Antibiotic resistant profile and some virulence factors of Çanakkale Coastline bacteria

Antibiotic resistance poses a significant public health concern, especially considering that microorganisms in marine environments serve as potential sources for the dissemination of resistance genes. In this study, antibiotic resistance profiles of 50 bacterial isolates obtained from coastal seawater in Çanakkale were investigated, along with the presence of tetM and vancomycin resistance genes, and various virulence factors (biofilm formation, siderophore production, enzymatic activity). Molecular identification was conducted for isolates with detected resistance genes. According to the antibiotic susceptibility testing, 90% of isolates exhibited resistance to penicillin, 76% to vancomycin, 68% to tetracycline, 54% to ampicillin, and 8% to gentamicin. Furthermore, 88% of isolates were found to have a Multidrug Resistance (MDR) index above the critical threshold; tetM was present in 30%, vanA in 10%, and both tetM and vanA in 2% of isolates. Additionally, all isolates showed high potential in terms of enzyme production, biofilm formation, and siderophore production as virulence factors. The high levels of antibiotic resistance and presence of resistance genes in these bacteria indicate uncontrolled antibiotic usage in the region, posing potential risks to public health.