• bla CMY ;
  • bla CTX-M ;
  • Escherichia coli ;
  • poultry


We characterized 67 Escherichia coli isolates with reduced susceptibility to cefotaxime obtained from 136 samples of healthy broilers housed in 36 Tunisian farms. All these isolates harboured blaCTX-M-1 and/or blaCMY-2 genes located mostly on self-conjugative IncI1 plasmids. qnrS1, qnrA6 and aac(6′)-Ib-cr were detected in six isolates. Considerable genetic diversity was detected among isolates from different farms. To our knowledge, this is the first detailed documentation of a high occurrence of blaCTX-M-1 and blaCMY-2 in E. coli at the poultry farm level in Tunisia as well as the first description of plasmid-mediated quinolone resistance in food animals in Tunisia which may contribute to the dissemination of these genes throughout Tunisia.