The association between ambient temperature and antimicrobial resistance of high-priority bacterial pathogens in China nationwide: A modeling study with difference-in-difference approach

Background: Climate warming not only affects humans, megafauna and other flora but also the world’s microbial organisms. However, the relationship between ambient temperature and antimicrobial resistance (AMR) of important clinical bacteria is still unclear; therefore, we explored the association between ambient temperature and AMR in China. Methods: Six bacteria-antibacterial combination, identified by the World Health Organization as high priority, were collected from the China Antimicrobial Resistance Surveillance System (CARSS) database for 30 provinces from 2014 to 2020. Meteorological factor, socioeconomic and health care factors were obtained from the China Statistical Yearbook. A revised Difference-in-Difference (DID) approach was applied to quantitatively assess the association between ambient temperature and AMR, and exploring the modified effects of socioeconomic and health care factors. Results: Ambient temperature had a significant protective effect on Methicillin-Resistant Staphylococcus Aureus (MRSA) (Relative risk (RR) = 0.959, p = 0.042) and Vancomycin Resistant Enterococcus Faecium (VRefm) (RR = 0.798, p < 0.001), and was positively associated with Penicillin Resistant Streptococcus Pneumoniae (PRSP) (RR = 1.556, p < 0.001). Whereas higher socioeconomic levels (higher GDP, higher income per capita, higher consumption per capita) and increased hospitalization rate will eliminate the protective effect of ambient temperature on them. The frequency of medical visit, institution per province did not have an interaction effect on MRSA and VRefm. Interestingly, PRSP was sensitive to the socioeconomic and health care factors, which almost modify its positive association with ambient temperature. Conclusions: Ambient temperature was significantly associated with AMR, having varied effects for different bacteria-antibacterial combination. Some certain socioeconomic and health care factors will influence the association between temperature and antimicrobial resistance, thereby increasing the risk of bacterial resistance. The effect of temperature on antimicrobial resistance, and interactions with socioeconomic and hospitalization rate should be seriously considered in antimicrobial stewardship within a changing climate.