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Backgrounds. Diagnostic markers of extraintestinal infection in Escherichia coli (E. coli) remain unclear in the literature. Extraintestinal pathogenic E. coli (ExPEC) is differentiated from other E. coli isolates in terms of virulence factors, such as host cell adhesion, invasion, cytotoxic necrotizing factor (CNF (cnf1-cnf3)) and cytolethal distending toxin (CDT (cdt1-cdt4) that are responsible for cell death. We aimed to investigate the frequency of CNF-CDT and the relationship between the clinical diagnosis and genotypes in E. coli isolates with different clinical origins. Methods. A total of 646 E. coli isolates (obtained from 645 patients) isolated from different infection sites other than the intestine were evaluated in aspects of the CNF, CDT virulence genes, phylogenetic grouping, and phylogenetic relationship by using PCR and PFGE. Results. At least one virulence gene was present in 156 (24%) of the 646 ExPEC isolates. We detected cnf1, cnf2, and cnf3, in 78, 12, and 20 ExPEC isolates, respectively. Also, cdt1, cdt2, cdt3, and cdt4 genes were present in 20, 4, 4, and 4 isolates, respectively. Some isolates harbored more than one gene, being cnf1-cnf3 (n = 6), cnf1-cdt1 (n = 4), and cdt1-cdt4 (n = 4). These 156 isolates were distributed into 106 large clusters by PFGE. Virulent ExPEC is primarily related to groups B2 (60%) and D (32%). Conclusion. To our knowledge, this study demonstrated the presence of cnf2, cnf3, cdt1, cdt2, cdt3, and cdt4 genes for the first time in the literature for Turkey. The widespread presence of the CNF gene in E. coli helps distinguish ExPEC from commensal isolates.

<b>Aim:</b> This study aimed to determine the susceptibility of carbapenem-resistant Gr (-) bacilli isolated from various clinical infections to various antibiotics and identify genes causing carbapenem resistance and their clonal relationships to elucidate the distribution of resistance in community and/or hospital-acquired strains.<br /> <b>Material and methods:</b> In this study, antibiotic susceptibilities of 450 carbapenem-resistant Gr (-) bacilli isolated from clinical specimens at Cukurova University, Faculty of Medicine, Balcali Hospital, were investigated using phenotypic methods. The presence of carbapenems and β-lactamase genes were searched using polymerase chain reaction (PCR) and sequence analysis methods. Pulsed-field gel electrophoresis (PFGE) method was used to evaluate the phylogenetic relationship of the isolates.<br /> <b>Results:</b> Based on the results, it was determined that 99.23% of the strains had gained resistance to meropenem, whereas 5.38% had developed resistance to colistin. The most dominant carbapenems genes in all isolates were OXA-51, OXA-23-like and OXA-24-like.<br /> <b>Conclusion:</b> It was observed that the only antibiotic that could be used safely in carbapenem-resistant Gr (-) bacilli infections was colistin. In addition, when the clonal relationship of the strains was examined, it was found that the clones considered to be closely related persisted, and these clones settled in different clinics of our hospital.