Summary of prevalence and characteristics of ESBL/AmpC enzymes found in the Dutch broiler production chain between June 2009 and December 2010.

GPS = Grandparent Stock, PS = Parent Stock. More details about the data displayed in grey are given in Figure 1.*With the primers used to sequence blaCTX-M-2 no distinction can be made between blaCTX-M-2 and blaCTX-M-97.†With the primers used to sequence blaSHV-12 no distinction can be made between blaSHV-12 and blaSHV-129.‡blaTEM-20 with silent mutations +144G->A, +480C->T and +723A->G compared to reference sequence blaTEM-20 Y17581 (nucleotide position according to amino acid count at www.lahey/studies.org).