Targeted inactivation of antibiotic-resistant Escherichia coli and Pseudomonas aeruginosa in a soil-lettuce system by combined polyvalent bacteriophage and biochar treatment

Abstract High abundances of antibiotic-resistant pathogenic bacteria (ARPB) and antibiotic resistance genes (ARGs) in agricultural soil-plant systems have become serious threats to human health and environmental safety. Therefore, it is crucial to develop targeted technology to control existing antibiotic resistance (AR) contamination and potential dissemination in soil-plant systems. In this work, polyvalent bacteriophage (phage) therapy and biochar amendment were applied separately and in combination to stimulate ARPB/ARG dissipation in a soil-lettuce system. With combined application of biochar and polyvalent phage, the abundance of Escherichia coli K-12 (tet R ) and Pseudomonas aeruginosa PAO1 (amp R  + fos R ) and their corresponding ARGs ( tet M, tet Q, tet W, amp C, and fos A) significantly decreased in the soil after 63 days' incubation ( p