title: Equine hyperimmune serum protects mice against Clostridium difficile spore challenge.
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.
authors.affiliation: Animal Health Diagnostic Center, Departments of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Yan
authors.forename: Kang-Soon
authors.initials: KS
authors.lastname: Shin
authors.forename: Shih-Jon
authors.initials: SJ
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Xiang
authors.forename: Thomas
authors.initials: T
authors.lastname: Divers
authors.forename: Sean
authors.initials: S
authors.lastname: McDonough
authors.forename: James
authors.initials: J
authors.lastname: Bowman
authors.forename: Anne
authors.initials: A
authors.lastname: Rowlands
authors.forename: Bruce
authors.initials: B
authors.lastname: Akey
authors.forename: Hussni
authors.initials: H
authors.lastname: Mohamed
authors.forename: Yung-Fu
authors.initials: YF
authors.lastname: Chang
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology* / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000276:immunology / Q000627:therapeutic use; D001427:Bacterial Toxins / Q000276:immunology / Q000627:therapeutic use; D016360:Clostridioides difficile / Q000276:immunology*; D003015:Clostridium Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D004768:Enterotoxins / Q000276:immunology / Q000627:therapeutic use; D005260:Female; D006734:Horse Diseases / Q000382:microbiology / Q000517:prevention & control*; D006736:Horses; D007106:Immune Sera / Q000276:immunology*; D007116:Immunization, Passive / Q000662:veterinary*; D051379:Mice; D008810:Mice, Inbred C57BL; D013171:Spores, Bacterial / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; D007106:Immune Sera; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile
keywords: Clostridium difficile; colitis; equine; immunotherapy