Biochar and theaflavins mitigate the antibiotic resistome and antibiotic-resistant pathogens in a soil-lettuce continuum.

Antibiotic resistance can be transferred into the food chain, leading to increased risks to human health from ready-to-eat vegetables. Mitigating the transmission of antibiotic resistance from soil to vegetables by green materials is of great significance. Here, we deciphered the roles of biochar and theaflavins in mitigating antibiotic resistance genes (ARGs) and antibiotic-resistant pathogens (ARPs) in a soil-lettuce continuum. Metagenomic results showed that biochar led to a significant decrease in the abundance of ARGs in lettuce leaves, while theaflavins contributed to a significant reduction in the diversity and abundance of ARGs in soil, particularly targeting dominant ARG types such as sulfonamide and aminoglycoside resistance genes. Meanwhile, biochar and theaflavins alleviated the potential mobility of ARGs, in lettuce leaves and soil, respectively, including the spread of ARGs to human pathogens. In addition, the diversity of ARG hosts was reduced in the soil-lettuce continuum and ARPs were not detected in lettuce leaves after the application of biochar or theaflavins. Overall, this study provides a novel perspective on green materials for mitigating the antibiotic resistome and ARPs in the soil-lettuce continuum, contributing to food security and human health.