Study of antibiotic resistant of Aeromonas hydrophila causative agent of Haemorrhagic septicemia in freshwater Angelfish

Objectives: Pterophyllum is a small genus of freshwater fish from the family Cichlidae known to most aquarists as angelfish . It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish. Aeromonas hydrophila is thought to be one of the most important bacterial pathogens of farmed freshwater fish, with a wide variety in pathogenicity patterns. This bacterium is a heterotrophic, gram-negative, rod shaped bacterium, mainly found in areas with a warm climate. Aeromonas hydrophila is associated with diseases mainly found in fish and amphibians, because these organisms live in aquatic environments. It is linked to a disease found in frogs called red leg, which causes internal, sometimes fatal hemorrhaging. When infected with A. hydrophila, fish develop ulcers, tail rot, fin rot, and hemorrhagic septicaemia. Hemorrhagic septicaemia causes lesions that lead to scale shedding, hemorrhages in the gills and anal area, ulcers, exophthalmia, and abdominal swelling.Materials Methods: In the present study antibiotic resistant of Aeromonas hydrophila isolated from angelfish was evaluated. A. hydrophila strains were isolated from angelfish tissues such as kidney and spleen. After culturing the bacteria, they were identified by biochemical tests and PCR. Results Conclusion: Ten isolated bacteria from 80 samples of angelfish organs (liver, skin, kidneys) were subjected to antimicrobial susceptibility testing by disk diffusion method on Muller Hinton agar plates using disks impregnated by the following antibiotics: penicillin, amoxicillin, ampicillin, oxytetracycline, tetracycline, erythromycin, flumequin, kanamycin, amikasin, nalidixic acid, enrofloxacin, and gentamycin. In conclusion, the highest resistance rates were related to ampicillin, penicillin, amoxicillin, flumequin, kanamycin, amikasin, nalidixic acid