Antimicrobial resistance poses a significant threat to global public health, and excessive antimicrobial use (AMU) in animals is a major contributing factor. We used national AMU data for food animals to examine the current status and trends for AMU in food animals in China from 2018–2020. In 2020, China used 32,776.30 tons of antimicrobials in food animals, amounting to 165 g of antimicrobials per ton of animal products. AMU in China increased throughout the 2018–2020 study period; however, the data still showed a consistent and notable reduction from those of 2017, coinciding with the implementation of the China National Action Plan for Combating Animal Antimicrobial Resistance. Among the antimicrobials used, tetracyclines, macrolides and β-lactams (including β-lactam inhibitors) were the most commonly used in food animals. Analysis by antimicrobial class revealed shifts in usage patterns, such as decreased tetracycline use and increased macrolide and β-lactam use. Furthermore, the use of antimicrobial growth promoters decreased sharply, from 51.78% in 2018 to 28.7% in 2020. Compared with AMU data from other countries, China used more antimicrobials, but the values were relatively lower when adjusted for population correction units. These findings highlight China's remarkable efforts in combating antimicrobial resistance and promoting antimicrobial stewardship, thus contributing significantly to global initiatives.

Staphylococcus aureus, a prevalent pathogen associated with infectious and foodborne diseases, is also a significant cause of intramammary infections in dairy farms. This study aimed to determine the phenotypic and molecular characterization of S. aureus in two different stock sizes of dairy farms in Henan province (HN) and the Inner Mongolia autonomous region (IM), China, through biofilm formation, antimicrobial resistance, virulence, and molecular type of S. aureus isolates. In HN, 74 S. aureus isolates (60.7%) were recovered from 122 bulk tank milk samples, while in IM, 24 S. aureus isolates (17.4%) were detected from 161 samples soured from various origins. Notably, 25.7% (19/74) of isolates in HN and 20.8% (5/24) in IM exhibited multidrug-resistant (MDR) phenotypes. Molecular typing revealed distinct patterns: ST97 (n = 32) and spa type t189 (n = 20) predominated in HN, whereas ST50 (n = 13) and spa type t518 (n = 11) were prevalent in IM. Additionally, three isolates harbored both tsst-1 and lukF-PV genes, and two MRSA strains displayed a MDR phenotype in raw milk samples from HN. Biofilm formation was observed in 91.8% strains. Phylogenetic analysis identified two subpopulations (lineages 1 and 2). Among them, cluster 6 in lineage 2 comprised S. aureus strains from three sources within a farm, suggesting potential cross contamination during different stages in IM. Remarkably, among 19 MDR isolates in HN, ST398 MSSA strains exhibited a higher multidrug resistance compared to non-ST398 MSSA strains. This study underscores the high prevalence and diverse characteristics of S. aureus in raw milk, necessitating enhanced surveillance and control measures to mitigate associated risk.

To address the escalating challenge of antimicrobial resistance (AMR) and disease control in livestock following the complete ban on antibiotic growth prom