Identification of Phenotypic and Genotypic Characteristics Diversity of Isolated Flavobacterium psychrophilum in Rainbow Trout Farms in Mediterranean Region

In this study, it was aimed to investigate the phenotypic and genotypic characteristics with presence of Flavobacterium psychrophilum in fourteen rainbow trout farms in Mediterranean Region. For this purpose, sperm, eyed egg, egg, yolk-sac larvae and 0,2-5 g fry were sampled from commercial trout farms between November 2012- March 2013. Isolation of potential F.psychrophilum from samples was made using conventional microbiological methods and a total of 172 obtained strains. Enzyme activity of all isolates was identified according to the API ZYM test system. As a result of the phenotypic tests, 65 isolates thought to be F. psychrophilum were identified. PCR assay was used in molecular confirming of these strains. It was determined that, 17 strains isolated from diseased fish (11 of them liver, 3 of them spleen, 3 of them kidney) gave specific 971 bp band which was specific to F.psychrophilum. RAPD-PCR assay was used to identify the clonal relationship between strains. F. psychrophilum isolates were yielded five different RAPD band patterns (F1-F5) according to this method. This strains detected to be grouped into 1 cluster and according to similarity coefficient %85 "unique" type (F1 the genotype). According to antibiotic sensitivity tests, isolates were found to be sensitive to trimetroprim/sulfamethoxazole, clindamycin, ampicillin, tetracycline, enrofloxacin, chloramphenicol, oxytetracycline, florfenicol and tobramycine. In conclusion, the findings from this study showed that the M13 primer used in RAPD-PCR can be used to determine the clonal relationship between F. psychrophilum isolate