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Streptococcosis on a red tilapia, Oreochromis sp., farm: a case study
Author(s) -
Hernández E,
Figueroa J,
Iregui C
Publication year - 2009
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/j.1365-2761.2008.00981.x
Subject(s) - histopathology , biology , broodstock , oreochromis , fish farming , veterinary medicine , tilapia , aquaculture , microbiology and biotechnology , fish <actinopterygii> , pathology , fishery , medicine
A commercial red tilapia farm was diagnosed with Streptococcus agalactiae infection using histopathology, microbiology and immunohistochemistry. One hundred fish were randomly taken from different weight/age groups including broodstock, market fish (larger than 150 g), on‐growing fish between 20 and 150 g, juveniles and larvae. Fish were clinically examined, anaesthetised and necropsied. Samples were taken from brain, liver, spleen, eyes and kidney for microbiology. All organs were processed for histopathology and an indirect immunoperoxidase test (IIP). Organs from wild fish and birds found in close proximity to the farm were also sampled for microbiology and IIP. The prevalence of lesions or infection found by IIP, histopathology and microbiology was 16%, 29% and 7% respectively. Clinical disease, lesions or infection were not seen in larvae or juveniles. By contrast, infection and disease were found in fish larger than 20 g, suggesting that the condition was linked to the intensive culture conditions of broodstock, on‐growing and market fish. S. agalactiae was not found in wild fish, or in birds, by microbiology and IIP.