Evaluation of Oxytetracycline Resistance in Aeromonas hydrophial Isolated from Reared Oncorhynchus mykiss

Zarghami, S.; Mirvaghefi, Alireza; Farahmand, Hamid; Nematollahi, Mohammad Ali

doi:10.22059/jfisheries.2012.28627

Evaluation of Oxytetracycline Resistance in Aeromonas hydrophial Isolated from Reared Oncorhynchus mykiss

Authors

S. Zarghami

Alireza Mirvaghefi

Hamid Farahmand

Mohammad Ali Nematollahi

10.22059/jfisheries.2012.28627

Abstract

The intensive use of antimicrobial agents worldwide for prophylactic and therapeutic purposes has been associated with increase of bacterial resistance in the exposed microbial environment. Oxytetracycline is the most frequently used antibacterial in the cold water fish industry because of its broad spectrum of activity and low cost. Aeromonas hydrophila and other motile aeromonads are among the most common bacteria in freshwater habitats throughout the world, and these bacteria frequently cause disease among cultured fishes. In this study, 50% of isolates from intestine of rainbow trout were identified as Aeromonas hydrophila by using biochemical technique. Oxytetracycline MICs were determined using agar dilution method at dosage 0,1,2,4,8,10 µl/ml. 40% of Aeromonas hydrophila was resistant to 30 µg/ml of oxytetracycline. The use of oxytetracycline in aquaculture might produce some negative impact on the treatment of human infections as a consequence of either direct transmission of resistant pathogens to humans, or indirectly through the transfer of resistance genes from environmental bacteria to human pathogens which is major risk for public health.

Keywords

Aeromonas

Antibiotic

hydrophila

Oncorhynchus mykiss

Resistance