Antibiotic Resistance Profiles of Bacterial Pathogens Isolated from VariousFish Species

The present study was performed to evaluate retrospectively the bacteriological identification results from wild, culture and aquarium fish admitted to the Fish Diseases Diagnostic Laboratory at the Veterinary Control Institute of Samsun for disease diagnose from 2009 to 2014 as well as the antimicrobial susceptibility profile of isolated bacteria. Vitek 2 automated systems were used following bacterial identifications with conventional culture methods. In the study, 132 samples were analyzed and a total of 19 isolates were identified. Of the isolates, 7 were isolated from Rainbow trout (4 Aeromonas sobria, 2 Yersinia ruckeri and 1 Hafnia alvei), 4 from Common carp (2 A. sobria and 2 A. salmonicida), 2 from Chub (1 A. sobria and 1 H. alvei), 2 from Discus fish (1 Citrobacter freundii and 1 Pseudomonas aeruginosa), 1 from Sea bass (Listonella anguillarum), 1 from Black Sea trout (P. fluorescens), 1 from Sturgeon (L. anguillarum), and 1 from Dolphin (A. salmonicida). The isolates were analyzed using 14 different antibiotics by Disc Diffusion method for in vitro susceptibility test. Among the antibiotics used, the highest resistance rates were detected against amoxicillin (89.5%), ampicillin (82.3%) and erythromycin (78.9%), while the lowest resistance rate was detected against enrofloxacin (5.3%). The remarkable finding of the study was two aquarium fish originated isolates showed antibiotic resistance against at least 11 antimicrobials. The present results showed the importance of choosing appropriate antimicrobial agents for treatment of fish diseases.