Distribution ofbla_CTX-M-gene variants inE. colifrom different origins in Ecuador

The increasing abundance of extended spectrum β-lactamase (ESBL) genes inE. coli, and other commensal and pathogenic bacteria, endangers the utility of third or more recent generation cephalosporins, which are major tools for fighting deadly infections. The role of domestic animals in the transmission of ESBL carrying bacteria has been recognized, especially in low- and middle-income countries, however the horizontal gene transfer of these genes is difficult to assess. Here we investigateblaCTX-Mgene diversity (and flanking nucleotide sequences) inE. colifrom chicken and humans, in an Ecuadorian rural community and from chickens in another location in Ecuador. TheblaCTX-Massociated sequences in isolates from humans and chickens in the same remote community showed greater similarity from those found inE. coliin a chicken industrial operation 200 km away. Our study may provide evidence ofblaCTX-Mtransfer between chickens and humans in the community.