Antimicrobial Resistance in Non-typhoidal Salmonella from Retail Foods Collected in 2020 in China

Objective: Non-typhoidal Salmonella (NTS) is a major cause of human salmonellosis globally. Food animals are NTS reservoirs. An increase in antimicrobial resistance (AMR) foodborne has led to clinical treatment failures. Here, examine the prevalence and perform characterization with AMR China, we tested susceptibility 1,256 isolates cultured from retail foods 2020 China. Methods: The 26 agents representing 12 classes was evaluated broth-microdilution method; presence ten mcr genes screened multi-PCR. complete closed genomes -gene-carrying were generated by hybrid assembly through whole genome sequencing on both PacBio Illumina platforms. Genomic features genetic environments mcr-1 gene analysed. Results: overall drug rate 92.28%, multi-drug (MDR) 76.53%. A total 341 profiles determined, highest nalidixic acid (63.38%). Among 887 MDR, 232 showed co-resistance cefotaxime ciprofloxacin, 25 resistant agents. isolated different regions varied. Isolates raw chicken sources most frequently resistance. Four carried represented four serotypes. gene-bearing plasmids classified into two replicon types (IncI2 IncHI2A). Two IncI2 type found be located between PAP2 family protein-encoding relaxase-encoding gene, whereas other structures IncHI2A variations insertion sequences. Conclusion: Our data demonstrated severe among food thus highlighting importance surveillance decrease spread AMR, particularly critical drugs medicine.