title: Phenotypic characteristics of Streptococcus iniae and Streptococcus parauberis isolated from olive flounder (Paralichthys olivaceus).
abstract: The etiological agents of streptococcosis were isolated from diseased olive flounder collected on the Jeju island of Korea. A total of 151 bacterial isolates were collected between 2003 and 2006. The isolates were examined using various phenotypic and proteomic analyses, including sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting, and glycoprotein assays. In addition, isolates were grown on blood agar to assess hemolytic activity, and biochemical assays were performed using the API20 Strep kit. Our results revealed that all isolates were nonmotile, Gram-positive cocci that displayed negative catalase and oxidase activities. Multiplex PCR assays revealed that 43% and 57% of the isolates were Streptococcus iniae and Streptococcus parauberis, respectively. These results were consistent with those of the SDS-PAGE and immunoblot analyses using whole-cell lysates of bacterial isolates. Significant differences were observed with respect to the Voges-Proskauer, pyrrodonyl arylamidase, alkaline phosphatase, and hemolytic activities of the S. iniae and S. parauberis isolates. Isolates of S. iniae displayed uniform profiles in the immunoblot and glycoprotein assays; however, immunoblot assays of S. parauberis isolates (using a chicken IgY antibody raised against a homologous isolate) revealed three distinct antigenic profiles. Our findings suggest that S. parauberis and S. iniae are endemic pathogens responsible for the development of streptococcosis in olive flounder.
authors.affiliation: Laboratory of Aquatic Animal Diseases, Research Institute of Life Science, College of Veterinary medicine, Gyeongsang National University, Jinju, Gyeongnam, Korea.
authors.forename: Seong-Won
authors.initials: SW
authors.lastname: Nho
authors.forename: Gee-Wook
authors.initials: GW
authors.lastname: Shin
authors.forename: Seong-Bin
authors.initials: SB
authors.lastname: Park
authors.forename: Ho-Bin
authors.initials: HB
authors.lastname: Jang
authors.forename: In-Seok
authors.initials: IS
authors.lastname: Cha
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Ha
authors.forename: Young-Rim
authors.initials: YR
authors.lastname: Kim
authors.forename: Yon-Kyoung
authors.initials: YK
authors.lastname: Park
authors.forename: Rishikesh S
authors.initials: RS
authors.lastname: Dalvi
authors.forename: Bong-Jo
authors.initials: BJ
authors.lastname: Kang
authors.forename: Seong-Joon
authors.initials: SJ
authors.lastname: Joh
authors.forename: Tae-Sung
authors.initials: TS
authors.lastname: Jung
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005393:Fish Diseases / Q000382:microbiology*; D005432:Flounder / Q000382:microbiology*; D015151:Immunoblotting; D007723:Korea; D010641:Phenotype; D016133:Polymerase Chain Reaction; D040901:Proteomics; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial