Whole-genome sequencing-based characteristics of Escherichia coli Rize-53 isolate from Turkey

Background. Urinary tract infections (UTIs) are one of the most common infectious diseases. Inappropriate and excessive administration of antibiotics has led to the increased antibiotic resistance in the pathogens that cause UTIs. This work focused on identifying genetic determinants of antibiotic resistance in a clinical isolate of UTI-causing Escherichia coli. Objectives. A clinical isolate of E. coli resistant to beta-lactam, tetracycline and aminoglycoside antibiotics was analyzed using whole-genome sequencing (WGS) to identify genes that contribute to its resistance. Materials and methods. The clinical isolate was obtained from a urine sample of a UTI patient in Turkey and identified via 16S rDNA sequencing. Antimicrobial susceptibility test was performed for 17 antibiotics using VITEK (R) 2 and the results were confirmed using minimum inhibitory concentration assay. Whole-genome sequencing of the isolate was performed using Illumina sequencing and analyzed with bioinformatic tools for multilocus sequence typing, replicon types, virulence factors, and antimicrobial resistance genes. Results. Whole-genome datum was submitted to the National Center for Biotechnology Information (NCBI; accession No. JAKSGM000000000). The isolate was only found to be resistant to piperacillin in the beta-lactam class of antibiotics. While the isolate was also resistant to aminoglycoside and tetracycline antibiotics, it was sensitive to other antibiotics tested. Ten antibiotic resistance genes were identified in the genome of the isolate: bla(OXA-1), bla(OXA-2), aac(6')-II, aac(6')-Ib-cr, tetB, catB3, qacE, sitABCD, mdfA, and sul-2. Clonal subtype (ST) and serotype of the isolate were identified as ST2141 and O107/H39, respectively. Plasmid replicon typing was used to identify 5 plasmid types in the genome of E. coli Rize-53 (Col(BS512), IncC, IncIA, IncFIB(AP1918), and IncFII(pRSB107)); however, none of the resistance genes were encoded on the plasmid. Conclusions. Genetic determinants of resistance to tetracycline, beta-lactam and aminoglycoside antibiotics were identified using WGS in a uropathogenic E. coli from ST2141 lineage and O107:H39 serotype, isolated in Turkey.