Genomic Features of an MDR Escherichia coli ST5506 Harboring an IncHI2/In 229 / bla CTX-M-2 Array Isolated from a Migratory Black Skimmer.

Migratory birds have contributed to the dissemination of multidrug-resistant (MDR) bacteria across the continents. A CTX-M-2-producing Escherichia coli was isolated from a black skimmer ( Rynchops niger ) in Southeast Brazil. The whole genome was sequenced using the Illumina NextSeq platform and de novo assembled by CLC. Bioinformatic analyses were carried out using tools from the Center for Genomic Epidemiology. The genome size was estimated at 4.9 Mb, with 4790 coding sequences. A wide resistome was detected, with genes encoding resistance to several clinically significant antimicrobials, heavy metals, and biocides. The bla CTX-M-2 gene was inserted in an In 229 class 1 integron inside a ∆Tn As3 transposon located in an IncHI2/ST2 plasmid. The strain was assigned to ST5506, CH type fumC19/fimH32 , serotype O8:K87, and phylogroup B1. Virulence genes associated with survival in acid conditions, increased serum survival, and adherence were also identified. These data highlight the role of migratory seabirds as reservoirs and carriers of antimicrobial resistance determinants and can help to elucidate the antimicrobial resistance dynamics under a One Health perspective.