Journal of Veterinary Science  2014;15(2):249-258

doi:10.4142/jvs.2014.15.2.249

Equine hyperimmune serum protects mice against Clostridium difficile spore challenge.

Weiwei YAN 1 ; Kang Soon SHIN ; Shih Jon WANG ; Hua XIANG ; Thomas DIVERS ; Sean MCDONOUGH ; James BOWMAN ; Anne ROWLANDS ; Bruce AKEY ; Hussni MOHAMED ; Yung Fu CHANG

Affiliations

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Keywords

Clostridium difficile; colitis; equine; immunotherapy

Country

Republic of Korea

Language

English

Abstract

Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 10(7) C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.