Determination of virulence factor genes and biofilm formations in clinical gram negative bacteria and investigation of antibiofilm activity of rumex silver nanoparticle

188 Gram-negative bacteria were isolated from various samples and antibiotic susceptibility testing were performed. 188 strains were screened by PCR for class 1 integron, virulence and antibiotic resistance genes. blaOXA-23 and blaOXA-51 genes positive samples were cloned into the pGEM-T vector and the plasmids were sent for DNA sequence analysis. The biofilm forming capacities of the strains and the antibiofilm effect of Rumex silver nanoparticle were quantitatively determined. Virulence factor genes were found in the isolates aer (29.78%), sfa (28.19%), afa (27.12%), cnf (21.27%), pap (12.76%) and hly (12.76%), respectively. Class 1 integron was detected high rate (88.82%) among strains. The observed that 46.27% of the isolates had the ability to form biofilms. PMQR genes were detected 15 strains. blaOXA-23 gene was detected in 16 and blaOXA-51 gene in 19 isolates.In this study, clinical isolate K. oxytoca carrying both blaOXA-23 and blaOXA-51 genes was identified first time from Turkey. Rumex silver nanoparticles (NPs) were revealed to exhibit antibiofilm activity against different isolates with moderate and strong biofilm-forming ability. The NPs reduced the biofilm-forming capacity of A. baumannii and K. pneumonaie by 2.66-fold and 3.25-fold, whereas they decreased the E.coli biofilm-forming capacity by 1.25-fold. The investigation of microbial biofilm could play an important role in developing new strategies for treatment options. In conclusion since the limited treatment options of antibiotic-resistant Gram-negative pathogens that cause serious infections are an important problem in terms of public health it is important to investigate antibiotic resistance, virulence factor genes and biofilm formation in these pathogens.