ABSTRACT The increasing abundance of extended spectrum β-lactamase (ESBL) genes in E. 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 investigate bla CTX-M gene diversity (and flanking nucleotide sequences) in E. coli from chicken and humans, in an Ecuadorian rural community and from chickens in another location in Ecuador. The bla CTX-M associated sequences in isolates from humans and chickens in the same remote community showed greater similarity from those found in E. coli in a chicken industrial operation 200 km away. Our study may provide evidence of bla CTX-M transfer between chickens and humans in the community.

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