Immunization with Bacillus Spores Expressing Toxin A Peptide Repeats Protects against Infection with Clostridium difficile Strains Producing Toxins A and B - Permpoonpattana,P; Hong,HA; Phetcharaburanin,J; Huang,J-M; Cook,J; Fairweather,NF; Cutting,SM (INFECTION AND IMMUNITY, 2011)