Isolation and identification of enterotoxin producing Aeromonas hydrophila from common carp (Cyprinus carpio)

Document Type : Disease


1 Department of Biology, Faculty of Basic Science, Islamic Azad University, Urmia Branch

2 Department of Pathobiology and Quality Control, Urmia Lake Research Institute, Urmia University


Infectious diseases are major economic losses in fish production facilities. Among the etiological agents of bacterial fish disease, the Aeromonas hydrophila is considered an important pathogen causing primary infection in wounds or the secondary problem following stress from temperature change, handling, or poor water quality. In the present study, six strains of Aeromonas hydrophila isolated from ten fish farms in diseased carp, West Azarbaijan province were characterized and compared with an American type strain by various methods including biochemical and physiological tests, PCR, antibiotic resistance profile and enterotoxin gene. Results showed that any differences were not seen between isolated strains and standard based on phenotypic and genetic properties. Antibiotic susceptibility test revealed that six strains of isolated Aeromonas hydrophila had different antibiogram profile, also higher and lower resistance was seen for enrofloxacin and sulfamethoxasole, respectively. It’s concluded that isolated Aeromonas hydrophila from carp in West Azarbaijan could produce enterotoxin and has antibiotic resistance genes.