Some Diagnosis and Therapy Techniques in Rainbow Trout (Oncorhynchus Mykiss) Furunculosis, in Intensive System Bred

Abstract

Clinical and paraclinical investigations (morpho-pathologic, bacterioscopic, bacteriologic and sensitiveness test to antibodies) done on 20 fish (rainbow trout), dead or in agony state, taken from a furunculosis pesthole in Salmonidae and proceeded from an intensive exploitation unit of trout, in Cluj county, put in evidence the following aspects :To clinical exam, in breeding basins, it appears individuals (5 %) which have presented locomotor troubles, listless and untidy swimming in water surface, lateral swimming anorexia, and on tegument it is observed diffuse hemorrhagic zones, lost of fish scale and necrosis of fins. It appears also secondary infections with fungi of Saprolegnia genus under the form of a white- dirty, downy film. From the 20 trut corpses were isolated 2 bacterial strains, from anterior kidney and from raclage in fin basis, with congestive lesions. Bacteria isolated are developing only after an incubation at 20 – 25⁰ C and does not grow up to 37⁰ C, and to microscopic exam directly from sauce, the mobility is absent Classic biochemical tests put in evidence the following positive biochemic properties: cataloze, oxidaze, indolal and the presence of hemolytic activity. Biochemical properties testing on API20E gallery also puts in evidence properties as : positive gelatinousis and sucraze fermentation.               Based on bacterial strains development isolated only to 20 - 25 ⁰C and the above mentioned biochemic properties, respectively the absence of pigment, bacterial strains isolated are appointed  in Aeromonas genus, Aeromonas salmonicida species, achromogenes subspecies. By sensitiveness test in different medicine substances, using antibiogram technique, bacterial strains isolated from pesthole are sensitive in a decreasing order to: nalidixic acid, oxitetracycline, florfenicol and eurofloxacin and resistant to ampicyline, amoxiclav and colistin.