Improved control of multiple-antibiotic-resistance-related microbial risk in swine manure wastes by autothermal thermophilic aerobic digestion

摘要

In this study, we microbiologically evaluated antibiotic resistance and pathogenicity innlivestock (swine) manure as well as its biologically stabilized products. One of new livestocknmanure stabilization techniques is ATAD (Autothermal Thermophilic Aerobic Digestion).nBecause of its high operation temperature (60–658C), it has been speculated to haveneffective microbial risk control in livestock manure. This hypothesis was tested by evaluatingnmicrobial risk in ATAD-treated swine manure. Antibiotic resistance, multiple antibioticnresistance (MAR), and pathogenicity were microbiologically examined for swine manure asnwell as its conventionally stabilized (anaerobically fermented) and ATAD-stabilized products. Innthe swine manure and its conventionally stabilized product, antibiotic resistant (tetracycline-,nkanamycine-, ampicillin-, and rifampicin-resistant) bacteria and the pathogen indicator bacterianwere detected. Furthermore, approximately 2–5% of the Staphylococcus and Salmonellancolonies from their selective culture media were found to exhibit a MAR-phenotypes,nsuggesting a serious level of microbe induced health risk. In contrast, after the swinenmanure was stabilized with a pilot-scale ATAD treatment for 3 days at 60–658C, antibioticnresistant bacteria, pathogen indicator bacteria, and MAR-exhibiting pathogens were allnundetected. These findings support the improved control of microbial risk in livestock wastesnby ATAD treatment.