Studies on Vaccine Development for Ovine Caseous Lymphadenitis

Abstract

Caseous lymphadenitis (CLA), which is a serious infectious disease of sheep and goats world-wide, has caused significant economic losses in Turkey in recent years. In this study, it was aimed to identify major antigens of Corynebacterium pseudotuberculosis strains isolated in Turkey and to evaluate the efficiency of the vaccine prepared from local strains of C. pseudotuberculosis against bacterial challenge in lambs. C. pseudotuberculosis strains were isolated from six different flocks in Turkey and were classified according to their similarities by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE revealed more than 21 bands ranging in size from 15 kDa to 194 kDa present in different concentrations in C. pseudotuberculosis isolates as determined by visual assessment of their approximate molecular masses. Lambs were vaccinated with a bacterin + toxoid + Freund's complete adjuvant (FCA) vaccine, and the vaccine efficiency against bacteriological challenge was evaluated. When a local C. pseudotuberculosis (PI 18) strain was used and formulated as per ml of the vaccine, 1.5x10(8) cfu of C. pseudotuberculosis bacterin + toxoid + 1/2 FCA of the toxoid, we obtained encouraging results regarding the potential of this vaccine to control of CLA in sheep.