Table 3.

Main findings of the specific questionnaire survey relating to AMR monitoring in Campylobacter spp., EU MSs, June 2018

Specific Topics	Collected Information
Sampling procedure	Variability in the number of samples collected and pooled (from 1 to 10) per slaughter batch was reported. For instance, a caecal sample from only one broiler was sampled in 8 MSs, whereas, in 15 MSs, a pool of caeca from ten broilers was collected.
Isolation method of Campylobacter	Although from 1 up to 25 different laboratories were involved in the isolation of Campylobacter spp. for AMR monitoring in the reporting MSs, a single method was reported to be used for isolating Campylobacter strains for AMR monitoring in 23 MSs. Direct plating, without enrichment, of caecal contents, as described in the detection procedure C of the standard EN ISO 10272‐1 for samples containing high numbers of Campylobacter spp. was carried out in 23 MSs. Inoculation of two different agar media was reported in 16 MSs, from which 15 MSs used mCCDA. Either Karmali (this was considered not optimal, as both media contain the same inhibitor (cefoperazone)), Preston, blood agar, CFA, CASA or Skirrow media were used as second plate.
Over‐week‐end culturing	There were also differences between laboratories in the procedures used for cultures over week‐end periods, resulting for certain laboratories in cultures set up only on certain week days, in order to avoid any week‐end working.
Species identification	Most countries reported using MALDI‐TOF mass spectrometry or PCR in accordance with the method of Denis et al. (1999). Microscopical examination, and/or oxidase, catalase, hippurate and indoxyl acetate tests were also performed by several countries. Regarding the number of colonies selected for identification, variability between countries occurred, with one to five colonies identified per sample. This may impact the assessment of the prevalence of Campylobacter spp. and the proportion of C. jejuni/C. coli in a sample.
Use of ISO Standarda	21 MSs reported its use in various contexts, and 19 MSs being accredited for this method.

AMR: antimicrobial resistance; MS: Member State; mCCDA: modified charcoal‐cefoperazone‐deoxycholate agar; CFA: campyfood agar plate; CASA: Campylobacter selective chromogenic medium; MALDI‐TOF: Matrix Assisted Laser Desorption/Ionization – Time of Flight; PCR: polymerase chain reaction.

^aEuropean standard EN ISO 10272‐1.