Development of DNA Vaccines against Nocardia seriolae Infection in Fish

摘要

This study presents the development of DNA vaccines against nocardiosis, using the Antigen 85-like (Ag85L) gene in Nocardia seriolae. An expression plasmid encoding Ag85L (pAg85L(wt)) and codon-optimized Ag85L (pAg85L(opt)) was intramuscularly injected into amberjack Seriola dumerili. Survival rates of the pAg85L(wt), pAg85L(opt) vaccinated group and PBS-injected group as a negative control were 88%, 98% and 51%, respectively, at 40 days after the N. seriolae challenge. In addition, the N. seriolae bacterial count in the spleen was significantly lower in the pAg85L(wt) and pAg85L(opt) vaccinated fish than in the PBS-injected fish (P < 0.05). These results suggest that the DNA vaccines pAg85L(wt) and pAg85L(opt) conferred protective efficacy against N. seriolae infection in amberjack.