Phenotypic, serotypic and genetic characterization and antimicrobial susceptibility determination of vibrio anguillarum, isolated from cultured sea bass (dicentrarchus labrax l., 1758) in the southeast Black Sea, Turkey

Abstract

In this study, identification of Vibrio isolates from infected sea bass (Dicentrarchus labrax L., 1758) in the Black Sea was performed by using conventional methods, and API 20E test kits. All isolates were confirmed by PCR assays specific to the 16S rRNA gene of bacterium. Lam agglutination test was carried out on all vibrio isolates by using raised rabbit serum against Vibrio anguillarum 01. According to the result of agglutination, biochemical and PCR tests isolated bacteria determined as V. anguillarum. API 20E profile for V. anguillarum isolates was usually determined as 3207526. the sequenced Vibrio isolates were found to be similar to V. anguillarum strain at the rate of 98-100% in GenBank under different accession numbers. in addition, in the treatment for vibriosis, it was intended to detect the most effective agents. Results of the testing susceptibility to antibiotics showed that V. anguillarum isolates were resistant to 100% ampicillin, 63.6% erythromycin, 59.1% sulfamethoxazole, 54.6% streptomycin, 45.5% sulfamethoxazole-trimethoprim, and 40.9% oxytetracycline, but all strains except two V. anguillarum were found susceptible to 9.1% other antibiotics (oxolinic acid, enrofloxacin and florfenicol). According to the results of the susceptibility test, florfenicol and enrofloxacin were suggested as the most effective chemotherapeutics for vibriosis treatment.