Seasonal distribution of (Oncorhynchus mykiss) bacterial diseases in Rainbow Trout cultured in Borçka Dam Lake

In this study, samples of rainbow trout with typical disease suspicion brought to our Faculty Diseases Laboratory in floating net cages in Borçka Dam Lake were examined. 44 pure bacterial isolates isolated from kidneys of diseased fish sampled monthly in four different seasons were used. Intensive fish stocking in aquaculture causes stress in fish due to deterioration of water quality. Increase and decrease in seasonal water temperature causes bacterial infections in rainbow trout due to heat stress of opportunistic pathogens. Intensive stocking in rainbow trout farms, low water quality (pH, ammonia, nitrite, etc.), negative effects on physical and chemical parameters of water as well as stress due to sudden water temperature changes, caused mass mortality of up to 70% and major economic losses due to bacterial fish pathogens such as Aeromonas hydrophila, Pseudomonas fluorescens, Yersinia ruckeri Lactococcus garvieae and Lactococcus petauri infections have been reported by different researchers. Bacterial disease agents in rainbow trout (Oncorhynchus mykiss) in Borçka Dam Lake were sampled seasonally. Bacterial isolates (44 bacteria were isolated) isolated from the cultures were stored at -80ºC. Identification of isolated disease agents was determined by PCR method and their antimicrobial susceptibilities to chemotherapeutic agents were determined in this thesis study. According to the test results, antimicrobial activity of all bacterial isolates against chemotherapeutic agents was determined by disk diffusion method on Müller Hinton Agar. According to the results of this thesis study, the highest resistance was detected in 86.36% erythromycin, 81.81% Ampicillin and 72.27% Amoxicillin. The lowest resistance was determined as 15.90% enrofloxacin and 6.82% doxycycline. The most effective of these chemotherapeutic agents were determined to be 86.36% doxycycline, 56.82% flamequine and 50% enrofloxacin, respectively.