Climate change affects Salmonella antimicrobial resistance dynamics in China: an ecological study across multiple temporal scales.

Climate change and antimicrobial resistance (AMR) are two pressing global challenges; however, how they interact remains unclear. This study focused on Salmonella, a major AMR pathogen, to examine the relationship between regional climate change and AMR risk in mainland China across multiple time scales, while controlling for socio-demographic and economic factors. The optimal fit was attained for both the southern and northern regions when a time scale of five years was employed. Here we showed that every 1 °C increase in temperature fluctuation led to a 0.9-fold decrease (95 % confidence interval (CI): 0.84-0.96) in the prevalence of antibiotic resistance genes (ARGs) in northern China. In contrast, the same temperature increase resulted in a 1.08-fold rise (95 % CI: 1.05-1.11) in the prevalence or intensity of ARGs in southern China. For AMR risk in Salmonella, ambient temperature fluctuations had a stronger impact than annual ambient temperature. Fluctuations within optimal ranges for temperature, humidity, and precipitation are crucial determinants affecting the AMR in Salmonella.