Characterization of Edwardsiella tarda isolated from Asian Seabass, Lates calcarifer

This study described the antibiotic and heavy metal resistance pattern of 17 isolates of Edwardsiella tarda obtained from Asian seabass (Lates calcarifer). E.tarda isolates were resistant to oleandomycin, lincomycin, novobiocin and spiramycin. In contrast, most of the isolates showed high level of susceptibility to tetracycline, doxycycline, florfenicol, chloramplenicol, nitrofurantoin, fosfomycin, kanamycin, oxolinic acid and flumequine. MAR value was 0.35 which indicated that the cultured Asian seabass have received high exposure to those tested antibiotics. Besides, very high level of heavy metal resistance among these isolates was observed. Genotypic profile of DNA fingerprintings generated by RAPD-PCR using M13 universal primer and M13 wild type phage primer showed high degree of genetic diversity with percentages similarity and genetic distance among the isolates were ranging from 10.5% to 100% and 0 to 0.895, respectively. This result indicates that strains that belong to the same origin were not always closely related genetically.