Closely related multidrug-resistant Salmonella enterica serovar Heidelberg isolates from imported poultry meat in the Netherlands

Imported poultry meat was sampled from 2011 to 2015 and antimicrobial susceptibility testing, PCR, and Illumina HiSeq2500 WGS were performed on S. Heidelberg isolates from Brazil (n=119) and Argentina (n=3). Of the 122 unique S. Heidelberg isolates included in this study, 120 (98.4%) were ciprofloxacin-resistant and among the 102 (83.7%) ESC-resistant isolates, 83.6% and 82.8% of the isolates showed resistance to cefotaxime and ceftazidime, respectively. Of these 102 isolates, 99 (97.1%) exhibited an AmpC phenotype and contained a CMY-2 gene, whereas the remaining three isolates contained an ESBL. Of the ESC-resistant isolates that contained blaCMY-2, incompatibility group I1 was identified in 56 (56.6%) isolates. Of the 122 isolates, 99.2% were assigned ST15.