Genomic Characterization of a Multidrug-Resistant Escherichia coli Isolate Co-Carrying blaNDM-5 and blaCTX-M-14 Genes Recovered from a Pediatric Patient in China

Background: Public health is seriously threatened by the rise of carbapenem-resistant Enterobacterales (CRE). However, the genomic characteristics of CRE detected in pediatric patients are largely unknown. Here, we reported the genomic characteristics of a multidrug-resistant Escherichia coli strain containing the plasmid-borne blaNDM-5 and blaCTX-M-14 genes recovered from a Chinese pediatric patient.Methods: The genome sequence of E. coli strain B379 was determined using Illumina NovaSeq 6000 and Oxford Nanopore MinION. Multiple bioinformatics tools were used to annotate the genome sequence, identify antimicrobial resistance genes and plasmid replicons and perform the in silico multilocus sequence typing (MLST) analysis. Using BacWGSTdb 2.0 server, a core genome MLST (cgMLST) comparison was made between E. coli B379 and all ST746 E. coli strains downloaded from the public database.Results: The E. coli B379 genome sequence is comprised of six contigs totaling 5,152,502 bp, including one chromosome and five plasmids. Nineteen antimicrobial resistance genes were predicted. The blaNDM-5, which is located on a 46,161 bp IncX3 plasmid and the blaCTX-M-14 gene which is located on a 147,204 bp IncFII/IncFIA/IncFIB plasmid are two examples of these 19 genes. E. coli B379 was resistant to ampicillin, ampicillin/sulbactam, ceftriaxone, ceftazidime, imipenem, cefepime, ciprofloxacin, ertapenem, trimetho-prim-sulfamethoxazole. This isolate belonged to ST746 and the closest relative was another one originating from a human material specimen in Denmark, which differed by 273 cgMLST alleles.Conclusion: Our study reports the emergence of a multidrug-resistant E. coli strain co-carrying blaNDM-5 and blaCTX-M-14 recovered from a pediatric patient in China. These data would help us better understand the prevalence, genetic characteristics, and mechanisms of antimicrobial resistance of this recently identified multidrug-resistant bacteria in children.