Detection of Yersinia ruckeri in naturally infected rainbow trout (Oncorhynchus mykiss Walbaum, 1792) from trout farms in Anatolia, Turkey

Abstract

The present study aimed to detect Yersinia ruckeri bacteria in fish samples collected from the rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) farms in the South Eastern Anatolia Region of Turkey through bacteriological culturing and polymerase chain reaction. Separate visits were made to trout farming facilities in Diyarbakır, Adıyaman, Şanlıurfa, and Batman in January and February 2021, and 30 fish with an average live weight of 200–250 g were collected from each facility. A total of 1,200 samples were taken from 40 trout farms. Liver, spleen, kidney, and tissue specimens were collected from rainbow trout. Yersinia ruckeri was isolated from the kidney, liver and muscle tissue of fish on McConkey Agar for bacteriological examinations. Isolated strains were identified by MALDI–TOF and PCR. It was detected the bacteria in the liver, kidney, and muscle tissue samples of fish from 23 out of 40 farms. In conclusion, these bacteria were detected in local farms. These farms must implement vaccination, minimize stress factors affecting the fish, and avoid overstocking. The best methods to protect against infection include avoiding overstocking, low oxygen levels, and underqualified labor force.