The effects of season and processing technology on the abundance of antibiotic resistance genes in air samples from municipal wastewater treatment and waste management plants

This study aimed to perform a qualitative and a quantitative assessment of the prevalence of genes encoding resistance to beta-lactam, tetracycline, and chloramphenicol antibiotics in samples of DNA isolated from air in a municipal wastewater treatment plant (WWTP) and a municipal waste management plant (WMP). Air samples were collected in the mechanical (MP) and biological (BP) processing units of WWTP and WMP in winter and spring. The samples of air were collected by impingement into PBS solution and subsequently, DNA was isolated. The prevalence of the 16S r RNA gene and ARGs was determined by PCR, and the most abundant ARGs were quantified by qPCR. The highest diversity of the analyzed ARGs was noted in air samples collected in the mechanical processing units of the WWTP (winter) and the WMP (spring). The copy of ARGs varied between treatment units and seasons. ARGs were most abundant in air samples collected in spring in the MP units of both the WWTP and the WMP. The study demonstrated that ARGs are ubiquitous in the air in both WWTPs and WMPs. The presence of ARGs in the air can exert a negative impact on the health of plant employees.