WASHINGTON--(BUSINESS WIRE)--Dec. 18, 2005--Researchers at the 45th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) have presented new data today on the in vitro activity of several products and product candidates against strains of Clostridium difficile (C. difficile), including recently described epidemic strains that have shown increased virulence. The data are among the first to report the in vitro activity of these agents against the strains of C. difficile suspected of causing recent cases of severe C. difficile-associated disease (CDAD).