and to Gene Distribution Characteristics in Gut Specimens from Different Regions of China.

Antibiotic resistance has become a global public health concern. To determine the distribution characteristics of and in China, gene screening was conducted directly from gut specimens sourced from livestock and poultry, poultry environments, human diarrhea patients, and wild animals from 10 regions, between 2010-2020. The positive rate was 5.09% (356/6991) for and 0.41% (29/6991) for , as detected in gut specimens from seven regions, throughout 2010 to 2019, but not detected in 2020. The detection rate of showed significant differences among various sources: livestock and poultry (14.81%) > diarrhea patients (1.43%) > wild animals (0.36%). The detection rate of was also higher in livestock and poultry (0.88%) than in diarrhea patients (0.17%), and this was undetected in wildlife. This is consistent with the relatively high detection rate of multiple genotypes in livestock and poultry. All instances of coexistence of the and genes, as well as coexistence of genotypes within single specimens, and most new subtypes came from livestock, and poultry environments. Our study indicates that the emergence of and genes in China is closely related to the selective pressure of carbapenem and polymyxin. The gene-based strategy is proposed to identify more resistance genes of concern, possibly providing guidance for the prevention and control of antimicrobial resistance dissemination.