title: Mouse relapse model of Clostridium difficile infection.
abstract: Clostridium difficile is the causative agent of primary and recurrent antibiotic-associated diarrhea and colitis in hospitalized patients. The disease is caused mainly by two exotoxins, TcdA and TcdB, produced by the bacteria. Recurrent C. difficile infection (CDI) constitutes one of the most significant clinical issues of this disease, occurs in more than 20% of patients after the first episode, and may be increasing in frequency. However, there is no well-established animal model of CDI relapse currently available for studying disease pathogenesis, prevention, and therapy. Here we report the establishment of a conventional mouse model of recurrence/relapse CDI. We found that the primary episode of CDI induced little or no protective antibody response against C. difficile toxins and mice continued shedding C. difficile spores. Antibiotic treatment of surviving mice induced a second episode of diarrhea, while a simultaneous reexposure of animals to C. difficile bacteria or spores elicited a full spectrum of CDI similar to that of the primary infection. Moreover, mice treated with immunosuppressive agents were prone to more severe and fulminant recurrent disease. Finally, utilizing this model, we demonstrated that vancomycin only delayed disease recurrence, whereas neutralizing polysera against both TcdA and TcdB completely protected mice against CDI relapse. In conclusion, we have established a mouse relapse CDI model that allows for future investigations of the role of the host immune response in the disease's pathogenesis and permits critical testing of new therapeutics targeting recurrent disease.
authors.affiliation: Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
authors.forename: Xingmin
authors.initials: X
authors.lastname: Sun
authors.forename: Haiying
authors.initials: H
authors.lastname: Wang
authors.forename: Yongrong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kevin
authors.initials: K
authors.lastname: Chen
authors.forename: Barbara
authors.initials: B
authors.lastname: Davis
authors.forename: Hanping
authors.initials: H
authors.lastname: Feng
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D057134:Antibodies, Neutralizing / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000276:immunology; D001427:Bacterial Toxins / Q000276:immunology; D016360:Clostridioides difficile / Q000276:immunology / Q000472:pathogenicity; D003015:Clostridium Infections / Q000188:drug therapy / Q000473:pathology / Q000517:prevention & control; D004195:Disease Models, Animal; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy / Q000473:pathology / Q000517:prevention & control; D004768:Enterotoxins / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D055502:Secondary Prevention; D014640:Vancomycin / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D057134:Antibodies, Neutralizing; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D014640:Vancomycin