Cloning and expression of a surface immunogenic protein in Streptococcus dysgalactiae isolated from fish and its application in enzyme‐linked immunosorbent assays to diagnose S. dysgalactiae infections in fish. Issue 12 (17th October 2013)

• Record Type: Journal Article
• Authors: Nishiki, I; Minami, T; Itami, T; Yoshida, T
• Is Part Of: Journal of fish diseases. Volume 37:Issue 12(2014:Dec.)
• Page Start: 1031
• Page End: 1039
• Publication Date: 2013-10-17
• Subjects: Fishes -- Diseases -- Periodicals; 639.3
• DOI: 10.1111/jfd.12180
• Languages: English
• ISSNs: 0140-7775

Abstract

<abstract abstract-type="main" id="jfd12180-abs-0001"> <title>Abstract</title> <p>Lancefield group C <italic>Streptococcus dysgalactiae</italic> (GCSD) causes severe necrotic lesions in the caudal peduncle in the genus <italic>Seriola</italic> farmed in Japan. To develop a sero‐diagnostic method for GCSD infection in farmed fish, we attempted to identify a surface immunogenic protein that induces an antibody after infection with GCSD by immunoblot analysis using sera collected from infected fish. A protein obtained from sodium dodecyl sulfate (SDS) extracts of GCSD was identified as <italic>S. dysgalactiae</italic> surface immunogenic protein (Sd‐Sip). Sd‐Sip exhibited more than 94% homology with a surface antigen or a hypothetical protein from <italic>S. dysgalactiae</italic> mammalian isolates at the nucleotide sequence level. Expression of the recombinant Sd‐Sip (rSd‐Sip) was confirmed by immunoblot analysis, that is, its reactivity to GCSD‐infected sera. Antibody detection ELISA using rSd‐Sip and their usefulness for diagnosis of GCSD infection were examined. GCSD‐infected sera collected from farmed amberjack, <italic>Seriola dumerili</italic> (Risso), showed strong reaction with immobilized rSd‐Sip. Meanwhile, sera immunized by other pathogenic bacteria of fish were showed ELISA values similar to those of non‐infected sera. These results of this study suggest that the antibody detection ELISA using rSd‐Sip is an effective diagnostic method for GCSD infection in fish.</p> </abstract>