A NARMS Survey of Antimicrobial Resistant Foodborne Bacteria Isolated from Retail Veal in the United States.

Little is known about the prevalence of antimicrobial resistant (AMR) bacteria in veal meat in the United States.  We estimated the prevalence of bacterial contamination and AMR in various veal meats collected during the 2018 U.S. National Antimicrobial Resistance Monitoring System (NARMS) survey of retail outlets in nine states and compared to the frequency of AMR bacteria from other cattle sources sampled for NARMS.  Additionally, we identified genes associated with resistance to medically important antimicrobials and gleaned other genetic details about the resistant organisms. The prevalence of Campylobacter, Salmonella, E. coli and Enterococcus in veal meats collected from grocery stores in nine states was 0% (0/358), 0.6% (2/358), 21.1% (49/232) and 53.5% (121/226) respectively, with ground veal posing the highest risk for contamination.  Both Salmonella were resistant to at least one antimicrobial as were 65.3% (32/49) of E. coli and 73.6% (89/121) of Enterococcus isolates. Individual drug and multidrug (MDR) resistance levels were significantly higher (p < 0.05) in E. coli and Enterococcus from retail veal compared to 2018 NARMS data from sampling dairy cattle ceca and retail ground beef.  Whole genome sequencing (WGS) was conducted on select E. coli and Salmonella from veal. Cephalosporin resistance genes (blaCMY and blaCTX-M), macrolide resistance genes (mph), plasmid-mediated quinolone resistance genes (PMQR, qnr), and gyrA mutations were found. We also identified heavy metal resistance genes (HMRG) ter, ars, and mer, fieF, and gol, and disinfectant resistance genes (DRG) qac and emrE.  An stx1a-containing E. coli was also found. Sequence types were highly varied among the nine E. coli isolates that were sequenced.  Several plasmid types were identified in E. coli and Salmonella, with the majority (9/11) of isolates containing IncF. This study illustrates that veal meat is a carrier of AMR bacteria.