Food safety aspect of enterococci isolated from raw and processed seafood products

The aim of this study was to evaluate antibiotic resistance potential and virulence characteristics of Enterococcus strains isolated from raw and processed seafood products. In this study, raw fish samples obtained from Bursa, İstanbul and Çanakkale fish markets which hunted daily from Marmara region. Processed seafood products obtained from supermarkets and charcuteries. For the characterization at genus level, Gram staining, catalase test and hemolysis test in sheep blood agar were performed. All isolates identified at species level by using API 20 Strep biochemical test kits and performed antibiotic resistancy tests against streptomycin (10µg), tetracycline (30µg), gentamycin (10µg), vancomycin (30µg), eritromycin (15µg) and chloramphenicol (30µg) on Mueller Hinton Agar media. Polymerase chain reaction (PCR) analyzes were performed to evaluate virulence (agg, gelE, cylA, cylB, cylM) and vancomycin resistance genes (vanA, vanB). As a result of disc diffusion method, most of the isolates (49/50) were found high resistant against streptomycin, 80% (40/50) of isolates to gentamycin, 30% (15/50) of isolates to tetracyline and vancomycin antibiotics. 72 % (36/50) of the isolates to eritromycin and 30% (15/50) of isolates to vancomycin were found intermediate level resistant. 24% (12/50) of isolates showed resistancy against chloramphenicol. It was determined that 88% (44/50) of the isolates showed multiple resistance at least two different antibiotics. Vancomycin resistance genes; vanA and vanB, were not detected in the isolates. In 72% of the isolates gelE gene and in 24% of isolates agg2 gene was determined.