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Experimental L actococcus garvieae infection in rainbow trout, O ncorhynchus mykiss , W albaum 1792: a comparative histopathological and immunohistochemical study
Author(s) -
Avci H,
Birincioglu S S,
Tanrikul T T,
Epikmen E T,
Metin N,
Avsever M L
Publication year - 2014
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/jfd.12132
Subject(s) - biology , immunohistochemistry , microbiology and biotechnology , rainbow trout , polyclonal antibodies , andrology , antibody , fish <actinopterygii> , immunology , medicine , fishery
The aim of this study was to induce L actococcus garvieae infection in young and adult fish through different routes [intraperitoneal ( IP ) and immersion ( IM )] and to investigate the pathogenesis and histopathological and immunohistochemical findings comparatively. For this purpose, a total of 180 rainbow trout (90 young, 20 ± 5 g and 90 adult, 80 ± 10 g) obtained from a commercial fish farm were used. The fish were divided into eight groups, four experimental groups ( Y oung‐ A dult IP groups and Y oung‐ A dult IM groups, each contain 30 fish) and four control groups ( Y oung‐ A dult IP C ontrol groups and Y oung‐ A dult IM control groups, each contain 15 fishes). The experimental study was conducted using L . garvieae , and confirmatory identification was performed by PCR . The sequence result of the PCR amplicon of 16S rDNA from isolate L . garvieae LAC 1 was determined and deposited in the G en B ank database under accession number KC883976 . Fish in the IP groups were intraperitoneally administered an inoculate containing 10 6 cfu mL −1 bacteria 0.1 mL. In the IM groups, fish were kept in inoculated water containing 10 8 cfu mL −1 bacteria for 20 min. Mortality as well as clinical and pathological findings was recorded daily, and significant differences in macroscopic and microscopic results were observed between the IP and IM administration groups. All tissue samples were immunohistochemically stained by the avidin‐biotin‐peroxidase complex and immunofluorescence ( IF ) methods using polyclonal antibody to detect L . garvieae antigens. In immunoperoxidase staining in the IP groups, positive reactions to bacterial antigens were most commonly seen in the spleen, kidney, heart, liver, peritoneum and swim bladder. In the IM groups, bacterial antigens were most commonly found in the eye, gill, spleen and kidney. In the IF method, the distribution of antigens in tissue and organs was similar to the reactions with immunoperoxidase staining. Finally, in this experimental study, an important correlation was seen between the distribution of L . garvieae antigens and lesions developing in many organ and tissues.