The aim of the study was the phenotypic and molecular characterization of Yersinia (Y.) ruckeri strains, the causative agent of Enteric Redmouth Disease (ERM), by antibiotyping, random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of whole cell proteins. For this aim, a total of 97 Y. ruckeri
isolates were analyzed. The isolates were distinguished into ten antibiotypes and six phenotypes according to their resistance properties and whole cell protein profiles, respectively. Also, a glycoprotein band of approximately 25.5 kDa was observed in all Y. ruckeri strains tested. In all strains, six different RAPD types were
observed. In conclusion, Y. ruckeri isolated from rainbow trout of fish farms in Turkey showed variation according to their phenotypic and genotypic characteristics, and the use of these three typing techniques in double and triple combinations could be more useful for discriminating the strains.