Molecular characterization of Shewanella putrefaciens and isolation and morphological characterization of its lytic phage

The studies concerning bacteria isolated using traditional di- agnostic methods, which have been employed for many years for the detection of pathogens in aquaculture, were restrict- ed to 15-20 bacterial species until the 1990s. Conversely, the number of bacteria identified has reached 70 through the util- isation of 16S rDNA sequencing, which has been identified as the gold standard for identification in recent years. Shewanella putrefaciens is a pathogenic bacterium that has been isolated from both marine and freshwater fish. The number of reports concerning Shewanella putrefaciens has increased markedly with the application of this method, and it has been identi- fied as an opportunistic pathogen in aquaculture. In this study, Shewanella putrefaciens bacteria were isolated from rainbow trout (Oncorhynchus mykiss) in cages in Karkamış Dam Lake and identified through the use of 16S rDNA sequencing. Furthermore, the lytic phages of this bacterium were isolated from the same dam lake and visualized by field emission elec- tron microscopy. It was determined that the phages obtained exhibited an icosahedral head structure, lacked a tail, and were approximately 50-60 nm in length. One of the primary factors influencing the efficacy of phage therapy studies is the prev- alence of opportunistic pathogens. This study demonstrated that the lytic phages of the opportunistic pathogen Shewanella putrefaciens, which has been increasingly reported in recent years, may have the potential to be utilized in phage therapy models.