Isolation and Identification of Aeromonas hydrophila from Cyprinidae Suspected with Hemorrhagic Septicemia in Pools of Warm Water Fishes in Gilan Province

Bacterial diseases in aquaculture fishes are one of the most important risk factors in fish industry. Aeromonas hydrophila is the main causative agent of hemorrhagic septicemia in warm-water fishes, especially Cyprinidae that plays an important role in public health through consumption of contaminated fish meat that can cause gastroenteritis, traveler’s diarrhea, wound infection, pneumonia, and meningitis. Considering the importance of culturing Cyprinidae in Gilan province and the need to identify and detect the presence of A. hydrophila in Cyprinidae fishes suspected with hemorrhagic septicemia, this study aimed to isolate and identify A. hydrophila in Cyprinidae fishes suspected with hemorrhagic septicemia in Gilan province. In this Experimental study, during summer and autumn of 2020 by referring to 71 different warm fish farms of Gilan province, 100 specimens of Cyprinidae fishes were collected. A. hydrophila strains were isolated from the surface wounds (n=15) and kidney (n=85) of fish suspected to hemorrhagic septicemia by inoculation of samples on blood and MacConkey agar media. Among samples from fish kidneys and skin wounds, 51 samples were positive for A. hydrophila. Forty two isolates were confirmed as A. hydrophila by PCR technique using specific primers which targeted 16S rDNA gene fragment. Due to the significant role of A. hydrophila in Cyprinidae mortality in Gilan province, preventive and diagnostic strategies are necessary to control the occurrence of hemorrhagic septicemia by undertaking identification tests of A. hydrophila in fish pools that can reduce costs in fish industry management.