A Trial in DNA Vaccine and Bacterial Stress Responses in zebrafish

The results of this study demonstrate that zebrafish can be infected through the three routes of infection including immersion immersion following abrasion and injection. So abrasion and injection is not required to infect zebrafish with E. tarda . At 45 days p.v. Vaccination with plasmid DNA vaccine encoding et46 antigenic gene et46 appeared to be weakly protective. The results showed that the accumulated mortalities of pet46 vaccinated fish were 80% 60% and 30% upon challenging with 3.2x108 107 or 106 CFU/mL of E. tarda respectively. Hence compared to vaccine construct-vaccinated fish pet46-vaccinated fish were significantly protected with a RPS of 40%. The results showed that the accumulated mortality of pet46-vaccinated fish (24%) was significantly lower than that vaccine construct-vaccinated fish (80 60 and 30% compared to100 80 and 60% respectively). The RPS of pet46-vaccinated fish was 20 40 and 25% compared to vaccine construct-vaccinated fish. Therefore compared to vaccination with vaccine construct vaccination with pet46 produced a RPS of 40% which is significantly higher than that produced by vaccine construct.