Evaluation and characterization of plasmids carrying CTX-M genes in a non-clonal population of multidrug-resistant Enterobacteriaceae isolated from poultry in Brazil

The increasing presence of ESBL-producing bacteria in food-producing animals might impact on public health. In this study, ESBL-producing enterobacteria were investigated in the microbiota of chickens produced in Brazil. We detected bla(CTX-M-2), bla(CTX-M-8) and bla(CTX-M-15) in 13 Escherichia coli isolates, within 9 different PFGE-types. Escherichia fergusonii and Klebsiella pneumoniae were found carrying bla(CTX-M-2). Plasmid Inc groups found included repF, FIB, FIC, I1, Y, B/O, A/C, K and HI1. F plasmids were present in 87.5% of the isolates, however, no resistance gene was harbored in this replicon. The pMLST for IncI1 showed ST113 and the novel ST130, ST131 and ST132 harboring bla(CTX-M-8). IncK plasmids carried bla(CTX-M-2) in one E. coli isolate. Non-typeable plasmids carrying bla(CTX-M-2) or bla(CTX-M-15) had up to 260 kb. bla(CTX-M-2) was also associated with class I integron and ISCR1 and bla(CTX-M-8) with IS10. Overall, similar resistance elements were disseminated among a diverse population of ESBL-producing enterobacteria. (C) 2016 Elsevier Inc. All rights reserved.