title: Isolation and characterization of Streptococcus sp. from diseased flounder (Paralichthys olivaceus) in Jeju Island.
abstract: Streptococcus sp. is gram-positive coccus that causes streptococcal infections in fish due to intensification of aquaculture and caused significant economic losses in fish farm industry. A streptococcal infection occurred from cultured diseased olive flounder (Paralichthys olivaceus) in May, 2005 at a fish farm in Jeju Island, Korea. The diseased flounder exhibited bilateral exophthalmic eyes and rotten gills; water temperature was 16-18 degrees C when samples were collected. Of the 22 fish samples collected, 3 samples were identified as Lactococcus garvieae and 18 samples were identified as Streptococcus parauberis by culture-based, biochemical test. Serological methods such as slide agglutination, hemolysis and antimicrobial susceptibility test were also used as well as multiplex PCR-based method to simultaneously detect and confirm the pathogens involved in the infection. S. parauberis and L. garvieae have a target region of 700 and 1100 bp., respectively. One fish sample was not identified because of the difference in the different biochemical and serological tests and was negative in PCR assay. In the present study, it showed that S. parauberis was the dominant species that caused streptococcosis in the cultured diseased flounder.
authors.affiliation: Department of Oceanography, Pukyong National University, Busan 608-737, Korea.
authors.forename: Gun Wook
authors.initials: GW
authors.lastname: Baeck
authors.forename: Ji Hyung
authors.initials: JH
authors.lastname: Kim
authors.forename: Dennis Kaw
authors.initials: DK
authors.lastname: Gomez
authors.forename: Se Chang
authors.initials: SC
authors.lastname: Park
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D017756:Aquaculture; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000382:microbiology*; D005432:Flounder; D006461:Hemolysis; D007723:Korea; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial