Isolation of Yersinia ruckeri in Rainbow Trout Farms in Middle and East Black Sea Region and Determination of Antibiotic Susceptibility Profiles

The aims of this study were investigated existence of Yersinia ruckeri and antibiotic susceptibility profile and pathological disorders in the organs in Rainbow trout farms in Central and Eastern Black Sea regions. In the study, Y. ruckeri was isolated from 37 samples in examined 205 samples. Isolates have been found sensitive to against antibiotics; ciprofloxacin and enrofloxacin, at high degree (100%), oxolinic acid, streptomycine, amikacin, trimethoprim/sulphamethoxazole, piperacillin, mezlocillin, cefoperazone/sulbactam, sulphonamide and flumequin at medium degree (89,2% -7 8,4%), ampicillin, carbenicillin and amoxicillin/clavulanic acid at little degree (5,4% - 24,3%). At the end of the histopathological examination from rainbow trout infected with Yersinia ruckeri, the edematous changes in the gill, heart, liver, spleen and kidney, dilatation of blood vessels, petechial hemorrhages and congestion were detected. The necrotic foci were detected in the liver, kidney and spleen. In the liver severe leukocyte infiltrations, mononuclear cells accumulations in periportal area, the loss of hematopoietic tissue in the kidney and damage of normal lymphoid structure in the spleen were observed in acute cases. The severe capillary congestion in meninges and medulla of the brain were observed in fish which is in the acute phase of the disease.