Draft genome sequence of a CTX-M-8, CTX-M-55 and FosA3 co-producing Escherichia coli ST117/B2 isolated from an asymptomatic carrier.

Objectives: Asymptomatic carriers can act as reservoirs of multidrug-resistant (MDR) bacteria. The aim of this study was to describe the draft genome sequence of a MDR Escherichia coli lineage recovered from a faecal sample of a healthy carrier.

Methods: Genomic DNA was sequenced on an Illumina NextSeq platform. Sequence reads were de novo assembled using CLC Genomics Workbench and the whole genome sequence was evaluated through bioinformatics tools available from the Center of Genomic Epidemiology as well as additional in silico analysis.

Results: The genome size was calculated as 5178340 bp, with 5442 protein-coding sequences and 5492 total genes. Presence of the bla, bla and fosA3 genes was detected in addition to other antimicrobial resistance genes. Interestingly, the strain was assigned to serotype O8:H4-fimH97 and was classified within the highly virulent phylogroup B2.

Conclusion: This draft genome can provide helpful information to elucidate genetic features that contribute to colonisation and adaptation of MDR and virulent pathogens in asymptomatic carriers.