Immunisation of mares with binding domains of toxins A and B of Clostridium difficile elicits serum and colostral antibodies that block toxin binding. (4th December 2012)

• Record Type: Journal Article
• Authors: Artiushin, S.; Timoney, J. F.; Fettinger, M.; Fallon, L.; Rathgeber, R.
• Is Part Of: Equine veterinary journal. Volume 45:Number 4(2013:Jul.)
• Page Start: 476
• Page End: 480
• Publication Date: 2012-12-04
• Subjects: Horses -- Diseases -- Periodicals; 636.108905
• DOI: 10.1111/evj.12007
• Languages: English
• ISSNs: 0425-1644

Abstract

<abstract abstract-type="main"> <title>Summary</title> <sec id="evj12007-sec-0001" sec-type="section"> <title>Reasons for performing study</title> <p>Enterocolitis caused by <italic>Clostridium difficile</italic> (<italic>C. difficile</italic>) is a serious, sometimes fatal, disease of neonatal foals and older horses. Toxins A and B (TcdA and B) produced by <italic>C. difficile</italic> are important virulence factors. Immunisation of mares with receptor binding domains of toxins may prevent or reduce the severity of <italic>C. difficile</italic> colitis in foals.</p> </sec> <sec id="evj12007-sec-0002" sec-type="section"> <title>Objectives</title> <p>To determine whether antibodies generated in the pregnant mare to the binding regions of TcdA and B will neutralise TcdA and B toxicity.</p> </sec> <sec id="evj12007-sec-0003" sec-type="section"> <title>Methods</title> <p>Sequences encoding the binding domains of each toxin were isolated by PCR amplification from <italic>C. difficile</italic> JF09, a foal isolate, and cloned and expressed into pET15b. Thirteen mares were immunised twice 2 weeks apart with 200 μg of each recombinant protein with Quil A 2 months prior to foaling. Antibodies were assayed in the sera and colostrum by ELISA and for ability to block the cytopathic activity of each of toxin for equine endothelial cells.</p> </sec> <sec id="evj12007-sec-0004" sec-type="section"> <title>Results</title> <p>All mares produced strong serum antibody responses to the binding domain of each toxin. A high level of toxin‐specific antibodies was also detected in colostrum and in most foal sera 2 days after suckling. Diluted sera and colostrum premixed with either TcdA or B had no effect on the morphology of equine endothelial cells. Application of the same concentration of toxins alone or premixed with nonimmune mare/foal serum or colostrum led to an unambiguous cytopathic effect that ranged from complete degradation to varying degrees of cell rounding.</p> </sec> <sec id="evj12007-sec-0005" sec-type="section"> <title>Conclusions</title> <p>Immunisation of pregnant mares with recombinant binding domains of TcdA and B of <italic>C. difficile</italic> resulted in the production of specific antibodies in serum and colostrum that blocked the cytopathic activity of toxins.</p> </sec> <sec id="evj12007-sec-0006" sec-type="section"> <title>Potential relevance</title> <p>Results of studies support the feasibility of a prepartum vaccine against <italic>C. difficile</italic> enterocolitis in foals.</p> </sec> </abstract>