Fate and driving factors of antibiotic resistance genes in an integrated swine wastewater treatment system: From wastewater to soil

• Published in: The Science of the total environment 2020-06, Vol.721, p.137654-137654, Article 137654
• Main Authors: Zhu, Ning, Jin, Hongmei, Ye, Xiaomei, Liu, Wei, Li, Danyang, Shah, Ghulam Mustafa, Zhu, Yanyun
• Format: Article
• Language: English
• Subjects: Antibiotic resistance genes; Bacterial community; Mobile genetic element; Soil; Wastewater treatment
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.137654

Swine wastewater (SW) represents an important source of antibiotic resistance genes (ARGs) in the environment. However, few studies have assessed the occurrence and removal of ARGs in the whole wastewater treatment process followed by its farmland application. This study investigated the ARGs profiles in an integrated SW treatment system and its receiving soil, as well as their relationships with SW parameters and bacterial communities. Results revealed that sulfonamide, tetracycline and aminoglycoside resistance genes were dominant in SW. The relative abundance of total ARGs in SW was reduced by 84% after the treatments. Among the SW treatment units, anaerobic digestion, primary sedimentation and constructed wetland contributed to ARGs removal while secondary sedimentation increased the total ARGs abundance. Farmland irrigation of the treated SW resulted in enrichment of persistent ARGs in the receiving soil, which might be attributed to the propagation of potential bacterial hosts and high horizontal gene transferability. Redundancy analysis indicated that the relative abundance of total ARGs was significantly correlated with total nitrogen, total phosphorus, antibiotics and bacterial communities. The shift in bacterial community was the major driving factor for ARGs alteration during SW treatment process. Our results highlight the effect of treated SW irrigation on the antibiotic resistome in agricultural environment, and can contribute in improving SW treatment system for better antibiotic resistance control. [Display omitted] •The treatment system could effectively remove conventional pollutants, antibiotics and most ARGs.•Long-term treated wastewater irrigation increased the diversity and abundance of persistent ARGs in soil.•Potential bacterial hosts and horizontal gene transfer contributed to ARGs enrichment in soil.•Bacterial community shift was the major factor that drove ARGs alteration.