RESEARCH PROJECTS

John F. Timoney, MVB, MRCVS, MS, PhD
jtimoney@uky.edu
(859) 257-4757 ext 81106

Streptococcal Diseases

Genomic sequences are being used to identify proteins produced by the virulent S. equi but not by the closely related S. zooepidemicus. Proteins with partial or complete amino acid sequences unique to S. equi are then characterized as to function including role in virulence, binding to host molecules including epithelial receptors and in generation of protective and diagnostic immune responses. The role of bacteriophage in formation of the clonal S. equi from S. zooepidemicus is being evaluated using recently determined genomic DNA sequence of P9 and other temperate bacteriophage of S. equi.

Leptospirosis

Genomic sequence of Leptospira interrogans is being used to identify proteins involved in the pathogenesis of recurrent uveitis (Moon Blindness) and in immune responses of pregnant mares and their fetuses. Regulation of expression of immunogenic proteins by environmental stimuli including temperature and nutrient level is also a focus of study. Information derived from these studies is being used in the development of novel tests for leptospira in clinical specimens and for assay of antibody.

Clostridial Enterotoxemia of Foals

Field trials of a Clostridium perfringens autogenous bacterin supplemented with recombinant ß2 toxin are being conducted to determine its protective efficacy for newborn foals following prepartum vaccination. Such a vaccine potentially could reduce the incidence of diarrhea caused by toxigenic Clostridium perfringens in foals in the first weeks of life.

Nasopharyngeal Mucosal Immune Response

The microscopic, histochemical, and ultrastructural features of the equine tonsillar complex are being studied to gain a better understanding of these tissues in attachment, penetration, survival and immune mediated disposal of Streptococcus equi. Methods of stimulating nasopharyngeal mucosal immune responses in the horse are being investigated including use of cholera toxin chimeras, attenuated Salmonella typhimurium and fusions of Se18.9, a mucosal binding protein of S. equi, as delivery vehicles.