ASSESSMENT OF METAL AND ANTIBIOTIC-RESISTANCE IN MARINE BACTERIA ISOLATED FROM IZMIT BAY AND BOSPHORUS ENTRANCE OF MARMARA AND BLACK SEA, TURKEY

Microbial characterization of marine habitat not only can shed a light on chemical and/or antibiotic toxicity with assessment of bacterial resistance, but also help us to understand the possible relationship between metal and antibiotic resistance. Therefore, this study aims to characterize the marine bacteria purified from Izmit Bay and Bosphorus entrance of Marmara and Black Sea together with determining their metal and antibiotic resistance. The results of the present study revealed that most of the selected isolates belonged to the genera Acinetobacter and Bacillus which can be referred to metal toxicity indicators with their significant resistance to Cu2+, Cd2+ and Cr3+. Majority of the metal-resistant isolates were also resistant to at least 2 antibiotics, and incidence of metal-antibiotic double resistance between the metals Cd2+ and Cu2+ and the antibiotics chloramphenicol and ampicillin was 100%. High level of coexistence of metal and antibiotic resistance observed in the isolates could possibly indicate the presence of plasmids and/or transposons encoding genes linked to both resistances.