RT Journal Article SR Electronic T1 C. difficile strain 20 times more virulent JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1279 OP 1279 DO 10.1503/cmaj.050470 VO 172 IS 10 A1 Eggertson, Laura YR 2005 UL http://www.cmaj.ca/content/172/10/1279.1.abstract