Detection of virulence factor genes, antibiotic resistance genes and biofilm formation in clinical Gram-negative bacteria and first report from Türkiye of K.oxytoca carrying both bla OXA-23 and bla OXA-51 genes

The Gram-negative bacteria were isolated from various samples and antibiotic susceptibility testing were performed. The 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 isolates were showed resistance to quinolone, cephalosporin, aminoglycoside, carbapenem and penicillin group antibiotics. Virulence factor genes were identified in 121 strain. The most common virulence gene was determined to be aer (29.78%), followed by sfa (28.19%), afa (27.12%), cnf (21.27%), pap (12.76%) and hly (12.76%). In addition, 34 different virulence patterns were observed. Plasmid-mediated quinolone resistance genes were detected 15 of67 quinolone-resistant isolates. Among carbapenem resistant strains, blaOXA-23 gene was detected in 16 and blaOXA-51 gene in 19 isolates. The strains producing OXA-23 and OXA-51 were Klebsiella oxytoca, Acinetobacter baumannii, E.coli and P.mirabilis. In this study, clinical isolate K. oxytoca carrying both blaOXA-23 and blaOXA-51 genes were identified first time from Türkiye. A high predominance (88.82%) of class 1 integron was detected. In addition, determined that 46.27% of the isolates had the ability to form biofilms. 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.