Antimicrobial resistance (AMR) is a critical issue likely to cause over 10 million deaths annually worldwide by 2050 (de Kraker 2016). While antibiotic stewardship has been emphasised as essential for controlling AMR, emerging evidence suggests that reducing antibiotic use alone may not suffice. This is because resistance mechanisms are becoming less metabolically costly due to compensatory mutations and genetic co-selection, allowing bacteria to retain resistance without antibiotic pressure. Additionally, environmental stressors such as pesticides, increasing temperatures, and heavy metal contamination can enhance the selection of AMR genes, even in the absence of antibiotics (Kelbrick et al. 2023).
Intensive agricultural practices are significant yet often overlooked contributors to the spread of AMR. Conventionally farmed soils, frequently exposed to chemicals and pollutants, harbour more AMR genes than organic farms. These anthropogenic stressors can promote AMR through several mechanisms: selecting stress-resistant bacteria that also resist antibiotics, inducing mutations in global stress regulators that enhance resistance, and facilitating the spread of AMR via mobile genetic elements.
Research on AMR has traditionally focused on isolated bacterial species, lacking insight into how complex microbial communities in agricultural settings evolve and spread resistance over time will be presented. Addressing AMR effectively requires a multidisciplinary approach that considers the broader environmental and agricultural contexts, recognising that the drivers of AMR extend far beyond clinical settings. Sustainable farming practices are crucial to mitigating these anthropogenic drivers and safeguarding public health.
References:
de Kraker MEA, Stewardson AJ, Harbarth S. (2016). Will 10 million people die a year due to antimicrobial resistance by 2050? PLoS Med 2016;13:e1002184.
Kelbrick M, Hesse, E, O’Brien S (2023). Cultivating antimicrobial resistance: how intensive agriculture ploughs the way for antibiotic resistance. Microbiology 2023;169:001384; DOI 10.1099/mic.0.001384