Abundance and diversity of ARGs in aerosol environments of waste recycling sites

Abstract

This study investigated the distribution and transmission of bacteria and antibiotic resistance genes (ARGs) in aerosol environments during the process of waste recycling in the stock landfill, including the excavation site, drying field, screening workshop and office area, to identify potential hazards to people and the surrounding environment. Results revealed that aerosols released during waste recycling had a significant impact on composition of environmental microorganisms and may affect nearby areas by diffusion. Eleven potential human pathogenic bacteria (HPB) from different sampling sites were observed and the predominant HPB genera in each sample were Acinetobacter, Pantoea and Klebsiella, especially the extremely high abundance of Acinetobacter (50.43%) in the screening workshop may be a threat to the staff. Four resistance genes and three mobile genetic elements (MGEs) in aerosols were detected by droplet digital PCR, and the most kinds and high concentrations of resistance gene subtypes were detected in screening workshop and office area. A significant positive correlation was observed between intI1 and up to 3 resistance gene subtypes (P < 0.05), while the correlation between ARGs and bacterial communities was weak. The study measured and evaluated the resulting risk of aerosols released during waste cycling to guide the necessary pollution control measures especially in the closed and humid environment when subsequent such projects are implemented.