Technical specifications on randomised sampling for harmonised monitoring of antimicrobial resistance in zoonotic and commensal bacteria
To monitor antimicrobial resistance in zoonotic and indicator bacteria from food-producing animal populations and meat thereof under Decision 2013/652/EC, a guidance for randomised sampling procedures is provided. Prospective and retrospective sampling plans for samples and isolates are addressed. The former involves collecting sufficient numbers of representative animal and food samples from which recovered isolates are tested for susceptibility; the latter involves selecting randomly Salmonella isolates from collections constituted within the framework of either the national control programmes in poultry flocks or from verification of the compliance with process hygiene criterion in broiler carcases. A generic proportionate stratified sampling process is proposed and numerical illustrations of proportional allocation are provided. Stratified sampling of Salmonella isolates from poultry primary productions is performed with proportional allocation to the size of the isolate collections available in the official laboratories. An alternative approach would be a simple random sampling within the sampling frame of flocks positive for Salmonella. Stratified sampling of caecal samples, accounting for at least 60 % of the domestic production of food-producing animal populations monitored, with proportionate allocation to the slaughterhouse production, allows for the collection of representative isolates of Campylobacter and indicator E. coli and enterococci in various animal populations. Stratified sampling of Salmonella isolates from broiler carcases is proposed with proportional allocation to the size of the isolate collections available in the official laboratories involved in verifying the compliance with the Salmonella process hygiene criterion. These isolates may be complemented with those recovered by the food business operator. Sampling of different chilled fresh meat categories is targeted at retail outlets serving the final consumer, with proportional allocation of the number of samples to the population of geographical areas accounting for at least 80 % of the national population, to test for the presence of ESBL-/AmpC-/carbapenemase-producing E. Coli.