The adjuvant effect of Corynebacterium ovis

Abstract

Corynebacterium ovis has a clear immunopotentiating effect when used as an adjuvant with several antigens including egg albumin, Salmonella typhimurium and foot and mouth disease virus, inoculated into guinea pigs. The optimal dose was found to be 400 mg of C. ovis mixed with antigen. However, a dose of 300 mg of C. ovis when mixed with incomplete Freund's adjuvant was enough to stimulate a sustained potent immune response which was superior to that obtained with the complete Freund's adjuvant. Immunopotentiation is a topic in immunology that is attracting increasing interest. In this field, oil adjuvants have proved their superiority and Freund et al. (10) have shown that the addition of some bacteria, such as mycobacte ria, to such oil adjuvants improves their immunopotentiating effect. Current studies carried out in our laboratory on crystal violet treated C. ovis have clearly shown its capacity as a non-specific immune stimulant, capable of raising the resistance of sheep to artificial infection with potential pathogens, in a manner comparable with that produced by BCG (5, 6). It was decided to test the formalin-killed C. ovis for its immunopotentiat ing ability when used as an adjuvant with inert antigens and killed microbial vaccines. MATERIALS AND METHODS Animals. Guinea pigs : 630 healthy albino adult guinea pigs, weighing approxim ately 400-500 grams, were used in this study. The animals were put in equal * Under-Secretary of State for Veterinary Affairs, Egypt.

Use of Inactivated Corynebacterium pseudotuberculosis as an Immunostimulant with Pneumobac Vaccine

“…The results in Table 4 indicated that the overall mean of antibody titer against M. haemolytica type A and P. trehalosi type T in the group of sheep vaccinated with a combined vaccine was significantly increased than the group of sheep vaccinated with Pneumobac ® (p < 0.05). The findings are in accordance with those of Barakat et al (1984) who showed that C. pseudotuberculosis ovis has an immune-stimulating impact when used as an adjuvant with various antigens, including egg albumin, Food and mouth viral disease, and Salmonella typhimurium. In addition, the above results are inconsistent with those obtained by Eggleton et al (1991) found that the protective efficacy of the vaccines was not improved by C. pseudotuberculosis ovis bacterin, but considered the toxin produced by C. pseudotuberculosis to be the main factor responsible for protection.…”

“…In Egypt, Marwah et al (2015) showed that the phospholipase D exotoxin of C. pseudotuberculosis was an effective nonspecific immune stimulant that could be used in combination with inactivated Newcastle and Mycoplasma vaccines to elicit an early, better, and longer immune response. Freund (1956) and Barakat et al (1984) explain the nonspecific ability of C. pseudotuberculosis ovis to raise the resistance of sheep to artificial infection with potential pathogens in a manner comparable with that produced by BCG, as the waxy material in the cell wall structure of C. pseudotuberculosis ovis appears to stimulate antibody production in the same way that Mycobacteria waxes do.…”

“…The waxy elements in the C. pseudotuberculosis structure stimulate antibody production in the same way as Mycobacterium waxes associated with Freund's complete adjuvant do. Freund's DOI: https://dx.doi.org/10.54203/scil.2022.wvj38 complete adjuvant can improve the antibody response to soluble protein antigens by stimulating the innate immune system (Barakat et al, 1984;Trott et al, 2008). Pneumobac ® is an inactivated oil adjuvant pasteurellosis vaccine that is the most effective used to control sheep pneumonic pasteurellosis (El-Kattan et al, 2019).…”