title: Application of immunoproteomics in developing a Streptococcus iniae vaccine for olive flounder (Paralichthys olivaceus).
abstract: Streptococcus iniae is the major etiological agent of streptococcosis, which is responsible for hemorrhagic septicemia in fish, particularly olive flounder (Paralichthys olivaceus). In the present study, we sought to understand the pathogenicity and immunogenicity of S. iniae in order to develop a vaccine for streptococcosis. Immunoproteomics, a technique involving two-dimensional gel electrophoresis (2-DE) followed by immunoblotting, was employed to investigate the pathogenicity and immunogenicity of two S. iniae isolates, Jeju-13 and Jeju-45, in olive flounder. The virulence of Jeju-13 was moderate whereas that of Jeju-45 was high. A vaccination trial with formalin-killed Jeju-45 demonstrated relatively low protection against the homologous isolate compared with the heterologous isolate. A significant difference in the secretion of extracellular products (ECPs) was noticed between the two S. iniae isolates. ECP antigens were highly immunogenic compared to those from whole cell lysates as determined by 2-DE immunoblot assay of Jeju-13 and Jeju-45 anti-sera collected from post-challenge survival fish. Furthermore, there were differences in the appearance of antigenic spots on 2-DE immunoblot profiles of ECPs of the respective sera. Interestingly, the mixture of killed-cells and concentrated ECPs from Jeju-45 led to significant protection against the homologous isolate of S. iniae in olive flounder. The present study demonstrates the usefulness of immunoproteomics in understanding the pathogenicity of S. iniae to aid the development of a vaccine for fish streptococcosis.
authors.affiliation: Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Gee-Wook
authors.initials: GW
authors.lastname: Shin
authors.forename: K J
authors.initials: KJ
authors.lastname: Palaksha
authors.forename: Young-Rim
authors.initials: YR
authors.lastname: Kim
authors.forename: Sung-Won
authors.initials: SW
authors.lastname: Nho
authors.forename: Suk
authors.initials: S
authors.lastname: Kim
authors.forename: Gang-Joon
authors.initials: GJ
authors.lastname: Heo
authors.forename: Se-Chang
authors.initials: SC
authors.lastname: Park
authors.forename: Tae-Sung
authors.initials: TS
authors.lastname: Jung
mesh_terms: D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology; D005432:Flounder / Q000382:microbiology*; D015151:Immunoblotting; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D022541:Streptococcal Vaccines / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D013291:Streptococcus / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D022541:Streptococcal Vaccines