First Report and Comparative Genomics Analysis of a blaOXA-244–Harbouring Escherichia coli Isolate Recovered in American Continent

The carbapenemase OXA-244 is a derivate of OXA-48, and its detection is very difficult in laboratories. Here we report the identification and genomic analysis of an Escherichia coli isolate (28Eco12) harbouring the blaOXA-244 gene identified in Colombia, South America. The 28Eco12 isolate was identified during a retrospective study and it was recovered from a patient treated in Colombia. The complete nucleotide sequence was established using the PacBio platform. A comparative genomics analysis with other blaOXA-244–harbouring Escherichia coli strains was performed. The 28Eco12 isolate belonged to sequence type (ST) 38 and its genome was composed of two molecules, a chromosome of 5,343,367 bp and a plasmid of 92,027 bp, which belonged to the incompatibility group IncY and did not harbour resistance genes. The blaOXA-244 gene was chromosomally-encoded and mobilized by an ISR1-related Tn6237 composite transposon. Notably, this transposon was inserted and located within a new genomic island. For our knowledge this is the first report of a blaOXA-244–harbouring Escherichia coli isolate in American continent.Our results suggest that the introduction of the OXA-244-producing E. coli isolate was through clonal expansion of the ST38 pandemic clone. Other isolates producing OXA-244 could be circulating silently on the American continent.