Magnetic biochar/quaternary phosphonium salt reduced antibiotic resistome and pathobiome on pakchoi leaves

Antibiotic resistance genes (ARGs) and human pathogenic bacteria (HPB) in leafy vegetable is a matter of concern as they can be transferred from soil, atmosphere, and foliar sprays, and poses a potential risk to public health. While traditional disinfection technologies are effective in reducing the presence of ARGs and HPB in soil. A new technology, foliar spraying with magnetic biochar/quaternary ammonium salt (MBQ), was demonstrated and applied to the leaf surface. High-throughput quantitative PCR targeting 96 valid ARGs and 16 S rRNA sequencing were used to assess its efficacy in reducing ARGs and HPB. The results showed that spraying MBQ reduced 97.0 & PLUSMN; 0.81% of high-risk ARGs, associated with seven classes of antibiotic resistance in pakchoi leaves within two weeks. Water washing could further reduce high-risk ARGs from pakchoi leaves by 19.8% 24.6%. The relative abundance of HPB closely related to numerous ARGs was reduced by 15.2 & PLUSMN; 0.23% with MBQ application. Overall, this study identified the potential risk of ARGs from leafy vegetables and clarified the significant implications of MBQ application for human health as it offers a promising strategy for reducing ARGs and HPB in leafy vegetables.

Automated summary

Antibiotic resistance genes (ARGs) and human pathogenic bacteria (HPB) in leafy vegetable pose a potential risk to public health. Traditional disinfection technologies and a new technology called MBQ spraying are effective in reducing the presence of ARGs and HPB in soil and on the leaf surface.