Determination of Phenotypic, Serotypic and Genetic Diversity and Antibiotyping of Yersinia ruckeri Isolated from Rainbow Trout

Abstract

In this study, 15 Yersinia ruckeri isolates that had been isolated from rainbow trout farms and 2 reference strains (serotype 1 and serotype 2) were examined in terms of phenotypic, serotypic and genotypic characteristics. Conventional microbiological and API 20 E tests were used to determine phenotypic characteristics of Y. ruckeri isolates and it was determined that the Y. ruckeri showed significantly homogenous profile by microagglutination test performed by using serotype 1 and serotype 2 immunsera, and 11 of 15 isolates were serotyped as serogroup 1 while the rest 4 were serotyped as serogroup 2. In Random Amplified Polymorphic DNA (RAPD) analysis, Y. ruckeri isolates were genotyped within 2 separate clusters according to 70% similarity coefficient index and it was detected that first cluster includes 2 genotypes (YR1 and YR2) and second cluster includes 3 genotypes (YR3, YR4 and YR5). Furthermore, antibiotic resistance profiles of Y. ruckeri strains were determined and it was found that they were resistance to florfenicol, erythromycin, oxytetracycline and trimethoprim-sulphamethoxazole which have been licensed for fish health in Turkey. It is considered that findings obtained will form a basis to develop diagnosis kit and/or vaccination for Y. ruckeri.