The present invention relates to methods of preventing Clostridium difficile infection (COI) in a human subject who is at high risk of developing this infection, comprising administering to the subject an effective amount of the compounds described herein. In some embodiments, the subject is further receiving concomitant antibiotic therapy to prevent and/or treat an infection other than Clostridium. In some embodiments, the subject previously was treated for a Clostridium infection. In some embodiments, the compound of formula I prevents the Clostridium infection.
