Intrinsic and Acquired Antimicrobial Resistomes in Plant Microbiomes: Implications for Agriculture and Public Health

Abstract

Antimicrobial resistance (AMR) poses a significant threat to both human and environmental health. Before human intervention, the natural resistome existed in a relatively balanced state, mainly regulated by microbial interactions and environmental factors. However, the continuous use of antimicrobials and other novel entities (chemicals or biological substances) in agricultural production and clinical settings has resulted in a huge release of residual antimicrobials into the environment. This may lead to a decrease in microbial diversity and an increase in selection pressure. The outcome is the alteration of resistome with mobile and clinically relevant antibiotic resistance genes (ARGs), posing a significant risk to human health. In the agricultural sector, the emergence of AMR is a result of multiple mechanisms. It involves intricate interactions between human activities, environmental factors and microbial processes. Direct exposure to antibiotic-resistant bacteria and ARGs in agricultural produce particularly raw eaten vegetables, salad, herbs and fruits may facilitate the spread of resistance between humans and the environment. This review aims to provide a comprehensive overview of antibiotic resistance in fresh produce microbiomes. It focuses on the impact of agricultural practices on the resistome and risks associated with antibiotic resistance to humans and the environment. More importantly, this review highlights several mitigation strategies and future interventions for a better understanding of ARG transmission within food systems.