First Characterization of CTX-M-15-Producing Escherichia coli Strains Belonging to Sequence Type (ST) 410, ST224, and ST1284 from Commercial Swine in South America

Abstract

We report for the first time the isolation of CTX-M-15-producingEscherichia colistrains belonging to sequence type (ST) 410, ST224, and ST1284 in commercial swine in Brazil. TheblaCTX-M-15gene was located on F-::A9::B1 and C1::A9::B1 IncF-type plasmids, surrounded by a new genetic context comprising the IS26insertion sequence truncated with the ISEcp1element upstream ofblaCTX-M-15 These results reveal that commercial swine have become a new reservoir of CTX-M-15-producing bacteria in South America.

FIG 1

Schematic representations of the genetic environment surrounding the bla_CTX-M-15 gene in swine E. coli isolates. (A) The plasmid bla_CTX-M-15 gene from E. coli 181 ST224 (BioProject accession number PRJNA279532). (B) The plasmid bla_CTX-M-15 gene from E. coli 223B ST410 (BioProject accession number PRJNA291430). (C) Genetic environment surrounding bla_CTX-M-15 found in an E. coli strain belonging to ST410, isolated from clinical and food samples from southern Spain (8) (GenBank accession number GU479916). Sections, open reading frames and genes surrounding the bla_CTX-M-15 gene; arrows, orientation of each coding sequence. Gene names are shown under the corresponding section.