Streptococcosis in Oreochromis sp.: is feed-based biofilm vaccine of Streptococcus agalactiae effective?
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Date
2019-04-03
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Publisher
Springer Nature
Abstract
This study was carried out to determine the potential of a biofilm vaccine of Streptococcus
agalactiae in protecting tilapia from streptococcocal infection. The tilapia were vaccinated
orally using the biofilm vaccine with 1091010 CFU/g (FBV) incorporated in feed and killed
whole-cell vaccine (FCV) of S. agalactiae also prepared in feed, and the unvaccinated control
group (Cx) was fed with standard feed formulation. Throughout the study, serum, mucus and
gut lavage fluid were collected to evaluate the antibody responses among the groups. The
results showed that tilapia vaccinated with FBV exhibited significantly (p < 0.05) stronger
immune response and high protection with the relative percentage survival (RPS) of more than
70% (85%) compared with the FCV group, which was only 56%. None of the tilapia in the Cx
group survived (0%) post-challenge. Thus, the study revealed that the feed-based biofilm
vaccine (FBV) significantly confers the immune protection against the high-dose challenge of
S. agalactiae by secretion of the protective immunity in the mucosal and humoral in tilapia.
Description
Keywords
Biofilm . Streptococcus agalactiae . Oreochromis sp. . Oral vaccination