Red Mouth Disease in Rainbow Trout (Oncorhynchus mykiss) - a Case Report on Lake Trout Farm from Bicaz, Romania

摘要

Yersiniosis or red mouth disease is a contagious infectious disease of salmonidscaused by the bacterium Yersinia ruckeri, which lead to significant economic losses in troutaquaculture worldwide. Sources of infection are the sick fish and asymptomatic carriers, whicheliminates yersiniosis faeces, causing contamination of water and feed.Triggers the disease was in March, the surge in water temperature values of 15-170 C. The fishaffected were the younger with low immune system, the sudden departure of the winter period.Histological examinations, immunohistochemical and bacteriological made from liver, spleen, kidneyand blood of the trout heart yersiniosis suspects resulted in the identification of the species bacteriumYersinia ruckeri strain, confirming the suspected diagnosis based on clinical investigations(pronounced anemia of mouth and gills mucosa, dark color of skin, bleeding on the lingual mucosa,protruding eye bleeding).Bacteriological confirmation was done by identifying the causative agent, based onmorphological characters (gram negative bacilli, mobile) and the distinctive biochemical characterstested using the API rapid tests.Histological examinations revealed colonies of bacteria in liver, spleen and kidneys wereconfirmed to be colonies of Yersinia ruckeri by immunohistochemistry with anti-Yersinia ruckeri.Antibiogram revealed sensitivity of Yersinia ruckeri at: Oxytetracycline, Flumequin,Trimethoprim and Ceftiofur, and moderate susceptibility to Amoxicillin and Enrofloxacin.