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Immunosuppression in rainbow trout, Salmo gairdneri Richardson, caused by the haemoflagellate Cryptobia salmositica Katz, 1951
Author(s) -
JONES S. R. M.,
WOO P. T. K.,
STEVENSON R. M. W.
Publication year - 1986
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.1365-2761.1986.tb01036.x
Subject(s) - yersinia ruckeri , salmo , biology , rainbow trout , immunosuppression , pathogen , microbiology and biotechnology , virology , fish <actinopterygii> , immunology , fishery
. An experimental Cryptobia salmositica infection in rainbow trout, Salmo gairdneri Richardson, produced suppression of the humoral response against sheep red blood cells as measured by direct haemagglutination. Two‐month and 5‐month infections produced equal suppression. The parasite also produced suppression of the humoral response against a bacterial pathogen, Yersinia ruckeri . Anti‐ Y. ritckeri titres were significantly lower in most fish infected with C. salmositica than in non‐infected fish. Immunosuppression became evident when C. salmositica first appeared in the blood (first 2 weeks of infection), Immunosuppression was confirmed by challenge with Y. ruckeri . Mortality at challenge occurred in 64·3% to 83·3% of the fish already infected with C. salmositica at the time of initial Y. ruckeri exposure. There was no mortality at challenge if fish were not infected with C. salmositica at initial bacterial exposure, nor in those concurrently infected with both pathogens. Antigenic competition may have caused the immunosuppression.