one of the studies, a new, virulent and resistant strain of the bacteria Clostridium difficile broke out in eight US hospital centers between 2000 and 2003.
  Provoked by antibiotics inside the intestines of hospital patients, the bacteria showed an ability to mutate and increase its resistance to drugs, the report said.
  Moreover, the bacteria, which infects the colon causing severe diarrhea and colitis, a severe inflammation of the intestine, has begun showing up in patients not taking antibiotics or visiting hospitals.
  Symptoms include watery, malodorous diarrhea and cramps.
  
  A second study of 1,703 patients in 12 hospitals in Quebec, Canada, demonstrated the lethality of the bacteria.
   What caused the lethal bacteria to grown resistant to drugs?
hypothesis: people being treated with antibiotics