Identification and investigation of phenotypic and genotypic characteristics of Flavobacterium psychrophilum in fry rainbow trouts (Oncorhynchus mykiss Walbaum, 1792) in some trout farms

In this study, it was aimed to identify and investigate phenotypic and genotypic charecteristics of Flavobacterium psychrophilum in four rainbow trout farms in Keban district of Elazığ province. For this purpose, eggs, fertilized eggs, ovarian liquid, sperm, eyed eggs, larvae with egg sac, fry under 5 g, fry over 5 g, water and food samples were collected.For isolation of Flavobacterium psychrophilum; Cytophaga Agar (CA), Cytophaga Broth (CB), Modified Anacker and Ordal agar (MAOA), Modified Anacker and Ordal Broth (MAOB), Tryptone Yeast Extract Salt Agar (TYES-A), Tryptone Yeast Extract Salt Broth (TYES-B), Enriched Anacker and Ordal + Fetal Bovine Serum+ Agar (EAO+FBS+A), Enriched Anacker And Ordal + Fetal Bovine Serum + Broth (EAO+FBS+ B), Tryptone Yeast Salt Agar + Tobramycin (TYESA+ T) Tryptone Yeast Extract Fetal Bovine Serum (TYFBS) agars were used. These media were incubated for 5-7 days at 15 oC and phenotypic characteristics of colonies pure yellow colour were identified. Antibiogram sensitivity test was also applied according to disk diffusion method.A total of 4024 samples; 175 eggs, 205 fertilized eggs, 185 eggs washed with povidin/iodin solution, 185 ovarian liquid (2 ml), 200 sperm (2 ml), 240 eyed eggs, 510 larvae with egg sac, 400 fry under 5 g, 200 spleen of healthy fry over 5 g, 200 liver of healthy fry over 5 g, 200 kidney of healthy fr fry over 5 g, 200 intestine of healthy fry over 5 g, 200 spleen of newly dead and suspicious from disease fry over 5g, 200 liver of newly dead and suspicious from disease fry over 5 g, 200 kidney healthy of newly dead and suspicious from disease fry over 5 g, 200 intestine of newly dead fry over 5 g and suspicious from disease, 120 food and 204 water samples obtained from fish farms were examined as bacteriologically. From these samples; 160 (3.97 %) Flavobacterium psychrophilum were isolated. 18 (10.28 %), 13 (7.02 %), 6 (3.24 %), 14 (6.82 %), 14 (7.77 %), 13 (2.54 %) and 15 (3.75 %) of these strains was isolated in eggs, ovarium liquid, eggs washed with povidin/iodin solution, fertilized eggs, eyed eggs, larvae with egg sac, and fry under 5 g respectively. 8 (4 %), 5 (2.5 %), 4 (2 %) and 1 (0.5 %) of Flavobacterium psychrophilum were isolated from spleen, liver, kidney and intestine of heallty fry over 5 g respectively. Again 10 (5 %), 10 (5 %), 6 (3 %) and 6 (2.94 %) of Flavobacterium psychrophilum were isolated from spleen, liver, kidney and intestine of healthy fry over 5 g and suspicious from disease and water of fish farms respectively.Two different primers were used to confirm 160 Flavobacterium psychrophilum with PCR after determined according to the phenotype and genotype characteristics. Subsequently, these strains were confirmed as Flavobacterium psychrophilum with DNA.Gene typing was performed with PFGE technique on strains confirmed with PCR. As a result of this, it was decided that strains obtained from four different fish farms wasclose relative with reference Flavobacterium psychrophilum NCIMB 1947T.According to the results of antibiotic disc, Flavobacterium psychrophilum strains showed strength against antibiotics; (78.75 %) Amoxicillin, Amoxicillin / Clavulanic Acid, Amikacin, Ampicilin, Chloramphenicol, Cefazolin, Enoxacin, Optochin, Neomicin, Vankomisin, Cefoxitin, Nalidixic Acid, Aztreonam, Linkomicin and Trimetoprim (100 %); Penicillin and clindamycin (78.12 %); Ofloxacin and gentamicin; (55.62 %) Erythromycin and Sülphamethoxazole (15.62 %) Furazolidone. It was detremined that Flavobacterium psychrophilum was moderately sensitive to antibiotics; (28.12 %) Erythromycin and Sulphamethoxazole; (21.87 %) Imipenem; (21.25 %) Nitrofurantoin, Tobramicin and Netilmicin; (16.25 %) Ceftriaxone, Cefoperazone, Clarithromycin, Piperacillin, Bacitracin and Trimethoprim+Sülphamethoxazole; (12.50 %) Penicillin and Clindamycin. Again, Flavobacterium psychrophilum was found sensitive to antibiotics; (100 %) Oxytetracycline, Florfenikol, Enrofloxacin and Ciprofloxacin; (84.37 %) Furazolidone; % (83.75 %) Trimethoprim+Sülphamethoxazole, Ceftriaxone, Cefoperazone, Clarithromycin and Piperacillin; (78.75 %) Tobramycin, Nitrofurantoin and Netilmicin; (78.12 %) Imipenem; (77.5 %) Streptomisin; (21.25 %) Ofloksasin; (16.25 %) Eritromisin and Sulphamethoxazole; (9.37 %) Penisilin and Klindamisin.Consequently, F. psychrophilum was determined in four fish farms in Keban district of Elazığ province. While the identification period of F. psychrophilum with culture method was taken three weeks, it was performed in 24 hours. Sub-typing of F. psychrophilum with Pulsed Field Gel Electrophoresis technique was performed successfully. However, it was thought that to well understand infection and epidemiology of F. psychrophilum, detailed information will be obtained by using strains isolated from different region of Turkey.