Professor, National Cheng Kung University Hospital, Taiwan. Prof. Wen-Chien Ko, graduated from the Department of Medicine of Kaohsiung Medical University, Taiwan, and received resident and infectious disease fellowship training in Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan. He has been an infectious diseases specialist for more than 20 years, and the director of Division of Infectious Diseases in National Cheng Kung University Hospital for more than 15 years. His major interest in clinical research included Aeromonas infection, antimicrobial resistance, and antimicrobial therapy. Recently, he focused on the epidemiology and pathogenesis of Clostridium difficile infection in Taiwan.