BOVINE IMMUNOGLOBULIN ACTIVITY TO CELL WALL ANTIGENS OF A GALACTOSE 4-EPIMERASE DEFICIENT RC MUTANT OF ESCHERICHIA COLI (STRAIN J5)

The basic principles of therapy in bacterial disease continue to be directed against the infecting organism and also the response of the host to bacterial products. Yet, gram-negative bacteremia, septicemia and the clinical manifestations of "endotoxic shock" remain difficult case management problems in veterinary medicine. The purpose of this thesis is to study a new concept in the field of immunotherapy directed towards mitigating the effects of endotoxic shock, thus reducing the severity of clinical signs and the mortality due to gram-negative disease in farm animals.;The production of antibody to gram-negative core antigen structures (anti-J5 antibody) was accomplished by active immunization with a boiled whole cell preparation. The bacterin was able to stimulate elevated anti-core antigen activity without adverse reactions (i.e. abscesses, anaphylactic shock).;A direct and indirect enzyme linked immunosorbent assay (ELISA) was developed to detect the immune response in the bovine to the whole cell E. coli J5. Increased IgM and IgG anti-J5 antibody activity could be produced; however, the use of an adjuvant enhanced this response significantly.;Endotoxic shock was induced in 5-8 week old calves by slow infusion of Salmonella typhimurium LPS over five hours. Clinical signs of endotoxic shock were less severe in the J5 immunized calves as compared to the nonimmunized controls. The results indicate a protective effect associated with IgG class antibodies directed at LPS core antigens of gram-negative bacteria during experimental endotoxic shock.;The study involved (1) investigating the concept of producing antibodies to the core antigen structures presented by a galactose 4-epimerase deficient Rc mutant of Escherichia coli J5; (2) developing an assay to detect core antigen (J5) specific serum immunoglobulin G, M in both the nonimmunized and actively immunized animal; (3) to detect any protective effects of the anti-J5 antibodies in a heterologous intravenous slow infusion challenge of Salmonella typhimurium lipopolysaccharide in the bovine.