Recovery of Hafnia alvei from diseased brown trout, Salmo trutta L., and healthy noble crayfish, Astacus astacus (L.), in Bulgaria.

Hafnia alvei was isolated in Bulgaria from healthy noble crayfish, Astacus astacus (L.), and then from farmed diseased brown trout, Salmo trutta L., with signs of haemorrhagic septicaemia. The isolates were identified initially with conventional phenotyping and commercial Merlin Micronaut and API 20E rapid identification systems, followed by sequencing of the 16S rRNA gene. Hafnia alvei Bt1, Bt2 and Aa4 were of low virulence to rainbow trout and brown trout, although cytotoxicity was demonstrated by Bt1 and Bt2, but not by Aa4.

[Protein studies of viral hemorrhagic septicemia in rainbow trout]. / Izsledvaniia vurkhu beltuchinite pri virusnata khemoragichna septitsemiia pri dugovi pusturvi.

Comparative investigations were carried out on the changes in the blood serum of normal and diseased rainbow trout with virus hemorrhagic septicaemia. Determined was the amount of the total protein and the protein fractions. The electrophoretic investigation of blood serum of rainbow trout revealed one dominating albumin fraction, 3 alfa-globulin fractions, 2 beta-globulin ones, and one gamma-globulin one. The following up of the protein fraction dynamic during the various seasons did not reveal any dependence on the temperature curve. Rainbow trout manifesting clinically virus hemorrhagic septicaemia showed lowering of the total protein amount and changes in the electrophoretic profile and the quantitative ratio of the protein fractions. There were a drop of the albumin percent and a rise of the beta- and gamma-globulin fractions. This led to a change in the coefficients alfa:beta (0.89) and albumin: globulin (0.14).