The role of greenhouse agricultural plastic waste as a reservoir of antibiotic resistance genes and vector of their environmental dissemination.

Greenhouses are exposed to multiple sources of antibiotic pollution. As plastics are prone to colonization by microorganisms and upon their exposure to antibiotics within greenhouses, greenhouse plastic waste may act as a reservoir and vector for antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs). This study analysed the resistome, mobilome and bacterial diversity of greenhouse plastic waste samples collected from three different sampling sites. Plastic waste samples harboured 295 different ARGs, including ones classified as of the highest risk to human health by the arg_ranker tool. A core resistome was found in plastics. Redundancy analysis revealed minimal differences in bacterial β-diversity between plastic and soil samples; however, a distinct plastic core microbiome was identified, predominantly comprising taxa common in halophytic and agricultural soils, as well as taxa capable of degrading plastics. Correlation analyses indicated that plastic associated bacteria exhibited unique interactions not observed in soils, as well as the potential role of MGEs in the transfer of ARGs from soil to plastic. These findings provide evidence of a core resistome and core mobilome in greenhouse plastic waste collected from field, offering critical insights of how the improper disposal of plastics could contribute to the global spread of antibiotic resistances. • The resistome and bacterial diversity were profiled in greenhouse plastic waste. • 256 different ARGs and 46 different MGEs were detected in plastic waste • 16 plastic ARGs were classified as rank I, the most dangerous to human health • Cores of the plastic resistome, mobilome, and microbiome were identified • Unique plastic bacterial zOTU-ARG, zOTU-MGE and ARG-MGE correlations were found