Varying characteristics and driving mechanisms of antibiotic resistance genes in farmland soil amended with high-density polyethylene microplastics

• Published in: Journal of hazardous materials Vol. 428; p. 128196
• Main Authors: Lu, Xiao-Ming, Chen, Yi-Lan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.04.2022
• Subjects: Anti-Bacterial Agents; Antibiotic resistance gene; Drug Resistance, Microbial - genetics; Farmland soil; Farms; High-density polyethylene microplastic; Microplastics; Phthalates; Plastics; Polyethylene; Soil; Farmland soil; High-density polyethylene microplastic; Phthalates; Antibiotic resistance gene
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.128196

The differential effects of microplastics and phthalates released from microplastics on antibiotic resistance genes in soil remain unknown. This study aims to analyze the varying characteristics and driving mechanisms of antibiotic resistance genes in soils amended with high-density polyethylene microplastics (with and without phthalates) through a 60-day microcosm experiment. The results indicate that the amended high-density polyethylene microplastics (containing phthalates) enhanced the abundance of antibiotic resistance genes in the soil, a phenomenon that markedly increased with the amendment period. Nevertheless, the addition of high-density polyethylene microplastics (without phthalates) mitigated the abundance of antibiotic resistance genes, which was less significant with increasing amendment period. Furthermore, addition of high-density polyethylene microplastics altered the soil properties, especially porosity. The phthalates released from high-density polyethylene microplastics and the changes in the soil properties transformed soil bacterial communities, resulting in increased abundance of bacterial hosts harboring antibiotic resistance genes (Calditrichaeota, Candidate division CPR1, Candidatus Delongbacteria, Candidatus Kapabacteria, Candidatus Spechtbacteria, Candidatus Wildermuthbacteria, and Ignavibacteriae), thereby enhancing the abundance of antibiotic resistance genes. These findings suggest that compared to microplastics, the phthalates released from microplastics considerably affect the antibiotic resistance genes in soils, thereby promoting the propagation of antibiotic resistance genes in agricultural environments. [Display omitted] •Phthalates released from microplastics enhanced soil resistance gene abundance.•Effect of phthalates on resistance genes was greater than that of microplastics.•The decrease in soil porosity increased resistance gene abundance in the soil.•Microplastics affected resistant bacteria by altering soil porosity and phthalates.