The research team, led by Professor Tong Zhang from The University of Hong Kong, together with Professors Lizhong Zhu and Baolan Hu from Zhejiang University, has provided new evidence that China’s National Action Plan to Contain Antimicrobial Resistance may have generated measurable environmental benefits. The study, published in National Science Review, analyzed 2,243 soil metagenomes collected across China between 2009 and 2022, together with 2,556 globally (other countries) collected soil metagenomes.
Antimicrobial resistance (AMR) is a major global public health challenge. While the effectiveness of AMR control strategies has been widely evaluated in clinical settings, their potential impacts on environmental resistomes remain poorly understood. Soil is an important component of the One Health framework, acting as both a source and a reservoir of antibiotic resistance genes (ARGs). Previous studies have suggested potential connectivity between soil and human-associated resistomes, raising an important question: can large-scale AMR interventions influence ARGs profiles in soil? To address this question, the team constructed a 14-year spatiotemporal profile of ARGs in Chinese soils. Across all land use types, they detected 2,043 ARG subtypes and 108 high risk ARGs subtypes. Croplands stood out as the land use type with the highest relative abundance, diversity and potential risk of ARGs. In Chinese croplands, the researchers detected 1,857 ARGs subtypes and 103 high risk ARGs subtypes, including clinically important genes such as bla NDM and mcr .
The most striking pattern emerged when the team compared samples collected before and after 2016, coinciding with the implementation of China’s National Action Plan to Contain Antimicrobial Resistance (2016–2020). In cropland soils, the relative abundance of total ARGs and high-risk ARGs declined by 52.6% and 77.0%, respectively, after 2016. More than 70% of ARGs types showed a significant decline during this period, including beta-lactam, quinolone, tetracycline, and macrolide-lincosamide-streptogramin resistance genes. These ARGs types correspond to antimicrobial classes with high use intensity in clinical or veterinary settings. The temporal trends in soil ARGs were also significantly associated with national trends in clinical antibiotic resistance, human antimicrobial use density, and veterinary antimicrobial consumption. Together, these findings suggest a close association between soil resistomes and antimicrobial use patterns across human and animal sectors.
In 2021, the researchers collected 110 cropland soil samples across China and analyzed them for 437 chemical contaminants, including antibiotics, metals, pesticides and residues, and non-antibiotic pharmaceuticals. Pollutant concentrations explained 29.0-31.7% of variation in residual total ARGs, while agricultural activities explained 23.9-25.4%. Tetracycline resistance genes frequently co-occurred with metal resistance genes related to manganese, iron, cadmium, cobalt, zinc, and copper, suggesting that non-antibiotic pollutants may help maintain ARGs through co-selection.
By comparing Chinese data with global soil metagenomes, the researchers further found that cropland core ARGs showed higher connectivity across countries and regions than those in natural land use types. Core ARGs in cropland soils exhibited greater global similarity, suggesting convergent resistome profiles driven by similar agricultural pressures. This findings highlight the need to move from national intervention alone toward coordinated international action.
To support future monitoring, the team also developed an open-access interactive map for Chinese soil ARGs from 2009 to 2022 (https://smile.hku.hk/map/). The platform allows users to explore ARGs abundance and diversity by land use type, year, province, ARGs type, subtype, and variant.
The authors emphasize that the observed temporal patterns represent associations rather than definitive causal relationships. Nevertheless, the study provides nationwide environmental evidence that AMR control policies may be accompanied by measurable changes in soil ARGs. These findings support integrated One Health strategies combining clinical and veterinary antimicrobial stewardship, chemical pollution control, and improved agricultural practices.
National Science Review
Meta-analysis