Immunogenicity of a recombinant Lactobacillus casei, surface-expressed H151P mutant of Clostridium perfringens epsilon toxin and its protective responses in BALB/c mice.

Abstract Epsilon toxin (Etx) is the most important virulence factor of type D C. perfringens in ruminants. The recombinant vaccines can be used against Etx intoxication. This study aimed to investigate the humoral immune responses of mice against a recombinant Lactobacillus casei which surface-expressed H151P mutant of Etx (L. casei-e) after oral and parenteral immunization routes. The protective immunity was determined by challenge with trypsin-activated Etx. Higher humoral immune responses were seen in parenterally vaccinated mice with Freund's-adjuvanted L. casei-e than non-adjuvanted and negative controls (P