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Antibiotic resistant pathogenic bacteria (ARPB) residual in soil-plant system has caused serious threat against public health and environmental safety. Being capable of targeted lysing host bacteria, phage therapy has been proposed as promising method to control the ARPB contamination in environments. In this study, microcosm trials were performed to investigate the impact of various phage treatments on the dissipation of tetracycline resistant Escherichia coli K-12 and chloramphenicol resistant Pseudomonas aeruginosa PAO1 in soil-carrot system. After 70 days of incubation, all the four phage treatments significantly decreased the abundance of the pathogenic bacteria and the corresponding antibiotic resistance genes (tetW and cmlA) in the soil-carrot system (p < 0.05), following the order of the cocktail phage treatment (phages ΦYSZ1 + ΦYSZ2) > the polyvalent phage (ΦYSZ3 phage with broad host range) treatment > host-specific phage (ΦYSZ2 and ΦYSZ1) treatments > the control. In addition, the polyvalent phage treatment also exerted positive impact on the diversity and stability of the bacterial community in the system, suggesting that this is an environmentally friendly technique with broad applications in the biocontrol of ARPB/ARGs in soil-plant system., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Soil contamination with antibiotics and antibiotic resistant bacteria/genes (ARB/ARGs) has becoming an emerging environmental problem. Moreover, the mixed pollutants' transfer and accumulation from soil to tuberous vegetables has posed a great threat against food security and human health. In this work, the application of two absorbing materials (maize biochar and sulfate modified eggshell) was able to reduce the poisonous effect of soil antibiotics on potato root system by stimulate the dissipation of water-soluble antibiotics in soil; and also improve food quality by increasing potato starch, protein, fat, and vitamins. Meanwhile, both amendments could effectively decrease the classes and the accumulative abundance of ARB and ARGs (sulI, sulII, catI, catII, ermA, ermB) in the edible parts of potato. The lowest abundance of ARGs was detected in the biochar application treatment, with the accumulative ARG level of 8.9 × 10 2 and 7.2 × 10 2 copies mL -1 in potato peel (sull + catI + ermA) and tuberous root (sulI), respectively. It is the first study to demonstrate the feasibility of biochar and eggshell derived from agricultural wastes as green absorbing materials to reduce soil antibiotic, ARB, and ARGs accumulation risk in tuberous vegetable., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

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 (tetM, tetQ, tetW, ampC, and fosA) significantly decreased in the soil after 63 days' incubation (p < 0.05). Similar results for endophytic K-12 and PAO1, and ARGs, were also obtained in lettuce tissues following combined treatment. Additionally, high throughput sequencing revealed that biochar and polyvalent phage synergetically improved the structural diversity and functional stability of the indigenous bacterial communities in soil and the endophytic ones in lettuce. Hence, this work proposes a novel biotechnology that combines biochar amendment and polyvalent phage therapy to achieve targeted inactivation of ARPB, which stimulates ARG dissipation in soil-lettuce systems., (Copyright © 2018 Elsevier Ltd. All rights reserved.)