Dissemination of antibiotic resistance genes

The prevalence and transmission of antibiotic resistance genes (ARGs) and opportunistic pathogens in water environments can pose great threat to public health. However, the dissemination of ARGs and opportunistic pathogens from water environments to humans is poorly explored. Here, we employed 16S rRNA gene sequencing and high-throughput quantitative PCR techniques to explore the seasonal distribution of ARGs and opportunistic pathogens in Yellow River water (source water) and tap water, as well as their relationship with healthy humans at Lanzhou, China. Physiochemical analysis was also applied to detect water quality parameters and heavy metal content. The absolute abundance and diversity of ARGs in Yellow River and tap water demonstrated distinct seasonal patterns. In winter, Yellow River water had highest ARG abundance and diversity, while tap water owned the lowest. Mobile genetic elements (MGEs) were the predominant driver for ARGs profiles either in the Yellow River or tap water. Null model analysis showed that ARG assembly in Yellow River had more stochastic processes than tap water independent of seasons. Total organic carbon and arsenic exhibited strong correlations with many ARGs . It is noted that the opportunistic pathogens Aeromonas and Pseudomonas may be potential host for ARGs. Approximately 80 % of detected ARGs were shared between water and human guts. These persistent ARGs cannot be entirely eliminated through drinking water treatment processes. Thus, it is crucial to protect source water from anthropogenic pollution and improve water treatment technologies to decline the dissemination of ARGs for ensuring drinking water biosafety and human health.